Energy balancing and storage in climate-neutral smart energy systems

This paper takes a smart energy system's approach to the analysis of the need for energy storage and balancing in a future climate-neutral society and thus supports and advances the United Nations' sustainable development goals, in particular SDG 7 (Affordable and clean energy). The study qualifies and quantifies that the best solutions to the transition can only be found by taking a cross-sectoral holistic approach – also known as a smart energy system's approach. Optimal investments in storage and resulting levels of curtailment are identified based on five smart energy system integration levels (SESIL), progressing from a sole electricity sector focus to a fully integrated system of electricity, heating, cooling, industry, transport, and materials. The study finds and quantifies that the overall least-cost solution is only identified in a fully integrated smart energy system, with affordable types of energy storage and little curtailment which cannot be found in a sole electricity sector approach. Furthermore, the study shows and quantifies that with the aim of a climate-neutral society, it becomes essential to take a holistic smart energy system's approach to identify least-cost storage and energy balancing solutions, and suggests a tool and a method to identify such solutions. Fig. 1: Energy and Carbon Flows of the “Smart Energy Denmark 2024” scenario. (1) Sources of energy and carbon from renewable energy and sustainable use of biomass are converted into (2) Energy and Carbon Carriers in the form of electricity, district energy and biofuels to cover (3) End Use of energy in all sectors as well as carbon for CCS and biochar to compensate other greenhouse gas-emitting sectors and CCU for the production of green fuels. CCU is thus both an end use and a source. [Display omitted] •Simulations of carbon-neutral energy system configurations.•Five smart energy system integration levels are defined and analysed.•Storage and flexibility requirements at different levels of cross-sector integration.•A full sector-integrated approach is required to identify optimal solutions.