Pumped storage power stations are equipped with dual purpose units for pumping and generating electricity, which can both pump water and generate electricity. During the day and in the first half of the night, the reservoir releases water, and the high water level passes through the dual purpose unit. At this time, the dual purpose unit serves as a generator, converting the mechanical energy of the high water level into electrical energy and transmitting it to the power grid. Addressing power shortages during peak electricity usage; In the latter half of the night, the power grid is in a low valley of electricity consumption, and electrical energy cannot be stored in the grid. At this time, the dual purpose unit is used as a water pump (the dual purpose unit can rotate in reverse), and the excess electrical energy in the grid is used to pump water from low water levels to high water levels and inject it into high water reservoirs. In this way, during the low valley of electricity consumption, the excess electrical energy in the grid is converted into mechanical energy for water storage in the reservoirs. At the peak of electricity consumption, the reservoir releases water and converts the mechanical energy of the water into electrical energy through a generator, which is then transmitted to the power grid. The water in the reservoir is used multiple times, together with two units, to complete multiple energy conversions. High water level reservoirs store a large amount of low water level water, which is equivalent to storing excess electrical energy in the power grid, solving the problem of electrical energy being unable to be stored. Due to the different electricity prices during peak and low periods, the peak electricity prices are high while the low electricity prices are low, which greatly improves the economic benefits of pumped storage stations.

There are also wind energy pumped storage power stations

Main functions: One is daily peak shaving, which is to use the electricity from the power grid to pump water during low electricity consumption periods, and to use water to generate electricity and supply the power grid during peak electricity consumption periods. The second is the annual regulation function, which refers to using electricity to pump water into high-level reservoirs when there is excess electricity during the rainy season, and then releasing water to generate electricity during the dry season to supply the power grid.

Ultra large battery pack

Utilize large capacity battery packs in combination with various new energy generation methods.

Latest Development of Energy Storage Technology Abroad

In recent years, the world's advanced energy storage technology has received strong support from various countries, continuously developed, and achieved a lot of results. Over the years, developed countries such as Japan, the United States, and Europe have invested heavily in battery energy storage technology, leading the way in technology. Japan leads the world in the research and application of sodium sulfur batteries.

In terms of battery energy storage, in 2001, VRBpowerSystems of Canada built a 250kW all vanadium liquid flow energy storage battery demonstration system in South Africa, achieving commercial operation of all vanadium liquid flow energy storage batteries. The all vanadium liquid flow energy storage battery built by VRBpowerSystems for HydroTasmaniaonKingsIsland in Australia, which is compatible with wind power generation, was completed in November 2003. The system has an energy storage capacity of 800kWh and an output power of 250kW. In February 2004, VRBpowerSystems built an all vanadium liquid flow energy storage battery system with an output power of 250kW and a storage capacity of 2MWh for CastleValley, UtahpacificCorp. At the end of 2006, the company began constructing the largest rated output power of 2MW (pulse output power of 3MW) and energy storage capacity of 12MWh all vanadium liquid flow energy storage battery system for Ireland to date. The United States has established demonstration operation systems for 2MW and 6MW all vanadium liquid flow energy storage batteries using the technology of Sumitomo Electric Industries of Japan and VRBpowerSystems, respectively [3].

In 2003, the production capacity of sodium sulfur batteries produced by NGK Company in Japan was 30MW, reaching 48MW (960 modules) by 2005, reaching a scale of 90MW (1800 modules) in 2008, and the development plan for 2010 is to produce 150MW annually. More than 100 sodium sulfur battery energy storage stations have been built worldwide. In 2009, the European Union invested 30 million euros to jointly establish the world's most advanced battery laboratory in Finland, which is compatible with intelligent management and monitoring systems. It is expected to complete the expansion of 100mAh product volume by 2012. Hitachi Japan will launch long-life lead-acid batteries in the North American market, which will be used for renewable energy grid connection. This product has been launched in Japan and has achieved success in 8 projects. Discharge time 1-4 hours, service life 15-17 years, recyclable. General Electric invested $160 million to develop a special Duration sodium halide battery system specifically designed for power systems, with a lifespan of 20 years. Capable of achieving optimal performance under extreme temperature conditions, without any toxic chemical emissions, and equipped with remote monitoring function, recyclable. Axionpower International, a company in the United States, has received a $248650 grant from the Pennsylvania Energy Development Agency for research on smart grid energy storage systems and is committed to developing lead-acid battery technology that uses a small amount of lead. This type of battery can provide high-speed transmission speeds similar to superconducting energy storage, with faster charging time and longer lifespan, and is used in integrated systems containing wind and solar energy.