Tower School Solar PV Production Exceeding Expectations

Tower School PV Array

Electricity produced from Solar PV is the whole point of installing the solar panels, right? What can you do to maximize the production from your small commercial or residential PV system? Maybe you should talk to Achieve about designing your system with micro-inverters. The Tower School solar array went live in August of 2012 and we now have performance data for the first year. Achieve built this 25 kW Solar PV system with individual Enphase Micro-inverters for each of the 105 solar panels. The micro-inverters are designed to minimize impact due to shading. Micro-inverters also allow each solar panel to start producing electricity at the first sign of morning light. This maximizes solar PV production. Having each solar panel independent has great advantages over more common central inverters. Central inverters that connect solar panels like strings of old-style Christmas Tree lights — if one has a problem they all have a problem. Using standard industry software, the Tower School array was predicted to produce 28 mega-watt hours per year. In the first year, Tower School produced 32 MWh. That is over 14% more than predicted. Tower benefited with the extra 4,000 kWh produced and with an extra 4 Solar Renewable Energy Credits (SRECs). That’s about $1,550 in extra cash due to increased solar PV production. Was it the micro-inverters? Hard to say for sure. We do know using micro-inverters make monitoring and troubleshooting a breeze. The graph below shows solar PV production predicted for the Tower School array and the actual production. Not every month exceeded the predicted output. The lower winter half of the year (October to March) had several months with lower than predicted PV production. All of the summer half of the year (April to September) had higher output.

Chart showing monthly Actual and Predicted Solar PV Production at Tower School