| > How do you cover the last 10-20% of the missing solar+wind+batteries output, at what cost? First of all, we're very far from this being a problem. If you "only" move 90% of the electrical grid to solar and use fossil fuels to make up the remaining 10% it's a ridiculously huge win anyways. The person you are talking to is just talking about "new power", not "replacing all existing power"... so unless the grid is growing by 5 to 10x your objection here is utterly irrelevant. Secondly, that whitepaper shows you can do this with incredibly unfavourable assumptions. Namely that they're 1. Ignoring transmission, in reality we can and will move power around from sunny to shady areas. The paper is assuming a single off grid facility. Because different areas are cloudy at different times this greatly reduces the peak amount of batteries needed. 2. Ignoring other sources of energy, like wind, hydro, etc. Because their failures are uncorrelated with solars failures, they greatly reduce the amount of storage needed to hit reliability targets. It's a lot more likely that you'll have a cloudy week than a cloudy and windless week. This is also why pairing wind with batteries makes a ton of sense. You aren't just pairing wind with batteries, you're pairing wind with a mix of other electricity and batteries. The more uncorrelated sources of electricity you have the less batteries you need to paper over outages. |