由于屋顶面积相对于占用空间的大小，建筑物在一年内获得净零能耗（NZE）的目标通常很难实现。通常，只有信号层建筑或住宅能够通过位于建筑屋顶的可再生太阳能发电实现NZE。对影响系统发电量的各种参数进行了优化分析，以找到使年发电量最大化的参数组合。优化旨在找到每个屋顶空间的最高年发电量，而不是关注每安装瓦特的标准最低成本目标。 优化分析显示为一种可应用于任何位置的设计程序。为了证明该程序的实际应用，进行了一个案例研究。优化表明，标准太阳能电池板设计不能提供最多的年发电量。然而，优化设计带来了其他挑战，如雪径流和更高的太阳能电池温度，必须加以解决。优化的结果将适用于北美的大多数地点，希望建造多层NZE建筑的设计师应考虑到这一点。 引用:德克萨斯州达拉斯ASHRAE Transactions第119卷第1部分。

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.