Sustainable Energy, USA and worldwide

If you get a rooftop solar system you're probably going to get a battery to go along with it (Tesla bundles its Powerwall with solar), and we've already discussed the potential use of electric vehicles as an assist to the grid.

Further, grid-scale batteries are already replacing natural gas peaker plants in many areas.

Without home batteries, rooftop solar supplies surplus electricity back to the grid during peak generation hours, allowing homeowners to get rebates on their bills and balance out the periods when they are drawing more power than their panels supply. With a battery, a home can be almost completely self-sufficient.

Edited by Fighteer on Mar 5th 2021 at 11:28:47 AM

The fact that tesla can market people into buying the storage, does not change the fact that local solar + storage is an insanely expensive and resource intensive solve. The same amount of money is spent, whether by end users directly, or the utility. Again, it makes no difference that the infrastructure happens to be physically located at a private residence. Heck, due to practicalities, it makes things more expensive.

And also, no, batteries are not replacing gas. Batteries are being deployed as ultra-fast grid response for the very most transient demand peaks. Good news for quality of grid service, but utterly irrelevant for carbon intensity.

You're not paying attention. Batteries have been replacing natural gas peaker plants all over the world and the adoption rate is accelerating. While it's not the only company making them, Megapacks are one of Tesla's most successful energy products to date and deployment is growing at a pace comparable to electric vehicles, if not faster.

Sure, but there's a hard cap on how far $10000+ storage systems can spread. Ordinary working folks cant afford that.

Megapack is grid-scale. Powerwall is on homes. You can't build a gas peaker plant in your backyard either so I don't know why the comparison is even coming up.

Edited to add: That said, Texans who just got $10,000 electricity bills would probably think a home battery is a pretty good investment at this point.

Also, for apartments and other large buildings, Powerpack is a product (again, going with Tesla since it's the most familiar to me) targeted for those situations. It's not a grid storage system but rather a battery backup for an entire building that can keep the lights on through blackouts and other disasters.

Edited by Fighteer on Mar 5th 2021 at 3:22:44 PM

Bah, this is Texas, we don't need no fancy lecktricky gizmos when we got a big honkin' diesel generator fillin' our lungs with carbon monoxide!

I hate to say it but that's just plain not true. Australia is the perfect counter-example. We are major uranium exporters, have the world's largest reserves and do technically have the capability to build and run a nuclear power plant since we do have one. And only one. (The Open-pool Australian lightwater reactor aka OPAL at Lucas Heights). Most of our power if from coal and gas plants. Some hydro with the Snowy Mountains Scheme and despite having large potential for solar and wind they still make up the minority of our production.

Actually, I think you are supporting his point. With only one reactor, Australia clearly has not chosen to invest heavily into nuclear as a power source. So they run coal instead.

That's not what was said. The exact statement was "so any nation with nuclear technology and the access to uranium will run those in stead of coal"

It's an "If A is true and B is true, C automtically follows" statement with A being access to reactor technology and B being access to Uranium and C being preference for nuclear power plants over coal-fired. Except for Australia A and B are both true but fact that Lucas Heights is the only reactor in the country means that C is categorically not true.

Edited by KnightofLsama on Mar 7th 2021 at 7:08:41 PM

Is hydropower that safe though? Don't dams really screw up ecosystems?

Edited by alekos23 on Mar 7th 2021 at 2:07:40 PM

It depends where they are built, if you’ve got a pre-existing dam then you’re find, if you’re generating the power using a self-contained water cycle without fish you’re also pretty safe.

It becomes an issue when you dam a major waterway, limiting fish migration and creating a giant reservoir in an area that previously had another use.

That’s why hydro is so limited by geography, not because we lack places to put hydroelectric dams, but because we lack places to put them that wouldn’t cause massive ecological knock-on effects.

Edited by Silasw on Mar 7th 2021 at 12:25:26 PM

Also note that Australia has been investing heavily in grid-scale batteries to manage peak loads, and that those have been stunningly successful thus far.

@Fighteer: Because Australia really doesn't have a winter. The same approach won't work in, say, Michigan.

@Knight: You forgot this part: "Nuclear is way, way too expensive to not run 24/7". IOW, first you have to build it, then it becomes too expensive not to run 24/7, and it delivers greater ROI than coal. The reason people stick with fossil fuels isn't because it's cheaper to produce energy that way (it isn't), but because it's cheaper to build in the first place. But if you meet the up front costs of nuclear and build enough plants, you will see a significant savings.

"Is hydropower that safe though? Don't dams really screw up ecosystems?" It does, and the other thing is that it just isn't available in very many places. Hydro, while a great source where it can be used, isn't going to fulfill more than a fraction of global energy needs.

Edited by DeMarquis on Mar 7th 2021 at 12:18:00 PM

You can use grid-scale storage with non-renewable power sources. The only thing you need to make them useful is power demand and power supply that aren't always in perfect sync. Also, why can't Michigan use solar power?

Michigan can and does use solar power, but what we can't rely on is grid scale electrical storage for an entire season, because nobody can, because they really haven't invented that yet.

Why would you need it for an entire season? Sure solar is less effective in winter, but it still works and so does wind.

Also, with as much cost as the state has it might be well placed to look at tidal power, which often gets missed between solar, wind and dam based hydro.

This is gonna be a weird question, were solar panels floating up in the Stratosphere where there's not as much clouds ever considered? I imagine just getting them up there wouldn't be practical.

@Silas: High use combined with low generation. It's the reason renewables are still a small fraction of overall energy production.

Edited by DeMarquis on Mar 7th 2021 at 7:25:01 AM

The problem is that you loose a fair amount of power if you have to move electricity much distance from generation to use. So even if you could get solar panels somehow gathering up there you don’t have en efficient way to get the power down.

Sure you’ll always get seasoned variance, the UK gets that, but we can still use solar, even if our grid can never be 100% solar. Wind is probably what we could theoretically go 100% on with proper storage systems, but realistically we’ll be looking at a mix of wind, dam based hydro, solar, nuclear and tidal.

Grid storage isn't a substitute for power generation; it is a load balancer. Obviously you can't run the grid for a week on batteries alone, but that's not a scenario that they were designed for.

You put energy into batteries when supply exceeds demand — this is usually when generation prices are cheaper — and you draw it out when demand peaks and generation prices are higher. This not only removes the need for peaker plants but makes electricity cheaper overall.

So I’m looking at the UK’s quarterly electricity generation mix, and it seems that we actually generate our peek “wind & solar” amount during quarter 1 of each year.

Now based on the UK’s climate that’s not going o be coming from solar, but it does indicate that in a northern latitude the seasonal drop in solar generation can be countered by a seasonal uptick in wind generation.

So you’d do your day-night balancing with batteries or pumped storage, and your summer-winter balancing with having strong capacity in both solar and wind.

Right now energy storage is the main barrier to expanding reliance on renewable energy. We are making progress, but we aren't quite there yet. An estimated 30 gigawatts of additional storage is needed in California alone to achieve a carbon free energy grid. Right now they are at 500 megawatts, and currently approved projects will provide an additional 1.5. The shortfall is worse for the US as a whole. The barrier isn't production, it's cost. In 2018 the cost of utility-scale battery storage $625 per kilowatt hour. For nuclear production, it's about $.096 per kilowatt hour (that's in 2014). Coal and gas are even cheaper.

It's cheaper to produce energy than it is to store it. That's the problem. Now, the reason we want to do this anyway are because of the hidden costs of "externalities", the principle one being carbon emissions. It's almost impossible to put a price tag on that, but historically, voters have been unwilling to significantly increase their energy costs in the short term in order to mitigate climate change in the long term. So— we are still hooked on fossil fuels.

Eventually, battery prices may come down to a competitive level with simply increasing production. Most of the current large scale energy storage systems utilize lithium-ion technology, and I don't know enough about that to say how much farther costs could fall. But that will take time, and we are out of time. If we can't build the storage now, we need to build low-externality production capacity that isn't dependent on storage, and that's nuclear.

Note that these are not mutually exclusive options. We should be investing in all of these technologies: renewable energy sources, storage solutions and new nuclear plant designs.

Really, we should have done all this 10 years ago, but here we are.

From what i understand about Australia, they burn coal because of a strong lobby. It doesn't really change the underlying math: coal and nuclear compete. Coal because it's too cheap to not burn, nuclear because it's too expensive to not run. Australia's just a place where coal beats out nuclear. Plus, the uranium there is on the expensive end of the scale to extract (unlike, say, Canada which also has very accessible reserves).

Anyway, the thing about powersources such as hydro is this: every watt you generate with hydro is a watt you don't have to burn fuel for. Every watt of geothermal is a watt you don't have to burn fuel for. It will require some extremely radical power overhauls to go full renewable, and i'm pessimistic that we'll even get that far (strong oil lobby and all that). But the future is an even more diverse electricity portfolio, not monopower.

In addition, climate change is also leading to new difficulties. Powerplants cool using rivers and seas, but with hot summers the cooling capacity is limited (for one, the "cold end" is a higher temperature bringing the efficiency down, and if you boil a river you kill everything in it and everything adjacent to it too, so the exhaust water can't be too hot). Airconditioning however leads to massive increases in electricity during the summer, meaning the worst situation for fossil power plants is summer (this situation might be different based on the nation). Solar power however is ideal during summer, so this is a case where renewable power sources also fix new problems.

>Really, we should have done all this 10 years ago, but here we are.

I mean the Kyoto protocol dates 20 years back, and popular discussion of the greenhouse effect dates from 1980, or 40 years.

Edited by devak on Mar 8th 2021 at 9:35:30 PM

By the way, I'm trying to find a news link, but Tesla is apparently building a Megapack grid-scale battery in Texas. So far it's just "news ticker" style tweets.

Edit: De Marquis, the point of battery storage isn't to generate power; it's to store it. The cost per kWh is misleading because it's not a one-time payment for the energy and that's it. To get the actual cost, you have to divide the price of the battery by the number of use cycles expected out of it.

To figure out the benefit, you take the expected difference between the cost of peak electricity with the battery vs. without it, then multiply it by the lifetime of the battery

So let's do some math. Our battery costs $500 per kWh and lasts 25 years. This gives a cost of $20/kWh/year. Let's say that in a given year it performs 100 complete cycles. Each cycle it takes electricity that was generated at $0.05/kWh and sells it to customers for $0.10/kWh. Those customers would otherwise have paid a peak rate of $0.30/kWh. The gross profit is 0.05 * 100 or $5/kWh/year, and the savings to end users is $20/kWh/year.

Not quite a break-even, but those hypotheticals are very hypothetical.

Edited by Fighteer on Mar 8th 2021 at 7:25:39 AM

That's true, but you're describing a household battery system, not a grid level one, which would respond to different price dynamics. If you're suggesting that power utilities are going to store excess power they produce during off peak periods, then sell it back to consumers during peak demand at the low demand prices, thereby reducing their profit margin, well, color me skeptical. That might even reduce their profits below operating costs.

What they might do is level out the price at some average, such that power costs the same regardless of when you use it. Ironically, I think that eliminates the business model for Tesla powerwalls.

Another implication: if everyone buys household storage systems, then there wouldn't be any high or low demand periods. Everyone would be charging their batteries at night, driving the price up.