We finally did it. After years of building energy efficient homes and renovation projects, many of which also had a solar component to them, we have installed a solar PV system at our office in Bolton. We are pretty excited about and really don't know why we didn't do it sooner.
We installed a 6.5 kWh system with 26 Canadian Solar 250 Watt panels, 26 Enphase microinverters, in 2 strings of 13 panels each. The system is operating well and in the month since it was installed it has produced 287 kWh of energy and projects to produce somewhere around 8500 kWh per year. That will be 8500 kWh I do not have to buy from the power company, at .10 for supply and .11 for delivery that works out to a savings of $1785! This will produce essentially all of the power we use at our office including our electric air source heat pump that is the source of our heating and cooling.
Let me tell you the process we went through to get this system installed. First, I had to decide if I wanted to own the system or lease it. Lease options are attactive for those who do not want or perhaps don't have the means to make the cash investment in the system up front. In those cases, the installer owns the system but the leasor receives renewable energy and saves on their electric bill. I choose to purchase my system and reap all of the benefits over the long haul
I had looked at installing a PV system several years back but was scared off by the number of trees I would have to cut down. I live in the woods and even though the barn roof is angled almost perfectly for a southern orientation and could support the panels it was shaded by trees all around it. After doing my research and selecting Transformations, Inc., a well respected and leader in green building, to install the system, they came to do the Solar Access and Shade reading. We started at about 63%, well below the 80% goal and threshold for the state rebate.
Here is what my yard looks like. The barn with my office in it is below the address in the picture. You can just make out the roof amongst all the trees:
I had a lot of work to do. In fact, after all was done I cut down 45 trees. It was a busy fall. I did get a new Huskvarna saw out of the process which was very nice. Needless to say it got a little messy.....
But we cleaned it all up and finished removing the trees and moved to the next step - signing the interconnection agreement with my power company, National Grid. This was pretty straight forward. Basically, they agree to buy the power you produce back by providing a net metering arrangement.
Once we had that agreement in place, and the installation was done (in the dead of winter....) we needed to set up our SREC monitoring contract. In Massachusetts, you can sell your renewable energy credits to the companies that are bound by law to produce a certain amount of renewable energy. We went with Sol Systems, and choose a brokerage type account. In this arrangement you choose to sell your SREC at a fixed rate for a perior of time (10 years) rather than being in the open market place and hoping someone will buy them. I expect to receive approximately $270 for every 1000 kWh I produce over the course of the year. This should amount ot approximately $2300 per year. Also I will save approximately $1800 per year on my electricity bill so the total payback per year will be about $4100. At that rate, my system should pay for itself in five years. The long term projections are a $40,000 cash return over 25 years at a 17% rate of return on the initial investment.
Monthly Energy Production Report