And we also have this looming thing called climate emergency, which should conceivably motivate us to forge ahead with renewables and adjust our energy usage patterns to match production peaks, lest we doom humanity to extinction

I feel like this is one of the biggest missed opportunities. Why do we insist on our energy system to be infinitely flexible and full power available 24/7? Is a habit of doing the laundry at night worth more than additional millions of tons of CO2 in the atmosphere?

I understand convenience, laziness and inertia (resisting change) but I also think changing the times when we click "power on" is a simpler solution than mining millions of tons of more lithium, no?

You would have to retrofit every residence to handle daily brownouts (circuits for lights, furnaces and medical equipment stay on, everything else off).

You would have to completely rebuild most of the manufacturing industry, as many plants have startup times measured in hours or days.

It'd be cheaper to just build nuclear.

Industry uses most of the energy. The industry is already moving towards their own price optimizing energy usage and/or storage.

Like computing, having high uptime has a value all its own compared to an unreliable system. Countries which do have regular brownouts you find people buying their own (inefficient, polluting) generators to get round it.

Smart demand-response may yet become a thing, but it's not yet a commodity product. You need a system to send out "turn off" notifications, and a system for measuring that in realtime, and a system for paying people. Some grids _do_ have this, but only for very large consumers.

Many grids do have this for normal residences, but it only covers your air conditioner not everything (and maybe water heater). By running your AC on half duty cycle all day your house still stays cool enough and they are able to reduce substantial peak demand. For most people HVAC and water heating are the two biggest demands, and also ones where simple management can result in a substantial changes in demand without affecting your comfort.

Making thermostats that are aware of dynamic energy pricing or, better yet, are in part controlled by the energy company (I want my house to be 21-24 C, I don't care when the cooling happens) would give us massive flexibility.

All power hungry devices should at least have that capability (maybe other than the kettle, lol). This is literally a cost of $20 hardware in many cases.

In most houses the HVAC and water heater are the only devices that the user can accept not being in full control. Everything else is like the kettle: when you turn it on you want it on now.

> Why do we insist on our energy system to be infinitely flexible and full power available 24/7?

I like to heat my home during winter. We have a (modern, highly efficient) heat pump, so we need most electricity during January, just when the least amount of solar insolation is available [1] and when it sometimes stays cloudy and below 0°C continuously for days. But I guess we'll just have to be more flexible and turn off heating, light, and electricity in general for a week, no big deal.

[1] I wonder if there's a causal relation between cold weather and low solar insolation?

Regarding [1] - are you being sarcastic?

Is that a serious question?

Yes. The dominant (essentially only at the surface) source of heat on the planet is the Sun?

Of course it was sarcasm. I meant to highlight the major problem for using renewables for heating: you'll need most of the power when the least amount of daily solar insolation is available – in winter. This means you either need a lot of storage capacity, or a lot of transfer capacity from far away places, to cover several days of dunkelflaute [1]. This problem is solvable, but it's hard and expensive to solve in practice.

[1] https://en.wikipedia.org/wiki/Dunkelflaute

I couldn’t tell because many people make arguments (or imply) that it doesn’t matter with an apparently straight face all the time! Including large scale gov’t programs.

Including other comments on this exact thread where people did exactly that.

You don't actually need your heat pump 24x7 even on those cold days, if you can run for 15 minutes one, 15 off that would make a big difference to the grid (your neighbor running the same schedule but opposite times) without making your house too cold. Managing the above is tricky though.

> You don't actually need your heat pump 24x7 even on those cold days, if you can run for 15 minutes one, 15 off that would make a big difference to the grid

That's already the case – the actual heat pump only runs intermittently, on demand. This happens quasi-randomly, so you automatically get some load balancing across a city.

The problem is that this is intra-day load balancing, which doesn't help one bit if there are several days of low supply (windless winter days).

What your thermostat does is not synchronized with your neighbors, so the peak load is not managed.

It also isn't synced to supply, instead most people have it set to different temperatures based on when they are home. It would be better to cool or heat the house based on supply. You want the house between 21 and 24c, you don't care when the system is on.

It's often >90 degrees Fahrenheit at night in for months on end where I live, and houses are built cheaply and in a style completely unfitting a hot climate (that is, thin walls, dark roofs, fully aboveground, thoughtless window placement, etc. Standard American Dumbass style). It's unhealthy to sleep in these conditions without AC, even fatal for some.

So yes, we could survive without power at night. We just have to rebuild every building.

As a long-term ideal I don't disagree with you. We should be building for resilience. But that's not a solution to climate change.

Demand shaping is part of the plan, but opportunities are currently limited. For most applications demand can only be shifted by a short time.

Water heating, AC, fridges and freezers, maybe even EV charging (in some cases) could be done at any time during the 24 hour period, if setup with proper hysteresis.

Shifting some load by a couple of hours is indeed often possible, shifting it by 12 hours is already difficult.

Interesting, I would have thought in many cases it is maybe not trivial, but easily doable at worst. Do you have some personal experience with that?

A friend is working at Siemens R&D on this topic.

Renewables alone won't let us decarbonise, they are too expensive and intermittent. We need lots of nuclear if we want to stand a chance.

I don't know why people always comment this on posts about renewables as if it's some kind of gotcha.

When there's no sun, then other countries probably have sun. When there's no sun, there's hydro. When there's no hydro there's wind. When there's no wind, there's tidal. When there's no tidal there's geothermal. And when there's none of those, there's stored energy in batteries.

And if for some reason all of those combined can't satisfy the demand, then there's nuclear as a last resort.

And if there's none of any of those at all, then we've probably got bigger problems anyway

Those things don't add up - there's often no wind, no sun, no hydro. Energy storage is also orders of magnitude too small to store reasonable amounts of energy. I would argue we should start with the cleanest source of energy (which is nuclear, of course) and fill the gaps with renewables.

Many of the plans for the future involve drastically undersized battery storage and decommissioning nuclear. That’s why.

So... my point still stands even without nuclear?

I can’t tell what your point is, frankly. That everything is fine until it isn’t, then we’re boned? Or that it will never go wrong, unless we have ‘bigger problems’? (Which are what exactly? alien invasion?)

Lack of power either way certainly won’t help!

If by design nuclear is offline, fossil fuels are offline, and battery capacity (or other storage) is insufficient for known (but infrequent) weather events, then we’re designing an inevitable and destructive catastrophe as we have no Plan B for when realtime production is insufficient.

And that will happen some day, regardless of how much capacity we build. It’s currently the norm on many days.

One that will kill a lot of people, especially the physically weaker ones, and be very destructive economically.

One that will also play out randomly based on weather, and for which we’ll have no real Plan B.

Being flippant about it seems rather macabre.

While other countries have sun when it is night here, realistically we cannot build the needed wires to get that energy here. We need 20,000km of wire to get power around the earth at the equator.

Wind suffers the same problem as the sun in that sometimes there is no wind anyplace close, and it is even less predictable. While tide power is predictable and consistent, I don't live anywhere close to the ocean so we still need 2000km of wire to get it to me. Geothermo is useful when lava is close to the surface, but I don't live in such an area.

Note that my power is 80% wind, but it was done via several decades of building wind turbines, and I live in Des Moines which nobody would call a big city, if you live in a big city you have even more work to build it (you are both way behind us in building wind, and have a lot more to build)

But you've just done exactly what I said people do wrong. Why do people only consider absolutes when talking renewables. We're not relying on a single source, and we're not relying on countries exactly the other side of the world.

Sure you don't have to have a single wire from one side of the planet to the other, but that's the point in a power grid. Even connecting two solar farms to the grid a time zone apart provides an extra hour of power to each of those time zones and reduces the risk of a single cloud bringing the country down

And as for the rest, you know what the electricity grid is right? Cables already run around the country, and if anything this reduces the strain on single connection as there are lots of smaller generators dotted around the country rather than a huge point of failure connected to a single power plant

> realistically we cannot build the needed wires

On the contrary, Europe, Africa, Asia, the Americas are all wide enough that they can do plenty of solar trading during the daytime. Of course that does not provide energy in the night and that's OK.

We also have space lasers and mirrors.

I can imagine some sort of orbital parabolic mirror setup that keeps a few acres at 2000C in the dead of winter and vaporizes any birds that fly over the power plant site.

We're nowhere near the point where that would make sense, but it could let us harness more than the earth's surface area of sunlight for energy production.

It will probably have to wait until after we plunge ourselves into some a perpetual winter trying to mitigate climate change. Of course, a ring world or dyson sphere would make it obsolete.