RE: Have I got my facts right20 Aug 2020 05:54
guys - this "powers 2000 households for a year stuff" is utter tosh and nonsense. It is what some journalists think helps explain a story about energy because the great unwashed like you and me don't understand megawatts proper not like wot us journalists do now was it megawatts or megawatt hours, doesn't matter we'll just put it down anyway.
What the claim should say is "would power 2000 households, for a year, if there was a nuclear war and all the energy generation in the country was destroyed" because that is what it assumes - zero generation from anything else. Assuming that there has not been a nuclear war and the sun has not exploded there will be ongoing generation all the time which often it will be virtually impossible to stop.
The batteries are going to be charged and discharged on a repeated basis, hundreds of times a year, at least once a day but quite possibly more than this as intra-day balancing is undertaken - the battery is a key component of a flexing grid - just as a transformer is. Transformers were invented 150 years ago and allowed Nikola Tesla to develop the concept of AC grids and high voltage energy transmission. Grid scale energy storage only became a thing 10 years ago so we are still getting our heads, and energy markets, around this concept.
Another way to think about the Dalian battery is that it can shave 8% of the city's peak energy at any one time.
Dalian City has a population of 6.7 Million people. - more than Ireland, Denmark, Norway or Finland.