Renewable fuel sources are already nearly 100% in use. So if you add electricity demand, that new demand usually comes from fossil fuel. That is, you need to consider marginal electricity generation.
In that context current electricity generation does not matter. It‘s an infrastructure change that allows for future zero emissions. Just like EVs.
The tools in our disposal to reach 20% or 30% are available today, if we can understand them. And also, as long as we don't let perfection be the enemy of good.
We will probably never tackle the 90% to 100% problem in our lifetime. It is best to focus upon the problems that are in front of us, and that we can in fact solve or fix within our lives.
Given the lifetime of gas furnaces and what we know about climate change it is madness to even consider using them in brand new construction now.
Gas was and is the right tech for transitioning. But you seem to be stuck in the 90s or early 2000s when that kind of policy would have made sense. It’s too late and getting later.
Ex: Your town might be fine with 100MW of power at 60F. But if the temperature drops to 40F, everyone turns on their heaters more, so the entire town uses 150MW or more. So how much renewables do you build? Not 100MW, but 150MW. Which is absurd, no one is going to overbuild capacity like that. And even at 150MW, if the temperature drops to 20F or 10F, even more energy will be used.
In contrast, the Fossil Fuel / Natural Gas peaker methodology is to overbuild on capacity, because capacity is extremely cheap. Maybe the town has a 200MW plant for example. You only use what the people need, so the 200MW plant consumes 100MW at 70F, 150MW at 40F, and everyone has capacity left to grow and expand the town.
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Renewables are great for baseload / constant loads that are predictable. But weather isn't always predictable. In this example, 100MW of baseload renewables would be ideal, and the gas-peaker plant is used for everything in addition to that.
On the scale from predictable to not predictable, heating loads are somewhere in the middle. For a given night that ends up having a low of 10F, it would be hard to know that exactly ahead of time, but we have a pretty good idea that it will be below 20F. So that's roughly only (65-10)/(65-20) - 1 = 22% additional heating load that wasn't predictable.
Plus HVAC is highly dispatchable - if there is excess electricity that needs to be used, heating an X-to-water heat pump's storage a few extra degrees is a perfect place to use it.
https://www.caiso.com/TodaysOutlook/Pages/default.aspx
See September 22, 2022. California required 51,000+ MW of power capacity as the state reached record high temperatures. Just a few days earlier on Sept. 9th, 42,000 MW was all that was needed.
See Yesterday: March 31st 2023. California only required 26,000 MW of power capacity. Even then, the low for March 31st was 17,000 MW at midday.
Given these stats from the last year... How much baseload should California build out? And how much "peaker" production should California have?
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The weather swinging +/- more than expected can cause 10,000MW (or 20% shifts) in power in just a couple of days. Seasonal differences are +100%/-50% differences in power capacity.
Its because of this that natural gas peaker plants are used. That's why H2 fuel, as inefficient as it is (but a potentially green source) is still being considered. Having day-to-day, or seasonal, storage of power through the use of chemical energy storage is one of the most promising technologies to tackle this problem.
I'm not versed in exactly how these numbers shake out to be making informed conclusions, but by your previous argument it doesn't seem like you are either. For example cooling load is going to be positively correlated with solar output. More bursty renewables (solar, wind) means less base load and more peaker plants to handle their droops. And just because a town builds one "200MW peaker plant" doesn't rule out adding renewables (and making the peaker burn less gas), even though the renewables only operate at their full capacity a small part of the time. The only way to figure out what to make sense is to tradeoff specific capex/opex/utilization/revenue, rather than talking in wide-sweeping generalizations.
Storage is the general solution to the problem, yes. The easy form of storage that we've become accustomed to is the chemical energy of natural gas. Another is end-user thermal storage, where consumption is accelerated/delayed depending on what the grid needs. Moving away from fossil fuels requires figuring out storage, especially how to utilize the inherent storage/slack we already have, rather than continuing to just take fossil fuels' convenient advantages for granted.
I never was against adding renewables. I'm simply pointing out rough estimates on our electricity usage throughout the year, and throughout the day.
Peaker plants, unfortunately, seem like the best solution. Natural gas is the best peaker plant for a variety of reasons. But then natural gas piped to a house for near 100% conversion efficiency is even better (rather than taking rather dramatic hits on conversion inefficiencies). Therefore, Natural Gas in homes is surprisingly useful, and will remain so for the foreseeable future.
We absolutely should be building renewables for the near and moderate terms. We don't have enough renewables for baseload yet.
> You've switched from talking about heating (presumably in climate that needs a significant amount), to talking about cooling California.
California has public electricity usage patterns. For better or worse, its the best data that we've got. I assume its somewhat representative of the energy requirements across the country.
Other parts of the country its way more complex because there's natural gas flowing everywhere. So its harder to convert Natural Gas heating vs electricity prices. Nonetheless, the concept of "This differs based on the weather" and "The weather changes dramatically every week" is universally true.
I don't think we'll ever have "enough" solar+wind to supply base load, since night exists and winds calm down. Talking about "renewables" as a group doesn't really make sense. For example hydro is highly consistent and highly dispatchable, but waterfalls are rare.
Spitballing, I would think cooling (especially with California's coast where it's rarely needed) would have much higher variability than heating, since people seem to tolerate a wider range of higher temperatures compared to colder temperatures. At least from personal experience once I enable the heat for the year it mostly stays that way, turning on when it gets even a degree too cold. Whereas air conditioning is a question each day of "can I get by with the windows open", and only when the answer turns out to be an unequivocal "no" do I turn on the AC (which then runs continuously to make up for lost time).