Back to Rants and Raves
Stone Marmot Goes Solar: Part 8, Four Months Later
By Sid of Stone Marmot
June 23, 2010
We now have had a completely finished and functional grid tied, battery backed up, solar electric system for over four months now. We have received four power bills during this time. For each of these billing periods, the electricity we generated was more than we used, so we have paid nothing for electricity from the power company over this period. Since Feb. 3, 2010, when the new power meter was installed, until June 7, 2010, when the last meter reading was taken by the power company, 297 kWh went into our house from the power company and 1086 kWh went from our house to the power company. So we have generated over three times as much as we have used.
This will probably not be typical. My analyzes shows we should generate about twice as much as we use over a full year. These same analyzes shows that we will generate the most electricity in March and April, when the sun is a little higher in the sky, there is little rain and cloud cover, and it is a little cooler. Power production will probably drop during the summer, even though there are more hours of sunlight. The reasons are that: 1) it is hotter, and PV panels are less efficient the hotter they get, 2) at our house, there is more shade on the panels in the summer, and 3) late summer is the rainy season here in Florida, so it will be cloudier. Also, we use the air conditioning system more in the summer, so that will increase our use. But, so far, the amount used and generated has pretty much matched my analyzes.
We have had no problems with the system since the installation was finished. After the installation was finished, Harrimans completed all the paperwork for the power company hook-up and Florida solar rebate, so all I had to do was check the paperwork, sign it, and send it in, which made life a lot easier.
Would I use Harrimans again? Yes. They said that I didn't have to send the final payment until I was satisfied with the job. The two potential problems I found they corrected with little argument or hassle. The one potential problem, using an inverter that was not ideal for my site, was really an SMA (the inverter manufacturer) problem as SMA had conflicting data on their website which led to the wrong inverter choice. The other potential problem resulted from using a substitute battery cabinet for the one they used to use that was discontinued. The first substitute had problems they didn't recognize until they actually received their first cabinet, which they then corrected with a better cabinet. So Harrimans did what the said they would do and it is working well so far. My problems with Harrimans were a lot less than I usually have with contractors and getting these problems fixed was much easier than with most contractors.
One warning is that most people would not have even recognized these things as potential problems. The building inspectors didn't notice the first problem and the second was caught before the final inspection. Like any major job, be it a solar power installation, adding a new room, a swimming pool, hot tub, new central heat and air system, anything, the consumer must do his/her best to get educated with what is involved with the job so that he/she can tell if it will meet their expectations. Local building inspectors sometimes find some problems, but they can't be at the job all the time and don't see a lot of what is going on. The local inspectors also often don't understand a lot of the new technology. These inspectors also aren't usually concerned with how well your system performs, but only if there are any safety issues. So you must be the final inspector and have some understanding with what is going on.
I did test the battery back up portion of the system during the two week period between when the installation was finished and receiving our new power meter, as we were running off grid during that time period so we would not get billed for the power we generated (see Part 6 of this article series). The battery back up worked well. But we haven't had a need for it since the new meter was installed.
Back to Rants and Raves
© 2003-2010 Stone Marmot Enterprises, all rights reserved.