Solar Panels, part 2

Yesterday we flipped the switch on our solar panels. PECO had completed the last task and left us a note that we were authorized to operate. So its time to write up the process of having solar panels installed. We originally signed a contract for the solar panels in mid-June. About a month was lost due to the contractor, so that leaves a process that took about 3 months from contract to operation.

After we signed the contract we had our roof replaced first. That took about two weeks once we were able to get a few quotes (that proved to be the hardest part, some roofers recommended to us didn’t return calls). The work took about a day (split into two days). We’re still finding the nails everywhere though. The roof should last at least as long as the panels. Taking panels off to replace a roof costs somewhere in the hundreds to over $1k to do, depending on the roof size. So its a good idea to replace the roof if it needs it to avoid that extra cost. During the roofing time, the contractor was preparing the system design.

Twenty REC solar panels with Enphase microinverters facing south.

On July 9th, the contractor submitted an interconnection application to PECO. The interconnection request is a three page document with supporting documentation such as the site plan, equipment spec sheets (battery, solar panels, microinverters and the battery gateway), and a calculation of expected production. PECO approved the request on July 20th – 11 days later.

At that point, the contractor filed the required building and electrical permits with the township, complete with a site plan. This process has since changed somewhat as the township has adopted a special permit for solar applications similar to Swarthmore to streamline the process. The permits have pretty basic information, mostly a subset of what PECO requires. The township approved the permits in a few days, but unfortunately the contractor somehow didn’t realize the permits had been approved and we lost several weeks before I intervened. We were then able to schedule installation.

Tesla Powerwall battery. The side glows green at night, but otherwise its a featureless white box.

Our installation date was the first week of September, but on the day of installation we found out that the battery electrician wasn’t able to come out. While the solar panels were installed that day, without the battery the system was incomplete and non-operational. It took another two weeks to reschedule the final parts. Once the whole system was complete, the township inspected the system in a few days and approved it. Then on October 4th, PECO received the request from the contractor to exchange the meters. Most meters are one-way, so the existing one had to be replaced with one that measures energy transfers in both directions to allow net metering – where PECO pays us for electricity we generate surplus to what we use. Yesterday PECO completed the swap.

Both the Tesla battery and Enphase microinverters are connected to the internet. The microinverters are already reporting power generation and working with Enphase seems straightforward. The contractor has not yet sent us the documentation necessary to access Tesla’s system. Good luck way figuring out any way of contacting Tesla support, they do not seem customer-focused. Our experience has been that the process for purchasing and installing solar panels is very much a mature process – everything has just worked out without us needing to do much, while for batteries, we’re still in an early adopter phase. My father has been trying to add a battery to his solar system in Chicago and is finding it hard to find compatible systems for the existing solar panels.

The bi-directional meter from PECO, Tesla gateway, shutoff switch and circuit breakers.

Once we get the permission to operate documentation, we’ll be able to sign up with a system to sell the renewable energy credits (RECs) the system generates. In Pennsylvania, demand for these is low so it won’t be a significant source of revenue – I think the estimate was around $100-200/year. This morning has been cloudy, and the system is reporting 2.6 kWh produced – so about 15 cents worth of electricity. Its a start – in theory the system could produce over 30 kWh in that time if there was sufficient sunlight. We probably won’t be covering all of our energy use with the panels until the spring when we get more daylight. I’ll update again when that happens.

Categories: Ramblings