Description

In Europe, heating and cooling represent half of the consumption of the total energy demand. However, integration of renewable energy sources (RES) in DHC-networks is still limited today, by several barriers mainly related to the unpredictability and lack of dispatchability on the monthly or seasonal base of thermal energy and electricity. Since the EU is committed to be climate-neutral by 2050, this is a matter of concern, in socio-economical and in environmental terms. The share of DHC in the EU heat market is today 12%, 578 TWh/year. Conventional DHC networks energy needs are mostly based on fossil heat-only boilers and combined heat and power (CHP) plants based on fossil fuels (natural gas: 46%, coal: 15%, fuel oil: 10%) and nuclear energy (7%). Several scenarios, however, expect a dynamic growth of RES in DHC, contributing to the EU binding target of 32% RES of the gross final energy consumption in 2030. Estimations for 2050 show several benefits of the decarbonization in the energy sector, see Figure 1.

A DHC-network requires both electricity (for cooling heat pumps and circulation pumps) and heat (for thermal need and absorption chillers) with a different share depending on the implemented technologies and the site location. Both energy streams can be ideally provided by RES, making the DHC-sector a strong lever for increasing the shares of RES in the energy sector as a whole. Moreover, DHC is, from a technical and an organizational point of view, an infrastructure for fast and cost-effective transformation processes to RES (compared to single measures in individual houses). DHC offers multiple benefits to the energy system as a whole, such as operation flexibility and the coupling of heat and electricity sectors. The main renewable source in DHC networks is biomass (about 11%) while other renewable technologies have a minor role: wind, PV and hydro, about 5% altogether while solar thermal energy, ambient heat and geothermal energy account for only 1.5% altogether. Moreover, it is important to consider that in the EU, the amount of heat produced from industrial processes and then wasted in the environment is estimated to be enough to cover from 25% to the totality of the heat demand in residential and tertiary buildings which highlight the enormous potential to cover this energy needs by sector coupling.

RESTORE project main objective:

Developing a technical solution able to overcome the current technological barriers that limit the penetration of RES in the DHC sector. Proposed technology allows to significantly increase the RES share and the reuse of energy waste from industry in DHC networks improving their competitiveness and environmental sustainability and promoting the involvement of stakeholder, consumers and industries, see Figure 2, eventually meeting the targets of the EU strategy for Heating and Cooling and the EU’s climate and energy goals.