The global hydropower resources are extremely impressive. The current theoretical reserves are about 40,000 to 50,000 TWh/year (1 terawatt = 10 12 watts = 1 trillion watts), of which about 13,000 to 14,000 terawatts. Time/year is technically feasible, and hydropower resources developed by current technology can easily meet global electricity demand. Per capita technology can develop hydropower resources 46,189 kWh/year. Norway is the world's largest, and its hydropower resources are as high as 19 times the global average of 2,400 kWh/year.
The ratio of land to sea area on the earth's surface is 29:71. The water resources are endless, pollution-free, and there is no need to mine and transport. However, the hydropower stations built by the rivers are shut down during the dry season, and the marine energy includes the gravitational attraction of the sun and the moon and the earth. The tidal energy (tidal current and tidal energy), wave energy, ocean current energy, seawater temperature difference energy and sea salt salt difference energy generated by rotation are higher. The construction of tidal power stations does not require immigration and no land loss. It can also be combined with tidal power generation to derive comprehensive utilization projects such as reclamation, aquaculture and marine chemicals. The tidal power generation has entered a mature stage.
Tidal power generation is mainly distributed on the coastlines of European countries. Similar to the principle of ordinary hydropower generation, tidal power generation will collect seawater into the reservoir during the high tide, and release it when the tide is low, and use the difference between the high and low tides to drive the water turbine to drive the generator. Japan first used artificial satellites to provide trend information to develop tidal energy, and the UK's wave energy and tidal energy development was the most developed. Wave energy resources are mainly in Scotland, England and Wales; the tidal energy distribution is relatively even, and the tidal range can be concentrated in England and Wales.
In 1913, Germany established the world's first tidal power station on the North Sea coast. In 1967, the Langs Power Station at the Langs Estuary in St. Malo, France became the first commercial utility and the largest tidal power station in the world today. The average tidal range of the Langs River estuary is 8.2 meters. The 750-meter-long dam spans both banks. The dam-pass road bridge passes through the vehicle. Under the dam, ship locks, sluice gates and generator rooms are installed. 24 sets of two-way water turbine generators with a total installed capacity of 240,000 kilowatts are in high tide. The ebb tide can generate electricity, and the annual power generation is more than 500 million degrees into the national grid.
In 1958, the first tidal power station was built in Jizhou, Guangdong, China, with an installed capacity of 40 kW. In 1980, Canada built a 20,000-kilowatt intermediate-test tidal power station in Fendi Bay to prepare for the construction of a larger utility. The total installed capacity of the Jiangxi Jiangxia Chaoshan Power Station, which was put into operation in 1985, was 3,200 kilowatts, ranking third in the world at that time. In 2009, the tidal power station in Strandford Bay, Ireland, was one of the top ten renewable energy projects in the world and the largest tidal power station at the time. In 2015, South Korea invested 820 million US dollars and installed 300 MW of Wando Hoenggan Waterways. Its 18-meter-high water turbine generator was fixed to the seabed by its own gravity.
The development of marine energy is on the rise, and more than 20 of the world's most suitable tidal power stations are being researched and developed. Including Cook Bay, Alaska, Canada, Bay of Funds, Port of Severn, UK, St. Joseph Bay, Argentine St. Joseph Bay, Australia, Darwin Van Dymen Bay, India, Cambe River Estuary, Russia's Far East Okhotsk Haipin Bay, South Korea's Incheon Bay, etc. . Due to the huge amount of tidal energy reserves, as the cost continues to decrease, the 21st century will continue to build large-scale modern tidal power stations.
In the field of ocean current power generation, the flow rate of more than 1 meter per second has the mining value. China's Taiwan has built the world's first deep ocean current energy test system for seven years. It is equipped with a low-speed ocean current energy water turbine. It successfully starts the generator for 60 hours at a flow rate of 0.45 meters per second. The average power generation is 1.27 meters per second. 26.31 kW, becoming the world's first power generation project to successfully extract the energy of the Kuroshio Current.
Most of the geothermal energy generated by the decay of the earth's lava and radioactive materials comes from the depth of the earth at temperatures up to 7000 °C, and drops to 650 °C - 1200 °C from 80 to 100 km from the ground. Geothermal lava is immersed in the crust 1 km to 5 km from the ground to heat the surrounding groundwater. Geothermal energy is mainly concentrated in the volcanic and seismic-prone areas along the edge of the tectonic plates. The easiest way to use geothermal energy at low cost is to collect the heat source and extract its energy, but the development and use of geothermal heat will also produce greenhouse gases.
