Thoughts on My Solar Panels after 10 Years

My relationship with my solar panels has been somewhat disappointing. The experience of having a solar photo voltaic system on the roof has been far from trouble free. I had imagined that solar panels without any moving parts would make free energy from the sun without any problems. However, starting in the second year of ownership I have had an ongoing series of failures of micro inverters, panels or wiring and a series of roof leaks in the last few years as the Black Jack used to seal the racks dried out and failed.

To make it worse, problems with the system have been hard to address because of the difficulty of finding a capable repair company (lots of fledgling firms have gone out of business) and the cause has not always been obvious to whoever was trying to repair the system. There has been a continual stream of problems that all come down to installation (the roof leaks), wiring and Enphase micro inverters. The micro inverters seem to fail with regularly. At the moment I have four panels that are not reporting which Enphase, Concentric and I all attribute to the failure of four micro inverters.

Concentric (and its predecessor firm) has been doing the solar repairs for me for the last few years and I have been happy with their abilities. I called them last summer when I had only two panels not reporting, but the rush for new installations before the reduction in the federal tax credit meant that they were too busy to come out to my house for a repair. After several attempt to try and schedule a repair, I decided to call back in the new year. By January I had four failed Enphase Micro Inverters. Concentric has ordered replacements for me, the last one is still on back order. The Enphase micro inverters have been disappointing in their lack of reliability.

Solar photo voltaic panels themselves have no moving parts so that the operating life of the solar panels is largely determined by the stability of the coating film, the quality of finish and fit of the panels and the proper sealing of the edging and connectors. The wiring, racking systems and inverters are all subject to damage by rain, snow, wind and hail.

Though troublesome, my solar panels still make financial sense. My system is about 10 years old. So, I have suffered by being an early adopter in Virginia. The installer had little experience beyond training and I have suffered the consequences. When I signed the contract to purchase my roof mounted solar system in 2009 the cost per kilowatt for the Sharp panels I bought was about $6,700 plus permits and installation. However, back in 2009 I was able to obtain a state rebate of $12,000 which is no longer available in Virginia. I also used the 30% federal tax credit which was recently stepped down. The net cost of the solar system in 2010 after rebates and tax credits was $32,578.

In addition, there is a property tax exemption in Prince William County (and most counties in Virginia). The exemption is based on the Energy Efficient Buildings Tax Exemption (Code of VA §58.1-3221.2) which allows any county, city, or town to exempt or partially exempt energy efficient buildings from local property taxes. In Prince William County the amount of the exemption is based on the installed cost of solar array. That translated to a savings of $656.82 a year for 5 years.

The largest portion of my return is from something called a SREC, a solar renewable energy credit. A SREC is a credit for each megawatt hours of electricity that is produced, but used elsewhere. SRECs have value only because some states have solar set asides from their Renewable Portfolio Standards, RPS, which require that a portion of energy produced by a utility be produced by renewable power. There are no RPS solar requirements in Virginia, thus no value to SRECs in Virginia today beyond the $10-$15 that a RPS credit is worth.

When I installed my solar panels, my system was eligible to sell SRECs in Pennsylvania and Washington DC and I registered my system in both markets. The Pennsylvania market has since collapsed, but the District of Columbia passed a law in 2011 which made the SRECs quite valuable. The law prevents out-of-state systems from registering after January 31st 2011, but my system was grandfathered. DC is currently the only under-supplied SREC market in the nation that I know of. There ae no large commercial solar farms nor large industrial installations. Thanks to the Washington DC SREC market my solar panels have earned $31,295.39 (after fees but before taxes), dwarfing the just over $11,000 in free energy they have produced. As you can see below the system has been profitable for me.

Enphase Energy has offered a discount on new generation Enphase Modules. Unfortunately, pulling a work permit for changing out all the modules of my solar array would require a new registration number for my system and thus void my grandfathered status in the DC SREC market. I have priced out the various options and find that despite the annoyance and expense of constantly failing Enphase modules, and repairs (at this point I have paid $6,502 in repairs) I am financially much better off waiting for the SRECs to expire in five and a quarter years and replacing the entire system when I have to replace the roof. These days the cost of system has fallen significantly, though there are far fewer incentives.

We’ll see what incentives are available when the SRECs expire. At that time I plan to purchase an integrated ground mounted larger solar system (with 10 KWH DC) with battery storage. I am keeping my eye on the Generac PWRCell System with an integrated solar system and a single system inverter. I have had a good experience with my Generac Generator over the past 13 years and want to see if they bring that kind of experience to the solar and battery storage market.