Impact of climatic, technical and economic uncertainties on the optimal design of a coupled fossil-free electricity, heating and cooling system in Europe

Abstract

To limit the global temperature increase to 1.5 • C, fossil-free energy systems will be required eventually. To understand how such systems can be designed, the current state-of-the-art is to apply techno-economical optimisation modelling with high spatial and temporal resolution. This approach relies on a number of climatic, technical and economic predictions that reach multiple decades into the future. In this paper, we investigate how the design of a fossil-free energy system for Europe is affected by changes in these assumptions. In particular, the synergy among renewable generators, power-toheat converters, storage units, synthetic gas and transmission manage to deliver an affordable net-zero emissions system. We find that levelised cost of energy decreases due to heat savings, but not for global temperature increases. In both cases, heat pumps become less favourable as surplus electricity is more abundant for heating. Demand-side management through buildings' thermal inertia could shape the heating demand, yet has modest impact on the system configuration. Cost reductions of heat pumps impact resistive heaters substantially, but not the opposite. Cheaper power-to-gas could lower the need for thermal energy storage.

Early decarbonisation of the European energy system pays off

“…Minor changes in solar generation 62 , and significant variations on the hydro inflow seasonal patterns are expected 61 . On the demand side, the increase in cooling demand in southern European countries, and more relevant, the reduction of heating demand in northern countries are expected to reduce the system cost 63 .…”

Solar photovoltaics is ready to power a sustainable future

“…PV can also contribute to decarbonizing the residential and services sector by successfully competing with gas for low-temperature space heating and water heating with the assistance of electric heat pumps. Solar can also supply refrigeration demand, which is highly correlated in time with solar generation 113,114 and is expected to increase due to climate change. As solar becomes cheaper, it begins to compete with gas and coal for industrial heating through the use of high-efficiency electric furnaces.…”

The role of photovoltaics in a sustainable European energy system under variable CO2emissions targets, transmission capacities, and costs assumptions

“…Moreover, it is also worth noticing that cooling demand, which is expected to increase due to climate change, is strongly correlated with solar PV generation and makes this technology particularly suitable to supply this demand via heat pumps …”