Imagine if we went the other way: "they spent billions on solar infrastructure, so that they could keep the lights on only when the sun was shining".

We don't have the storage. We are not close to sniffing the amount of storage we need to be 100% reliant on solar + wind.

To get a sense of scale: The USA uses on average ~76 twh per day. Tesla produced ~100 gwh of batteries over the whole last year.

So if we nationalized all the tesla gigafactories, it would take us over 760 years to produce enough batteries to store a single days worth of electricity.

I do not think grid storage is solvable with current technology.

So don't use batteries. Pumping water uphill is still the most efficient large-scale technology for electrical storage.

Pumped hydro is a lot more promising than batteries for sure, in that current capabilities is off by a factor of a thousand instead of a million.

The largest pumped hydro station[1] provides up to 24 gwh of storage. So three thousand of these stations (costing $12 trillion) would store one day's worth of electricity.

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

Agreed that pumped hydro is the most efficient storage solution but it's limited by geography: You can only do it where there's an existing significant elevation change. Building a sufficiently elevated lake artifically by heaping thousands of cubic kilometers of dirt is not cost-effective. That is, the energy that would be required to build it would vastly exceed the total energy it could store integrated over its lifetime.

> That is, the energy that would be required to build it would vastly exceed the total energy it could store integrated over its lifetime.

Storage ‘buys’ energy when it’s cheap and ‘sells’ it when it’s expensive, where ‘cheap’ can even mean ‘free’ at times.

You would build it using averagely priced energy (using only cheap energy is impractical, as it would keep machines and personnel tied up waiting for prices to drop)

Also, having a large buffer can mean having to spend a lot less money on excess solar and wind farms. They wouldn’t have to meet all peaks in demand.

Those still could make it economically viable.

Yeah building mountains is not a realistic solution. Thermal storage is probably the best replacement where pumped hydro isn't feasible.

Inventing absurd versions of sound ideas just to have something to criticize is such a standard dishonest argument mode as to have been named.

We all know the name, but its main feature is its dishonesty.

What's the sound idea for build pumped hydro storage on flat land?

There is such a thing as a water tower, but that also is probably not practical utility-scale energy storage.

The sound idea is water stored up an existing hill. On flat land you store your energy some other way: underground hydrogen or compressed air, or iron-air batteries, or liquified air, or any of various other choices that are more expensive and less efficient than pumped hydro. Or just run a wire over to someplace that does have hills.

It is a good thing, then, that pumped hydro is not limited to existing dams, or even to places where a hydroelectric power station would be practical. Pumped hydro does not need the large watershed and elevated river valley a hydroelectric dam needs. All pumped hydro needs is an elevated depression somewhere not too porous. There are myriads of those, and building a penstock up to one is very cheap.

Some places have no hills, so are not candidates for pumped hydro storage, and would need to rely on something else, such as long-distance transmission lines, or liquified air, or synthesized hydrogen, or synthesized ammonia, or underground compressed air, or iron-air batteries, or numerous others, or (most usually) some combination of them.

What a terrible argument. A global energy supply system is a huge thing. That means it will make sense to spend literally trillions of dollars on it. This will mean building enormous capacity to build its components, including as many battery factories as we need.

Once we agree that the solar + wind solution will cost trillions and take decades to scale up anyway, the benefits of fusion start to shine through. We may as well invest all that time and money in scalable production that doesn't exhaust the earth's supply of natural resources.

That sounds like a proposal for just not de-carbonizing until fusion is ready. Is that what you mean? When do you think we could have say 5% of the worlds power coming from fusion reactors?

I'm happy to increase renewable energy production where possible. My point is that saying "we can just be 100% solar" is just as impractical and far fetched as saying "we can just be 100% fusion".

Renewable advocates would be more successful if they were realistic about the problems with significant solar reliance.

I disagree. 100% solar is much less far-fetched than 100% fusion, because the latter is a much larger technological and economic stretch.

What benefits? The fusion solution would be even more expensive, and not available for decades, if ever.

We do not have enough energy storage capability to rely completely on Solar and Wind yet. Both are intermittent producers so to get truly reliable power from them we need storage capacity. There are projects that promise to meet that need but positioning solar and wind as all we need is not a true statement.

> We do not have enough energy storage capability to rely completely on Solar and Wind yet.

How is this an interesting argument? Of course we don't have things before we build them. That's true of nuclear power plants, too. We can likely build out storage faster than NPPs, with more aggressive cost decline with cumulative production.

>We can likely build out storage faster than NPPs

First, this is yet to be determined. Even assuming it is true, which I'm not sure it is, The problem is not limited to storage - you also need massive transmission system upgrades that will cost on the same order of magnitude as an Apollo program. I think in the long term it should certainly be done, but pretending that the cost of solar and wind power is the cost of solar panels, or even the cost of solar panels + storage is not comparing apples to apples.

Energy is huge. The world will likely spend the equivalent of approaching a quadrillion dollars over the next century on energy. The Apollo program, in comparison, was less than a rounding error.

We are down for many, many times the cost of Apollo, regardless. The only question is how much available power we will get for that. The very best one running is solar+wind+storage, far ahead of the others.

I put numbers in another comment, but this isn't a "just build some more batteries" type of problem. The scale of storage needed completely dwarfs our current production capacity. This problem cannot be solved in the near future, with current production/technology.

It is dishonest to pretend batteries are the only viable storage method.

Yes dispatchability is an issue with renewables. We need more transmission too. Both can be solved (and are being solved) with existing technology today, and both are improving all the time. It's both practical and economical today to build an off-grid house with PV and enough Li-Ion storage to bridge the nighttime gap and charge an EV.

With distributed electricity generation e.g. microgrids, the need for big, centralized storage decreases, as does the need for large-scale transmission.

By the time fusion generators exist in a practical form (at least 20 years from now), we won't need them.