A PowerPoint (in PDF) by RENEW Wisconsin’s Executive Director Michael Vickerman presents the preliminary conclusions of a forthcoming white paper on solar hot water system:

 When energy prices rise above $1.00/therm and incentives are available to reduce system cost by half, the internal rate of return (IRR) on investment in a commercial SHW system will surpass those of traditional investments. Moreover, it is as risk-free an investment as one can make.

 Natural gas price volatility will invariably impart a herky-jerky pattern to annual returns and installation activity.

 To ensure the steady of expansion of SHW technology, governments should consider policy options to provide some buffer against fuel price volatility and reduce front-end costs.