MIT maps solar potential of Cambridge

MIT researchers have developed a new technique that can be used to accurately predict the annual yield of a photovoltaic solar array located anywhere on the planet, taking into account local climate, panel orientation, and obstructions from nearby buildings. As a proof of concept, the scientists have mapped out the 17,000 rooftops of Cambridge, Massachusetts and created a user-friendly web interface that residents can use to look up their homes and get an accurate projection of the cost and return on investment of placing a PV panel over their heads.

Solar System takes data on photovoltaic panel potential and overlays it on top of Google satellite imagery. Selecting a building within the map will bring up a host of information on installing PV panels on that specific rooftop, including the system size in kilowatts, the projected cost to the owner (including deductions and local incentives), the carbon offset, and the projected yearly revenue generated by the array.

To create the map, the researchers combined Google's satellite imagery with LiDAR (Light Detection and Ranging) data from a prior aerial survey, and in doing so they were able to create a 3D model of the entire city. Using the model, the researchers knew the precise shape of rooftops and the possible obstructions – trees, nearby buildings, and so on. They combined this information with local weather station data, and, crunching the numbers in computer simulation package Radiance, were able to map the solar potential of the rooftops throughout the year, and overlay the data on the aerial and satellite imagery.

Even with its slightly pessimistic estimate, the tool shows that if photovoltaic panels were installed on all of the locations classified as either "good" or "excellent" on the map, the city of Cambridge could generate about one third of its energy needs by means of solar panels, for an investment of €2.1 billion that would certainly pay off in the years to come.

Source: gizmag.comAdded: 14 June 2013