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Comment by jdauriemma | Hacker News Reader

Can someone ELI5 why renewables are more expensive for consumers where I live? In Pennsylvania my electric utility allows me to choose my supplier. Invariably, the renewables are more costly than the fossil fuels. What gives? Is this just a regional phenomenon?

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Political corruption.

You may think I'm joking, but one of the fuels that meets Pensylvania's Renewable Energy Portfolio Standard is "waste coal":

https://www.tandfonline.com/doi/abs/10.1080/0894192090344333...

That’s interesting and pretty outrageous

For people wondering what "waste coal" is like I was:

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

Pennsylvania (particularly western and northern PA) is right on top of the Marcellus shale, which is loaded with frackable gas. Your renewables are competing with cheap gas, locally sourced with low pipeline cost, that isn't being charged for CO2 emissions.

Makes sense, thanks for that perspective

Renewables are cheap per kWh, but they are only intermittently available, and since storage is basically nonexistent at grid scale, these kWh are only worth anything if there is demand for them, and are useless when there is demand, but sun is not shining or wind is not blowing. In effect, you still need to have some other way to produce electricity on demand, when there is no renewable supply. What’s worse is that if these more flexible sources of electricity (typically coal or gas) cannot compete with renewables when they do produce, they need to charge much more when renewables are out, in order to stay profitable — otherwise, they’d close, and we’d wouldn’t be able to meet the demand at all times. This would result in customers getting disconnected with very little notice, making them very unhappy.

To sum up, it’s more expensive, because even as renewables grow in installed capacity, we cannot reduce installed capacity of fossil sources on 1-1 parity, and also we pay more per fossil generated kWh than we used to in all-fossil grid. Cheap grid-scale storage would solve this, but it’s no going to happen any time soon.

Thanks! Hopefully that means that, if renewables keep getting cheaper, then the economics will keep getting better.

Not really, unless we can figure out how to make sun shine or wind blow 24/7. The intermittency is fundamental problem of solar and wind, and unless we figure out cheap storage, prices of electricity will not go down.

But if the price keeps falling for electricity generation, isn’t there some sort of break-even point where you overcome the increased distribution costs?

This is not about distribution. When sun is not shining, there is no solar energy to distribute. You can build as much solar as you want, but you won’t get any electricity from it during the night. Peak demand, however, is right after sunset, and only slowly peters out until midnight. Where are you going to get energy during that time? If you build enough wind all across the country, so that it is by itself enough to cover the peak demand even during low wind conditions, then it could work — but it’s cost prohibitive, and you wouldn’t then build any solar anyway (if wind was enough to cover peak demand in the evening, it would also be enough to cover demand during the day, no solar necessary).

In practice, until cheap storage is invented, and as long as nuclear energy is eschewed, renewables will be paired up with fossil, and prices will stay up.

Cheap storage is already invented, many times over. But it needs to be built out. That is delayed in part because prices are falling so fast; waiting means you get it cheaper. But most storage techs are very cheap or free to operate, so any built today will stay in use.

If the sun isn't shining and there isn't sufficient buffered storage (batteries, etc) then even if the solar panels are a penny each, their kwh costs are infinite until the sun shines again.

If you can cover 95% of the time but still need a natural gas power plant for the last 5%, you haven't saved any money except the cost of the natural gas itself. In the US, it is stupid cheap, so you haven't saved much at all.

I presume by "renewable" you really mean solar and wind. Hydro is generally pretty cheap, but also mostly tapped out. With that in mind, renewables are often more expensive for consumers due to a combination of a few factors:

1. The sun doesn't shine at night and the wind doesn't always blow strongly 2. People want to use power at all times of the day 3. Fixed costs in fossil fuel electricity generation are non-trivial 4. The utility scale electricity storage story is dire

The result is that renewables need to be overbuilt compared to their nameplate capacities to make up for less-than ideal weather and expected daily and annual weather cycles. I've heard those renewables produce something like 30% of their annual nameplate where a coal or gas plant will produce 90+%.

This overbuilding then ruins the wholesale price of electricity during high production times. For example, on a bright sunny spring day solar might push wholesale spot electricity prices negative. So the generating companies don't make as much money as you would expect from looking at average wholesale prices.

But people still want to use power after the sun has gone down and even if the wind has stopped blowing. So those generating companies need generating capacity to fill in that several hour long gap. Utility scale power storage in batteries isn't anywhere near being able to affordably store several hours worth of electricity. Also a cloud can roll across quickly or the wind might die suddenly. Therefore that backup generation is almost uniformly natural gas turbines because they can spin up and down quickly.

But even if no power is being sold by those plants, they need to be kept running to be instantly ready. So they are constantly burning some fuel to keep hot and spinning. The maintenance hours still keep racking up. There still needs to be people working 24/7. The costs of all that "idle" time need to be made up in the twelve hours of active generation.

So you end up with essentially double the generating capacity, half solar/wind half natural gas, and are continually paying the costs for both. Obviously that's going to be more expensive than simply burning a bit more fuel to run the natural gas plants near capacity full time. Or even build more efficient base-load plant types like coal or nuclear which have troubles scaling up and down quickly enough to balance out changeable renewable generation.

Renewables need buffering capacity, indeed

https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectric...

Or decentralized battery packs.

How does psh compare to electrolysis and burning hydrogen?

Massively more efficient. But when you have a lot of hydrogen synthesis capacity, it can keep working to produce valuable industrial product when the tanks are full. There is a large and fast-increasing demand for hydrogen.

Capacity factor of latest floating offshore wind can be as large as 57% (https://www.equinor.com/en/news/20210323-hywind-scotland-uk-...). 30% is typically what you get onshore.

Also there are a lot of renewables just sold on the grid without consumer marketing. The only reason the have a "renewable consumer plan" would be to charge people more. It wouldn't make sense to have a consumer plan with renewables and charge people less than the market rate.

putting variable inputs like solar and wind on the grid makes the grid more expensive to manage.

Same reason internet bandwidth if more abundant and cheaper than ever, but your Comcast bill seems to actually only go up.

Local rooftop solar, with no reliance on utility monopolies, is the most important thing in the global energy picture, and I'm afraid it isn't even close. And I'm pro nuclear. But it's past time to recognize that it's the distribution monopolists that are the problem. Solar and batteries free you from that.

Let’s stipulate that I don’t know why broadband bills are getting more expensive, if you don’t mind.

https://arstechnica.com/information-technology/2021/05/ajit-...

The phenomenon is that consumer prices for broadband go up, even as the wholesale cost of bandwidth (what Comcast is reselling to you) goes down. The cause of this is a mix of two things:

1. Cable companies have regional monopolies. Without a choice, they can raise prices on consumers without losing customers

2. Cable companies face ever increasing 'infrastructural' costs, such as environmental review, trenching, construction, permitting, easements, etc... These costs are well established as going up in excess of inflation (part of why we can't build new infrastructure anymore) and therefore even while the product itself (internet access) gets cheaper, the 'last mile' of distribution keeps getting more expensive.

Forgive me but I’m not understanding the example. Would you mind explaining why this comparison is valid for renewables but not fossil fuels?

That is what 5 year olds around you understand?

Yes, I violated eli5 rules. Sorry

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