[Sparty]

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.