> Modelling in Australia with simulations that multiply up current wind and solar (using real-time data of actual renewable generation) [1] showed that well over 99% of demand can be delivered with only about five hours of storage, so we're not really talking about days.
That's still a gap two orders of magnitude larger than existing standards:
> Meanwhile, reliability standards in industrialized countries are typically very high (e.g., targeting <2–3 h of unplanned outages per year, or ~99.97%17). Resource adequacy planning standards for “1-in-10” are also high: in North America (BAL-502-RF-03)18, generating resources must be adequate to provide no more than 1 day of unmet electricity demand—or in some cases 1 loss of load event—in 10 years (i.e., 99.97% or 99.99%, respectively)19.
Even leaving 1% of demand unfulfilled amounts to multiple orders of magnitude more frequent electricity production shortfalls. Figures like "fulfill 99% of electricity demand" might sound promising, until you compare against the standards of reliability modern society expects of the electrical grid.
And that's in Australia, quite literally the best-case scenario for renewables. By comparison, in Germany even 12 hours of storage would only satisfy 80-90% of demand.
The thing is you can calculate when there will be short falls and you can amount to that perfectly.
We now know the weather pretty much 1 day before it happens. adjusting that 1% of course amounts to maintaining natural gas facilities but it's really not that big of a deal.
Using natural gas means climate change still progresses. Not to mention you'll be paying all of the overhead cost of maintaining natural gas plants, but only use them for a fraction of the time. So net cost per watt hour will be very high.
That's still a gap two orders of magnitude larger than existing standards:
> Meanwhile, reliability standards in industrialized countries are typically very high (e.g., targeting <2–3 h of unplanned outages per year, or ~99.97%17). Resource adequacy planning standards for “1-in-10” are also high: in North America (BAL-502-RF-03)18, generating resources must be adequate to provide no more than 1 day of unmet electricity demand—or in some cases 1 loss of load event—in 10 years (i.e., 99.97% or 99.99%, respectively)19.
https://www.nature.com/articles/s41467-021-26355-z
Even leaving 1% of demand unfulfilled amounts to multiple orders of magnitude more frequent electricity production shortfalls. Figures like "fulfill 99% of electricity demand" might sound promising, until you compare against the standards of reliability modern society expects of the electrical grid.
And that's in Australia, quite literally the best-case scenario for renewables. By comparison, in Germany even 12 hours of storage would only satisfy 80-90% of demand.