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Old 04-21-2016, 08:43 AM
Sparty Sparty is offline
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Default Pumped storage and generation

The principle behind pumped storage is both simple and ingenious at the same time. Pumped storage power plants are an energy storage system and a hydroelectric power plant in one. If there is surplus power on the grid, the pumped storage power station switches to pumping mode: an electric motor drives pump turbines, which pump water from a lower reservoir to a higher storage basin. If the demand for electricity in the grid rises, water is released from the upper basin via a pressure pipeline to the bottom. The water causes the pump turbines to move, which now operate in turbine mode and are used in turn to drive the generators. Within seconds, electricity is generated and fed back into the electricity grid. http://www.renewableenergyworld.com/...iscussion.html

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Read more: https://www.aph.gov.au/About_Parliam...onsPumpedHydro

 

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Old 06-11-2023, 02:58 AM
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Default

https://www.sciencedirect.com/scienc...42435120305596

Solar photovoltaic modules (PV) and wind turbines are now the largest and second largest sources of net new electricity generation capacity, respectively, with 97 GW of solar PV and 59 GW of wind installed in 2019.1 The economics of these technologies have reached the point where they are now the lowest cost sources of electricity generation in many regions, resulting in expectations of continued growth. These sources of generation are variable in nature—the amounts of energy delivered depends on the amount of wind and solar insolation available.

Energy storage will be necessary to support large fractions of wind and solar PV penetration in electricity networks. Studies at a world wide2,3 and country-level scale4, 5, 6, 7, 8 have identified that storage will be key to managing a future grid with very high penetration of variable renewables. Storage technologies in these studies include batteries, power to gas (hydrogen or methane), thermal storage, and pumped hydro energy storage.

Pumped hydro energy storage is a form of potential energy storage. A system comprises two reservoirs at different elevations connected by either pipes or tunnels. The difference in elevation is called the “head.” When providing electricity to the electricity network, water flows from the upper reservoir to the lower reservoir along the pipes or tunnels through a turbine connected to a generator, much like a conventional hydroelectricity generation scheme. However, when there is an excess of electricity available, water is pumped from the lower reservoir to the upper reservoir. The pump can be a separate unit or, as is often the case, the turbine/generator is reversible and acts as the pump/motor.

Pumped hydro energy storage was originally developed to manage the difference between the daily cycle of electricity demand and the baseload requirements for coal and nuclear generators: Energy was used to pump water when electricity demand was low at night, and water was then released to generate electricity during the day. Consequently, pumped hydro is currently the largest source of electrical energy storage with more than 95% of the world’s electricity storage power (GW) capacity and 99% of the storage energy (GWh). Despite this, many studies considering high fractions of renewable energy in future electrical systems ignore pumped hydro storage.3,5 Others assume no growth in pumped hydro energy storage2 or limit the growth in pumped hydro to the scale of the conventional hydroelectricity resource. The topography requirements of conventional pumped hydro are often cited as a reason for the need to develop other storage technologies.9,10

A closed-loop, “off-river” pumped hydro overcomes these constraints. The upper reservoir for these schemes is located high in hilly areas rather than in a river valley. Closed-loop schemes recycle water between the two reservoirs; that is, the water is cycled between the upper and lower reservoirs during operation with no aim to capture water in the upper reservoir for additional power generation. Water consumption is only required to replace the difference between evaporation and seepage, and rainfall. The reservoirs are also typically small, of the order of tens to hundreds of hectares. Locating upper reservoirs away from rivers and the small area of the reservoirs greatly reduces the environmental impact. It also minimizes the need to manage large flood events, which substantially reduces construction cost. Since most of the world’s land surface is not near a river, there are vastly more potential areas for off-river compared with on-river pumped hydro systems.

The Ffestiniog Power Station, as shown in Figure 1, is an exemplar for closed-loop, off-river systems. This site has good head (300 m), low separation keeping tunnels short (1.3 km), small reservoir areas (10 and 30 Ha) and limited upper reservoir catchment (160 Ha). It is designed purely for energy storage with no rivers dammed for power generation (as usually associated with conventional hydro schemes). Raccoon Mountain pumped hydro schemes in the United States is another example of a closed-loop, off-river schemes with no intent to capture additional water for energy.

 

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Old 03-11-2024, 08:02 AM
Sparty Sparty is offline
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Default Pumped storage dominates

"pumped hydro is currently the largest source of electrical energy storage with more than 95% of the world’s electricity storage power (GW) capacity and 99% of the storage energy " is that correct?


The first part is correct. Pumped hydro is the dominant form of electrical energy storage by a wide margin. Here are some sources that confirm this:

Department of Energy: https://www.energy.gov/eere/water/pu...age-hydropower says pumped storage hydropower is "the most dominant form of energy storage on the electric grid today".

International Hydropower Association: https://www.hydropower.org/factsheets/pumped-storage states pumped hydro accounts for "over 94 per cent of installed global energy storage capacity".

The second part about 99% of the storage energy is likely an exaggeration.
While pumped hydro holds a significant share, it's not quite that high. It's difficult to get a definitive number on total storage energy because unlike capacity (the potential amount that can be stored), storage energy depends on how the system is used. However, most sources agree it's well below 99%.

Here's a breakdown:

Pumped hydro is very efficient at storing and releasing energy, but some energy is lost in the process.

The amount of energy stored depends on how much energy is used to pump the water up in the first place.

So, pumped hydro is undeniably the leading energy storage solution, but 95% of capacity is a more accurate figure than 99% of storage energy.

 

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  #4  
Old 03-11-2024, 08:17 AM
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Default Snowy 2 Hydro Scheme is two separate, but connected, projects

Australia's Snowy Two Hydro Scheme actually refers to two separate, but connected, projects:

Snowy Mountains Hydro-Electric Scheme (Snowy 1.0): This is the original and massive hydroelectricity and irrigation complex built between 1949 and 1974. It's a truly impressive feat of engineering, considered one of the most complex water and hydro-electric power schemes in the world [Wikipedia: Snowy Mountains Scheme]. It uses a network of dams, tunnels, and power stations to generate electricity and provide irrigation water.

Snowy 2.0 Pumped Storage Power Station: This is a newer project under construction that expands upon the original Snowy Scheme. It's essentially a giant pumped-storage battery using the existing dams and a new underground power station. By pumping water between reservoirs, it can store excess energy and generate electricity on demand [Snowy Hydro: About Snowy 2.0]. This will be a major boost for Australia's renewable energy transition.

Both projects are in the Snowy Mountains of southeastern Australia and are considered nation-building endeavors.

How is this "It's essentially a giant pumped-storage battery using the existing dams and a new underground power station. By pumping water between reservoirs, it can store excess energy and generate electricity on demand" powered?

Snowy 2.0 itself isn't powered by any one source, it's more like a giant energy storage system. Here's the breakdown:

Charging: During periods of high energy production, typically from solar and wind farms, Snowy 2.0 uses surplus electricity from the grid to pump water uphill from the lower Talbingo Reservoir to the higher Tantangara Reservoir. This pumping process uses electricity, but it's essentially storing that energy for later use.

Discharging: When there's high electricity demand, the stored water is released back down through tunnels to the new underground power station. This water flow drives turbines which generate electricity and feed it back into the grid.

So, Snowy 2.0 utilizes the power of gravity and stored water to act as a battery, but the initial energy to pump the water comes from the electricity grid, which can be from various sources. Ideally, as Australia transitions to more renewable sources like solar and wind, Snowy 2.0 will use that excess clean energy for storage.

 

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  #5  
Old 03-11-2024, 08:26 AM
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Default World's largest pumped storage projects-

Here are some of the largest pumped storage projects in the world:

Bath County Pumped Storage Station (Virginia, USA): This 3,000-megawatt (MW) facility is the largest pumped storage station in the United States. It uses two reservoirs, with a height difference of nearly 1,000 feet (305 meters), to generate electricity.

Y pumped storage power station (Japan): With a capacity of 2,800 MW, the Y pumped storage station is one of the largest in Japan. It uses two reservoirs located in different prefectures and is connected by a 16.6-kilometer (10.3-mile) tunnel.

Fengfeng Pumped Storage Power Station (China): This 3,000 MW facility is one of the largest pumped storage stations in China. It is located in Hebei Province and uses two reservoirs with a height difference of about 700 meters (2,300 feet).

Guangzhou Pumped Storage Power Station (China): This massive facility has a total capacity of 2,700 MW and is located in Guangdong Province, China. It uses two reservoirs with a height difference of about 500 meters (1,640 feet).

Reversible Pumped Storage Plant (Israel): With a capacity of 1,530 MW, this facility is the largest pumped storage station in Israel. It is located near Haifa and uses two reservoirs with a height difference of about 400 meters (1,300 feet).

It's important to note that Snowy 2.0 (when completed) will likely be among the largest pumped storage projects in the world. While its capacity (2,000 MW) might not be the biggest, its historical significance and construction complexity make it a remarkable feat of engineering.

 

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