Heat pumps are devices powered by electricity that extract heat from the air or ground to warm a fluid that is compressed to boost the temperature. In effect, they operate like a refrigerator in reverse.
Though the technology has been in use for some time, there are impediments to scaling it up. Heat pumps are refrigerator-sized, while installation can be costly and disruptive. Still, nearly 20 million households purchased heat pumps in 2019, according to the International Energy Agency (IEA), meeting five percent of global home heating demand. The IEA estimates this share needs to triple by 2030 to meet net-zero goals.
Innovation is needed to reduce the size of the units while offering a cooling option as well as heating.
Policy support will also be needed to speed up adoption of this new technology. In the UK, from 2025, gas-fired boilers will be banned in newly built homes, while the installation of new replacement gas boilers in existing houses will be prohibited by the mid-2030s. To encourage the use of heat pumps, the UK government is offering a number of grants to households.
Homebuilding may also see big changes. Either the key raw materials used today, steel and cement, will be processed differently, or substitutes will have to emerge.
The steel and cement industries are massive CO2 emitters, each accounting for roughly seven percent of total global emissions, according to the IEA. “Greening” these heavy industries will be important to achieve net zero.
Several emerging technologies, which are close derivatives of well-understood and commercial processes used today, could yield significant emissions reductions in the medium term. In the steel industry, pilot programs are using hydrogen to complement or replace coal in the high-temperature combustion process. Meanwhile, feasibility studies suggest the use of hydrogen could substantially reduce the amount of carbon that is emitted from a cement kiln. At the same time, it appears mixing carbon dioxide with the water used to cure concrete can add usefully to its strength, meaning less cement can be used while simultaneously locking away the carbon in the concrete.
Engineered timber frames for buildings are another innovation that will increasingly be used to replace steel and cement. Cross-laminated timber (CLT) is produced by gluing planks of wood together, layering the grain of the wood at right angles. CLT was first used in a high-rise building in Vancouver in 2017, and other skyscrapers have made use of it since.
Window panes could even be made of wood. Swedish scientists found ways to extract pigments from wood, resulting in a transparent material that can be used much like glass but weighing less and insulating more.
Finally, roofs will increasingly be covered by solar panels or vegetation to provide a natural form of insulation and reduce energy consumption.
Transformed transport
It’s widely expected that electric vehicles (EV) will be ubiquitous, but their capabilities will likely be far more efficient than today’s models.
For one, an EV that is not in use may feed energy back to the grid via two-way charging points. In this way EVs can act as an aggregated megabattery, helping the grid offset the inevitable vagaries of wind and solar power. After all, cars are idle most of the time and a large amount of battery power is unutilized.
