So it's been a full year since my solar panels started generating electricity for me and it pretty much went as expected. My 5kW array generated 6 MWh total, earned me 6 SRECs and saved me $1,000 off my electric bill over the course of the year.
Here's a breakdown of my savings:Period Ending Production As % of Usage Savings Dec 21, 2011 223 kWh 32.5% $45.05* Jan 24, 2012 288 kWh 34.5% $59.26* Feb 23, 2012 419 kWh 72.2% $86.81* Mar 23, 2012 484 kWh 87.7% $106.48* Apr 24, 2012 663 kWh 116.1% $145.86* May 21, 2012 536 kWh 117.3% $81.62 Jun 22, 2012 707 kWh 121.8% $107.72 Jul 23, 2012 767 kWh 75.1% $116.86 Aug 22, 2012 660 kWh 67.9% $98.93 Sep 21, 2012 616 kWh 77.6% $92.34 Oct 23, 2012 449 kWh 69.7% $67.32 Nov 23, 2012 313 kWh 50.2% $46.93 Overall 6,125 kWh 73.7% $1,055.28
*NStar 100% Green Energy rate
If there seems to be some inconsistency, it is due to monthly usage fluctuations, differences in the number of days per billing period and NStar price changes.
So I ended the year producing just about 6,000 kWh, saving a little more than $1,000 and producing almost 75% of the electricity I used. These figures met or exceeded my original expectations so I’m happy that my estimates proved to be accurate.
My maintenace expectation was accurate also as there was hardly any. I did spray them off with the hose once in May when they were covered with pollen but that was only because I didn't want to lose several days' worth of production until it rained.
There were a couple issues, however, that I feel must be addressed. I started out on NStar’s 100% Green Energy program. Electricity on that program costs almost 40% more than it does on the normal residential rate. So my savings are inflated from December through April and I don’t expect to save a full $1,000 in future years unless the cost of electricity rises.
Another disappointment was my income from SRECs. I had conservatively estimated that they’d sell for $400 each. However, the SREC market proved to be binary: selling near the maximum of $600 when undersupplied and near the minimum of $285 when oversupplied. And unfortunately, the market became oversupplied just as my SRECs became available to sell. I still plan on selling them for the $285 minimum in the Last Chance Auction next July, but if I cannot I will probably keep them until the market potentially becomes undersupplied again in 2015. They will be worth much more at that time, but I still have to wait. I will get paid for them but they are not the automatic quarterly payment I had budgeted them for.
All in all, it was a successful solar year and I still feel my solar panels are a great investment. My 4-year payback window should still be valid but due to the delay in selling my SRECs, I won't see most of that money until the end of that time.
If you have any questions, please leave a comment or visit my website and blog at www.MassSolarInfo.com.