An Excel-based project analysis program, RETScreen evaluates the energy performance, cost and financial viability of projects based on solar, wind and other renewables. The tool was developed by CEDRL together with NASA, the US aeronautics and space administration, and 50 experts from government and industry to overcome the perceived high cost and high risk of evaluating renewable energy options. GPCo, which was project manager on behalf of M & N Wind Power and Kenetech Windpower in the development and implementation of the 100 MW Le Nordais Wind Farm, also assisted in the development of the initial RETScreen computer model.
The RETScreen development team has recently signed a collaborative agreement with the United Nations Environment Program (UNEP) to add additional features to the software. The collaboration will enhance both RETScreen's international appearance and financial modelling for tax and depreciation analysis. UNEP's Mark Radka says the new version will also include a greenhouse gas emissions worksheet to be developed by the organisation's Collaborating Centre on Energy and Environment. The worksheet will allow users to estimate the greenhouse gas emission reductions associated with a renewable energy technology project and assign a market value to the reductions that can be included in the financial analysis.
Head of the software development team, Greg Leng, says that with the tool, a project developer can look at rough estimates of an area's local wind speed data. In just a few minutes, a sensitivity analysis can be run using local financial data and different possible wind speeds from the proposed site to assess a project's payback or rate of return, says Leng. If the analysis looks promising, the developer can then go to the next stage.
One of the most powerful features claimed for the software is the solar radiation and wind speed database that has been compiled from 1000 ground stations around the world as well as satellite data from NASA. Leng says development banks are using the tool as part of a due diligence check for funding.
The economic advantages of employing RETScreen showed up early in CANMET's own projects in Canada's remote communities. "Prior to RETScreen, we received quotes for pre-feasibility studies that averaged US$ 15,000 per study," says Leng. After using RETScreen on 50 studies with 11 different consulting companies, Leng says the cost was an average of just $2000 per study.
In the 18 months since its first release, RETScreen now has 6,000 registered users. Leng says that a nice surprise has been the adoption of the program into the engineering curriculums of many universities, particularly in some unlikely places. A visiting group of engineering students from the small African nation of Gabon stopped Leng when he started explaining RETScreen. We already use it, they said.
One of the spin-offs of the RETScreen development has been a collaboration with NASA on satellite-derived weather data, including wind. Currently, the accuracy of satellite data on solar radiation and wind speed is within 10% (on average) of data gathered from ground stations.