A citywide building energy model for Boston has been developed by researchers at the MIT Sustainable Design Lab (SDL) and the MIT Lincoln Laboratory and the Boston Redevelopment Authority (BRA) as cooperation partner. According to MIT, the new tool enables to plan the energy future of Boston on an unprecedented scale and spatiotemporal detail. It calculates the needed gas and electrical energy for each individual building (about 92,000 total) in Boston with a time resolution of one hour, one day or a year. “Nobody has ever modeled a city the size of Boston at this level of detail,” Reinhart says. “It’s also the first time that these data are being used by a city to guide energy policy decisions.”
Besides buildings, this holistic solution involves photovoltaic systems, battery storages, ground source heat pumps, and combined heat and power systems
As announced by the City of Boston and the BRA, the new building energy model is an integral part of the Boston Community Energy Study. It supports stakeholders and decision-makers to figure out saving potentials and opportunities regarding greenhouse gas emissions, energy demand and costs in Boston.
“Community energy solutions such as targeted energy efficiency, district energy, microgrids, local energy generation, and energy storage represent an opportunity to fundamentally change the way our energy system works,” says Austin Blackmon, chief of energy, environment, and open space for Boston, “but to get there we need a better understanding of the existing system and a way to identify the most promising solutions.”
One important aim of the model is the identification of more holistic solutions instead of isolated analyses of buildings. For example, photovoltaic systems, battery storages, ground source heat pumps, and combined heat and power (CHP) systems outside of a building, adjacent buildings or sites across Boston, are taken into consideration to reduce greenhouse gas emissions and reduce costs. “If you have a building consuming a lot of electricity at certain hours, you need buildings around them that can use that waste heat,” Cerezo says. “Our model is built for figuring out where those things happen.”
In order to process the data and develop the model, the approximately 92,000 buildings in Boston have been classified in 48 different building types. Furthermore, twelve use categories were specified to distinguish the different characteristics influencing supply and demand of energy over the time. The geographic information systems dataset of Boston with its building geometry, property tax assessment records, and the several types of parcel use are also taken into account.
Building Energy Model for Lisbon and Riyadh currently being developed
According to Reinhart and Cerezo, their decision-making tool is designed to focus on problem areas, for example, peak electricity demands of buildings on hot summer days, and to identify worthwhile saving opportunities.
“Every city has long-term goals,” Cerezo, a PhD student in the Building Technology Program, says. “But nobody knows exactly how to plan for and measure them. With this model, the city has a map to help them target and reach those goals.”
The SDL team is not confined to any borders and now working on new models for Lisbon (Portugal) and Riyadh (Saudi Arabia). They are also validating their Boston model by comparing the calculated results with the real energy consumption. “We’ll do this using any building-level energy dataset that we can get our hands on, so the models become more and more accurate,” Reinhart pledges. “Ultimately, our goal is for every city in the world to rely on a citywide energy model to meaningfully manage its future energy supply and carbon emissions.”