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FindTheRemnant t1_isuyjiy wrote

Reply to comment by Tigen13 in Investment in wind and solar is set to outpace oil and gas drilling for the first time this year by Frubanoid

Capacity factors for wind power are very low. Ie less than 30%. That turbine won't be making 14MW day in, day out like a gas plant would. And building more wouldn't help since when the wind doesn't blow, it's just does blow. Also grid scale energy storage has not even been successfully demonstrated anywhere in the world.

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AnonymousWritings t1_isw7p4d wrote

This is just straight up lies.

Capacity factor average for wind in the US (primarily on shore with smaller turbines) is recently (last 5 years) about 35%. Recent large off shore wind farms, such as the Hornsea 1 project in the UK (largest off shore farm until this year) easily crack 40% (47% lifetime capacity factor for Hornsea 1), and larger turbines are expected to increase this.

Gas plants ALSO don't "make 14MW day in and day out". Actual gas capacity factors can be found here for the US. 55% for combined cycle gas turbines typically used for 'baseload' type operation, and more like 15% for gas turbines that are used as peakers plants. The weighted average capacity factor of gas plants in the US is actually about 36% for 2021, and similar for other recent years.

So yes, on an average basis, 14MW of wind capacity will approximately replace equivalent generation of 14MW of gas capacity.

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Warpzit t1_iswbef1 wrote

Thanks for bringing you knowledge to the discussion.

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Tribunus_Plebis t1_isyhzr7 wrote

Thanks for the explanation. Now I'm all for wind instead of gas but I have a question here.

Isn't a big downside of wind power that it cannot be planned? I.e. you might not get the power you need when you need it. Is that an issue and if so, how would that be mitigated so we can rely more on wind power?

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AnonymousWritings t1_isyjpl8 wrote

You're right, this is often talked about as a power source being 'dispatchable' or not. Gas generator, particularly peaker plants, are dispatchable because you can easily turn them on and off as needed, and quickly ramp up and down.

Wind turbines, on their own, aren't really dispatchable because they depend on wind conditions.

Ways to make wind power into a pseudo-dispatchable source include:

  1. Overbuilding wind turbines. If you overbuild them enough such that you always (or almost always) generate at least the required amount of power, you can just activate / de-activate some of your wind turbines to modulate your power output as needed depending on wind conditions . Conceptually this really isn't that different from having a whole load of gas peaker plants in existence, which only operate on average 15% of the time. On average a lot of 'idle' capacity sitting around with both situations.
  2. Building long distance transmission lines to link up grids with wind turbines that experience different weather conditions. This will work well in conjunction with 1) because it means that a smaller fraction of your wind turbines are expected to be seeing calm weather (and hence low generation) at the same time, meaning that your required over-building factor becomes lower.
  3. Pair wind turbines with energy storage. Batteries, compressed air storage, pumped hydro, possibly hydrogen storage, etc. Wind provides the (uncontrolled variable) power input, storage systems let you modulate when you release it to the grid.
  4. Pair wind power up with other renewable generation (e.g. solar) which typically has favorable weather conditions when wind is low. This reduces the over-build factor required to maintain the needed energy output.

​

Wind turbines do need to get a bit cheaper for 1) to be realistically viable in large scale, but they are certainly tending in that direction. Locally it kind of already happens in some areas; wind power is routinely curtailed in Scotland because at peak wind times there is more installed capacity than the grid can use, which means a higher fraction of the time where wind can cover the demand (This situation will change if and when more north-south transmission lines are installed to let southern England use more of the Scottish wind power, but still).

All of these increase the cost of renewable electricity over the base cost of wind power itself, but with wind and solar power dropping south of $40 / MWh, and gas power rising north of $100 / MWh, the economics are still quite attractive

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Tribunus_Plebis t1_isyp068 wrote

Thanks a lot for that. I suppose it's in the end gonna be a combination of all those factors you mentioned. I don't know why I never considered just over-deploying. Seem like an obvious answer now that you point it out.

By the way, what is your source for the cost figures? I'd like to learn more about what those numbers include.

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AnonymousWritings t1_isyv6z3 wrote

Lazard levelized cost of energy analysis a nice place to look at summaries overall of the cost of different energy sources.

For off-shore wind, you can also take a look at recent UK off-shore wind contracts, which are coming in at <40/MWh GBP (37.5GBP which is $42 USD). That's the guaranteed price the wind producers are contracted to sell their electricity at, so the actual pre-profit cost is absolutely lower than that.

Can also see back here discussion of on-shore wind purchase agreements in the US for $20 / MWh in 2019, which was noted as being more expensive than just the natural gas fuel itself per MWh (before this whole Russian gas crisis skyrocketed the prices), without considering actually amortizing the cost of building the gas power plants.

I'll admit though, my 'north of $100 / MWh' number for gas is a bit fluffy. It's true if you look at peaker plants in general (which are expensive because of such low capacity factor meaning ammortized capital costs / MWh generated are high), or if you look at current natural gas prices for gas generation in general, but for pre-crisis CCGT baseload, costs were definitely still well under $100 / MWh.

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Global-Date t1_iszgqrs wrote

>>wind power is routinely curtailed in Scotland because at peak wind times there is more installed capacity than the grid can use,

This isn't completely true. If you look at where 'constraint payments' are paid in the UK a lot more go to Scottish farms, and hardly any to the modern offshore farms

Some of this is because the wind farms in Scotland are connected to the grid really badly. Grid infrastructure was not upgraded and so they need to be turned off more regularly. There is rumblings that this was done on purpose as the old old subsidy schemes paid a very high price to wind turbines if they needed to be shut off.

That incentive is gone in the more modern turbines so it pays for companies to ensure solid grid connectivity.

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Frubanoid OP t1_isv175k wrote

Grid storage has helped in both Australia with the Tesla battery system and also in California (not sure what company) during recent heatwaves.

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Global-Date t1_iszg2x8 wrote

>>And building more wouldn't help since when the wind doesn't blow,

In addition to what others have said, you spread them out. So yes building more does help. So the UK is putting them all round the UK and connecting to European ones. So the wind is always blowing somewhere.

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Atom_Blue t1_iswg0r6 wrote

Careful or you’ll banned for misinformation. Mention energy reality and throwing cold water will get you censored.

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Global-Date t1_iszgtjn wrote

Except everything he said was pretty much bullshit as anyone who works in the sector can tell you

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