Energy efficiency –using resources wisely
Efficient power generation and transmission
Efficient power generation involves converting as much of the primary energy used in a power plant as possible into electricity and usable heat. Increasing efficiency in fossil fuel power plants by just a few percentage points can save substantial resources and significantly decrease CO2 emissions. In case of renewable energy sources, the efficiency determines the costs of energy generation and thereby how competitive they are compared to conventional power plants.
Efficient fossil power generation
Fossil fuel will remain the primary source of energy through the middle of the 21st century. There is great potential for improvements in efficiency when renovating coal-fired plants. In China,the average efficiency of coal-fired power plants is 36%. In conjunction with the independent innovations of Waigaoqiao No.3 Power Plant, the advanced technology from Siemens helps the power plant achieve the power supply net efficiency of more than 46%, which sets a "China Benchmark" for the power sector in the world.
Waigaoqiao III is the most efficientcoal-fired power plant in the world.
In fossil fuel generation, the highest efficiency – over 60 percent - is today achieved by gas and steam turbine power plants. Due to very fast start-up times, they are ideal for compensating natural fluctuations of wind and solar energy generation. Even higher efficiencies – more than 90 percent – are possible with combined electricity and heat generation plants. One of these,the Huaneng Shanghai combined-cycle power plant, which is equipped with gas turbines from Siemens, was named Best Gas Power Plant in Asia in 2007.
Renewable energy
The greatest challenge in the utilization of solar and wind energy is their fluctuating power feed. Their economic viability depends on the right choice of location and the most efficient possible use of their naturally low energy densities. China is the world’s fastest-growing wind market, and its installed wind energy capacity has doubled each year since 2005. By 2020 China hopes to have wind energy plants with a total combined capacity of 150,000 MW in operation. With the opening of its rotor blade plant in Shanghai in November 2010, Siemens as world market leader in offshore wind parks is part of this development.
Transmission with minimal losses
Renewable energy is often generated at locations far removed from the centers where it is consumed. A highlight project is the 1,400 kilometer “Electricity Autobahn” that uses high-voltage direct current transmission between the Chinese provinces of Yunnan and Guangdong.It features a transmission capacity of 5,000 megawatts and a transmission voltage of 800 kilovolts, the highest in the world for this type of project. It transports environmentally friendly electricity produced in several hydroelectric power plants, thereby eliminating 30 megatons of CO2 emissions that would otherwise be produced by conventional local power plants.
Among the Siemens high voltage direct-current transmission projects, the Yunnan – Guangdong HVDC features a transmission capacity of 5,000 megawatts.
