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Our Do It Yourself Solar Array
Jump to Decisions, Opinions, and Stories
solar sun rise

Alternative Renewable Energy is Important,
but it also needs to be practical!

A word about my sponsor: For those of you that came in through a search engine. If you have any interest in real estate in North West Wisconsin please visit my sponsor at www.crexrealty.com. Located in Grantsburg Wisconsin. If you are not interested in real estate we also have regional information on the Grantsburg and Burnett county areas. Some of the highlights include: Crex Meadows wild life area, a growing list of Burnett county lakes information, links to the web pages of businesses in the Grantsburg area, and lastly, regional events and tourist attractions. Disclaimer: This information has been put here in the hope that someone finds it useful, We do not claim to be experts at installing a solar array, nor do we claim that the information you find here is the “best way”. The information that follows is simply how we installed a functioning 10.8 kilowatt array, that is tied to the electric grid and Co-Generates electricity with Polk Burnett Electric Cooperative. I also want to point out that working with various power tools, and working with electricity is hazardous. You need to decide for yourself if you want to do these things. Also here in Wisconsin we can still legally do our own construction and wiring. In your location that might not be true, so please check with you local building codes, if you are considering a project like this.

THE DATA

Data from past months,
and explaination of the PDF charts

Dec. 2018 solar performance (PDF)

Dec. 2018 Impact on our Electric purchase (PDF)

2.66 Peak KW hrs per day
From: 08/17/2018 To: 01/09/2019
Explain Peak KW hrs


Our list of Material

solar_array_bom.ods
Spreadsheet in Open Office format.

solar_array_bom.xls
Spreadsheet in Excel format.

thumbnail image This information details the installation of a ground mounted solar array with a transformerless single phase grid tie inverter that is wired into our main electrical power source which can power our home, as well as feed power to the electric grid via a special smart meter that Polk Burnett Electric installed. thumbnail image

Batteries Not Included!

First and foremost, I want to make clear that with this solar array, we are just as dependent on the power grid as we ever were. Meaning that if our power is interrupted for some reason, perhaps a storm, or a downed power line, our electricity will shut off just the same as anyone else, even if the sun is shining on a crystal clear day. I will explain this further later on, but I want to mention it right away, so that if you are only interested in “off grid” solar, or some other means of emergency power you may not want to continue reading this page. Also, I would like to quickly mention that this is a 10.8 kilowatt array, which means, the maximum power that it can generate is 10.8 kilowatts, it will normally output much less wattage, and I will explain that further as well.

Questions that need to be answered

  • Is it important that the system will pay for itself?
    • For us, this was the most important question, and that is why I listed it first. It is possible that the system will pay for itself, but it will take years for it to do so. How long it takes comes down to how much power it actually produces, and how long it will run trouble free. These are the two biggest unknowns that we currently have with this system. Our average power usage is approximately 40 kilowatts per day, equaling almost 15,000 kw per year, which equals about $1,600 a year in cost of electricity. Our cost to install the system comes to roughly $20,000, so 20,000 divided by $1,600 equals about 12-1/2 years. So if the system does produce an equal amount of power, to the power we use, it should pay for itself in under 13 years. Considering that most of the solar panel manufactures are claiming to give a 20 year warranty on their solar panels, we decided that it was worth the risk. At the time of this writing the federal government is offering an income tax credit, equivalent to 30% of the cost of the installation, since we have not yet received this credit, it is not part of the calculation. There are many more factors to add to this relatively simple calculation, and I will go into more details later, but I feel the above calculation is a pretty good starting point.

  • Do you have a space on your property that has adequate sunlight to make installing solar panels feasible?
    • For us, the answer is easily, “yes”. Our house roof was never an option, due to the shape of the roof, and the fact that since we were going to be the ones to install it, we did not want to be climbing on the roof of a two story house. However directly south of our house is open, and exposed to sunlight virtually the entire day. So again, for us a ground mount system was clearly the way to go. Since with a ground mount you are starting with nothing to mount the panels to, the cost increase of the system is significant, and thus adds more time to the possibility of payback. However, we are very content with our choice of mounting the system on the ground.

  • Another all important question to answer is how big should the solar generating system be?
    • We struggled with this question for quite a while. A smaller system would pay for itself quicker, the best return on investment (roi), comes from offsetting your current electric bill. If your system generates more than you need, the credit obtained from that unused power does not go very far in terms of pay back on your investment. A net meter system means that at the end of the billing cycle, which in our case is each month, the amount of wattage that has come into our house from the grid is calculated against the amount of wattage that went from our solar array out to the grid. So, to keep it simple if we used 1000 kilowatts from the grid, and we provided 1000 kilowatts to the grid, then our “net” electricity balance equals zero. This is kind of like being paid back full price for each kilowatt used, and of course if the system fell short of providing the total amount used it would be calculated the same. So, let’s say on the next month we still used 1000 kilowatts, but our system only generated 900 kilowatts, then we would be billed for the “net” which equals 100 kilowatts but it is still kind of like being paid back for the cost of the 900 kilowatts. Now let's say on another month we still use our normal 1000 kilowatts of electricity, but we have a very bright sunny month, and the system generates a whopping 1500 kilowatts during the billing cycle. Then we would have an excess of power and Polk Burnett agrees to credit the bill for the unused kilowatts at rate equal to their “avoided cost”. The avoided cost is a calculation that I will not pretend to understand but at the time of this writing, the avoided cost that Polk Burnett is paying is approximately $0.025 per kilowatt. So, in our record month above the extra 500 kilowatts times $0.025 equals $12.50. At the time of this writing my current monthly meter fee is approximately $36.00 per month so even though hypothetically, we produced all that extra power, we still get a bill of $36.00 minus the $12.50 credit, which equals, $23.50. It is better than nothing, but it won’t be putting any money in your pocket. What I’m trying to get at here is, it is not lucrative to generate a bunch of extra power. Also, it is important to understand that your power company probably has a limit on the size of a “net meter co-generating facility”. In our case Polk Burnett has a size limit of 20 kilowatts or less. There can be bigger systems, but different rules apply, I can't speak to those systems. As I go through the installation of our system, I will try to revisit these questions and explain our reasoning for why we decided to go one direction instead of another. To try to sum up the answer to this question, you need to decide how much power you want your system to generate, and then try to estimate how much sunlight your system is going to receive. As far as sunlight light goes, there are some pretty decent Internet tools that you can use to estimate the average sunlight hours for your area. We ultimately based the size of our system on a slightly pessimistic idea, that our solar panels will probably average about 80% of peak power for 4 hours per day. This comes down to simply making an educated guess, but now that we are up and running, we will be tracking the data to find out what the real average is. Again, this is one of the tougher decisions to make, so if you have the opportunity, I highly recommend that you talk with some people that have running systems and see how it is working out for them.

To back up just a little, questions #2 and #3 need to be answered in order to really have an answer for question #1. You need to have some idea of what size system, you want to install in order to be able to estimate the cost. You also need to make some kind of educated guess as to what the system will produce when it is running. This really comes down to the size of the system, times, the average daily sunlight that will fall on it.

There are many more questions to answer, and decisions to make, but I will try to explain some of the options, and why we chose one over another as we get on with building the system. So let’s get started!

Why did I get interested in solar?

A short version of the story goes a little like this. I was looking for a small inexpensive generator on line to be able to have around for short term emergencies, like running my basement sump pump during a power outage, or warming my diesel tractor enough to start it on some cold winter morning, again, during a power outage. Now this is not to say that we have a big problem with power outages, but I really like knowing that I do have some means of generating some power if I need it. As I was searching for generators, I came across an advertisement that claimed solar generating systems with as little as a 2 to 4 year payback. I thought to myself, “yeah right”, the last time I checked the system would have to run for about 45 years to pay for itself. Anyway, I have always wanted to come up with some way to be independent from the power company, it is just really hard to compete with the cost of electricity from the grid. The above advertisement captured my interest enough to go check it out. We even went so far as to go visit this solar power outfit, and talked with the owner. At that point all I was really looking for is some basis to answer question #1. The person we talked to was kind of pushing a 5.4 kilowatt system, that he ball park quoted at a cost of $5,000 to $6,000. When I asked what about doubling the system to a 10.8 kilowatt system, he said going larger is a little less than double, because you still only need one inverter to make the system work, so he roughly quoted us about $19,000. Now I need to point out that the system we were talking about would primarily a (DIY) do it yourself system however they would take the time to show us step by step, how to do it right. This was all very appealing to me because I not only wanted to save money, but gaining the knowledge of how everything works as we put it together was also very important to me. To sum up our very brief initial conversation, he gave us information on how the grid tie inverter works, and talked a little about the government incentives that were currently going on. He also mentioned that they take care of dealing with the power company on the customers behalf, so we would be able to focus on installing the system, they would teach us how, and they would deal with the engineering and legal details. Now all of this was starting to sound pretty good to me, however we still needed to take a step back and look at really, how can this provide payback in 2 to 4 years? Since I had been tracking our electric bill for quite a few years, it was relatively easy for me to get an idea of our average power usage, and total cost of electric. I used this information and the rough cost quotes along with some of the information about government incentives that I acquired. No matter how I calculated it, I kept coming up with a payback on the system that ended up much closer to 10 years payback instead of 2 to 4 years. Even so a 10 year payback is not so unreasonable to quit looking at doing this project. In an email to the company I let them know what I was calculating for a payback time and asked if I was missing anything. I also requested a better quote on 5.4, and a 10.8 kilowatt system, so that I could run the numbers some more. In the meantime even though we really don’t have much for bills, we were not able to write a check for say $10,000 to $20,000 so we began the process of setting up a home equity line of credit, (HELOC) loan. While waiting for approval of a loan, I had not received the information I requested from the solar power outfit. If requested I can go into more details about that, but it is really water under the bridge now. In order to proceed, I really needed to come up with some way to reasonably answer question #1. I started to search the Internet primarily searching for what do we need, to make it work, and how much will it cost. Obviously the more I searched the more questions it produced. I tried to stay focused on what we need, and cost. I figured If I answer question #1, then I would worry about the “how” part of the equation later. By the time we were approved for the loan, I had come up with a total cost figure of around $18,000 for a system, knowing that we would change our mind on a few things, and the final cost would ultimately depend on exactly what we use for a ground mount, and if I forgot anything important. With this cost figure, I came up with an optimistic payback of maybe 6 to 7 years, including government incentives, and so forth, and a pessimistic payback, as much as about 13 years, including interest on the load, no government incentives, system producing less than expected, etc. So, with cost and payback all figured out to the best of my ability, it's now time to think about the “how”.

Hold your Shovels!
We have some technical stuff to still work out.

Because nothing that I researched would include batteries, or even bring me close to going off-grid, the fanciest solar generator I could build would not do much good without getting approval from our power company to do the interconnection. I decided to see what I could learn from www.polkburnett.com. Their website turned out to be quite informative, but like everything else, it did leave me with a few questions and points that I didn’t confidently understand. So, I used their web form mail to email Polk Burnett and ask them some of these questions. I was somewhat disappointed by their response, because instead of a reply to my email with the answers, I received a phone call from a person at Polk Burnett Electric Cooperative, while I was at work, in which they left a message stating for me to call them, and left a phone number. The problem was that I don’t have a convenient time to call them during their business hours. Now this really didn’t surprise me, because I had already decided that Polk Burnett would probably be less then helpful when it came to telling me how to generate power for myself. I would like to take this opportunity to clearly point out that through a somewhat humbling experience in working on this project, and out of all the dealings with on-line orders, shopping for parts etc. I am happy to report that it turned out that Polk Burnett Electric Cooperative was the EASIEST TO DEAL WITH. Back to the story. Because of the hours I work, it isn’t terribly convenient to talk with people on the phone, I stewed on this lack of email reply for a few weeks and then decided to write a somewhat polite new form mail explaining that talking to someone on the phone during their working hours was not exactly easy for me and then I laid all my questions out as best as possible in an answer, “Yes” or “No” format. I then got a prompt reply to my email in which they did answer the questions that I asked with “Yes” and “No” answers as well as some explanation to the points that I was little fuzzy on, and they pointed me to other documents to read for more information. Polk Burnett also has a flow chart that sort of graphically explains the process of being approved for co-generation system. Here is a PDF version of the Question/Answer email that I sent. The questions with the answers are toward the bottom.


Time to do the paper work!

You fill out an application form in which you detail specifics of your proposed generating system. In our case I filled out the application as detailed as I could, however I was still undecided about which inverter I was going to use, so I attached data sheets of two different grid tie inverters, and I highlighted the specs. I also put a note in the comment section that purchasing the equipment was pending the approval of co-generation. They also require a single line drawing (SLD) with the proper ANSI (American National Standards Institute) symbols that depicts your electric service and how the co-generation system interconnects to it. They also request some kind of layout drawing so that they can tell where the generating facility is, and where they can switch it off, etc. ALSO NOTE: That filling out the application is not any kind of binding contract. During the approval process if you change your mind and decide not to continue, that’s okay. Also depending on your current power entrance, the cost of upgrading it to co-generate might make you decide it is not worth it. Once Polk Burnett receives your application, they look it over and also check what they have on file for your current electrical service to see if anything needs to be upgraded in order for your electrical service to properly handle the generation system that you are proposing to install. If something does need to be upgraded, or they need more information from you, they will let you know. Otherwise if everything checks out okay, they will then send you an approval letter, basically saying go ahead and build your system, and then contact Polk Burnett when your system is installed and ready to be tested. In our case we filled out the application form as well as we could, we created a single line drawing that showed all the major components of our current electrical service entrance, and the proposed solar generator, which shows a disconnect switch and how it is back-fed through a circuit breaker on our main distribution panel. We enclosed an overhead picture of our property, and I used a computer paint program to draw lines in for our existing service, as well as the proposed solar panel system. Within about a week we received an application approval letter from Polk Burnett Electric, briefly stating to go ahead and build the system.

NOTE: These are links to the documents that were current at the time of this writing. They aren't necessarily current at the time that you are reading this, so please use these as examples only.

  • Distributed Generation process flow chart
  • Distributed Generation Application Example
  • Example Single Line drawing
  • Example Site layout drawing

    TIMEOUT! I don’t want to deal with all this mumbo jumbo…

    Do it yourself doesn’t mean you have to do EVERYTHING yourself. If you find the paperwork a little intimidating, there are people out there that will do the whole application process for you, or just help you where you need help.

    We chose to do it all because we figured, why not try? What do we have to lose?

  • Approved!

    So, at this point, we have a rough idea of the cost, we have an official “okay” from our power company, so now it is just to make the final decisions on what we want to buy and how we are going to install it. In a nutshell, for us making these decisions and getting to this point, probably represents about ½ of the time spent on the total installation.

    What we are going to put them on?


    SnapNrack System

    Got Auger?

    Got Wood?
    We have a good idea of where we want to put our solar array, but what do we put it on? A quick list of options includes, wood, and variations of steel pipe, or any other way you can think of to prop up your panels. Keeping in mind of course that it would be very unpleasant to watch your investment blown away in the first thunderstorm that comes along. For me this decision was very difficult for mostly two reasons. One there isn’t really an abundance of detailed pictures on the Internet of ground mounted solar arrays. They are out there, you just have to look at a lot of roof mount installations in the process. Two, in the beginning of my research I was really only interested in some means of the array being adjustable, to get the best performance of the system as the seasons change. I do not regret doing the research at all, however every adjustable system I found either weighed heavily in the cost department, seemed complicated, or I was worried about the blown away in the first thunderstorm factor. Ultimately, I came across one website that completely changed my mind on the whole adjustable array concept. I don’t remember the words exactly, but it basically said, that an adjustable array will potentially yield about 30% more production, so rather that add the cost of a more expensive and more complicated mounting system, just add 30% more panels, mount it, and leave it alone. I don’t want to say that an adjustable system is by any means wrong, but right now we are interested in a fairly large, sturdy, long lasting trouble free mounting system as we can get. In my research that led me down two paths. It was more or less a toss-up between IronRidge, and SnapNrack. Both systems have a very effective on-line design tool, where you basically plug in information about the panels you want to use, how many, what wind conditions it will be exposed too, and so on. Ultimately for us SnapNrack won out, due to the fact that it is constructed with smaller more manageable pipe. Since a lot of the time, it was just my wife and I working on the installation, not needing special equipment to deal with very heavy pipe was very appealing to us. Now I should note that light pipe does not make it weaker, in fact with the bracing and so forth it might actually be a little stronger, but I don’t care to make that claim. It really comes down to the fact that since the SnapNrack system uses pipe that is half the size of IronRidge, you end up putting twice as many anchors in the ground, and with bracing you probably end up using about twice as much pipe. For this reason, the cost of either system is very comparable to the other, so it really was a choice of which size pipe do I want to try to lug around the yard.
    Preparing to Break Ground!

    I started by making some crude CAD drawings, to get some idea of how the system would be laid out, and what the angle measurements should be. Anyone with some basic knowledge of geometry could probably whip these numbers out with a calculator. Anyway, armed with some layout measurements, and a tape measure, my wife and I went out and put some stakes in the ground just as soon as the ground was soft enough to drive a stake into.
  • Pier layout
  • North, South pier spacing with Height measurements
    We used one of the 21ft pipes for the Horizontal run to suspend the vertical piers with the SnapNrack "tee" fittings, and the "X" support frame.
  • "X" support frame I found this support frame idea on another website, and modified it to fit our needs.
  • As I previously mentioned, the SnapNRack system has an on-line design tool, so all you need to do is input the specifications of the system you want to build. It then creates an Excel file that lists all the materials you need, approximate dimensions of the lengths of pipe, and even an estimate of how much concrete that you will need. Originally, I wanted to build a 10 kilowatt system, and I was looking at doing it with 250 watt panels. So, in the design tool I specified mounting 40 panels in a landscape configuration that would be arranged in 10 columns each being 4 panels high. (40 panels X 250 watts each, equals 10,000 watts). In our system there are 16 piers, 8-front, and 8-back. The design tool shows different depths for the front and back piers, but we augered 12 inch holes, 48 inches deep for all the piers. We suspended the vertical pipes in the hole surrounded by a premade re-rod made up of 3, 6 inch circles welded to 3 vertical rods. Most people would probably say the re-rod was not necessary, but I figure if I’m going to pour cement, it will have some kind of re-rod in it as well. We also mixed in the nylon concrete fibers with each batch of concrete simply to help strengthen the mix. For us the whole idea of going with a ground mount system is that hopefully the ground mount will far out last the solar generating components, so eventually when it is time to replace the array, then new panels, and probably electronics can be put right back on this long lasting mount. We’ll see how it works out. To go into a little more detail about the SnapNrack system, as well as the IronRidge system. The Idea is that you buy all the connecting components, and panel mounting rails etc. in kind of a kit. Then the structural pipe that you will use can be purchased through a local supplier. In our case we ended up getting all our 1-1/2 inch schedule 40 galvanized pipe from a local Menards store.

    The ground was not exactly level so the wood bracing is bolted together to allow it to pivot. This way the support height can be easily adjusted by the distance that the legs of brace are spread. Once we had the support bracing up and located where we wanted it, we measured across to horizontal pipe to mark the locations of the vertical pier. We then dropped a plumb bob to give us the location to auger the hole. We placed the re-rod assembly in the hole, and then a custom cut vertical pier with a piece of re-rod welded to it as sort of an anti-rotation 'key'. All the vertical piers were suspended approximately 1 foot above the bottom of the hole. Since we were mixing our own cement, we did 2 to 3 piers at a time. Once everything was setup, we mixed the concrete and poured it in via a wheel barrow. The square form is made of 2x6 boards and is 18" X 18" (inside), and it is mostly for looks. Its functional purpose is to allow me to weed whip around the vertical pipe, without actually whipping the pipe, thus helping to preserve the galvanized plating and prevent premature rust.

    Installing the ground mount system.

    Finishing up the ends of the back piers. Steel re-rod assembly used in each pier base. 48" tall with 3, 6" rings welded at 18" apart. NOTE: The picture below actually shows the re-rod assembly in one of the front pier holes.
    Since the desired face angle was 45 degrees and we couldn’t really depend on measuring from the ground, we set the two front pier outer corners, one at a time. We drove stakes in the ground, approximately 3 ft square around where the pier was to be placed. Sorry I never took a picture of this, but the idea here was to clamp boards to the stakes at the right height. Then we could place a horizontal pipe across the boards to suspend the front pier at the right height and location to produce the 45 degree angle. At this point we simply temporarily mounted one of the solar panel racking rails with a 45 degree level on it to adjust the suspended pier, and hold it in place until the poured concrete set up. Once we had both the outside corners of the front piers placed and the concrete was hard, we then placed a string line from one to the other so that we could mark and stake drill holes for the remaining front piers. When we were ready to set the piers, we did 3 at a time using supports that we made up from the existing square cement forms that were used on the rest of the piers. We suspended the pipes with the forms using the string line to guide the height and location.
    Suspended vertical piers ready for cement. Vertical pier with re-rod suspended in drilled hole.
    Ground mount piers with bracing.

    Time to rough in the electrical.

    We laid two conduits underground from the main power panel to the inverter power panel out at the solar array. The bigger 2” conduit has the #4 awg wire for the 240 VAC circuit running in it. The smaller 1” conduit has the CAT5 ethernet communication wire running in it. For the ground wire it simply worked out really nice to lay it in between the two conduits, in which it was connected to two ground rods, in the conduit trench. We put one ground rod basically right under the power panel, and then another one ten feet out from the panel but still in the trench. The conduit was buried a minimum of 24 inches deep. To make sure we stayed on track with the depth we made a simple wooden gauge that we dropped in the trench and slid it along as we dug.
    2 poles for the future power panel to hold the solar inverter. We augered 6” diameter holes 48” deep. We suspended the poles about 1 foot off bottom in the same manner as the piers.
    Main power panel. On the reverse side is the meter box, and the main distribution breaker panel. On this side the upper left box is the future Solar Interconnection Disconnect Switch. The Wisconsin rules of co-generation requires this switch to be lockable (Meaning it can be switched off, and a padlock can be put on it to “lock” it in the off position.) for safety reasons, so that the power company can lock out the system while performing repair or maintenance to the local power grid.
    NOTE: Part of the co-generation agreement with Polk Burnett Electric, is that they can come on the property and lock out this switch, any time it is necessary to perform work on the grid.
    The box on the lower left is a junction box that is serving more or less as an adapter, sizing down the 2” conduit to 1” which fits the switch box without modification. There are many ways we could have downsized the conduit. I chose the junction box so that I could leave a loop of extra wire in there just in case I need it in the future. The Box mounted lower on the right side is a disconnect switch that completely shuts off the power coming from the grid. I installed that more for personal preference, and protection then necessity.
    The Future solar power panel. We originally intended the panel to stay very much like this, with the inverter and junction boxes mounted to them and just leave it that way. The Inverter is designed to be indoor/outdoor, they just don’t want it placed in direct sunlight, or other extreme environmental conditions. Otherwise it is designed and supposed to handle being outdoors just fine.
    Trench leading to the main power panel. The trench is a minimum of 24 inches deep.
    NOTE: Please don’t throw caution to the wind here. Call to have any underground systems located before you dig.
    To make sure we stayed at the proper depth we made kind of a depth gauge. ( The ‘T’ shaped 2x4 thing laying on the left.) As we went along, we dropped that in the trench to see actually how deep we were. It was quick and easy, and seemed to work quite well.
    As previously mentioned, the larger conduit contains the power wires and the smaller conduit contains the network communication cable. Since at peak power the solar inverter could be outputting as much as 45 to 50 amps we wanted a little bit of space between the two conduits to help prevent the electromagnetic fields of the heavy current from effecting the communication wire. They could have been spaced apart with anything, but I printed spacers which made it very easy to provide a place to clip the ground wire into as well. Here is the STL file for anyone interested in using it, or getting a better look at it.
    Grounding the System. Here we have two 8 ft. ground rods placed 10 feet apart from each other. We figure more grounding is better, so even though the electrical system was grounded with two 8 ft rods on the other side of the power panel at the time of the service entrance upgrade, we added two more ground rods shown in this picture. The Ground wire shown here is leaving the main power panel and going out to the inverter panel where it loops into the solar inverter, and then back out to two more 8 ft. ground rods that were placed on the south side of the array.

    Why is grounding important? Properly grounding your system has much more to do with preventing the lightning strike instead of arresting the lightning after it hits. If an electrical system does get hit by lightning, there is very little that can be done to protect or arrest the electrical currents as the voltage generated by the strike drains off. A properly grounded system tends to drain the potential differential energy in a controlled manner, and thus hopefully prevent the lightning strike from ever happening.

    The soil we have here is a heavy clay mixture that doesn’t drain real well. When it came time to fill in the trench, we covered the conduit and ground wire with a few inches of heavy soil. Then we partially filled the trench with rock to act as a drainage ditch out to the pasture area. Hopefully that will help drain off some of the snow melt, and extra water during the spring time.
    Solar Inverter Power Panel. The more I thought about it, the more I couldn’t stomach the idea of the brand new solar inverter (Fronius) being directly exposed to the weather. We found what I like to refer to as an outdoor closet at Menards. it is basically a simple to put together small plastic shallow storage building that you might put some shovels, rakes, or garden supplies in. To prepare for mounting the ‘Fronius Closet’ we poured a slab of cement.
    NOTE, the small wood box, around the conduit, and the short pieces of PVC around the two poles. The idea here is knowing that the cement slab is going to move around a little bit, due to the frost, we are hoping to isolate the slab from the poles and the conduit to allow the slab to move without putting pressure on the poles and conduit. We’ll see in a few years how that all works out. The PVC was a cut from an extra piece of conduit that I split in half with a hack saw. I then taped it back together around the poles with electrical tape. The re-rod has vertical threaded rods welded to it to eventually bolt down the ‘Fronious Closet’.
    Here we have the cement finished, and the ‘Fronious Closet’ all mounted in place, ready to have a solar array built around it. This set us back a couple weeks, but for now I really like the way it turned out, and I think it will end up being well worth the small investment, and delay in completing the project.
    This picture is a bit of a ‘fast-forward’ as you can see that most of the wiring is complete. We decided that since we now have this nice little enclosed power panel, that a couple outlets to plug into would be nice as well. More importantly though, since knowing that the solar inverter is going to generate some heat while it generates power, we needed a means of exhausting the heat out of the closet. The silver box above the panel is an inexpensive bathroom fan, which will eventually be controlled by a temperature controller to exhaust heat out as necessary.
    The large box with the exposed wiring is the mount for the Fronius solar inverter. The D.C. voltage comes in from the solar panels on the left side. The RED wires are simply black wires covered with red heat shrink to differentiate the positive and negative leads. The A.C. voltage goes out the right side. The large WHITE wire again, is simply a black wire with white heat shrink, to show that it is the neutral wire. The large bare wire is of course the #6 awg ground wire that I mentioned a few pictures up. The smaller wires are the ‘Hot’ (L1) neutral and ground of the small branch circuit to supply power to the outlets and fan.

    Let’s Get’r Done!

    So now we have a ground mounted rack for the solar panels, an electrical circuit to tie in to the main electrical service, and a place to mount the inverter in which we can tie in the electrical power coming from the solar panels. For us the next logical step is getting the panels mounted on the rack, and getting the system running!

    If you look closely, you will see some black electrician’s tape at the bottom of the rail. We placed and measured a rail at each end. Then we ran a string line from across the bottom of the two outer rails to create a reference point to keep the rest of the rails in line with each other. Since the end of the aluminum rail was rather sharp, I taped it up with some electrical tape first, to prevent cutting the string line.
    On the lower (front) horizontal pipe, we used a tape measure, and a carpenter pencil to mark where the ‘U’ clamps for mounting the panel rails would go. To do this I took the recommended spacing of the rails provided in the SnapNrack instructions, and since I wanted 1 inch of spacing between each column of panels, I simply added an inch to the distance of every other rail. Since my attention span is quite short, I actually wrote all of the progressive measurements down on a list, so that we could simply pull a tape measure, and mark off each measurement of where a ‘U’ clamp would go from the list. Only in a couple places, we ended up with a clamp location that was on a ‘TEE’ bracket, or a coupling. At those places I simply deviated from the recommended spacing an inch or two. Once we started mounting the rails onto the rack, I made up a crude heavy duty square out of some pieces of 2x4 that I had laying around. The square just made it a little easier to get the rails truly perpendicular to the horizontal support pipes.


    The SnapNrack system certainly lived up to its name. All the fittings for mounting the rail to the pipe, and mounting the panels to the rail, snap right into place, and then could be slid into their final position. I’m not trying to be a commercial for SnapNrack here, but I can honestly say if I were going to start another project like this, I would certainly use the SnapNrack system again.

    The rails are all in place, to the lower left is my homemade square that we used to align the rails.

    If you look closely toward the bottom center, you can see my crude but effective spacer that we used to set the 1 inch gap between the panels.
    We quickly found out that getting to the hold down clamps between the panels to tighten them up, was a long reach. What worked out the best for us is to place the bottom panel, and the next panel working upward. For the 2nd panel reaching across the bottom to tighten the intermediate clamp between the 1st and 2nd panel worked out pretty well. Then with the 3rd panel we went up from the back side and lifted the panel up over the top of the rail, and slid the panel into place on the rails from the top down. We could then use a ladder to climb up and reach over the top of the 3rd panel to tighten the hold down clamp. We set the 4th panel in the same fashion.

    When we set each bottom panel, we used a homemade spacer that consisted of a 1 inch wide piece of scrap 2x4 that I ripped on the table saw, with another scrap board, screwed to the top of it to prevent it from falling through. We used the spacer on the bottom panel only, then we used the red 4ft level as a straight edge to help keep the rest of the column in line.

    We used the red 4ft level as a straight edge, to slide each panel into place, in line with the panel below it.

    The panels are up, but nothing is connected. The next steps are the “Home Run” lines, and connecting the panels into strings.
    The system appears to be unfinished due to the fact that we originally planned to install 40 panels that were 250 watts each. 40 panels times 250 watts/ea. = 10,000 watts. However, when we came to the point of purchase, we were able to buy panels that were 300 watts each for only a few dollars more per panel. This allowed us to purchase 36 panels at 300 watts/ea. at almost the same price as buying 40, 250 watt panels. So, with 36 panels times 300 watts/ea. = 10,800 watts, which was almost like getting 800 watts of production for free!

    Eventually I would like to fill the last set of rails with panels that will operate independent from the rest of the array. Perhaps to experiment with, or provide power, and maybe a little heat to my tiny greenhouse just to the west. Right now, we are more interested in collecting data on the performance of the existing array.

    Now that the panels are installed and exposed to whatever comes along, it was time to inform our home owners insurance that we made an addition, and want it to be protected.

    Let’s make these things useful!

    String Theory isn't just to describe the Cosmos
    There are basically two major types of grid tie solar inverters. String Inverters convert the DC electricity from a group of solar panels wired in series into usable AC electricity used by your house and the electrical grid. Micro Inverters convert the DC electricity from a single panel, or in some cases a pair of panels into usable AC electricity used by your house or the power grid.

    Since this system uses a String Inverter, that is what we will be explaining in detail, but I would like to point out the pros and cons of both. String Inverters are basically one large inverter capable of handling the entire array of solar panels, so they are typically less expensive than a group of Micro Inverters that would handle the same size array with the same power output. However, a string of solar panels wired to a String Inverter depends on the exposure of sunlight to be the same across the entire string to work at its full potential. If something like a tree, or maybe a dormer shadows one of the panels in the string, then the entire string will be reduced in performance to the level of the shadowed panel. A system with Micro Inverters takes the power from each panel, so each panel is not affected by the exposure of sunlight to the panel next to it. So even though Micro Inverts may cost more to install, they may greatly offset the extra expense of installation by the better performance. This is completely dependent on your individual location and how your array will be exposed to the sun.
    Going back to our particular situation, since our array will be exposed equally to the sunlight for virtually the entire time the sun is up, the choice for us was clearly a String Inverter. I also believe the String Inverter maybe uses a little less wire to get it all hooked up, but on the flip side if a string inverter fails, then your entire array goes down, as opposed to if a Micro Inverter fails, the rest of the system will continue to run. So again, if your situation involves moving shadows, as the sun tracks across the sky, then you should at least look into Micro Inverters. However, if your situation involves equal exposure to the sun, a String Inverter will probably be the best choice.

    Home Runs aren’t just for Baseball anymore!


    These are the Home Run conduits leading to the junction box that transition to the flexible conduits that go to the Fronius inverter. These conduits are anchored to the back side of the panel mount rails using the snap in bolt mounts, and the conduit clamps that we 3D printed.

    If you look closely at the picture to the left you can see the conduit ends at a TEE fitting. We used the TEE fitting to extend to end fittings where we brought the Home Run lines into the conduit. We printed the plug below to serve as kind of a grommet. We simply ‘glued’ them in with silicone sealer.

    snap-n-rack_conduit_pad_01.stl
    This printed spacer was used with the snap in rail anchor below, to mount all of the conduit fittings, in order to stand them off of the rails the same distance that the conduit clamps hold the conduit off of the rails.

    Here we have the conduit clamp assembled with 1/4” bolts held by the SnapNrack mount, which you can see up inside the rail. We used nyloc nuts, but that probably wouldn’t really matter.

    conduit_j_box_lid_01.stl
    The Junction box is actually a switch, or outlet box. I was not able to find blank covers for them, so I printed covers to fit.

    conduit_wire_plug_01.stl
    A 3D printed plug that we pushed into the conduit fitting, to protect the wire and keep stuff out of the conduit.

    snap-n-rack_mnt_base_01.stl
    This is the printed snap in anchor that was used for mounting all the Home Run components to the rails. We simply inserted the right length 1/4” bolt so that the head was captured in the hex pocket.

    snap-n-rack_conduit_clamp_01.stl
    Just to Clarify…
    The pictures show the wires all connected because
    the pictures were taken after everything was up and running.

    The Inverter we installed is a Fronius 10 kilowatt String inverter that has two MPPT channels. An MPPT (Maximum Power Point Tracking) is an electronic way of adjusting the load on your solar panels to draw the most amperage off of them while still holding them at a useful voltage. The Inverter can also accept a fairly wide range of voltages. In reality they have to be able to do this, due to the wide variation of exposure to the sun that they get. Since our array will have sun exposure equally across the entire system, we simply divided the 36 panels up into 4 equal strings of 9 panels each. We wired two of the strings in parallel to MPPT channel A and two strings in parallel to MPPT channel B. What is important here is that any two or more strings that are going to be wired together in parallel need to have the same voltage coming from them. There is a positive and negative ‘Home Run’ line for each string. In our case we have four strings, if you look at the picture up above the conduit plug, showing the wire entering the conduit, you will notice that there are two wires. This is because I setup the conduit in a TEE fashion at each end, so wire comes into the conduit from the two bottom strings, into the bottom box of the TEE. The two top strings then go into the top box of the TEE. You may also notice in the picture, that the wire is RED, this is actually red heat shrink tubing that I put over the wire coating to visibly mark that this is the positive side of the string of panels. The negative home run lines are all at the East end of the solar array. Once I had all of the wires ran through the conduit, I then hooked the wires up to the solar inverter terminals, inside the mounting frame of the Inverter. At this point no panels are hooked up yet. I was able to finish all the wiring in broad daylight without doing anything unsafe due to the fact that the solar panels were still not hooked up.

    If you would like to learn the details of series (or ‘string’) and parallel wiring, there are lots of websites out there to explain it. In short though, let’s say you have two 2 volt batteries, but one is bigger than the other. The big one puts out 2 volts at 2 amps, whereas the small one puts out 2 volts at 1 amp. It would be okay to wire these batteries in series or parallel however the results will be quite different. Wired in parallel (positive, to positive, to output, and negative, to negative, to output) you will still get two volts from the batteries, but the amperage that they will put out will be combined to equal 3 amps. Now if you wired them in series (positive, to output, negative to positive of 2nd battery, negative of 2nd battery to output) your output voltage will increase to 4 volts, however it will only output 1 amp at 4 volts because the little battery can only output 1 amp. Now let’s say you have a small battery that puts out 1 volt at one amp, and a bigger battery that puts out 2 volts also at 1 amp. You can wire them in series and end up with 3 volts at 1 amp. The batteries don’t have to be the same amperage, but you will only get amperage output of the weakest battery. Now if you wire these two batteries in parallel, you will get something less than two volts, because the 2 volt battery is going to try to charge the 1 volt battery. Since the 1 volt battery is not designed to run at two volts the least that will happen is you end up with a heater, the worst that could happen is one or both of the batteries could explode due to the current transfer. Now, this does not EXACTLY pertain to solar panels, but when exposed to light, solar panels behave very similar to batteries. If any of this information is confusing, please study further or consult an electrician before you do any of the physical wiring.

    Going back to the MPPT channels… All the string inverters that I looked at had at least 2 MPPT channels, and I started wondering why you would need two or four or whatever. I believe the biggest reason they do this is to allow you to configure your array the way it will work best for you. For example, let’s say I decided to put a bunch of solar panels on my barn roof. My barn runs North and South, so the panels would be mounted either facing East to get the morning sun, but would sharply drop off in output right after noon. Or they could be facing West to get the afternoon sun, and into the evening. But how about putting panels on both sides, then if all the East facing panels were wired into MPPT channel A, and all the West facing panels were wired into MPPT channel B, I could receive solar power through most of the day. One more example, is that maybe your system would work out really nice if you could hookup one string of 6 panels because they fit on the south side of your roof, but it also works out that you can put 4 more somewhere else. Now a string of 6, and a string of 4 are going to output different voltages, so then they would need to be hooked up to your inverter, into two separate channels. There are also other options like combiner boxes etc. So, If you have a place to put some solar panels, chances are you can get the best performance from them, with the right configuration. Again, if all this sounds confusing, then take a step back and either consult someone with experience, or spend some more time on websites that sell solar equipment.

    THINK BEFORE YOU WIRE!
    On our system the open circuit voltage rating for each solar panel is 40 volts. So, with our panels wired together in series of 9 panels for each string, we have a voltage potential of 9 times 40 volts, which equals 360 volts! I deal with electricity in some fashion almost every day, but I certainly would not want to get hit by 360 volts from anything. Now even though we are talking about some really dangerous voltages, if the system is installed correctly it does not have to be dangerous at all. I cannot tell you exactly how to wire your system, simply because your system probably won’t be exactly like mine. However, I can tell you how to wire your system safely without putting yourself in any danger at all. THIS DOES NOT involve wiring your system in the dark. Actually, even with subtle moonlight, solar panels wired in series can still produce very dangerous voltages. On our system I did all the wiring, in daylight conditions, completely safely, in the following sequence of events. First, I completed all of the AC wiring. Now the only way to safely do this is by having the AC power turned off. Remember those disconnect switches at the main power panel, in the pictures above? Those switches allow me to turn off the power coming from the power grid and keep me safe. When all the AC wiring was complete, but with the power still turned off, I then began running the ‘Home Run’ lines. These are the wires that carry the DC voltage from each end of the string into the DC side of the inverter. We ran the Home Run lines through the pvc conduit which we had previously mounted on the back side of the solar panels. NOTE: At this point none of the solar panels are hooked up to anything, the individual panel wires were still looped and taped from shipping.

    With all of the Home Run lines, (Positive marked with RED heat Shrink, Negative left BLACK) pulled into the Fronius inverter mount, I terminated all of the DC wires in their proper locations. ("terminated" is just a fancy way of saying I carefully stripped all of the wires and put them into the terminals and screwed them down TIGHT.) At this point the far end of the Home Run lines were not hooked to anything. I installed the special solar connectors to each Home Run line obviously being very careful to correctly install the mate for the Positive connectors on the Positive end and vice versa on the Negative end. The picture up above, in the group of 8, that shows the Home Run line entering the conduit, shows a connectorized Home Run cable (positive) plugged into the solar panel cable.

    A Quick Recap

    All the AC wiring is done. All of the DC wiring that deals with any exposed wires, or tightening terminals is done. Now all that we have left are unconnected solar panel DC wires that all have connectors on them. The only thing left then is to start hooking the panels together one by one, in a string fashion. I started at the bottom panels and with the Negative side, I attached the Negative panel wire to the mating Negative connector of the first Home Run line. I then proceeded across the array hooking the Positive wire of the previous panel to the Negative wire of the next panel. When I got to the end I connected the remaining Positive panel wire to the mating Positive Home Run line which completed the circuit for that string. I repeated this with all four strings to complete all the DC wiring.

    Some Optional steps that you might consider if you do your own install.

  • After all the panels were mounted, I picked a moderately cloudy day to take a meter reading off of each solar panel just to verify that each panel was capable of producing power, and that the panels in general had fairly equal readings. Since I wanted take both voltage and amperage readings, I did it on a somewhat cloudy day so that when I took the amperage reading, which is basically short circuiting the panel, it would not be at full power. Just to clarify, the panels are protected against short circuit but it is less stressful on the panel to do this test at less than peak exposure to the sun. Also doing this testing is not required, and I’m sure professional installers would only test like this if they were experiencing some kind of trouble with the system. I just did it because I wanted to know that each panel was working individually and I wrote down all the information, to verify that they were all basically equal.

  • Since the Fronius inverter is made in such a way that you can mount and wire the back of its enclosure, it made it really simple to test all of the wiring prior to physically putting the inverter in place. For this reason, once I was finished with all the AC wiring, I was able to turn on the AC power and test the voltages at each of the terminals on AC side of the Inverter to verify everything was correct without any chance that the Inverter would start up, because it was not yet attached.

  • Another nice feature of the Fronius inverter is that in this back mounting enclosure it has individual DC fuses for Positive and Negative of each string input. By pulling all of the fuses out I was able to Isolate each string of panels, and after I finished the DC wiring, I was able take a voltage reading from each string. I was happy to see that they were all within 1.5 volts of each other, which basically confirms that everything is hooked up properly, and we are ready for the inverter.
  • Connecting the panels into strings
    The SnapNrack system bill of material called out some wire management clips that snap into the rail and are designed to hold wires in, so that you can kind of use the rail as a wire trough. The clips certainly pop in tight and would do their job nicely, and if I were stringing the panels together in a vertical fashion this probably would have worked just fine. However, we had set everything up to connect the panels together horizontally across the array. In this case we really didn’t have any way to support the individual panel wires that made up the strings. Our solution was to go buy the cheapest 1/2” pvc pipe that we could get. We originally used zip ties to strap the pvc pipe to the underside of the panel mounting rails. We did four horizontal pipes across the array, which provided a convenient support structure to tie the panel wires to. I later made some clamps and anchors, again using the 3D printer, to make solid permanent mounts for the pvc pipe. It all came together quite nicely and added very little expense to the system. Wire management is critical in building a long lasting system. Any wires allowed to flap around in the wind, or have the weight of snow or ice build up on them are going to seriously reduce the life of the system.
    The small black box to the right of each panel is the junction box where the positive and negative wire comes out. These boxes are sealed to the back of the panel. Care must be taken to prevent anything from pulling on the wire. We used the pvc pipe to support all the inter-panel wiring.

    s-n-r_pvc_mnt_base_02.stl
    s-n-r_pvc_wire_support_clamp_01.stl
    The pvc pipe clamped in the underside of the rail. In this case we pressed the nut into the hex pocket of the snap in mount, and used stainless screws to secure the clamp.
    Solar panels interconnected, with connector and wire supported by pvc pipe.
    Turn on the Sun! Let's generate some power!
    NOT QUITE YET, but almost!
    So, we have the system completely built, wired, and ready to turn on to see whether it all works or not. THE MOST IMPORTANT REASON WE ARE STILL NOT READY TO TURN THE SYSTEM ON AT THIS POINT, IS BECAUSE THE POWER COMPANY STILL DOESN’T KNOW THAT THE SYSTEM IS READY. The following is a “check list” of sorts to make sure everything is done prior to having the power company visit and if all goes well, they will install the new smart meter that will interconnect the system to the power grid. You will sign an Interconnection agreement, and then you are approved to run your co-generation facility.
    • Update the application information. Remember way back in the beginning when we applied for permission to Co-Generate, that we didn’t have anything purchased yet, and we didn’t know exactly what was going to be installed. Well now is a great time to get that all that up to date and fill in any missing information, such as the model and serial number of the inverter, the exact size of the system, and anything else that may be missing or changed since the project started.

    • Contact the power company and let them know that your system is ready to startup. They will then schedule a time when they can come and test the system prior to installing the smart meter. It sort of surprised me when they asked if we had turned it on yet. I wanted to turn it on and see if it worked, however there are very good reasons why I didn’t and you should not either!
      • First: SAFETY, because of the way the system operates it will only startup and generate power if it is “turned on” to the incoming power source. What if I turned on my system and It started generating power while someone happened to be working on the power lines. Since I have not had it turned on yet, I don’t know that it is safe to operate. The results could be deadly to any individual that might be out working on the power line.
      • Second: I don’t know how my current power meter will react to power being pushed back through it. I certainly didn’t want to have to explain to the power company why their meter might have been damaged by me turning on the system before I was supposed to.
      • Third: In reading the manuals for the Inverter it was indicated that the system logs data, on power output and any error codes etc. Here again, I would not want to have to explain why my system had any data stored on it, prior to getting approval from the power company to turn it on.

    • PROPER LABELING: Last but certainly not least the system needs to be properly labeled so that a power company worker can clearly see that co-generation is taking place, and clearly see where and how to shut it off. The “Wisconsin rules for interconnecting distributed generation facilities” has labeling guidelines in “Subchapter III — Design Requirements” PSC 119.20. This part gets a little confusing, because the labeling really needs to be as custom as the generation system that you designed, however you also want to follow the symbol and color standards so that a worker can quickly identify important information about your system. We did a combination of custom and standard labels that you can see pictured below.

    Meter Box and main distribution circuit breaker panel.

    We 3D printed a custom sign (above the meter box) to inform the power company worker that the main switches are on the back side of this panel. The meter box and the main circuit breaker box have specific NEC stickers on them as well. The breaker box is also labeled inside as to which breaker is being “backfed”.


    Main Disconnect switches.

    The upper left switch is clearly defined as where to turn off the solar generator. The lower right switch is more of a “nice to have” than a necessity. I can turn this off if I am working on the system, or during emergencies. Example, when the power is out during a bad storm, when surge potential from lighting is higher. The point here is that anyone who needs to turn if off can quickly see what the switch controls.


    The Fronius Closet.

    This is where the solar generation begins, and anyone going in there should be aware of the voltage potentials.


    The solar inverter.

    This also needs to be clearly labeled with what is powering it, and how much power potential that there is.

    A quick Note: The digital display in the upper left is a temperature controller which controls the bathroom exhaust fan directly above the inverter. We put this in to make sure the Inverter doesn’t overheat on hot summer days when it is outputting close to maximum power.


    All comments are welcome!
    Positive or Negative. If you would like to make a comment,
    please E-mail me at dean@crexrealty.com.



    Thank-you for taking the time to visit!



    Other fun pages on this site

    Crex Meadows

    Memory Park | St. Croix River

    Grantsburg Parade | Thoreson Park | The Dark Side

    Free CD Rom | Ramona's Craft Page


    Decisions, Opinions, and Stories…

    Why Grid Tie Instead of Batteries?

    The number one reason for keeping our solar array ‘On-Grid’ is because we were already on the grid. We wanted to generate our own electricity, but it is a really big step to become your own power plant. I will be the first to admit that I have complained about paying my way too expensive electric bill ever since I had to start paying it. However, if you think about it for a little while, you will realize how inconvenient it is when the power goes out. We have become so dependent on electricity, that it really upsets our lives when we don’t have it. Now, right here would be a good argument for being Off-Grid so that you never have to depend on the big bad power company again. Right? I am not trying to be a commercial for your local power company in any way, but from our experience the power that we buy from the power grid is pretty darn reliable. When the power does go out for some reason, we can be very confident that some one is out on the job trying to fix the problem. So, to put this in perspective, it seems like we can never walk into a Walmart without spending a hundred dollars or more, but yet we sorely disapprove of paying for our monthly electric bill. I personally believe the only real phone is one that still has a cord attached to it, and yet I know many people who pay as much or more for their cell phone plan as they do for electricity.

    During my research on Grid-Tie compared to Off-Grid, I found out that there really is no middle ground. The components that make up a system are either designed to use storage batteries, or they are designed to not have any storage and be connected to the grid. You certainly could design a system capable of doing both, however, I believe the cost would quickly out weigh the benefit of designing such a system.

    It is my opinion that at this point, battery technology simply is not good enough to compete with being on the grid. Batteries wear out, lose energy due to heating while they are being charged, lose energy due to heating while they are being discharged, and also lose energy just sitting there. At the beginning of this whole project, the 1st objective was to build a power generation system that will pay for itself in as little time as possible. At the time that we made the decision to install solar panels, a grid tie system seemed to be the best way to do this. Please don’t get me wrong, I am still looking for the perfect energy storage solution. I just don’t believe that right now, batteries would be a good investment. A couple things that I would also like to point out. Hypothetically speaking, let’s say that you have a solar array with a battery bank that is capable of storing 3 days worth of power. Obviously you can manage your power usage, for example, save bread baking or cloths washing for the sunny days, and try to minimally use appliances at night, or on cloudy days. Now let’s say you have two weeks of beautiful sunny weather, and after one week all your clothes are washed, bread is baked, and life is good. When the batteries have reached full charge, they can’t take any more. To do so, will damage the batteries. This means that at the end of all your sunny days you still only have 3 days of reserve power. Now, compare this to a Grid-Tie system where every day that is sunny will put power into the grid, of course, this is any power above what you are currently using. So, going back to our hypothetical situation, when the bread is baked and the clothes are washed, your solar array continues to put power into the grid, which will never become fully charged. As long as the sun is shinning the system keeps outputting, and the Net Meter keeps track of power going out compared to power coming in. This very reason is why it is such a big step to go from being on the grid, where you simply plug in your appliance and let it run, compared to being off the grid, and constantly managing how much reserve power you have left.

    Why Fronius Inverter?

    I didn’t even know the name, Fronius, until we had spoke with with the owner of the solar power outfit that I mentioned above. He had talked up Fronius by explaining that Fronius is world wide, but they have USA head quarters right down in Portage, Indiana and if you have any questions or trouble, that Fronius has great support. When I checked into Fronius myself, I found out that they have been making welding equipment for a very long time, and have been using inverter technology in that equipment as well. Now, this all sounded good, but when you get right down to it, Americans can make some pretty good stuff too. I started searching for solar grid tie inverters to see what was available, especially made in America. If you look, you will find some American made inverters that are supposedly actually made in America. However, the ones that I found have not been in business long enough to prove themselves. We simply were not prepared to take the risk of a large investment on an inverter that is made in USA with out some substantial history of performance. I came across the “Sunny Boy” made by SMA who proudly promotes that they are USA based. It might be stupid, but I really liked the name, and that kept me interested enough to really look into what they have to offer. The Sunny Boy has a unique feature that apparently no one else had thought of, but I thought was really great! This feature is a separate “emergency” outlet that is isolated from the grid tie circuit. So if your power is out, meaning your solar array is shutdown for safety reasons, but the sun is still shining, it can output up to 2000 watts of power directly from the solar panels. Here is a link to a website that explains it in more detail.
    grid-tie-solar-home-system-blackout
    At that point I was pretty much sold on the Sunny Boy! I mean, great name, able to draw power during a power outage, what more could you want? Well I kept researching to find out something that turned me off a little. It didn’t completely turn me off, but I came across an article that said that people were getting upset to find out that the Sunny Boy inverters were starting to be manufactured in China. This was a though decision due to the fact that I really liked the Sunny Boy features, but I liked the Fronius features as well, and to top it off, the cost was too comparable to help me decide. So, it really came down to this. Take the chance on the cool name and really neat emergency outlet, or go with what should be the more reliable time tested technology of Fronius. It finally dawned on me to start thinking about when I would need that nice emergency outlet, and the times in the past that the power had gone out and it was out long enough that I had to run a generator. I can only remember one time that was not at night, or during a storm, or was such a short outage that it didn’t matter. That one time was a bad storm that came through on the 4th of July, and it took down trees everywhere which took a lot of power lines down too. The storm came through, not long before night fall so, I would have needed something to keep my basement from flooding, and the freezers operating through the night anyway. It was the next day that we still didn’t have power, and the sun came out plain as could be. Once I thought about the likelihood of that happening again, that really cool emergency outlet didn’t seem so great anymore. That is when I decided Fronius is the one I want. One more point to ponder about the Fronius inverter is that all the owners manuals, and installation manuals were readily available on-line to download. I was able to read and understand all of the details of installation, wiring, setup, and communication, with the Fronius inverter long before we ever purchased it. I won’t hold this against any other inverter manufacturers because, they also might freely provide all the information you need. I’m stating that knowing all of the requirements of the inverter up front, was a huge help with planning the rest of the system.

    Why SolarWorld panels?

    As we were looking into the whole possibility of installing this solar co-generation system, the news was riddled with updates about increased tariffs on imported products. The owner of the solar outfit that we had talked to had said that they sell and install Peimar solar panels, which are made in Italy. At some point in our conversations, he had mentioned that the tariff would probably be about $50.00 dollars per panel. This fact didn’t immediately persuade us against buying Peimar panels, actually in the beginning, all of my cost estimates included Peimar panels. When we got more serious about actually installing the system, I figured I would start researching some other solar panel manufacturers and see what might be available that is made in the USA. After all, if I have to spend an extra 50 bucks per panel, maybe I could find something that doesn’t just cost $50.00 more, but is actually worth $50.00 more, in quality, or performance. In doing some research to find that most reliable panel that might actually have a chance of surviving the length of time that would allow it to pay for itself, I found out that there are literally hundreds of solar panel manufacturers. However, as you might have guessed not all that many of them are made in the USA. Oh, and of course they all claim to have the best quality, longest lasting, and best performance. As I researched on, I came across a Youtube video that demonstrated how well SolarWorld solar panels are able to withstand hail balls shot at them at 200 miles per hour, or something like that. Anyway, I was impressed enough to start looking up SolarWorld panels specifically. The following is an excerpt from a website that sells solar equipment which basically had me sold. I mean, they can’t put anything on the Internet that isn’t true, right?



    Now, take a close look at the picture of the specification label on the back of the solar panels.
    (click on it to see full size)

    I was sorely disappointed to see that label, not so much that it was made in Germany, but that it didn’t say it was made in the USA! Due to European Unions, Politics, and various experiences with other products, I have a pretty low opinion on anything that comes from Europe. As of right now, we do not have anything bad to say about the SolarWorld panels however, for this reason, if I were to start building another array, it probably would not be with SolarWorld panels.
    Digging the Trench
    June 29, 2018

    I got up a little early, to start to prepare for my trench digger to arrive. Weather had set us back a few times, but today it appeared that we would be able to finally get the conduit in the ground. My nephew, Joe Moyer, was due to arrive after his driver's education class during summer school. At the time he had finished his sophomore year of high school, but he was also already an expert backhoe operator. Today he would be using a “DIG IT” which is a small backhoe that was originally used for trenching by a telephone company.

    I had previously prepared the beginning of the trench by digging holes at each power panel down to the 24 inch depth that I wanted the trench to be. It had rained a few days prior so, I had to try to pump the water out of my starter holes as best I could.
    I had made a crude depth gauge out of some scrap lumber, to allow us to quickly check the depth of the trench. The digging was a little rough going through the driveway, but all in all, it went very smoothly.
    I was able to follow along, scraping the bottom of the trench, and also periodically check the depth.
    By the time we had reached the very welcome shade of the tree, the temperature was well into the 90’s and it was humid. As we went along I was becoming more concerned that we might have a thunder storm later in the evening and it seemed like this summer so far, every time it rained a little, it rained a couple inches. The last thing I wanted was to have to deal with a trench full of water, caving in, as we are trying to lay the conduit in it.

    Ultimately, it all turned out fine, but when the trench was dug, we scrambled to get the conduit glued, and laid down as quickly as possible. As we were laying the conduit in the trench, I was having visions of a trench full of water, with the conduit floating to the top. We kept going and by night fall we were ready to push some of the dirt in onto the conduit. We didn’t want to fill the trench with dirt, because we had planned to pour rock in the trench as well, to serve as sort of an underground drainage path. Anyway, after we had pushed enough dirt in, that we were confident that the conduit wouldn’t float, we called it day, which turned out to be around 23 hours for me.

    The next day, thankfully it had not rained so we were able to spread the heavy soil out over the conduit. The idea here is to cover the conduit, and ground wire in the heavy soil, to basically buffer it from the rock, as well as make a good electrical path for the ground wire. We then put rock on top of the heavy soil to hopefully allow for water runoff in the future. After putting rock in, we finished covering the trench with heavy soil again which will eventually become sod, and hopefully help keep the rock layer somewhat clean. I don’t know if it will help drain or not, but we figured it was worth a try, since we had to dig the trench anyway.
    Adam, my son, moving rock while I worked on connecting the conduit to electrical boxes.

    Nala, one of three cats that we have, (I call her Naughty Nala), needs to be involved with whatever is going on. She seemed to be particularly fascinated by the trench. She was in and out of that thing for hours while we worked on finishing it up.

    The Story of Mr. Owl

    You won’t find Mr. Owl on the list of materials that we used to build the array, but his job is important, none the less. As I was talking with some co-workers about getting the array running and excited to see what it is capable of producing, one of them mentioned that he put up some solar panels to run an aerator for a pond. He said that every time he goes out there, he finds that the birds have sh*t all over them! At the time I had not thought a whole lot about that, but I was hopeful that the panels would generate enough heat to deter the birds from hanging around the area too much. Then it was mentioned that I might need to get a statue of an owl which people use as a scarecrow so to speak, to keep birds and rodents away. I had never heard of this before, but when we looked it up on Amazon, sure enough, there was quite a variety of scary owl statues that you could buy as a decoration, or a deterrent for other animals.

    It was only few days later, in early fall that the weather had cooled down slightly, and low and behold the solar panels had gained all sorts of attention from various bugs that wanted a warmer place to stay. Then of course the bugs gained the attention of the birds. When I got home from work, I noticed that the top edge of the top row of solar panels was almost completely covered with birds perched on them, while more birds were flying over the panels apparently catching bugs. Now, as the birds were perched, and/or flying over the solar panels, they had also been dropping there cargo, all over the place. I quickly realized just how big a problem that this could turn into. If you read the part about “String Theory” up above, you understand that if one panel is shadowed in some way, then the entire string is also effected. It probably wouldn’t take much bird cargo to reduce the performance of the solar panels 10 to 20 percent.

    After seeing this problem with the birds up close and personal, we decided that we needed to try something. On Amazon these owls varied in size and features and they mostly had mixed reviews from “works great”, to “doesn’t do anything”. Some had moving heads that would rotate in the wind, but people also complained that there head pops off. We tend to have some pretty windy days since we are basically surrounded by fields so, I wasn’t real crazy about the ones with moving heads. Well, we decided that simple was better, and that we would get an inexpensive plain owl statue just to see what happens. It is only fair to mention that the manufacture recommends that you move the owl from place to place at least every few days in order for it remain effective. Sorry Mr. Manufacturer, that is NOT going to happen. I made a mount for Mr. Owl, and he has been perched at that same spot ever since. So far, since labor day weekend, he has weathered a rather severe thunder storm, many heavy rains, some relentless winds, and has been completely plastered with icy snow. Yet, he remains perched there, kind of, just like a statue!

    After Mr. Owl was put on his mount, I started to wonder what else could be done, as sort of a plan ‘B’ because I’m sorry to say, I didn’t have a whole lot of faith that Mr. Owl would make any difference what so ever. It finally dawned on me, that maybe if I made a better perch for the birds to land on, then top edge of the solar panels, then maybe they would land on that instead. I had some ½ inch pvc pipe, and fittings still left over from the solar panel wiring so, I printed some brackets, and made up a pvc rail that spanned the top of solar array, slightly above, and out from the panels themselves. I figured with the perch being out away form the panels, if the birds land to rest, and subsequently drop their cargo, at least it probably wouldn’t be on the solar panels, and that would be good enough for me.

    This is now the middle of January, 2019 and since I mounted Mr. Owl out there on the array, I have only twice witnessed any bird activity near the solar array. Once in early November, I believe, I saw one bird coming from the south, and it swooped down as if it wanted to do a surprise fly by near Mr. Owl. The bird flew by, probably 15 to 20 feet away from Mr. Owl and kept going. Another instance was just the other day. It actually may have been the day I started writing this story, that I saw two medium sized dark birds, (probably cow birds) that came in for a landing. One landed on the edge of the solar panel right next to Mr. Owl, the other one landed on my pvc perch about 10 feet to the east. They were only there for a few seconds, and then took off. It was almost like a dare to who was willing to see if Mr. Owl would react.

    So there you have it, I personally believe that the owl statue works. I believe that birds flying around probably see Mr. Owl from a long distance away and simply choose to keep their distance. I have no idea about the effectiveness toward rodents. We have cats to help us out in that department. Anyway, Mr. Owl has earned his place here, and the solar array wouldn’t be the same without him!


    bird_perch_pvc_clamp_01.stl

    This clamp uses the same snap in bolt mount as the Home Run conduit clamps. I cut 12" lengths of pvc pipe, and used the clamp as a drill guide to drill through the pvc.

    bird_perch_pvc_hldr_02.stl

    This clamp uses the same screws, as the pvc clamps that support the panel-to-panel wiring.

    Last Updated 01/20/2019