How easy is to write $1T, but with that you can basically install enough solar cell to power all of USA energy need.

Here's some rough numbers, hopefully i haven't made any mistakes:

Total US energy generation 2021: 4 trillion kwh

Average power generation: 457Gw

Cost of Topaz solar farm: $2.5bn Potential output: 550 Mw Cost per Mw $4.5m

Spend a trillion on similar capacity, you get 220Gw potential output.

But that's assuming you get 550Mw average. In fact, it produces about 1282Gwh output a year, so average is more like 145Mw.

So at a rough estimate, you need more like 10 trillion to meet US electricity demand. And that assumes you have unlimited battery storage for free.

And of course electricity is a small minority of total energy use.

Incidentally, I think it's amazing you get to about 10% of total electricity needs with only $1tr, i.e. around 4% of US national output.

https://en.wikipedia.org/wiki/Topaz_Solar_Farm https://www.eia.gov/energyexplained/electricity/electricity-...

```python trillion_dollars = 1e12

mw = 550

cost_farm = 2.5e9

cost_dollar_per_mw = cost_farm/mw

num_mw = trillion_dollars/cost_dollar_per_mw

num_gw = num_mw/1000

num_gw

kwh = 4e12

mw = kw/1000

gw = mw/1000

gw ```

Don’t forget that, 1 trillion can get you lots of leverage and cost benefits In installation and solar panel production. I’ll do it for 1 trillion.

> Cost per MW: $4.5m

That's quite high. Here in Germany they assume 530-800€ per kW_peak for a utility-scale ground-mounted system (2021) [0]. You can add additional CAPEX for inflation and expansion of the grid, but <$1500 per kW_peak (aka $1.5m per MW) should be quite possible. Especially if you include scaling effects.

If you add batteries for night-time balancing, LCOE roughly doubles for now.

Economically, no other energy source will beat non-winter day-time PV in the foreseeable future. Imo, as long as other plants are running during those times, investing in PV is a no-brainer.

[0] https://www.ise.fraunhofer.de/en/publications/studies/cost-o...

No you can't because solar isn't a continious source and fusion is.

No amount of investment into solar power can make the sun magically shine 24 hours a day.

Of course you can invest enough and make solar equivalent to continuous power.

Solar + reverse hydropower, solar + synthetic fuel manufacture, solar + appropriate sized batteries, solar cranes-with-weights, etc.

Solar is so cheap that all those are plausible. Fusion is still far from ready.

I suggest we do not lay all of our eggs in one basket. Climate change can be best countered if we use the sweet spot of all current available and anticipated technologies, including photovoltaic, long & short term storage solutions, and fusion. There is no need to bet on one technology at this stage.

There is a market need.

Solar panels are cheap and the market appears to be fine with unreliable power[0] if it's cheap enough.

[0] Unreliable, but predictable that is. You can estimate with decent confidence what the weather will be like tomorrow and you can definitely tell what it's going to be a few hours from now, so energy auctions a day ahead are feasible.

Do you have week long blackouts currently? In any given year you can count on a week where a panel only produces 10%. It just has to be cloudy or rainy. However much solar we add, even with storage to get through a night, needs some other source to get through the cloudy week, unless we are ok with blackouts.

A panel. Panels spread over hundreds of thousands of square kilometres produce power averaged over that area, so they're much more consistent and predictable.

HVDC lines help with this a lot. It has gotten to a point where there are serious plans to build a long, undersea HVDC line from the UK to Morocco which, get this, is poised to cost less than the equivalent(GWh delivered annually) Hinkley Point C nuclear power plant:

https://xlinks.co/morocco-uk-power-project/

That's how cheap the combination of solar and HVDC is.

Glad it will work there. There has been local opposition to new transmission lines in the USA (see Maine recently) so when folks say “just build powerlines” all I can think of is the difficulty of the land assembly and permitting. Technically it is easy, it is all the humans in the way that make it hard.

I mean, you could literally build a ring of solar power collectors and microwave transmitters in orbit. It would always have 50% coverage.

Or just have a bunch of power lines running east-west.

Energy storage is not an unsolved issue.

Batteries

<during the day>. $1T doesn't buy nearly enough batteries for the storage we would need.

We should be installing more solar & wind, but that alone is not a solution to our problems.

Fusion can give us 10x our energy need. Imagine a world where energy is simply not a blocker for anything.

Solar can't do that without massive batteries that don't exist. Even then it's not viable in areas where there isn't sufficient sunlight.

The batteries do exist, but it’s better to use them in cars. If we start diverting our battery supply for grid storage it will drive up the price of EVs.

Will not be a silver bullet, electricity production contributes less than half of global CO2 emissions. Still need other solutions for transport, industrial processes, agriculture, etc.

Further, it's possible that fusion plants might be prohibitively expensive to build and maintain, even if their fuel is cheap.

People should understand that it is all an energy problem, regardless of how that energy is currently delivered. Transportation can be (and, of course, is being electrified), most industrial processes and agriculture currently use fossil fuels as inputs because its the cheapest source of input.

For example, nitrogen fixation for fertilizer currently uses natural gas almost entirely for the source of hydrogen. Vastly cheaper energy means it would make much more sense to switch this to electricity, https://www.frontiersin.org/articles/10.3389/fenrg.2021.5808....

But I agree with your sentiment, there are a lot of engineering details to consider before one can shout "free energy".

If there’s a glut of cheap electrical energy, there would be a rapid push to electrify things like iron and steel production (8% of emissions), heating (10% of emissions) and transportation (10%)… and so on.

I’m not thinking about just replacing grid energy, but carbon removal. If we can get fusion scaled up and efficient it should be no sweat to use it to just remove carbon from the air

In fact carbon removal might be a great way to subsidize fusion at the outset so that it can be overprovisioned/have a guaranteed minimum price

$600 per ton of CO2. The industry is trying to get to $100 per ton of CO2.

Energy estimated is 1,200 kilowatt-hours per ton of CO2 removed.

Nuclear fission energy averages 0.4 cents/kWh. That's $480 in energy costs alone (ignoring profit margins for removal, etc).

Why would bleeding edge fusion that requires cutting edge lasers, magnets, and various other containment stuff have a cheaper energy generation cost? I could be wrong, but I don't think nuclear waste (which is the primary difference with fusion) is the primary cost contributor. So why would you want to invest in more expensive fusion to remove all this carbon instead of cheaper fission? Nuclear waste by the way isn't waste. It can be reused in breeder reactors and it's used a lot in medicine (I could be wrong but one of the reasons nuclear imaging has gotten more expensive is because radioactive materials are more difficult to obtain due to reduction in global fission energy).

Those are figures for current electrical production schemes.

After decades of R&D fusion should become significantly cheaper than fission per kWh if only due to having less of a regulatory burden and smoother permitting process.

It’s more expensive now, but in the long run it will be cheaper.

You hope. It’s not “more expensive now”. It’s infinitely more expensive because we can’t even build one. It’s unclear how much a fusion reactor will end up costing but I wouldn’t use hope to blind myself into thinking it’ll be 10x cheaper than fission. There’s certainly reason to be hopeful because solar and wind are cheaper, but construction for those is also relatively simple and easy to mass manufacture most of it. Fusion reactors will probably look more like fission than not (ie complex to mass manufacture, still require complex structures, need regular complicated maintenance due to radioactive decay in the containment materials etc). Additionally, solar and wind don’t pose real threats to established fossil fuel interests. Fusion would and it’s unclear how they might respond from a regulatory hurdle perspective.

Fusion plants should be able to save a lot of money though simpler permitting processes, not needing the same level of containment structures, needing less security, and less regulator scrutiny. The equipment itself might be more expensive at the start but if we build these plants at scale those costs should reduce over time.

The first commercial reactor designs are probably 50 years away and another 50 years before costs come down to be reasonable / we can build enough to start replacing existing fission and coal. This is from the CEO of General Fusion a leader in the space. I think if even the fusion people are saying “build fission today to solve global warming” then that tells you something about the time scale this is happening on.

I suspect the regulatory environment is from regulatory capture by the fossil fuel industry. Otherwise why would Gen IV reactors, which can’t meltdown, be suffering many regulatory delays? What kind of nuclear proliferation concerns exist for reactors built and deployed within the US?

Most of those other things you mention can be electrified with current technology. Once that happens we'll need the electricity to power them.

There are a lot of bigger picture items around energy. Part of Europe's challenge with the war in Ukraine is that a lot of countries buy Russian gas & oil.

>Russia accounted for about 55% of Germany’s natural gas imports and 35% of Germany’s oil imports last year, causing Germany to resist a blanket European Union ban on Russian energy.

If every country could assure their energy independence, geopolitics would look very different. Yes, there are still many problems, like natural resources. But if you can assure all your residents can keep the lights on, their houses warm and the economy moving (EV's for transit, technology)... its very reassuring.

Cheaper and cleaner energy has never in the history of enery lead to global reduction of pollution, actually pretty much the opposite. Plus, nuclear power is already virtually free and has been available since the 1970s. If stopping climate change was an energy source problem, it would have already been solved then.

I’m not anti fission. But the reality is that many are and the NIMBY effect is strong. You don’t necessarily have that with fusion.

Also, there should hopefully be much less pomp and process around fusion compared to fission due to the safety/radiation profile being much safer.

“nuclear power is already virtually free”

What? Cost is THE problem with nuclear energy.

You must have some bizarre way of framing things to make today statement - you should at least tell us what that is since you must know that you are making a controversial claim.

Basically the only energy that is cheaper and cleaner than fossil fuels is wind and solar, which have only gotten to that point in the last 1-2 decades, so it seems difficult to make claims about what has happened in "history".

With abundant electricity wouldn't we face another type of global warming? We will would start to consume so much electricity that this will heat up the planet?

Relative scales of various factors matter here:

We aren't "heating up the planet" .. we're "insulating the atmosphere".

Increased C02 (and the close following methane and water vapor increases) serve to trap more of the heat radiated outwards that would otherwise escape.

The vast bulk of that heat comes from the visible light of the sun which passes easily through the atmosphere coming in, gets converted to IR energy as it warms the earth and oceans, and then escapes outwards.

Our changes to the atmosphere have disturbed that balance.

Your comment has some small merit, but you would need to work through the heat output of human generated power and then compare that to the daily heat energy originally from the sun that radiates outward.

> We aren't "heating up the planet" .. we're "insulating the atmosphere".

We are doing both. We are doing more insulating than heating, but we obviously generate more heat.

Did you actually read my comment to the end?

If so, how'd you do on the numbers?

Of course I did. It is rude to suggest otherwise. Your blanket assertion followed by your long explanation is confusing and less helpful to anyone asking the original question than it would be without it.

Good, so by what rough order of magnitude does the sun heat us up more than human power generation then?

Is it x10, x100, x1000, .. more?

This is after all the part that matters.

I have no idea. Obviously we get more heat from the sun than we generate on our own. That does not make your blanket assertion true.

The original question is a good one. We will use more energy as it gets cheaper (see monster trucks, Las Vegas, Dubai). We should be thinking of what we will do with the waste heat when everyone has a fusion reactor.

Your repeated assertion that I made a "blanket assertion" suggests you're either someone with english as a second language or else someone who stubbornly digs in (unless there's another explanation here?).

To be clear I made a qualified assertion; the phrase "Relative scales of various factors matter here" does the work.

> Obviously we get more heat from the sun than we generate on our own.

Yes - but, again, How much more?

If it's barely twice as much (which seems unlikely) then heat from our activity is a major factor in all this.

If it's 100,000x times more then I stand firm, heat from our activity has effectively zero impact on the AGW issue (although other by-products from our daily routines are the crux of the problem).

If it's some other factor then what relative signifigance does our human heat generation have?

> I have no idea.

It's a shame you didn't grab an envelope and make use of the back, it's a classic Fermi problem [1] of the kind I and my class mates were posed in high school and the kind of thing many other HN commeters would delight in taking a run at.

If you're feeling game you might like to start with the daily heating of the earths surface from the sun, and then look at the petajoules of energy generated and consumed per day and take a stab at guesstimating the waste (unused, released into the lower earths surface layer) heat as a percentage (or google efficiencies, etc).

Have fun!

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

Stubbornly digs in, indeed.

I'm not going to set my thermostat to 78 degrees because electricity is practically free.

But some people would start driving 6 ton vehicles because fuel is free. Limiting factor for crytpo mining would be only number of hardware you can get (provided crypto survives for so long). Some people would probably do the math and decide that thermal insulation is too expensive, and run heating/cooling on max. I could probably come up with more examples.

EDIT: from quick google query it looks like per day earth receives equivalent of yearly power consumption (not only electricity but also fuel). So we would need to x356 our energy consumption which is not that much unreasonable if you could have for example heated outdoor pool for free anywhere in the world.

Way more than that. This would shift the entire geopolitical structure of the world. Humanity would never be the same.

Good riddance.

> silver bullet to stop climate change alone

nothing will stop climate change. The earth’s climate will continue to change regardless of any human interventions

LMAO. Good luck to get funding passed through GOP-controlled congress with all these oil and gas companies rallied behind. There is zero chance that the USA will ever do that.