this post was submitted on 17 Nov 2024
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What isn't sensible about nuclear? For context, I'm coming from the US in an area with lots of empty space (i.e. tons of place to store radioactive waste) and without much in the way of hydro (I'm in Utah, a mountainous, desert climate). We get plenty of sun as well as plenty of snow. Nuclear should provide power at night and throughout the winter, and since ~89% of homes are heated with natural gas, we only need higher electricity production in the summer when it's hot, which is precisely what solar is great for.
So here's my thought process:
If we had a nuclear plant in my area, we could replace our coal plants, as well as some of our natural gas plants. If we go with solar, I don't think we have great options for electricity storage throughout the winter.
This is obviously different in the EU, but surely the nordic countries have similar problems as we do here, so why isn't nuclear more prevalent there?
Because it makes no sense, environmentally or economically speaking. Nuclear is, as you said, base load. It can't adjust for spikes in demand. So if there's more energy in the grid than needed, it's gonna be solar and wind that gets turned off to balance the grid. Investments in nuclear thus slow down the adoption of renewables.
Solar is orders of magnitude cheaper to build, while nuclear is one of the most expensive ways to generate electricity, even discounting the waste storage, which gets delegated the the public.
Battery technology has been making massive gains in scalability and cost in recent years. What we need is battery arrays to cover nighttime demand and spikes in production or demand, combined with a more adaptive industry that performs energy intensive tasks when it's abundant. With countries that have large amounts of solar, it is already happening that during peak production, energy cost goes to zero (or even negative, as traded between utilities companies).
About the heating: gas can not stay the main way to heat homes, it's yet another fossil fuel. What we need is heat pumps, which can have an efficiency of >300% (1kWh electricity gets turned into 3kWh of heat, by taking ambient heat from outside). Combined with large, well-insulated warm-water reservoirs, you can heat up more water than you need to higher temperature during times of electricity oversupply, and have more than enough to last you the night, without even involving batteries. Warm water is an amazing energy storage medium. Batteries cover electricity demand as well as a backup in case you need uncharacteristically much water. This is a system that's slowly getting adopted in Europe, and it's great. Much cheaper, and 100% clean.
You bring up heated water as a method of storage, and it reminds me of a neighborhood in Alberta, Canada that uses geothermal + solar heated water storage for 52 homes. They've been able to successfully heat the entire neighborhood with only solar over the winter in 2015-2016 and have gotten > 90% solar heating in other years.
https://en.wikipedia.org/wiki/Drake_Landing_Solar_Community
There's a huge number of new storage technologies being developed, and the fact that some even work on a seasonal basis for long term storage is amazing.
That's pretty cool! Still seems to have some issues, but as the technology matures, that seems like a promising technology. I didn't know seasonal warm water storage was a thing
We also should consider HVDC lines. The longest one right now is in Brazil, and it's 1300 miles long. With that kind of range, wind in Nebraska can power New York, solar in Arizona can power Chicago, and hydro all around the Mississippi river basin can store it all. We may have enough pumped hydro already that we might not even need batteries, provided we can hook it all up.
HVDC is much more expensive than Hydrogen pipelines, which doubles as storage and transmission, and can provide continent wide resilience, even when local renewables provide much cheaper power when it is available than either long distance electric or H2 power.
The studies on hydrogen pipelines tend to assume there's some existing reservoir of hydrogen. Making hydrogen in a green way is expensive, and that completely ruins its economic viability.
The expense part gets taken care of with OP's solar prices. Battery costs help too.
Not at all. Hydrogen electrolysis efficiency is about 70-80%. When turning it back into electricity, fuel cells are 40-60% efficient. That means your electricity costs are about double for the complete round trip.
Conversely, lithium batteries (and most other types) are over 90% efficient and directly give you electrons.
The difference is that the electrolysis can be done at producer convenience. Sometimes wholesale electricity prices (midday due to high solar penetration) are negative or ultra cheap. Transporting H2, even by truck, can be cheaper than the US typical 8c/kwh electric transmission charge. For many areas, enough solar in winter has 3x more summer production and essentially unusable. A balance of solar and H2 produced in summer, can provide the cheapest necessary energy for winter. An alternative is summer exports with winter imports.
Batteries alone are also subject to curtailment, or not enough charging in winter. H2 can be stored at $1/kwh, where a pipeline is free transmission of withdrawals different from deposit locations. The energy efficiency round trip is less important than the $ efficiency of energy delivery.
I absolutely agree. My support for nuclear is not instead of renewables, but in addition to it. Nuclear is a proven technology, and at least in the US, we have a lot of space where we can store waste relatively inexpensively (nobody's going to care about a massive landfill in Nevada).
The problem with going for 100% renewables is that I don't think we can really keep up with battery production, and if we push for dramatically increasing our energy storage capacity (whether that's chemical batteries, pumped hydro, etc), it's going to cost a ton to transition. Solar is cheaper than nuclear, but solar + battery backup currently is not, especially if it needs to run over the winter when solar generation is much lower.
I'm not saying we should stop installing battery-backed solar projects, but that we should add nuclear to the list. Our electricity demand will only continue to increase, so we need multiple solutions to replace coal and eventually natural gas. One of the major cost and time limitations for nuclear is construction, and that's because we don't build many of them. If we line up multiple plant projects at the same time, we can make better use of our engineering resources (it's a lot easier to build 10 of something back to back than 10 of something months or years apart), which will make nuclear more attractive compared to other options.
Agreed, and I've actually been looking into heat pumps for my own home. I already have an external AC unit, so theoretically the transition shouldn't be that hard (air ducts already exist).
The problem is that, in my area, winters get pretty cold, and heat pumps are a lot less efficient at heating when it's cold. The solution is to dig a deep hole to bury the heat exchangers so they get a more consistent temperature to maintain efficiency, and that's a really expensive project for existing structures (not bad for new construction). The transition to heat pumps is going to be very slow because of that large upfront cost/poor efficiency in winter.
Even if this wasn't an issue, there's still the massive problem of existing electricity production (in my area) being fueled by coal and natural gas. If I switch to a heat pump, I may be polluting more than if I stuck with gas (it's pretty close last I checked). My state (ignoring transportation) gets something like 1/3 of its energy from coal, about half from natural gas, and most of the rest comes from solar (and a little from wind). We need something to handle that base load supply, and installing batteries is going to be expensive (esp. since hydro isn't really an option in our desert) and probably take many years regardless. Nuclear can be built today, and in my area, it can be built on the other side of a mountain range from the bulk of the population.
I doubt we have enough water here in the desert to handle that. We already have problems with our existing inconsistent water supply for regular users, locking up even more water is going to be a really tough sell.
I agree it's going to be a challenge. But I'm sceptical nuclear is going to help there; from historical experience, it takes upwards of 20 years to build a reactor. Even if that gets expedited through modern technologies, we're still talking something like 15 years until they come online, and you're still paying all the upfront costs throughout that time. Whereas solar can go from concept to grid in 2 years, and batteries aren't much worse.
The desert indeed makes large-scale warm water storage infeasible, but the kind of home setups I mentioned first should still be good to go, it's basically only your preexisting heating loop times 2 or 3, that's negligible compared to farming demands, and it stays in the loop forever (except for leakage). Storing warm water that you'd use anyways also doesn't increase demand.
The desert has the benefit that solar can be really well calculated, since you (mostly) need to consider seasonal changes in sunlight, not cloud cover. That can be planned around
You got a point about the heat pump efficiency though. For new communities there should be a trend towards centralized heating that provides for a whole city block, to make use of economy of scale and raise efficiency beyond what is reasonable for a single home. But that's dreaming to far, probably
From some reading, it seems a lot of that is bureaucracy (non-safety related), construction delays, and lawsuits. I wouldn't be surprised if we could get that down to 10 years average with a concerted effort, assuming we can build multiple in parallel.
Sure, on a small-ish scale. A nuclear plant will put out way more electricity than a typical solar project will. So while the time to getting value from it will be a lot shorter w/ solar, they tend to chip away at existing infrastructure instead of completely replacing plants.
Oh yeah, solar is incredibly effective here, the main problem is storage. Hydro isn't really a thing since our dams are intended to keep water for summer use, and they refill when we'd want to be generating power. Warm water also isn't feasible at scale, and promising technologies still aren't proven. I'm especially interested in hydrogen storage, since it could be really useful for long-haul trucking (we're a pretty big hub for that) in addition to storage for winter generation.
I was interested in EVs being used for overnight power storage (basically recharge during the day while at work), but it seems like that hasn't materialized.
I don't think we'd need to go that far, putting in buried heat exchangers on new construction isn't that expensive, and I'd expect coordinating billing and whatnot would be more annoying than it's worth (need an HOA, and HOAs can really suck).
The better option, IMO, is to create mixed-use zoning near transit hubs, which would encourage use of mass transit and allow for those economies of scale you're talking about without annoying planned communities w/ HOAs (i.e. business below you could pay your heating/cooling bill). Maybe that's what you were getting at, my point is that it doesn't make as much sense for residential areas IMO, but it could make sense for mixed zoning areas.
I do want to point out that I'm not obsessed w/ nuclear or anything, I just think it's a good option to replace existing base-load plants running on coal and natural gas.