Much of our thinking about the built environment is focused on individual buildings, which is generally a useful framework. Buildings align with ownership, buildings are regulated by zoning and codes, buildings frequently represent a utility customer, and buildings typically have their own heating and cooling systems. But many of the services that buildings receive are developed as part of a broader infrastructure, such as community water and sewer plants, transportation networks, and electricity.
As we begin the process of decarbonizing buildings, where do we draw the boundary between buildings and infrastructure?
For electricity services, the modernizing grid includes room for utility-scale, community-scale, and building-scale generation. For example, we can stick photovoltaic (PV) systems just about anywhere. Over time, these choices will begin to reflect economics and customer-preferred business models. Moving to community-scale rather than building-scale can bring improved economies as well as a variety of business models that improve consumer options. Customers could purchase a PV array, buy a piece of the output from a PV system, or pay a monthly bill for solar generated kWhs. Having more options for buying solar power means that more consumers can find a way to utilize solar energy.
What about heating and cooling? Are there new models for ownership of systems and are there good reasons to consider community-scale systems? As with solar power, systems that serve more than one building might offer better economics and more options that might encourage greater consumer participation.
Currently, there are over 800 district heating and cooling systems in the U.S., most of them associated with universities, military bases, or other large campuses of buildings with a single owner. Can we innovate off these larger systems to find ways to provide heating and cooling to other groups of buildings as part of decarbonization efforts?
An earlier blog about Boston-based non-profit Home Energy Efficiency Team (HEET) reviewed options for shared ground water heat pumps systems as an alternative to investments in repairing leaking gas lines. Just recently, I found a couple of very divergent projects that demonstrate ways of dealing with “bigger than a building” concepts. One project is in a small town in the Orkney Islands of Scotland, while the other shows the struggles of adapting to higher temperatures in already hot cities, such as Phoenix Arizona.
I visited the Orkney Islands earlier this year and loved my time there, so when I see something about them – it grabs my attention. They develop a lot of renewable energy on the islands, including a very large tidal energy generator. The particular project that caught my eye was the renovation of a warehouse with the addition of some new construction to house a library, an office building, and a retail store. Being close to the sea, they stuck a sea water loop in the harbor to provide energy for a heat pump that serves the buildings. Seems like a great solution for some of our densely populated coastal cities. (Of course there are similar projects in the U.S., such as the Exploratorium in San Francisco).
The firm that manufactured the system for the Orkneys, Kensa Heat Pumps is the United Kingdom’s only manufacturer of ground source heat pumps. While they have put sea water-based systems in coast guard stations and even boats, their major business is ground source heat pumps, with an emphasis on shared ground loop arrays.
In Britain, about 40 percent of housing is provided by locally-controlled “social housing” organizations that own and manage low- and mid-rise housing complexes that serve a variety of housing needs in the community. These social housing organizations are looking to reduce costs, improve comfort, and meet the U.K.’s carbon goals. Putting shared-loop ground source heat pumps in social housing has become a substantial business in the United Kingdom, and there are various incentive programs to encourage installation. While there are shared-loop ground source heat pumps in place in the U.S., it seems that the prevalence of social housing complexes and incentives in the U.K. might be driving the market in ways that have not developed in the U.S. yet. I believe that shared-loop ground source and sea water-based systems have significant potential to serve both new and retrofit markets in the U.S.
Changing climate zones entirely, a recent Rolling Stone magazine article by Jeff Goodell entitled “Can We Survive Extreme Heat?” raises the question of how cities can adopt strategies to reduce heat build up. The article focuses on how people – especially at-risk populations such as homeless, low-income and elderly – survive in an increasingly hot urban environment. The article starts and ends in Phoenix, but travels the world looking at similar problems and, unfortunately, a very limited array of solutions. The article notes that the World Health Organization anticipates 38,000 additional deaths each year from 2030 to 2050 from extreme temperatures across the globe, and that extreme heat already causes more deaths each year in the U.S. than do hurricanes or tornadoes.
While better buildings can be part of the solution to extreme heat, cities really need to fight the urban heat island effect and provide better conditions for all inhabitants. We can re-engineer aspects of buildings to do their part with more insulation, windows that reflect solar gain, white roofs, and better cooling systems. Shade trees, reflective road surfaces, and green belts are a few ideas for cities that operate at a different scale– but these ideas are insufficient for the challenge ahead. A portfolio of ideas that are “bigger than a building” needs to be developed so that urban areas, especially those already in warmer climate areas, can help mitigate some of the heat related problems ahead.
Redrawing the boundary between how buildings provide heating and cooling and what communities can do with infrastructure and larger-scale approaches will create more options and ultimately provide an enhanced solution set. Buildings certainly need to change, but there is also a need for larger scale solutions that have better economics and can reach more people.