3 ms·

Absolutely, I don't see batteries being helpful for annual cycles, just for daily. Hence my mention of getting through windless nights. The article I referenced

Absolutely, I don't see batteries being helpful for annual cycles, just for daily. Hence my mention of getting through windless nights. The article I referenced was mainly about that too, suggesting we'd need about a week of battery storage. For annual cycles, the easier method is simply to overbuild your generation. If you have half as much solar input during the winter, then build twice as much solar. Here's an article covering a study based on US data, suggesting that four days of storage and a 2X overbuild is roughly optimal there: https://caseyhandmer.wordpress.com/2023/07/12/grid-storage-batteries-will-win/ https://caseyhandmer.wordpress.com/2023/07/12/grid-storage-b...

credit_guy 2y ago
> For annual cycles, the easier method is simply to overbuild your generation. If you have half as much solar input during the winter, then build twice as much solar. At latitudes such as of New York or London the solar input during the winter is 5 times lower than in the summer, or more. That's because there are three effects that all go in the same direction: shorter day, lower inclination and thicker atmosphere for the rays to cross (because they come more slanted). If you build five times more solar than you need during the summer, it means you have to idle 80% of the capacity at that time. Long before this will happen the marginal profit of building a new solar plant will become negative for the investors, and long before that happens the profit will be positive, but the risk too high for the investors to secure financing.
- DennisP 2y ago
  Sure, if you're Canada, you probably need to go ahead and build nuclear. Even if solar keeps getting exponentially cheaper, it'd be nice to be reasonably efficient with land use. What has surprised me is that a solar/wind/battery grid is starting to look feasible anywhere, even if not everywhere. It could probably handle a decent portion of the US now.

credit_guy 2y ago

> For annual cycles, the easier method is simply to overbuild your generation. If you have half as much solar input during the winter, then build twice as much solar. At latitudes such as of New York or London the solar input during the winter is 5 times lower than in the summer, or more. That's because there are three effects that all go in the same direction: shorter day, lower inclination and thicker atmosphere for the rays to cross (because they come more slanted). If you build five times more solar than you need during the summer, it means you have to idle 80% of the capacity at that time. Long before this will happen the marginal profit of building a new solar plant will become negative for the investors, and long before that happens the profit will be positive, but the risk too high for the investors to secure financing.

DennisP 2y ago
Sure, if you're Canada, you probably need to go ahead and build nuclear. Even if solar keeps getting exponentially cheaper, it'd be nice to be reasonably efficient with land use. What has surprised me is that a solar/wind/battery grid is starting to look feasible anywhere, even if not everywhere. It could probably handle a decent portion of the US now.