Developing Distributed Energy to Improve Energy Efficiency

Distributed Energy System (DES) refers to a high-efficiency energy supply that can be installed near a user in a small-scale, small-capacity, modular, decentralized manner and converts fuel into electricity, hot water or steam, and cold water at the same time. The system is a distributed energy supply system based on the concept of energy cascade utilization and integrating cooling, heating (heating and hot water supply) and power generation processes. A major technology form of the distributed energy system is Combined Cooling (Heating and Power, CCHP), which provides electric energy, heat, and cold energy in various forms at the same time through the input of primary energy sources.

Distributed energy systems have the following advantages:

Energy efficiency is high. The distributed energy system can effectively unify the three energy requirements of high-quality electricity and low-quality cold and heat to achieve cascade energy utilization, and further increase the comprehensive energy utilization rate, which can reach 75% to 90%.

Unit start and stop flexible. The distributed energy system has small capacity, simple operation, intelligentization, quick startup and shutdown, and flexible features. It can meet the needs of users for various energy forms through different cycles of organic integration, and can also serve as the second standby power source for important users. It is of positive significance to the peak and valley filling of the large power grid and its security and stability.

Environmentally friendly. The primary energy used by a distributed energy system is mostly gaseous fuel, and pollutant emissions are reduced by 3/4 or less than coal burning.

Save on investment. The distributed energy system is close to users, and it is not necessary to construct a large power grid with long-distance high-voltage or ultra-high-voltage power transmission, which saves investment and operating costs for power grid construction.

China promises "to reduce carbon dioxide emissions per unit of GDP by 40% to 45% compared to 2005 by 2020." It can be seen that the task of energy saving and emission reduction is very arduous. It has been estimated that if 50% of buildings were converted to use CCHP from 2010, CO2 emissions would be reduced by 19% by 2020; if the proportion of CCHP existing in existing buildings were increased from 4% to 8%, then by 2020, The annual carbon dioxide emissions will be reduced by 30%. Therefore, distributed energy systems have great potential for development, and the driving force for the development of distributed energy systems will become larger and larger. Distributed energy systems, especially those based on biomass, solar energy, geothermal energy and other renewable energy sources The energy system will have a promising future.