District energy plants are beginning to use renewable energy. Renewable energy derives energy from naturally replenished sources such as the sun and wind. On the other hand, non-renewable energy comes from finite resources like coal, natural gas, and oil.
District energy systems provide heating, cooling, and sometimes electricity to buildings from a central plant. Integrating renewable energy into district energy systems can effectively reduce greenhouse gas emissions. They also improve energy efficiency and make urban areas more sustainable. Renewable energy sources like biomass, geothermal heat from the earth’s crust, sunlight, water, and wind can be converted into usable forms of energy.
Collectors on rooftops or nearby land harness solar power for generating hot water or steam for heating purposes in the district energy system. This eliminates the need to burn fuel for this purpose.
Solar PV panels can generate electricity to power components of the district energy system or offset the need for electricity purchased from the grid. Excess electricity generated can feed back into the grid or be stored for later use.
Wind turbines produce electricity that can help meet the energy requirements of the district energy system. Although wind energy tends to be more decentralized when compared to other renewable sources, it can still contribute to overall renewable energy integration in the area.
One of the shortcomings of solar PV and wind is their fluctuating nature. Integrating energy storage technologies such as batteries can help balance fluctuations in renewable energy generation and demand within the district energy system. Energy storage will be a key component in the growth of large-scale solar and wind systems.
Geothermal heat pumps can extract heat from the ground to provide space heating or hot water for the district energy system. This energy can also provide steam for turbine generators, instead of burning fossil fuels for this purpose. This second use is highly location-dependent, though. Depending on location, geothermal energy is usable for large and small-scale installations.
Biomass boilers or combined heat and power (CHP) plants can utilize organic materials such as wood chips, agricultural residues, or biogas from anaerobic digestion to produce heat, steam, or electricity for the district energy system. Also, CHP plants simultaneously produce electricity and useful heat from a single fuel source. This approach can improve overall energy efficiency and reduce emissions in district energy systems.
Industrial processes, wastewater treatment plants, or other waste heat sources can supplement heating or cooling in the district energy system, improving overall energy efficiency. Unused waste heat emits to the surrounding environment in the form of exhausts or effluents at different temperature levels. Recovering this waste heat can reduce the use of primary fuels and emissions.
Federal and state governments are implementing goals to phase out or eliminate fossil fuels as a form of energy generation over the coming years. By combining the approaches described above and tailoring them to the specific characteristics and needs of the local area, district energy systems can play a crucial role in facilitating the transition away from fossil fuels and towards a more sustainable and resilient energy future.
