Both Heating and Cooling Are Needed for District Energy to Decarbonize Buildings

Many European countries (e.g., Sweden, Denmark) have been increasing the use of renewable energy (e.g., biomass, wasted heat, solar) for district energy ([DE] i.e., heating and cooling) to reduce dependence on fossil energy. However, a recent Multidisciplinary Digital Publishing Institute research article indicates that the share of the energy demand for district cooling (DC) corresponds with 1%-2% of the EU27+UK energy demand in general, although the penetration of DC varies considerably from country to country. However, some regions other than Europe are using more DC for DE.

DC Can Contribute to Decarbonization

Some countries and regions, such as the US, Japan, and United Arab Emirates, use DC more than Europe, according to the International Renewable Energy Agency. According to this report, in Japan, the absorption chiller contribution of DC (over 60%) is high. In Korea, DC systems also utilize absorption chiller technology to provide cooling as a decentralized DC unit. As Figure 1 shows, this decentralized cooling unit can leverage provided heat from a combined heat and power (CHP) power plant or utilize recovered wasted heat because the absorption technology requires heat to provide cooling. The utilized heat for the Starfield Goyang shopping mall is waste heat and hot water from the nearby CHP plant. The Korean government also provides a subsidy for district cooling equipment, and the budget for subsidiaries was about $2 million in 2022.

Figure 1. DC System Configuration Using an Absorption Chiller

(Source: Kyunghyang Newspaper)

An additional benefit is that DC can use various renewable energy for decarbonization. For example, UAE-based Diamond Developers is planning to integrate solar-powered district cooling facilities within The Sustainable City Yas Island project in Abu Dhabi. The developers plan to install 10 distributed DC plants supplying chilled water to communities. In the project, the communal PV on the roof of parking areas can power the distributed DC facilities.

Europe's Decarbonization Plan May Need to Leverage DC in the Future

Although some European regions have not needed much cooling due to mild summers, the current climate issue, such as sudden heat waves, may increase regional cooling demand throughout Europe. Thus, European green district heating plans (e.g., Germany's Green District Heating Fund) that improve heat networks efficiency need to consider cooling as well in the future. Using more DC is also closely related to Europe's hydrogen utilization plan. For example, integrating hydrogen-powered fuel cells and absorption chillers can be a very efficient heating and cooling solution according to the U.S. Department of Energy. Consequently, for the future decarbonization of Europe, European countries may need to study technologies and market trends, such as DC, outside of Europe.