3 ms·

For large scale energy storage, pumped hydro is much cheaper and has a much larger capacity, but they take years to build and are harder to get approved due to

For large scale energy storage, pumped hydro is much cheaper and has a much larger capacity, but they take years to build and are harder to get approved due to environmental concerns. For example, the planned Snowy 2.0 pumped hydro scheme in Australia: 2 GW, 350 GWh, US$2.8-3.3 billion. Will take 5 years to build. Compared to Tesla's previous 'world biggest battery' in South Australia (the 'Hornsdale Power Reserve'): 100 MW, 129 MWh, US$74 million. Built in 4 months. i.e. $9.43 versus $574 per kWh.

fpoling 8y ago
According to [1] the total price for the project will be up to 7e9 AUD or 5.1e9 USD, so the storage cost will be like 15 USD/kWh. Tesla promises that by 2020 they will have batteries costing bellow 100 USD/kWh. The difference is still big by the factor of 6, but at least it is no longer 2 orders of magnitude. [1] https://www.theguardian.com/australia-news/2017/dec/21/snowy-hydro-2-viable-government-backed-study https://www.theguardian.com/australia-news/2017/dec/21/snowy...
dillondoyle 8y ago
I don't know energy units at all so sorry if this is dumb. But is 2 GW the same as 20 * 100 MW? So $74mm * 20 = 1.48 billion which is less than 2.8 ? E.g. battery is cheaper?
- gsbraitberg 8y ago
  The relevant unit is storage (kWh-- kilowatt hour), not power (MW-- megawatt).
  - Tepix 8y ago
    Both are relevant, depending on the purpose.
  - dillondoyle 8y ago
    Ah ok. So kWh is like the length of time of that amount of energy delivered. What's the 2 GW then, like max through put at a given moment in time? So the two examples water storage lasts a really long time but a smaller relative rate of discharge versus battery could discharge the amount stored a lot quicker?
    - pouetpouet 8y ago
      kWh is for energy stored in this example, the "size of the tank". kWh is analogous to toe (tonne of oil equivalent) or gallons of gas. kW is for power, that is the flow of energy (energy/s), another non SI unit is horsepower. The SI unit for energy is Joule (J), the SI unit for power is J/s. 1 Watt is 1 Joule per second.

fpoling 8y ago

According to [1] the total price for the project will be up to 7e9 AUD or 5.1e9 USD, so the storage cost will be like 15 USD/kWh. Tesla promises that by 2020 they will have batteries costing bellow 100 USD/kWh. The difference is still big by the factor of 6, but at least it is no longer 2 orders of magnitude. [1] https://www.theguardian.com/australia-news/2017/dec/21/snowy-hydro-2-viable-government-backed-study https://www.theguardian.com/australia-news/2017/dec/21/snowy...

dillondoyle 8y ago

I don't know energy units at all so sorry if this is dumb. But is 2 GW the same as 20 * 100 MW? So $74mm * 20 = 1.48 billion which is less than 2.8 ? E.g. battery is cheaper?

gsbraitberg 8y ago
The relevant unit is storage (kWh-- kilowatt hour), not power (MW-- megawatt).
- Tepix 8y ago
  Both are relevant, depending on the purpose.
- dillondoyle 8y ago
  Ah ok. So kWh is like the length of time of that amount of energy delivered. What's the 2 GW then, like max through put at a given moment in time? So the two examples water storage lasts a really long time but a smaller relative rate of discharge versus battery could discharge the amount stored a lot quicker?
  - pouetpouet 8y ago
    kWh is for energy stored in this example, the "size of the tank". kWh is analogous to toe (tonne of oil equivalent) or gallons of gas. kW is for power, that is the flow of energy (energy/s), another non SI unit is horsepower. The SI unit for energy is Joule (J), the SI unit for power is J/s. 1 Watt is 1 Joule per second.