A solar PV-thermal energy design optimization study of a building footprint limited net-zero energy facility

The goal of a building obtaining Net-Zero Energy (NZE) consumption over the course of a year is often difficult due to the size of the roof area relative to the occupied space. Typically only signal story buildings or homes are able to achieve NZE from renewable solar energy generation situated just on the roof of the building. An optimization analysis was done on the various parameters that effect system electrical production to find the parameter combination that maximizes annual electrical production. The optimization seeks to find the highest annual energy generated per roof space and it does not focus on the standard lowest cost per installed watt target. The optimization analysis is shown as a design procedure that could be applied to any location. To demonstrate a practical application of the procedure, a case study was performed. The optimization demonstrated that standard solar array designs do not provide the most annual energy generation. However the optimal design introduces other challenges such as snow runoff and higher solar cell temperature that had to be addressed. The results of the optimization will be applicable to most locations in North America, and should be considered by designers looking to build multistory NZE buildings.