5. Conclusion The results of our analyses indicated that with the current equipment pricing and financial incentives in place, a net-zero energy campus does not make financial sense. In fact, our analyses showed that any solar PV array greater than 1 MW did not meet the financial requirement of having an NPV greater than 0. Furthermore, despite having a solar PV array that could produce all the electricity needed over the course of a year, the campus would still continue to pay over $250,000 associated with facility and demand charges incurred at night. The impact of a carbon tax or a cap and trade system on developing renewable energy technologies is unknown. It is likely that such programs will have a positive impact on the financial viability of solar PV arrays. However, it is important to reiterate that using standard financial tools to evaluate a renewable energy project does not provide a comprehensive portrait of its full value. This makes it difficult to compare renewable energy systems to conventional fossil fuel based systems. A newer method to evaluate the impacts of externalities should be developed for decision making on renewable energy systems e or for any environmental related projects for that matter.