> Solar and wind are cheap, but intermittent. Batteries can help store energy from day to night.
You don't need batteries per se, only energy storage systems.
Pumped storage, pressurized air, flywheels, ultracapacitors, and of course chemical batteries. Pumped storage and compressed air systems store orders of magnitude more energy and power than batteries.
> You don't need batteries per se, only energy storage systems.
That's true, but there are synergies. We will need lots and lots of batteries for electrifying the transportation. There's lots of R&D money in battery research. Much less in other types of storage. There's all the reasons to believe batteries will become cheaper in the long run by a factor of 2, or even more [1]. There are also a few advantages that batteries have over other types of storage: they don't have moving parts, they have quite high round-trip efficiency, their maintenance is cheap, the failure mode is not that bad.
Realistically you want different types of batteries for grid-scale or even home scale storage and transportation. With static installation mass and volume are little of concern, where as with transport they are critical. On other hand scale is also big difference. And lithium batteries in current form do have many risks. I can't even imagine what sort of project it would be to even control a fire in grid-scale installation...
We don't need a small volume. A water reservoir up a hill stores lots of energy efficiently. Iron-air batteries, when fully charged, are just a lot of pure iron.
Lithium, when it burns produces gaseous lithium oxide, which becomes lye, drain opener, when it gets to your nose.
You need systems with different performance for different problems. In particular although spin-up time for pumped storage is much better than for fossil fuels (pumped storage may be able to go from nothing to 80% power in under a minute, lots of coal stations take an hour, combined cycle gas might be 20 minutes) you can't sit around for a minute or the lights go out, batteries can do that same-cycle balancing you need to give other systems time to come online.
Pumped storage in particular is also geographically dependent. If you've got lots of spare lakes on mountains, pumped storage is just what you needed, if you're the Dutch not so much.
Pumped storage has a serious problem: you can’t build it just about anywhere. There is very limited number of sites, and the most practical ones are already built out. This also ignores the issue of environmentalists being almost certain to block destroying entire valleys or mountain ranges.
There are hundreds or thousands of times as many places to store pumped hydro as there are places to put hydroelectric dams. The latter needs a river valley and a watershed. The former only needs an elevated basin. An elevated box canyon would do; you just build a dam across the end. Sometimes, you dig a pit, or build a dam all around a flat hilltop.
Furthermore, underground reservoirs have been demonstrated, in both natural and abandoned mining cavities.
A hollow sphere anchored to the sea bed can have the water pumped out with surplus power, and allowed back in to generate power.
Draining water from an elevated reservoir to a deep underground cavern can multiply the energy storage capacity. Height is strictly limited to hill height, but underground cavities may have any depth, to the limits of drilling.
what you can do is retrofit existing hydro dams, add more generation capacity (penstocks/turbines) and then let them fill when the sun shines/wind blows and empty when it doesn't, this is actually more efficient than pumping water uphill
I'm personally a huge fan of carbon capture -> synthetic hydrocarbons + fossil fuel plants, in theory.
Maybe a mix of storage systems will ultimately be the best solution for whatever reasons, but this idea makes so much sense to me because of how it takes advantage of all of our existing infrastructure. Just stand up renewables at existing plants, use spare capacity to power capturing CO2 from the output and/or the air, formulate the captured CO2 into a usable fuel on site, and then swap out the dirty fuel supply for the synthetic one. Now you have the functional equivalent of renewables + batteries — with the advantages that the plants are already built and wired into the grid, battery supply is no longer a bottleneck to rollout, and a lot of jobs are saved. So as a whole, as I see it, this would be faster, easier to plan, less wasteful, and more politically viable, as compared to replacing existing plants with brand new renewable ones that use battery storage.
The same concept applies to vehicles. Our entire infrastructure around gasoline is already sitting and waiting to be used as a massive energy storage system. If carbon could be captured from the air using renewables and centrally processed into a backwards-compatible fuel, it would no longer be necessary to push so heavily for a transition to BEVs. Instead, consumers could choose solely based on the costs and benefits to themselves; maybe gas cars would be less efficient than BEVs (like the equivalent of running an app in Wine or Rosetta), but that would be reflected in the price of the fuel if so, with consumers eating the full cost rather than passing part of it along to society as a negative externality.
Ditto for existing gas-powered stoves, heating, etc.
Additionally, once it's running at scale, this system would naturally lend itself to the next step: transitioning from net-zero emissions to net-negative emissions. Governments could allocate funds toward buying carbon capture fuel and simply sequestering it away for emergencies, at least until atmospheric CO2 drops to pre-industrial levels. Maybe the same method would prove useful for terraforming other planets with inhospitable atmospheres as well.
I'm very interested in seeing how United's experiments with synthetic fuel go for these reasons. Last time I brought this topic up on HN, someone shared Prometheus Fuels with me: https://en.wikipedia.org/wiki/Prometheus_Fuels.
Does anyone know how far along this kind of technology is? What factors have prevented the idea from already being implemented in traditional power plants at scale?
Imagine a lossless conversion from electricity to making hydrocarbons from atmospheric co2. Car engines are very very inefficient (about 35% of chemical energy converted to mechanical, out of a theoretical max of 46% or so iiuc.) comparatively, electric motors are like 80% efficient.
Now it’s true that bev have transmission and battery losses, but synthetic gasoline is going to have inefficiencies and cost to transport, too.
The case wher e it makes sense is where the weight of batteries matter, ie: jet packs and airplanes.
If internal combustion cars powered by renewable synthetic fuel could be anywhere near half as efficient as BEVs, wouldn't that be a great problem to have?
"Imagine a lossless conversion" is obviously doing a lot of work here, but even if they're only 1% as efficient end-to-end as BEVs, that would still be fine in a world where we had more renewable power than we needed without the capacity to store it all. BEVs would eventually be pushed to dominance by market forces, while in the meantime we would accelerate our transition to net-zero emissions.
I mean, if it were up to me then right now. Whenever the technology is sufficiently mature that it's only a matter of giving companies like Prometheus the capital they need to scale up production (if it isn't already), I would do that.
You don't need batteries per se, only energy storage systems.
Pumped storage, pressurized air, flywheels, ultracapacitors, and of course chemical batteries. Pumped storage and compressed air systems store orders of magnitude more energy and power than batteries.