We have been experimenting with solar panels for about eight years now and quite frankly the modern glare of glass panels just does not blend in with the wooded rustic environment and the connection to nature we are looking for. Our goal was to have a solar array that would power all the modern electrical conveniences in a regular house but we did not want to see it. We have used a flexible photovoltaic laminate product from Uni-Solar, this product actually rolls onto a metal standing-seam roof and in our application it is virtually invisible.
Above is a picture of the Barn House around the first week of September 2007. The chimney is under construction but the solar panels are on the roof. Can you tell which part of the roof has the solar panels? We have asked many people that come by the property and so far no one has been able to tell where the panels are.
The selection of the color of the standing seam roof was critical to blending in with the Uni-Solar Photovoltaic Laminate panels. On the Barn House roof we chose Matte Black manufactured by Englert Inc. to match the solar panels.
These Uni-Solar panels also come in specific sizes and are rolled into the standing seem panels. Initially we have only covered the sugar house roof section of the Barn House with panels. At a later time we may cover the rest of the roof but we wanted to insure that the solar panels were invisible. The standing seam roofing width needed to be 16 inch wide in order to fit properly with the 15 ½ inch solar panels. The sugar house roof section has 24 panels of Uni-Solar's part number PVL-68. These panels are 9 foot 4 inches long by 15 ½ inches wide so the sugar house roof was made to fit these perfectly. The panels are rated at 68 watts each so 24 panels gives us 1,632 watts of power. This is not quite enough for the house so we also put panels on a small barn that is adjacent to the Barn House.
The Barn House (and thus the panels) face 45 degrees east of true south so that will diminish the effectiveness of the panels to a small degree. The roof pitch is 8/12 which is good for shedding snow and effective for the solar panels as well.
The existing Small Barn was equipped with 17 Uni-Solar PVL-136 panels.These panels are 18 feet long by 15 ½inch wide and are rated at 136 watts each thus giving us 2,312 watts on this roof.This roof faces 35 degrees west of true south so it also is a bit diminished but does catch more of the sun during a different time of the day than the Barn House. The total for both roofs are rated at 3944 watts but with reductions lets call the combined system 3800 watts or 3.8kw.
Now the big question is this enough solar capacity to power the complete house? We have done calculations and shading studies especially during our long winter months but the bottom line answer is maybe, and we think so. We do have a backup generator that can recharge our battery bank in a few hours but that will use propane which we do not want to do. Time will tell and we can add more solar panels to the rest of the roof if we really see the need to.
Small Barn Solar Panels
Above is a picture of the Small Barn with 17 panels on the standing seam roof.If you look closely on the right hand side there are a couple of partial roof panels that do not have solar panels on them.We also made the mistake of putting a Charcoal Gray color from Englert Inc which was recommended as matching the solar panels but as you can see it does not.In order to blend this in a bit closer we will be taking a Uni-Solar panel and cutting and pasting it to the roof section that does not match. For right now it is a good example of why it is important to match the color a bit better like we did on the BarnHouse.
You will notice in the Small Barn picture above there is an ash tree on the left of the roof that at certain times of the day does shadow the panels. This tree will be removed and used for building material for the Barn House. The Barn House also has the shading of the chimney which during certain times of the day will cast shade on some of the panels. The other shading that will affect the panels is New England weather especially the winter. California or Arizona sun we do not have and it sometimes feels that we can count the sunny days during the winter on our fingers and toes.
The Uni-Solar panels have what is called bypass diodes between each cell. This means that if a cell should stop working due to shading or damage, power will bypass the shaded cell and the panel will still produce close to the rated output. We are told that the traditional crystalline solar panels almost shut down when they are partly shaded. We have a number of the crystalline panels on a solar wagon and if we shade a small section with our hand it greatly reduces the power generation but not so with the Uni-Solar panels. Ok California, this is not a big deal for you because you have sunshine 300 days a year but in New England we have what are called clouds and they bring rain and snow which gives us more character in our weather. These clouds also create shadows on our solar panels.
Connecting Two Building with Solar Panels
The Small Barn is about 200 feet away from the Barn House so we needed to run a cable from the Small Barn solar panels to the inverter in the lower level of the Barn House. Well, this does not sound like a big deal but apparently the longer the cable run, the thicker the cable needs to be so it does not loose the energy along the way. This cable was close to 700 pounds and we actually used a tractor to help pull it through the pipe that ran between the buildings.
Wiring of Solar Panels Under the Ridge Cap
Each of the solar panels on the Small Barn and House Barn needed to wired under the ridge cap of the standing seam roof and this ridge cap needs to be installed very carefully with close attention to Uni-Solars installation instructions.
Electronic Components for Solar System
Our solar consultant, supplier and installer, GroSolar, recommended Outback Power Systems to supply most of the "stuff" that goes between the solar panels, the batteries and our electrical wiring for the building. Staying with a consistent company for most of the components facilitated compatibility and serviceability later on.
For ease, we will list the components and what brochures, manuals and installation documentation we can find. Bottom line, we were looking for ease of use not only for ourselves but for anyone else that needs to use the system. We have no intention of spending days in a class or pouring through manuals in order to figure out how to turn a light switch on. Granted, knowing the foundation of the system is important to maintain it properly but as with computers, we should not need to know how to write Java Script in order to use a website. It needs to be intuitive. The solar industry has a ways to go in taking the "mystery" out of solar power systems. It seems they are still in the development stage of "make it appear difficult" and that way they can charge more. Hey, solar industry, we did that in the computer field until we realized we made more money by making it easier and thereby expanding the marketplace.
In our prior solar learning experience we initially purchased four deep cell batteries with which after a number of years we realized we needed more power and to add more batteries. I wanted to double the battery bank to eight. Well, guess what? I was told that our four older batteries would bring the strength of our new batteries down so it was recommended that we purchase eight new batteries and find a home for the older not as robust old batteries. Ouch. This time we doubled the amount of batteries we wanted to go with right up front and went with 24 Surrette Rolls 2V, 1850Ah deep cycle batteries. These batteries weigh 204 pounds each and cost between $500 and $600 each. The following is from their website Surrette.com:
Surrette Battery Company Limited is one of North America's leading lead-acid battery manufacturers. Established in 1935, with a production facility in Salem, Massachusetts, Surrette relocated to Canada in 1959 and is the Nation’s only remaining independent battery manufacturer. Modern ISO 9001 registered production facilities are located in Springhill, Nova Scotia with a distribution network throughout North America.
An important aspect of the battery box is an installation of a fan that will vent outside of the building.This needs to be completely separate from your building ventilation system.The fan is set to automatically go on when the batteries are charging and subsequently off gassing.