Articles

New technology allows the coupling of electricity, heating, and cooling in an electrothermal energy storage system.

By Raymond C. Decorvet, MAN ETES Business Development, MAN Energy Solutions Switzerland Ltd.

Illustration above: Visualisation of the new ETES heat-pump, district-heating plant in Esbjerg, Denmark, illustration by Arkitema

To reduce CO₂ emissions, global energy markets are moving away from centralized generation based on fossil fuels and towards renewable energy systems (RES) like wind and photovoltaic. However, renewable energy is not always available when needed, creating instability in the grids due to its fluctuating nature. Efficient and intelligent energy management systems are required to reconcile the growing human demand for power with the fluctuating supply.

Today, the most significant challenge lies in making this growing renewable energy supply usable for the heating and cooling sector. According to the REN21 “Global Status Report”, heating and cooling account for 48% of global energy consumption and 39% of CO2 emissions because renewable sources deliver only 10% of the energy. Therefore, to reduce emissions and decarbonize the whole energy industry, it is crucial to develop solutions that consider all sectors, not just electricity generation.

Connecting electricity, heating and cooling

A new technology links electricity, heating, and cooling and solves two fundamental challenges: It helps balance the grid by absorbing large amounts of surplus or off-peak electricity from renewables and feeding it back into the grid on demand. It integrates multiple sectors by generating, storing, and providing thermal energy for heating and cooling purposes.

The heat (up to 150+°C) can be made available in district heating and for manifold industrial processes, e.g., food and beverage. Typical applications for the cold include cooling data centers or air-conditioning large facilities like airports and shopping malls.

The trigeneration energy management solution allows the conversion of electrical energy into thermal energy in hot water and ice and vice versa. The energy is stored in a series of thermally insulated water tanks. Like a domestic refrigeration unit, in ETES, the closed CO2 cycle sees the working fluid compressed or expanded through turbomachinery to store or extract energy.

Depending on specific demands, energy stored as either heat or cold may be directly distributed or efficiently reconverted back to electrical power as required.