Sustainability, Scandinavian StyleDecember 2014
by Paul Eldrenkamp
This past October I was in Sweden and Denmark with four colleagues from the Northeast Sustainable Energy Association (NESEA). We were on a study tour of sustainable design and green building practices in Scandinavia, a trip inspired by a similar tour we did of Upper Austria and Saxony four years ago. My traveling companions were architects Chris Benedict and Tom Hartman, engineer Andy Shapiro, and energy analyst and graduate student Heather Nolen.
While doing our research to plan the trip we had been advised that we may not find many particularly remarkable buildings to visit. This was true, in its way: the best buildings here in the Northeast are possibly the equal of any of the buildings we saw in Sweden and Denmark.
One key difference, though, is that the average building in Scandinavia is built to a higher performance standard than the average building in the Northeast because their codes are more stringent than ours. And it’s not because Scandinavia has harsher winters than we do: in fact, their climate is very similar to ours.
One of the Swedish building standard researchers we met with told us that this tradition of stringent energy standards goes back centuries, to a time when the growing Swedish steel industry was burning most of the native forests and leaving less and less wood available for home heating. The result was an early energy crisis that led to the development of ways to heat Swedish homes with relatively little wood (including some wonderful masonry stoves).
But there are social norms at work here, too: Just as Scandinavians do not tolerate extreme poverty and income inequality, there seems to be a general outlook that all people deserve high quality housing, and that the best housing should not be too much better than the worst housing.
Even more interesting than the more stringent energy performance standards, however, are the systems that have developed over the years for delivering heat and electricity to buildings in Scandinavia. Combined heat and power plants proliferate in the region, certainly in the more urban areas. Traditional electrical generating plants burn fuel (typically, coal or gas) to create steam that spins turbines that in turn generate electricity. It’s not unusual for these plants to be only 30% to 40% efficient—most of the energy created by burning the fuel is lost as waste heat (this is one of the reasons that what you pay for electricity is over three times what you pay for the same amount of energy delivered to your house as natural gas; the wasted energy accounts for the premium price).
A combined heat and power plant, however, captures that waste heat and transfers it to water that is distributed through well-insulated underground pipes and used for space heating and domestic hot water in the buildings near the plant. Most Scandinavian cities have these systems, and you won’t find any boilers in the basements; instead, there’s a network of pipes and heat exchangers. Because of good engineering and good pipe insulation, the distribution losses are minimal. It’s a very efficient way to deliver energy.
In essence, it’s like having one very large, very efficient, fuel-flexible boiler for a whole large neighborhood, rather than tens of thousands of small boilers for each of the buildings in that neighborhood. I say “fuel-flexible” because of the options these systems offer for producing energy. They can burn fossil fuels (and most still burn coal at times, though a diminishing quantity), biomass, trash, and biogas (mostly methane harvested from the sewage system).
In the US, we tend to think in terms of high performance buildings. In Scandinavia, they tend to think in terms of high performance neighborhoods, cities, regions, and whole countries. Because of the centralized heat and power generation facilities, at which it’s relatively easy to switch fuels as needed, this larger-scale strategy tends to be a higher-leverage and more cost-effective way of reducing carbon emissions. It was fascinating to see this sort of thinking in action.