May 30 2023
Should You Get a Heat Pump?
Starting around 1550 and lasting through the 1600s, England had an energy crisis. They were running out of wood, which was the main source of fuel for residential and commercial heating. England also needed a lot of wood for their massive navy – it took about 2,000 trees to build one of the larger warships. As a result they turned to coal, which has a high energy density and worked nicely for heating. It has the not-insignificant problem, however, of generating a lot of pollution, choking large cities like London in black smoke. This lasted into the 20th century, culminating with the great London smog of 1952.
The world still burns a lot of coal to generate heat, but generally not in homes. There are other options, especially where people live. We can generate heat by burning cleaner sources of fuel, like natural gas. We can also generate heat through electrical resistance, producing no pollution directly (only in the production of electricity, which is likely remote from the user). Heat can also be harvested from waste heat and pumped into buildings. Or heat can be moved from one source to another using a heat pump.
Moving to more efficient and environmentally friendly methods of producing heat is at least as important to minimizing global warming as generating clean electricity. About half of world energy is used simply to generate heat, more than any other use (generating electricity is 20% and transportation is 30%). Decarbonizing heat production is therefore arguably more important than decarbonizing either electricity production or transportation, although of course they are all important.
Two technologies are likely to make the most difference in decarbonizing heat production. The first is harvesting waste heat from energy production and other industrial processes. This requires producing energy somewhat close to where the heat is needed, which is another advantage of more distributed rather than centralized energy production. Harvesting waste heat needs to be designed up front for any installation that will generate a lot of heat. Data centers, for example, expend a lot of energy just cooling all those computers. That heat can be put to good use.