I often get asked about which software tools to use to determine the feasibility of a solar energy investment. Here are some of my favorite software tools (apart from our very own Discover and GO tools, of course!):

  • RETScreen: This is a great software tool developed by Natural Resources Canada. It includes solar resource analysis as well as financial analysis. The accompanying website is full of useful examples. You will need Microsoft Excel to install and use it. RETScreen can be used to analyze solar energy projects as well as many other types of renewables.
  • HOMER: NREL's excellent software tool is a desktop application for Windows. Both solar thermal and solar photovoltaic applications are covered. Solar resource information can be accessed within HOMER or by using an external file.
  • PVWatts: NREL's online software includes insolation data for the US and Canada. It also includes an online calculator for estimating photovoltaic system performance.
  • System Advisor Model: Another excellent analysis tool provide by NREL, SAM can be used to analyze the performance and financial feasibility of renewable energy investments.
  • PVGIS: Provided by the European Union, this web-based analysis tool includes solar resource maps as well as an online performance calculator. Data coverage is limited to Europe, Africa and parts of Asia.