A sustainable, reliable and efficient energy system is essential for our society, as it uses renewable and carbon-free sources to provide society with energy. These include solar, wind, hydropower, geothermal heat, and biomass. So, a sustainable energy system does not use fossil fuels, such as oil, coal, ad natural gas, because these sources contribute to climate change and are finite.
Making the energy system more sustainable requires a major shift in the way we generate and consume energy. Both large-scale and local, small-scale solutions play a role in replacing non-renewable energy systems with renewable energy systems.
As well as renewable and carbon-free sources, a sustainable energy system also involves energy-efficiency measures, used to reduce energy consumption and waste. For example, the insulation of existing buildings and homes, the design of buildings and homes, the development of energy-efficient equipment and devices, and transport systems that run on clean sources of energy. In addition, energy production, storage, and conversion must be done efficiently to keep costs for consumers low and ensure the transition remains affordable.
A sustainable energy system also means more electrification. As such, lower energy use means more electricity consumption. Transport, heating, and industrial processes will largely switch to electric applications. Demand response, both in households and industry, is also becoming ever more important because the supply (particularly of sustainable electricity generation from wind and solar) is weather-dependent.
After all, a reliable power supply is essential. A reliable provision of energy requires investments in carbon-free flexible capacity.This comprises storage, demand response, but also carbon-free production, such as the use of hydrogen in gas power plants, biomass with CCS and probably nuclear power. A framework should be developed to safeguard sufficient investment, especially in carbon-free flexible production.