Comment by moloch-hai | Hacker News Reader

Comment by moloch-hai | Hacker News Reader

Parent Full thread

> For every deliverable GW of of solar you have have a GW of backup

That is utterly silly. Think.

You need only just enough backup generation capacity to fill a shortfall. In contrast, you overbuild solar and wind so you can charge up your storage while also satisfying peak load even under reduced yield.

You will never, ever charge storage from your backup generator: that would be beyond idiotic. So you need only a very strictly limited backup capacity, no matter how much renewable generation you have overbuilt. You will overbuild, because it is by far the cheapest way to get power, and you can sell the extra.

Wind and solar are variable, but not random: you know well ahead of time what they will produce, and whether and when your storage will run low. So, you can schedule a fuel delivery or a slice of transmission line capacity. You might charge storage from the transmission line if you are not producing enough excess, which will be cheaper than ordering in liquid fuel.

Your figures on transmission lines are badly dated. UK is building a transmission line to a solar farm in Africa, which is rather more than 300km away. (Siting a solar farm in the desert is also idiotic, but people who control money love the idea, so here we are.) China wants to build one to Chile, their antipodes; they figure on 50% loss, which is fine.

We will need a lot of power generation and transmission. Renewable generation is cheap and still getting cheaper fast. So it is obvious what to do: build that. Keep building that.

Diverting capital to nukes (or geo) would radically cut generation capacity. More expensive means, exactly, fewer watts per dollar. Fortunately nobody with money is dumb enough to buy a nuke, even with DoE doing their level best to sucker somebody on board.

If we are very, very lucky, civilization will not collapse before enough is built out.

> Your figures on transmission lines are badly dated. UK is building a transmission line to a solar farm in Africa.

Perhaps I have not made it clear enough that I am dealing in reality rather than things that do not exist? This cable and project are not real yet. They have yet to build the very factory that will manufacture this cable.

Also, I am talking about land-based power. The US infrastructure. Europe is screwed in so many forms that they have to resort to such things.

This cable is horrifically dangerous in so many ways. Talk about boiling the ocean! 10 GW will do that. I wonder how that accident will compare to an oil spill?

From a strategic perspective, bringing in 8% of your nation's power needs from a place like Morocco via an underwater cable does not sound like a great geopolitical strategy. Unless we want to imagine something like a large or regional war can never happen...

Then again, the UK might have few choices. I don't think they can do solar at this scale in-country. I would think they can do a massive amount of offshore wind. This is puzzling to me. I don't understand a strategy that creates such a dependency. Look at what happened to Germany and others with Russia. I don't get it.

An underwater cable pushing that kind of voltage and power for such a long distance is likely an ecological disaster waiting to happen. I'm sure they have safeguards...just like offshore oil rigs.

You want to 'deal in reality'? Do you really doubt UK's transmission line will work? Maybe look into existing HVDC lines already in service, then.

UK's folly in relying on Morocco for power is way off topic. UK certainly is not limited to relying on power from Morocco. They could put up solar fencing in their abundant pasture, sharing with livestock that will keep down weeds. But UK is not known for excellent governance, lately.

> Talk about boiling the ocean! 10 GW will do that.

10GW, ignoring the ability to shed energy over time, would take ~16 million years to boil the ocean.

> Talk about boiling the ocean! 10 GW will do that. I wonder how that accident will compare to an oil spill?

Yet another demonstration of a complete inability to perform basic arithmetic or critical reasoning. If for some reason it were to break and put all the energy into the ocean, and then for some reason the operators decided to put $100k of energy into the ocean each hour rather than turning it off. Then it would be about 20% more than browns ferry dumps into wheeler lake under normal operation.

>> For every deliverable GW of of solar you have have a GW of backup > That is utterly silly. Think

Here's a concept: How about we have a conversation without insults?

Explain this to me then:

Let's say you have a 1 MW array in, say, Los Angeles. Let's assume not a cloud in the sky most of the year. Not true. Let's go there anyway.

We then get pounded with rains and have black clouds and dark skies for a couple of months (pretty much the kind of thing that happened in December/January).

Power output goes down from one million Watts peak to 75000 Watts peak for days and days.

How much backup --in any form, any technology-- would you propose to have in order to ensure the town, homes, people, hospitals, traffic lights, etc. relying on this 1 MW of power does not go dark during those two months.

Pick any technology. I don't care what it is. What I want from you is: We need x Watts of power as backup to survive this period. Power, not energy. There's a huge difference.

Since you think my statement is silly, I am assuming you think you can supply this town with a lot less than the 1 MW they lost during this blackout. How?

You seem to miss what "overbuild" means.

Nobody is relying on 1000 kW from that array. If it is a 3x overbuild, then they are counting on only 300 kW from it, with any extra going to charge storage or put on a transmission line to sell. Their shortfall under stormclouds is then 300-75=225 kW. After their storage has been depleted, if power from elsewhere is already spoken for, that is how much they will draw from their backup generator. At night, when the array produces zero, demand is lower, but anyway their backup generator can take the whole 300 kW load when necessary.

But it is not often necessary. Often they can fill the shortfall from storage or from a transmission line with power from elsewhere, maybe wind, or maybe even from the next town's storage if they predict they won't need it right away. The town will deliver excess stored energy they have on the same terms.

After developing some experience, and prices for panels have plummeted further, maybe the town builds out another 2x. Then they generate 125 kW under storm conditions, and the shortfall is only 175 kW. The rest of the time they can charge their storage faster and then sell more to the grid.

How much to spend overbuilding generation vs. how much on growing storage capacity is a complicated calculation. Both are capex for equipment that cuts hard-to-predict costs. Building more later gets you lower prices, but only starts saving you money after it's built.

Of course in practice all the solar and wind farms push to the grid at the bid price, and the town draws power from the grid at the asking price. Storage and gas generators push power to the grid when bid price exceeds their profit threshold. Storage draws from the grid to charge when the asking price is low enough, which is never when the gas generator is pushing. Nukes never see the bid price exceed their cost, but must take what is offered or shut down; all not heavily subsidized via tax will shut down.

Anything you write that is not silly, I promise not to call silly.

Very convenient way to reduce the number by 66% so your argument has an opportunity to survive.

If you NEED 1 MW, you also NEED 1 MW for backup from a different source. It can be solar or wind 300 miles away, where, perhaps, the weather is different. Yet, you still need 100% backup.

You are all so focused on having a verbally violent argument that you cannot help but deflect with tangential issues and fail any attempt to try to understand and be understood.

There, I just gave you the perfect refutation to my suggestion of using nuclear for backup. Use solar or wind from a few hundred miles away. Perfectly doable? In principle, yes. It requires analysis but it does sound plausible.

I'll give you another refutation to challenge a claim that nuclear power is the solution: While the technology has gotten better and we can build better reactors, hell will freeze over before we build a few more reactors in the US, much less hundreds. A case of "Yeah, that's great. You just can't build them. Ever".

There, that's how you try to have a conversation with someone if you care to actually have one from a basis of respect and the potential of mutual edification. I am so sick of people who use online conversations as free-for-all confrontational battlegrounds. Nobody learns anything other than who might be the biggest jerk or who subscribes to the same mob.

This "conversation" is over.

Maybe read what you just wrote.

Cry bullying and sulking about how people are mean when you're consistently condescending and insulting is not a good look. If you NEED 1MW, you don't try to provide it with a single 1MW array of solar. You supply it with 3MW of solar and 2MW of wind over a wide region.

Your 1st percentile weather event brings your peak power down to 1.5MW and the average over the week down to 500kW.

Your 500kW shortfall is filled with whatever combination of storage and dispatch you have, and is rare enough that planning to fill it with fossil fuel gas for the next century is a lower cost and lower total emissions strategy than spending an extra 15 years waiting for Uranium mines to open even if you pretend all the other dispatch options are impossible.

Reply on news.ycombinator.com