Why store energy?
Ensuring uninterrupted delivery of electricity is a prerequisite for energy security and economic development of every country. On the other hand, what grows the fastest in the world’s energy landscape is renewable energy sources (RES) – often depending on weather (sunlight, wind, partly water) and therefore, not always providing power on demand. A partial solution to the problem of non-flexible RES is energy storage.
Data of International Energy Agency („World Energy Outlook 2016”)I)https://biznes.newseria.pl/news/magazynowanie-energii,p324676830 show that the current energy storage capacity is less than 3 per cent of world’s electric power production capacity and is dominated by a single technology – pumped storage power plants. They convert electricity into gravitational energy of water pumped into the upper reservoir and carry out a reverse processII)https://pl.wikipedia.org/wiki/Elektrownia_szczytowo-pompowa.
Poland, too, uses them traditionally for storing energy and the abovementioned report estimates their power at 1,800 MW. However, as this game is worth the candle, people all over the world have been experimenting and developing various innovative energy storage technologies.
Do you know where world’s largest energy storage is?
The largest storage of energy is located in southern Australia. It has been built by Tesla following an unprecedented interruption in electricity delivery. On 28 September 2016, a violent storm of several decades damaged almost the entire electric power transmission infrastructure in the regionIII)http://www.bbc.com/news/world-australia-37481257. The entire state of South Australia, covering an area of 980,000 km2, (about three times the size of Poland), with about 1.7M inhabitants, was cut off from power and plunged into darkness. After the systems were recovered and reactivated in 2017, the state kept suffering from minor power failures.
World’s largest lithium ion battery system, with the power of 100 MW and capacity of 129 MWh, was built by Tesla, did change Australia’s energy landscape and in the future it is to prevent another blackout of such a range and also to react more efficiently than coal-based systems to similar events. There is an interesting anecdote to the construction of this project as it all apparently started from a betIV)https://www.forbes.pl/technologie/tesla-zbudowala-w-australii-najwieksza-baterie-na-swiecie-musk-wygral-zaklad/wdhsww7. In early 2017 Mike Cannon-Brookes, an Australian billionaire, commented on a tweet by Elon Musk, Tesla’s founder. Musk claimed his company’s batteries would solve South Australia’s power problems within 100 days. Then, Cannon-Brookes made an offer to finance such an investment project on condition Tesla keeps the 100-day deadline or else it will pay for the entire project itself. Tesla, however, kept its word and in late 2017 offered the completed project for use.
Undersea spheres as state-of-the-art energy storage
Germany’s The Fraunhofer Institute is carrying out interesting works on energy storage. It is working on a project that would enable storage of energy in the sea (so-called Stensea » Stored Energy in Sea). Speaking more precisely, this is about storing energy generated in the sea and at the seaside at the bottom of the sea. This could be achieved by putting there, about 700m underwater, special, gigantic concrete spheres (about 30 meters in diameter, with 3m-thick walls) with built-in turbines. When electricity is plentiful, water would be pumped from the sphere into the sea. However, when the energy is scarce and must be generated when needed, the pump would operate reversely and the water would be pumped into the concrete space and would generate power. According to estimates, 200 spheres would be able to generate 4 GW of power. The undersea spheres would effectively resolve the wind power problem, stemming from the simple and unquestionable fact that wind blows sometimes, with various intensity, and some other times it stops completely. In the target design, the spheres would be interconnected with wind farms, solar and tidal power plantsV)http://www.rp.pl/Nowe-technologie/311219904-Energie-elektryczna-mozna-magazynowac-na-dnie-morza.html.
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