Thursday, November 19, 2009
Lots of rain is keeping folks off the roof. We did get some shingles and brackets installed, but not many. The interesting development yesterday concerned our inverter. The inverter changes the generated energy into a form that can be used on the electric grid. I guess several companies make inverters, I think they function in two different manners. One of them has all the solar panels connected to it and it does the job for all of them. The second is a mini-inverter connected to each panel to do the conversion. The mini-inverter system allows for easier expansion as regular inverters are sized to the size of the kwh (in our case 5.16). There is another key difference, apparently the inverters work at the minimum level of effeciency of each panel or array of panels. For example, our system was originally going to be two 12 panel arrays. If one arrangement had a few panels in the shade or one panel that worked at 80% efficiency, the inverter would only work at the level of energy generated by the shady panels or the 80% panel. With the mini-inverter system, this is not a problem, as each panel has its own inverter allowing it to generate energy as able.
When Joe with Alt Energy was giving us our owners manuals, I started asking more questions about how our inverter would work. I did not realize that the mini-inverters were an option. Now that they are available for us, it is what we are going to go with. I believe they will cost a little more for the parts, but the installation is easier and cheaper. Ceteris paribus, price should work out to be the same. There might also be an added benefit. The system will come with some kind of a computer gadget that will allow remote monitoring. I look forward to learning and playing around with this.