Heat pumps are a key heating technology in buildings. But Europe's building stock is leaky and some people are troubled by the potential impact of massive heat pump use on the electricity grid. What role for hybrid heat pumps?
Hybrids combine a heat pump with a fossil fuel system. In our paper, we focus on air-to-water heat pumps combined with a gas boiler in an optimised control strategy.
Europe's largest countries rely heavily on gas for heating and one of the key uses for hybrids could be adding a small heat pump to an existing gas boiler in an "add-on" configuration.
Out this week for Regulatory Assistance Project (RAP), Dr Richard Lowes and I look at some of the possible benefits of hybrids, discuss the risks of relying on them and provide some recommendations for policy makers.
In the worst-performing buildings, hybrids could postpone upgrades to the building envelope and heating system. In Europe's chilliest regions, they can help provide full heating on the coldest days. They can be a source of flexibility to congested power grids.
But many of these challenges can be met via alternative means. Actions such as electricity grid upgrades and renovating buildings are likely to occur regardless of the heating system concerned. So what value are hybrids?
At energy system level, our paper discusses the power grid, energy system costs, heat pumps in the cold and GHG emissions. On GHGs, we find that in almost all EUcountries, heat pumps are more climate-friendly than gas boilers. Hybrids would lead to significantly more emissions than a heat pump.
For households, we dig into claims that hybrids make heat pump installs easier, boost consumer confidence and lower running costs. We find that only in countries with very high price ratios would hybrids deliver savings compared to a standalone heat pump. And that's if your system is optimised.
Fans of hybrids will tell you that they're useful as an intermediate step. This idea has problems.
As a government, that means you're probably subsidizing twice. As an individual, that means you have to go through a heating system replacement not once, but twice. In the meantime, you now need to maintain two devices and make sure they're optimised or you may pay more than you intended.
We find that hybrids may offer some benefits, such as early partial decarbonisation of heating systems and a slower expansion of the electricity grid, they also bring risks and may deliver only limited benefits compared to standalone heat pump systems. Policy makers should approach them carefully.
That means developing a regulatory definition on hybrids, aligning financial support with the value provided by hybrids, regulating and monitoring the systems, accounting for infrastructure and considering hybrids as a policy package for clean heating.
Read the report for more and reach out if you wish to discuss. https://lnkd.in/eAatr_6h