Originated by the City of Portland and the Portland Sustainability Institute (PoSI), the term EcoDistrict refers to a conceptual framework for planning, designing, implementing and maintaining sustainable solutions at a district level.
EcoDistricts can be thought of as geographically defined areas, such as a neighborhoods, institutional campuses, or employment districts within which flows of energy, water, nutrients, resources, information, financial capital and cultural resources are localized, integrated and synergized.
A city neighborhood or district can be seen as an urban ecology, made up of hardware systems (buildings, streets, sidewalks, parks and pipes) and software systems (flows of energy, people, food, resources, financial and social capital, services and information) that function together as a whole system. Building on this notion, an EcoDistrict seeks to enhance this urban ecology, improving performance of both the hard and soft systems.
The key concept behind EcoDistrict thinking is that different systems optimize at different scales. For example, stormwater collection and reuse systems might function best when shared by property owners within a several block radius of each other, or within a distinct watershed. Likewise, energy-efficient central-mechanical plants that provide thermal energy (heating and/or cooling) will more likely be most economical when scaled to serve a cluster of high-performing buildings rather than just one.
By way of example in our region (Northern California), the City of San Francisco currently has four Eco-Districts in various stages of the planning process of which the Central Corridor project is slated to be San Francisco’s first implemented Eco-District. Coordinated improvements at the neighborhood scale include greenhouse gas reductions, zero waste, water conservation, efficiency, and reuse, stormwater management, renewable energy, transportation, and parks. More specifically, among the goals its sets out to establish a Net Zero Carbon Energy District including incentives towards implementing community-scale clean energy projects. The EcoDistrict organization of the Central Soma is anticipated to achieve Net Zero by three strategies:
By enabling the enrollment of numerous properties in a solar group purchase, which secures discounted pricing. Solar group purchasing can greatly reduce the costs of installing solar by leveraging the collective purchasing power of individuals, businesses, or municipal agencies to secure discounted pricing by buying in bulk.
- Facilitating community-shared solar, shared photovoltaic systems supplying electricity to multiple customers. Participating customers pay to subscribe to a portion of the solar system itself or it’s output. As the system produces electricity, they receive credit on their energy bill based on their pro rata share. As with on-site solar, the electricity produced by the system offsets charges for the participant’s monthly electricity use. Community shared solar does not require the solar system to be located on a participant’s property, however, allowing multiple participants to invest in and benefit from a single, centralized PV system.
- The EcoDistrict model will admit of a district energy system, which produces steam, heated water, and chilled water at a central plant and distributes the energy to multiple connected buildings, so they do not need to have their own boilers or chillers.
San Francisco’s Central Corridor is only one of many Eco-District projects now in proposal stages throughout the United States. American advocates of EcoDistricts consider them to be the ‘next wave’ of green building and sustainable development. Precedents on the European continent include Hammarby Sjöstad in Stockholm, Vauban and Rieselfeld in Freiburg, Germany, and Bo01/Western Harbor in Malmö, Sweden.