Decision making in solar energy: A lesson from financial analysis

The scientific method is only one of many tools that people use to make decisions. Increasingly, environmental managers are also turning to financial analysis in addition to hard sciences and social sciences.

This article looks at payback analysis and internal rate of return (IRR) to examine whether or not to by solar water heaters for a home. The question now is which is more reliable? Payback analysis or IRR? It is difficult to tell from this article without having access to the data that the author was working with.