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Comment by edhelas | Hacker News Reader

All this energy !

Can't be stored (don't tell me about lithium, please do the math…), and it's not there at night.

It still means power for air conditioning is ~free during the day when it's most needed, and you could pre-cool or pre-heat a bulk block with high heat capacity, then slowly use the heat/cold during the day.

You can charge the electric cars when there's an excess, so in particular all the extra load from electric car charging that some people were so worried about is no longer a concern.

If it gets cheap enough, you can overbuild capacity so that you have just enough power if it's a bit overcast, and way too much when there's sun (since solar cells can be safely "turned off" as far as I know, unlike conventional plants).

If we now get some process for capturing carbon from the air where electricity is the main cost (i.e. overbuilding capacity and using it only 20% of the time is affordable), we now have a place to put all the excess electricity during peak.

I think that you don't see how much land you actually need. Maybe in America there is plenty of space, but in Europe it's way more difficult. To replace one nuclear reactor, you need ~ half of Paris in solar panel. And still need energy "at night".

Yes heating water, or cooling places are nice. But your trains ain't gonna work "only when there is sun".

If you need backup at one moment, you need 0C0² backup and basically: Or you build dam, or you build nuclear plants.

If you build nuclear plants, it's basically dumb to have plenty of renewable next to it…

I don't think much thought has been given to the cost structure of nuclear peak plants. A nuclear facility which only generated power part of the time should have a longer service life and generate less waste per unit time. Meaning the high capex decommissioning process may be pushed back decades or more.

One of the things limiting the life of nuclear power plants is damage from thermal cycling. So a nuclear facility which only generates power part of the time can have a shorter service life in terms of calendar time (and will almost certainly have a shorter life in terms of time spent operating or power produced).

It makes sense that a nuclear peaker plant could last longer, but it's probably a challenge to sell an investment where the payoff comes after the investors are dead. In the short to medium term, that unused capacity is lost profit.

Maybe with a carbon tax, this could work... otherwise natural gas peakers will take all the money off the table.

Fortunately space and land are cheap in the vast scheme of things.

There are very large amounts of "free" space, on rooftops, for example.

The last time I flew to Europe, I was pleasantly surprised by the number of residential rooftop solar there was.

Half of Paris city or half of Paris metropolitan area? Where the former is inconsequential on the scale of France, and the latter is merely small.

Paris city :) This a lot, but not that much.

> you need ~ half of Paris in solar panel

So put solar panels on roofs in Paris then. Europe has plenty of space if you actually look for it.

I actually did some calculations based on my previous apartment. We had remote heating and hot water, so only needed power for cooking, PC's etc. I found that if I covered the section of the roof above my apartment with solar panels, I could be "off grid" almost then entire year.

Except my apartment was on top, and there were four more just like it below me...

It’s not as far off as you might think - even for individual homeowners. I’ve got a far from ideal house with a 8.4KWh solar array on my roof and 3x Tesla Powerwalls in my basement. Yesterday I produced 43KWh of electricity and exported 27KWh to the grid. The only reason I’ve needed grid connectivity in the last nine days has been to export power. In essence, I’m largely off grid from March through October.

Now, this wasn’t cheap (thankfully incentives made it more affordable and Eversource provides the most expensive electricity in the United States), after incentives it was about $22000. That’s a lot, but it’s not hard to imagine this becoming scalable in the near future for climates with better solar potential than Connecticut.

$22,000 would pay my electric bills for about 12 years, not even factoring in opportunity cost. What are the ongoing maintenance costs/total cost of ownership over 12 years of such a system?

As far as Powerwalls go, I'd definitely want something like that in an outbuilding and not in my house. Last thing I want to do is wake up at 3:00am with a raging battery fire in my basement.

If we're talking about nerds buying this stuff, $22k is comparable to what people spend on nice homelab setups. I would pay $22k just because it's cool and not because it saves money.

Yeah, but we're talking about 0.1% of the population. For mass adoption, prices have to be much, much lower.

There's some places where you can't put the Powerwalls indoors. In CT where I live it's just fine. I did add in a fire suppression system in my basement when I had them installed. This was not a requirement and was included in my overall cost figure provided. It's a big red thingy in between the rafters that goes "boom" when there's a fire. That's a technical term.

How much would you pay for electricity / month if you did not have any of that?

In the 12 months prior my electric bill averaged $140/mo at an average rate of $0.23/KWh (includes supply and delivery - split about 1:2).

If the solar is almost free, you can shift investment to storage, transmission, demand response, and other (more expensive) low carbon generation.

One would expect a similar cost decline curve for batteries [1] once every automaker is required to buy batteries when they can only sell EVs.

[1] https://news.mit.edu/2021/lithium-ion-battery-costs-0323

Please do the math, check how much you'll need to cover the consumption of a small city for a night.

Just an idea, you have ~500kg of lithium-battery in an average EV for a few hundred km of autonomy.

95% of stored electricity today is water pumped behind dam. You want to store electricity, build dam.

There is only a few decades of lithium left to be extracted by the way.

> There is only a few decades of lithium left to be extracted by the way.

Julian Simon's bet with Paul Ehrlich. You're not apparently aware of the amount of lithium worldwide, it's availability or its price trajectory. All minerals are significantly more abundant than people think, supply chain dynamics in mining do no equate to scarcity on earth, they relate to the economics of exploration and extraction and shipping.

I'll make an exception for pink diamonds. Lithium is not in 10 year decline. Lithium is also not the only battery mineral of interest and battery tech is not stand and die on lithium for either cost, or energy density, or recharge speed.

Sure, we have plenty of minerals left ! But where and how much energy you need to extract them.

In France we have lithium in Alsace, we could dig-it-up, but it's really not worth it energy wise and environmentally wise.

> But where and how much energy you need to extract them

Luckily I just read an article about how much energy solar is generating!

As far as I know lithium extraction from brine is both in development and an area of active research which would allow to tap a lot more lithium resources than previously expected. I remember reading something about a test plant in Cornwall and some similar stuff from Germany as well. Maybe that would help you in France as well?

http://large.stanford.edu/courses/2010/ph240/eason2/

2010 blog article ?

https://pv-magazine-usa.com/2020/09/16/how-long-will-the-lit...

> The scenario which assumes 73 Mt of lithium supply left, best policies (recycling, V2G, second-life) implemented and around 3 billion EVs on the road sees lithium fully depleted a few years beyond 2100. If the same policies and number of cars were matched with just 26 Mt of lithium, but recycling efforts would only grow slowly, battery manufacturers will close shops even before 2040.

3billion cars. Exhausted at 2010 extraction rates by 2100 so in 80 years not 10, and for 3 billion cars, and that's from resource availability figures from 11 years ago.

Please, don't do this. You said 10 years. It's not exhausted in 10 years and a mining report from 2010 doesn't tell you anything in 2021. Mines are developed when economics justify it. Available lithium is huge.

Oh, boy! You probably don't want to read about peak oil extraction :-D

Oil was supposed to run out in 1865, 1880, 1900, 1920, 1940, 1985, 2005, ...

If there's a demand for a specific resource, prices go up and people find a way to extract more of it, if it's present on this planet. And lithium is the 25th most abundant element, so there's a ton more of it than there's oil in the crust.

https://carbontracker.org/solar-and-wind-can-meet-world-ener...

https://news.ycombinator.com/item?id=26928343

Storage is a component, but renewables will get so cheap we'll overbuild and throw away (curtail) the excess versus optimizing for storage.

The world has sufficient lithium reserves for storage and EV demands.

Sure :) 500B€ (yes, half a trillion !) invested in wind turbines in Germany over 20 years.

Check the result https://www.electricitymap.org/zone/DE, Germany is ~300g of CO²/kwh, France is 50g.

Why ? Because when there is no wind, no sun, you need power. And then you're burning gaz or coal. So you "erase" all those 0CO² days.

Also solar panel efficiency fades over time, you loose 50% of efficiency after a few decades. Wind-turbines have 25y life expectancy.

I thought it was because Germany shut down its nuclear power plants and ramped its coal generation up? [1] Germany poorly managing its power grid doesn’t imply that renewables aren’t economically rational; it implies Germany makes irrational national policy. France is primarily nuclear powered, as you point out with their low CO2 emission footprint (compare the generation mixes of both countries in ElectricityMap, I’m familiar having contributed generation data for Europe).

Solar panels retain 90% of their production rating after 25 years, and can be recycled at end of life, as can wind turbine blades (with the turbines repowered, typically generating more power than the previous equipment).

What’s with the FUD? Definitely feels like there’s an agenda when the data is objectively clear.

[1] https://www.wired.com/story/germany-rejected-nuclear-power-a...

Germany's fossil fuel use for grid generation was steady after Fukushima. Coal use declined. After 2017, coal use fell off a cliff (as CO2 allowances became more expensive in Europe.)

Wind turbine blade recycling is hard. I wouldn’t call it a proven technology. For example, all recycling options discussed in https://designedconscious.com/plastics-in-the-ocean/sustaina... are into inferior products (shorter glass fibers, ash, etc)

I think this notion of recycling turbine blades is a bit of a fetish. Why do they have to be recycled?

How I look at it, had they spent the same amount of money in a different way, they could be carbon neutral. Climate change is an emergency but no one is acting like it.

It's one thing to say "we don't think it's worth the money" and another to spend the money but not achieve much, it's even worse IMO!

> Climate change is an emergency but no one is acting like it.

Yes, it sometimes makes me wonder what the real agenda is.

> Also solar panel efficiency fades over time, you loose 50% of efficiency after a few decades.

Perhaps it's more relevant that the solar panels that were installed decades ago were 50% less efficient; that's technological progress.

https://sites.lafayette.edu/egrs352-sp14-pv/technology/histo...

Progress that was enabled substantially by there being a market that would buy the early inefficient solar panels, providing capital for further research.

> Please do the math, check how much you'll need to cover the consumption of a small city for a night.

It sure would be nice if we had a transnational energy infrastructure, as the sun is always shining somewhere. Think DESERTEC and Gobitec but for the whole planet.

Oh yes, thousands of km of high power copper cables.

Crossing west-to-east Europe with electricity is already loosing 30% of it. Let's transport electricity from Australia to India !

And for wind, it's the same issue, when there is wind in Finland, there is wind in Spain. So you can't "balance thing" between countries.

> Crossing west-to-east Europe with electricity is already loosing 30% of it. Let's transport electricity from Australia to India !

From the DESERTEC website:

> For long transmission distances direct current transmission is superior to alternating current. Alternating current has high losses due to capacitive and inductive resistance, which do not occur in direct current transmission. With that technology, a 3000 km line (for example Cairo to Munich) has losses lower than 10%.

That would be high reactive losses due to unbalanced inductive and capacitive reactance in an ac load.

If the energy is practically free from the sun then 30% loss can be manageable if that's the cost of renewable reliable energy. Heck coal is only about 44% efficient to begin with and we currently accept that loss.

Over large distances, high-voltage direct current transmissions would be used which has losses in the low single-digit percentage per 1000km. See following link for details:

https://en.wikipedia.org/wiki/High-voltage_direct_current#Ad...

Power lines don't use copper. They're aluminum with a steel core.

I was interested in what it takes to recycle a Li-ion cell and this was a pretty good overview for others:

https://cen.acs.org/materials/energy-storage/time-serious-re...

It's expensive now to recycle, and according to the article, the costs don't drop to recycle because if it's cheaper to dig up ore vs. recycle, well, the business doesn't exist.

Redwood Materials, founded by JB Straubel (Tesla co-founder and previously CTO), is working on this problem.

https://www.redwoodmaterials.com/

I run the utilities at night because electricity is cheaper then. I'd run them during the day if I had solar.

While the battery of an EV is heavy, there is not 500kg of lithium inside it. For example a Tesla S with 100kWh, one of the biggest battery on the market, has about 7kg of lithium.

How do you know how much lithium there is? Every year we discover more accessible lithium than the year before. Do the history!

This is correct.

Here is the USGS mineral commodity summary for lithium in 2010: https://s3-us-west-2.amazonaws.com/prd-wret/assets/palladium...

Here is the same report for 2021: https://pubs.usgs.gov/periodicals/mcs2021/mcs2021-lithium.pd...

World lithium reserves went up from 9.9 million tons in 2010 to 21 million tons in 2021 even as extraction accelerated. Companies have been putting more effort into discovery which has increased known reserves much faster than increasing extraction is drawing them down.

And most of our lithium doesn't come from proper "reserves" but from what is categorized as "resources," which is several times the quantity of "reserves." I don't know how much lithium is out there but we've barely even begun looking and there's never been demand for much in the past.

> At 20 mg lithium per kg of Earth's crust,[45] lithium is the 25th most abundant element.

https://en.wikipedia.org/wiki/Lithium

I'm too lazy to do the math, but that's probably enough lithium to plate the entire planet with it if we want to :-)

Heat the swimming pool during the day and then use the heat pump at night.

How does that store energy for the grid?

Reduces grid demand by localizing the energy, storing it on site thermally. Air conditioners that make ice at night and cool during the day do the same.

Freeman Dyson devised an a/c system at Princeton that involved using snow making machines to generate a large pile of ice in an insulated shed during the winter (with the doors open) and circulated coolant through the ice pile and the buildings in the summer (with the shed doors closed).

There is a passive ice pile technique, but for producing water https://en.wikipedia.org/wiki/Ice_Stupa

Freeman Dyson wrote about it, but it was Ted Taylor who did it, I think.

I think aluminum batteries are coming along nicely in that area of battery tech and they have a very large capacity. The problem with aluminum has always been high energy costs to produce. So you can store the energy in the aluminum itself by using it to produce Aluminum for use in batteries.

Aluminum battery stations could replace gas stations.

https://en.wikipedia.org/wiki/Power_to_gas

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