Just a quick post. I’ve mentioned my little house in the country many times… I finally found the energy hog!! It was my septic aerator pump. It’s a 3/4 horse air pump, and it was running far too often. Changed the timer settings and cut my biggest energy user by 70%. I added panel #13, and I think I’ve almost reached NET ZERO energy for this little house!! Thought I’d share this bill with my readers! Hope to see this happen about 6 months out of the year! Nothing makes me happier than seeing a ZERO or near ZERO electric bill. Keep in mind, the solar also covers the “fixed” portion of the bill that is NOT electric usage! It renews my belief that doing this is the Right thing, right now. Solar has never been more affordable, so if you’re 50 or younger, and plan on staying in your home for the next 20 years, CALL ME and I’ll show you how to do DIY SOLAR in a quick, effective and above all AFFORDABLE manner! It just makes good sense.
Missed this photo on the first part of this adventure. The owner had materials on hand, and made the posts of Steel L channel, the beams from Steel S-channel, and the barn support brackets from 2 inch steel L material. The owner (George) is a VERY resourceful fellow – some might call him a scrounger, but I call him SMART! I passed along a great vendor deal on the solar panels and he purchased them direct. The BOS (balance of system) materials was purchased through Cinci Home Solar at great pricing, bringing the whole project in at about $3/watt, and this includes the battery bank and backup power inverters in addition to the Enphase micro-inverters behind each panel. The work was spread over 4 full days, with the helper crew varying from 1 to 3 guys and myself. Plenty of manpower to get this rather large project done in a timely fashion. Winter is really variable in Cincinnati, and whenever the weather was predicted to be above 40 and sunny, George called and we got the job done. Fortunately, this job was a quick drive from my home, and it wasn’t a problem. Normally, these 3 or 4 days would have been all condensed into one extended visit! I aim to please, whenever possible…
After we finished the 32 panel array, George saw that some minor grading of the ground near the bottom would allow plenty of room for 2 more rows! A week later he called me and said “Hey Joe, come on out and lets get these 2 rows installed – tomorrow’s weather looks great. So we did! When I ordered the extra components, we also added 8 more rails – one under each of the 8 columns of the upper 4 rows. You can see them mid-panel in the picture to the right. This provided the extra strength and rigidity that the span required for both wind and snow loading. Splicing the extra rails that extend to the newly installed lower beam also provided a counterbalance to the free span above.
The two missing panels at the lower left were intentionally left off because of a stone access road to the hay barn that George didn’t want to move.
This is what the backside looks like after everything is in place. After the rails were set, the Enphase M215 Micro-inverters were mounted. Then the #6 bare copper ground wire was run in series to each inverter. We grounded BOTH ends of the #6 copper, just because we could. Next came the Enphase TRUNK Cable, mounted with stainless steel clips to the rails. Then the panels were added, the micros were plugged in to the trunk cable and the panel leads connected to the micros. One end of the trunk cable is sealed with a weather tight cap, and the other goes to a weatherproof junction box (white) to transition to standard exterior rated 12-3 with ground romex. The romex connects to a breaker box with a 20 amp 2 pole breaker for each string of 16 and 1 string of 14 panels. Then, the entire array is nicely dressed using tie wraps so that all the wiring is suspended between the panels and the bottom of the rails to keep it from whipping in the wind or getting snagged by anything.
Here’s the power panel. Public Utility Commission in Ohio says any array over 6Kw must be metered by a UTILITY GRADE meter. Got one on Ebay for $35. Breaker box on left contains the 3 solar breakers. That feeds through the meter to the master breaker box on the right. Master breaker box connects to the utility grid via a buried conduit over to the other barn that had power in it already. Below the utility grade meter is the Enphase ENVOY monitoring unit that ties all this to the internet so George can watch things from his home computer. He can share a link with his friends as well. I’ll post this link soon as I get it from George! The Utility voltage here is rather high – close to the limits for most inverters, at 254Vac. This causes a few of the inverters to occasionally shut down (to protect themselves). I’ll be looking into this further on my next visit to see how we might correct this…
Here’s the finished array. Still need to trim the excess rail length at the bottoms. If you look close, you might just spot some mis-alignment within the array. George got 2 pallets of panels. Same part number, same vendor, but one pallet was 1/2 inch shorter on the long side (out of spec…). We didn’t catch this till 5 were mounted in the top row. George, being a prudent and thrifty fellow, called the panel supplier and negotiated a compromise that didn’t require a return of the panels. The size only affects the esthetics slightly, and a cost reduction is pending! The Enphase ENVOY normally communicates over the power lines, but there’s a half mile of them back to the house and that’s too far for it to work, so I added an Engenius EOC-1650 at the house as an access point, and atop the array as a client/bridge. It works great – with 100% signal integrity, and also provides WIFI to his customers and visitors! The EOC-1650 is that little white gadget at the top right of the array.
I’ve never discussed this, but these devices are cheap insurance (not really, but you get the idea…) against all kinds of problems that can come about as a result of electrical storms. I’ve used the powered type in the past, and have one installed currently, but I came across a totally passive version that uses no power, is self resetting, and if it does fail, it fails OPEN, so it won’t cause problems. Best of all, you can get them for 30 bucks on ebay, brand new, including shipping. Just search for “LA302R”. It has 3 wires, and you simply install it in your electric box to a breaker connected to L1, L2 and Neutral. If you’re not an electrician, hire one to do this. It takes about 2 minutes. It takes longer to get the cover off your breaker box than it does to install one!!
Nestled in the middle of a 26 acre plot is this cozy updated farmhouse with almost 6KW of solar power. The home is well insulated, and fitted with all the high efficiency goodies. Propane fired DEMAND water heater, wood stove for heating, LED lighting and more! At first I assumed he wanted a ground mount to keep it away from the house, but when I arrived on site I knew right away the real reason – no room on the roof! But seriously, this setup goes way beyond just a large array. The owner wanted plenty of AUTONOMY – that’s lots of days of off grid operation without worry of running the battery bank down. And plenty of power, so that if he wants to do laundry while off grid, it won’t be a problem. So we got together and discussed the options and the owner decided to DO IT RIGHT the first time. I explained that batteries would be a large part of the project cost, and he would have to understand and CARE for the battery bank if he expected it to last 10 years or more. He was more than willing to listen, read, study and understand the care and feeding of his battery bank, and as a result is VERY pleased with his installation.
While all this activity was going on outside, I was busy in the basement, hanging the TWO Sunny Island inverters on the wall, mounting the small EMERGENCY POWER breaker box and running conduit between the inverters, the main breaker box and the new Emergency power box. I’d come up for air once in a while to check on the ground mount work, just to make sure it was square and plumb, but these guys knew what they were doing and got it all right on the very first pass! Looking at the pics below, we chose to use TWO Sunny Islands for several reasons. 1st and most important was that the Sunny Island is without question the best BATTERY TENDER around. It can use the grid or the array charge the batteries, and it has sophisticated software to monitor the battery health and adjust things as needed to optimize the battery care. It LEARNS over the 1st 8 weeks how the battery supplies power and how it accepts charge and then adjusts itself for the best possible care. We used TWO Sunny Island inverters so that we could SLAVE them together and create 240VAC “split” phase. The Sunny Island is a 120VAC unit and would otherwise need a lossy transformer to boost the output to 240VAC. We doubled the available continuous output power to 13,000 WATTS by doing this. That is a LOT of backup power, and will allow completely normal living in an off grid situation. The owner wanted lots of autonomy (days of power off grid) so we went with the largest batteries withing the budget – Rolls FLA 6 volt 820AH. EIGHT of them to reach the 48VDC the Sunny Islands need. That’s almost 40KWH of backup power. And remember, when off grid, the sun on the array will recharge them, as well as power the house! I didn’t have time to hang around while a battery BOX was built, so we put up a poly tent and connected the vent fan. This was only a temporary fix and has since been replaced by an appropriate battery box. The exhaust fan is programmed to come on while the batteries are charging – since this is when they give off Hydrogen gasses which are explosive in small amounts. The owner has since also installed RECOMBINATION CAPS which reduce the outgassing by 99% and reduce fluid losses considerably – making it only necessary to check acid levels in the battery every two months or so, rather than every 2 weeks. A wise investment – since it minimizes outgassing of Hydrogen if the vent fan were to ever fail! Batteries are a VERY serious bit of hardware and you MUST care for them if you expect to get 10+ years of service! Always wear safety glasses, a rubber apron and rubber gloves when checking/filling the cells!
When a lead-acid battery is discharged, the electrolyte (sulfuric acid) and the active material on the plates of the battery (lead) are consumed to produce water and lead sulfate and current flow. The chemical equation for a lead-acid battery during discharge is: PbO2 Pb 2H2SO4 –>PbSO4 2H2O Ideally it’s just hydrogen gas, but when doing Equalization charging, you’re going to get some hydrogen sulfide as well – you’ll know it by it’s Sulfur smell and the stinging sensation to your eyes! Make sure the battery box power exhaust fan works BEFORE you turn on your system. In this setup, I programmed the fan to run whenever the batteries are charging. As long as the fan is running, there is negative pressure in the box (or temporary tent in this case) so even any holes or leaks will take fresh air IN to the box/tent and then OUTside the house through the white PVC vent at the left. Happy to say that the 1st charge cycle was free from problems and there wasn’t even the tiniest hint of any gas in the room. The use of RECOMBINATION caps is HIGHLY recommended. They will eliminate almost all of the outgassing and make the battery liquid levels go down MUCH slower.
Wow, it’s taken a while to get this posted, but I’ve got the grid-backup system completed at our little house (we fondly refer to it as THE BUNKER…). I was recently out there during a freak snow storm that dumped 5 inches of wet snow in about 2 hours, and when the power went out, there was just a slight flicker of the lighting as I was sitting at the computer checking my email. The UPS on the computer didn’t even get a chance to kick in! I excitedly went downstairs to the basement to check out the inverter, and sure enough, it was on line, quietly humming away, providing full power to the main electric breaker box for everything that was presently on in the house. The Magnum MS-PAE 4024 inverter can provide about 4,000 watts of continuous power until the batteries discharge 80% of their capacity. Since the house normally consumes only about 500 watts (average) power, this represents about 20 hours of run time. Fortunately, when the backup system is in operation, the solar PV system can “back feed” through the breaker box and provide the power the house needs as well as re-charge the batteries, so this setup can run pretty much indefinitely, as long as there is a few hours of sun each day. Even on a cloudy day, the 2.4KW (Twelve 220 watt panels) solar array provides about 500 watts, so that extends the capacity of the system pretty well.
It took a little studying and research, but I figured out how to SIMULATE the voltage and signals that normally come from a GENERATOR SET that would connect to a WHOLE HOUSE TRANSFER SWTICH on the V+, GROUND, and PIN 23. These are the 3 wires that are standard on any gas or diesel generator. Since I’m using an electronic inverter (Magnum MS-PAE 4024), such signals were not available, so I came up with a little box that has 2 relays in it. One is standard and the other is a 5 second delay unit so the system won’t “chatter” if power drops in/out rapidly. If you’d like the details on how to build one, I’ll be glad to send you a schematic. Just drop me a line at: Joe@cincihomesolar.com
These are the batteries I chose. Since I’m on a tight budget, I chose the best bang-for-the-buck, and it ended up being the Rolls 6 volt 520AH model. I splurged on the funky looking RECOMBINATION CAPS, rather than the normal vented caps that come with the batteries. By installing the RECOMBINATION CAPS, the hydrogen gas generated during charging is sealed inside the battery 99%, and the battery loses MUCH LESS liquid over time than a VENTED battery would. A box and vent fan are still required for safety though, and I will add this to complete the project very soon. Without these special caps, in just 30 seconds of charging at 90 amps, the hydrogen gas coming from the batteries would reach 4% concentration and become highly explosive, so this is nothing to fool around with! VENT YOUR BATTERY BANK TO THE OUTDOORS!
Just finished (and passed) the new EERE Residential PV Solar inspector training program. It’s FREE, for now, at http://www1.eere.energy.gov/solar/sunshot/index.html and it’s very educational. It covers every aspect of a residential solar install and not only instructs on the backing materials, but offers a chapter by chapter self assessment (test) to see if you learned what they were trying to teach! All but ONE chapter was a breeze for me, and the tough chapter was on equipment. I think the questions/answers could be a little more clear in this chapter, but HEY, this is a BRAND NEW TRAINING AID, and I recommend that ALL installers take it and PASS it, just for the sheer value of knowledge!!
These are the slides that backed up my solar presentation at this year’s MEN Fair in 7 Springs, PA last weekend. There’s some text in the basic solar section, but they’re mostly slides. Primarily examples of things you’ll need to do/file/apply for if you are contemplating a DIY solar project. All the things I help out with if you sign up as a DIY solar client!! Also includes some great pictures of a variety of ground mount systems that I researched 2 weeks ago while attending the Solar Power International trade show in Orlando Florida. Please feel free to download and pass this around. No problems with that at all…
Mother Earth News Fair 2012 presentation
I’ve not been on the roof to clean my panels since I put them up last July. This past Spring, I had to wash my car twice to get rid of a sticky yellow buildup of pollen, but it didn’t occur to me that this same pollen could be on my panels. Imagine my surprise when I went up there and found the entire surface of all the panels to be COVERED with pollen – it was like 150 grit sandpaper! This most certainly caused the light to diffuse and reduce the amount of solar energy impacting directly on the solar panel glass!! About 15 minutes with a bucket of soapy water and a cleaner/squeegee made them good as new. Solar output increased immediately by about 5% compared the the day before (both days equally sunny with no clouds). Moral of the story: if you want max power, you need clean panels! If you can reach them with a stream of water from a hose, do this regularly to prevent buildup of dirt and pollen!
I was honored to hear from ENPHASE that one of my recent solar consulting installations was chosen as ARRAY OF THE WEEK! Check out the link and photos at:Enphase Array of the Week Truly an honor – and good demonstration that with my SOLAR DIY assistance you can end up with an array that is professionally designed, installed, commissioned and functional! If you’re suffering from commercial installer sticker shock when getting your special project quoted, just give me a call at Cinci Home Solar! I cover the Ohio, Indiana, Kentucky and Western Pennsylvania area, and will go farther if the job warrants!!