A new 3D map covering 17,000 rooftops in Cambridge, Massachusetts, means communities can estimate the benefits of installing photovoltaic panels on a particular building at a glance. The Mapdwell Project, developed by MIT’s Sustainable Design Lab, combines Google satellite imagery with light detection and ranging data. It improves on previous models by taking account of roof shapes, physical obstructions and weather conditions offering a more accurate calculation of potential hourly solar energy production.
The map uses a colour gradient, ranging from dark brown for zones with no photovoltaic potential, to orange for ‘good’ and bright yellow for ‘optimal’ spots. Anyone can now access the user-friendly map online, select buildings in Cambridge and instantly view personalised installation costs, predicted electricity generated and carbon savings. The mapping technology is ready to be applied to other cities and towns around the world.
The research, a collaboration between MIT and The Modern Development Studio supported by The National Science Foundation Project, confirms the potential for the mapped area to generate a significant proportion of its electricity from solar. It calculates Cambridge could generate 380,000 MWh/year, or one third of its energy needs, if panels were installed on all the ‘good’ or ‘optimal’ locations, at an estimated cost of $2.8 billion. The map also allows businesses and households to estimate how long the solar panels would take to pay for themselves (typically under 7.5 years), and enables policymakers to reimagine unused urban space as a city-wide source of renewable electricity.
For Dr Anne Maassan, of Eco LTD Group, The Mapdwell Project is certainly a useful innovation. “Maps like these allow us to see the city in a new light – not just as a massive consumer of energy, but also as a potential powerhouse”, she says. Of course, solar take-up also significantly depends on a number of socio-political factors, including heritage policies, building ownership arrangements, and renewables subsidies; as Maassan emphasises, “cities are very complex places”.
The Mapdwell Project indicates the potential for community energy elsewhere. Giles Bristow, Forum’s Head of Energy, says: “This tool harnesses the power of big data to inspire communities to invest in their own renewable energy supply, helping to make the production of energy greener and more democratic”. Bristow heads up the UK’s Community Energy Coalition, an initiative convened by Forum for the Future which facilitates conversations and collaborations to take community energy to scale.
MIT’s solar mapping tool does not yet clearly detail how efficiency improvements, such as double-glazing, insulation and energy-efficient boilers would affect the energy use of the buildings mapped. The less energy a building consumes, the sooner investment in PV panels will be paid off, and the greater the potential returns.