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Sometimes, a Greener Grid Means a 40k% Spike in Power Prices (bloomberg.com)
49 points by Bostonian 54 days ago | hide | past | web | favorite | 62 comments

This is energy industry FUD

In Australia the complete opposite happens. Extremely hot days cause coal and gas plants to fail https://www.theguardian.com/commentisfree/2019/jan/31/what-h...

Whereas renewables have been causing power prices to occasionally fall to $0. https://reneweconomy.com.au/electricity-prices-across-the-gr...

Prices falling to 0 isn't a good thing; it means there is too much power and nothing to use it for. Nobody wants that, it is pointless.

The people building the capital will make a profit over the year, so consumers will make up for the 0s with higher prices when there is not enough energy. And over the long term $0 prices potentially lead to building less infrastructure leading to blackouts.

Basically we know the average price is not going to be 0. Therefore, 0 prices signals variance. Variance is pretty much always risky and expensive in big infrastructure; and the electricity market is a good example. It can hopefully be managed to only be a minor inconvenience but it is certainly not a positive for anyone.

It does signal that there is a golden window to, eg, run a desalination plant. If anyone takes advantage of that opportunity then it would be a win, but the symptom of that happening would be non-0 prices.


Also, coal plant failures in hot weather are probably a symptom of them not being maintained. Australia has already seen a Labor-Green coalition in federal politics; you'd have to be an idiot to spend money maintaining a coal plant in that political environment. Better to let them run down and try to extract money from the government in a crisis situation which seems to be the current strategy.

All it takes is a reasonable storage of that energy for later use. I saw a crane design that didn’t require any major tech.

If we had reasonable storage the price wouldn't be 0. Or negative. It would just be low, because the storers would be competing to buy near-0 energy.

High prices mean "we need more", low prices mean "carry on", $0 means "don't produce this stuff, please". Negative prices mean "We're begging you, turn it off, it is hurting".

Not sure the economics here are this simple?

It seems like, if this distinction was meaningful, renewable operators would be turning off generation capacity when prices dropped this low. There's some economic, effort, or technological incentive to keep the spiggots on (i.e., either the marginal costs of producing this power are so low there's no incentive for operators to stop, or the costs/risks of stopping it are too high to bother).

Ignoring storage tech, it's also a signal that demand is too inflexible to redistribute power consumption (that is, an opportunity...).

> Not sure the economics here are this simple?

The economics are pretty simple; electricity is about as pure a commodity as it is possible to get. The timeframes this plays out in are the 1-10 year windows where people make big long-term capital decisions.

> It seems like, if this distinction was meaningful, renewable operators would be turning off generation capacity when prices dropped this low.

In the short term people ignore market signals for all sorts of good reasons. I can ignore market signals all day if I want to. If they ignore a signal all year they will start to go bankrupt.

But the fact that renewable are ignoring a market signal is not a positive benefit to cite when talking about "energy industry FUD". When market signals get ignored; consumers pay more. This has played out in Germany, and it is playing out in Australia. $0 wholesale prices mean high retail prices over the year.

> Ignoring storage tech, it's also a signal that demand is too inflexible to redistribute power consumption (that is, an opportunity...).

Massive opportunity. If prices are $0; nobody is seizing the opportunity. It is waste. If someone were making use of this they would be being charged a low but positive number.

Not really looking to press this; it seems like you know more about the economics of energy production than I do. But, some examples of why I wonder if it's this simple:

- Part of redistributing less time-sensitive forms of consumption around the grid/clock is demonstrating quantity and stability of cheap power at those times. One possibility is the producer is just being subsidized or obligated into production they wouldn't undertake without a distortion. But it seems like low/negative prices are also how you'd prove the supply. - In responsive real-time energy markets, driving prices down should force higher-cost producers to reduce output. Over time, that signal should take less-competitive producers completely offline. It's not obvious to me that they're ignoring market signals if their strategic decision-making function could more complicated than just "produce when the rate is profitable."

Press away if you feel like it.

The things you are talking about here seem to be details of very short term decision making. There are a lot of complications in the small picture, and unless one of us works in an actual power plant we are probably going to get them wrong.

But the big picture has some basic balance laws that have to hold: a company cannot consistently give away product for free and stay in business. Even if it is theoretically possible, it just happens to be a well known fact that that isn't how electricity markets work for any of the participants. The electricity isn't a by-product or anything strange; this is electricity produced to be be sold for money. We know that the average price has to be positive.

Therefore it is misleading to point out "renewables have been causing power prices to occasionally fall to $0" as though that were any sort of positive. The falls to $0 are balanced by rises to some larger positive number so that over the full year the total price is positive. These falls do represent an opportunity, but they represent an opportunity that nobody is taking advantage of yet. Those prices signal strongly that there is energy being produced that isn't useful to anybody (or they would, y'know, be willing to pay for it). When somebody finds a use for this power that is presently being basically dumped then prices will rise to some low-but-positive value and that will probably be a very good sign.

Some people have pointed out that maybe there are subsides for renewables; in which case governments are paying renewables to produce something nobody is using which is also not a positive for renewables.

The big issue is we've seen exactly this situation play out in Germany. The game changes slightly from normal because we know that the renewable producers don't have the sort of control over when they supply powers as conventional power; periods of 0 wholesale prices leading to anomalously high retail prices at the end of the year as the intermediaries deal with the problem of uncontrolled generation. Those $0 prices are a likely a tell that things are getting expensive. They are not a good sign. Hopefully they are a neutral sign.

Usually when this happens it's because the producers have fixed/guaranteed price contracts so there's just no to stop producing.

The problem isn't a lack of technology. It's a lack of demand. We have several dozen technologies that in combination can solve this problem. However it's going to be slightly expensive and since most countries do not generate more than 70% of their electricity from renewables they can simply get away with the far cheaper option. They already have gas plants which emit less CO2 per kWh than coal plants. The difference between a 80% and 100% reduction in CO2 is less significant than the difference between a 20% and 50% reduction.

Just to add to your point, per unit subsidies can also cause negative prices.

What if I were to tell you that it costs you 0$ for the air that you breath?

I'd it a bad thing that the market price for the air that we are currently breathing is 0$?

Precisely nobody is in the business of mass-producing commodity breathable air. It isn't a market. There are neither buyers nor sellers. If there was someone stupid enough to try and create a commodity market in air, it would signal to any producer "get out, you are crazy".

If we lived in a utopia where electricity was produced without any human intervention whatsoever then a $0 price would be fine. Producing electricity does require human action. Maintaining solar farms requires human action. Maintaining wind farms requires human intervention. Acquiring fuel requires human action. These are not charities; free is going to turn out to be quite expensive.

$0 doesn't imply a problem with the market, it implies an issue of oversupply. If the "problem" ends up being that coal/oil plants only run during the winter months, that seems like a net win for the world.

I dont get how the crane factors in to this unless you're suggesting that the extra energy could be stored as as gravitational potential energy, which probably doesn't fit the definition of "reasonable storage". I presume you'd get the energy back out of the system by dropping heavy things from the crane? A dubious proposal imho. I don't think there is a well-tested reliable way to harness energy from falling objects and convert it into some useful form.

> I don't think there is a well-tested reliable way to harness energy from falling objects and convert it into some useful form.

We do it with water. I'm not sure why the GP leapt to "crane" rather than "pump" but for sure we can achieve that. As for objects, a few designs spring to mind but they all seem less efficient than just pumping fluids.

Not sure what you are talking about. Seems like prices are high in Australia: https://www.theguardian.com/australia-news/2018/jul/01/austr...

It is pretty much basic physics and math:

1. Power supply must balance power consumption. 2. No one wants blackouts. 3. Intermittent power sources must be backed up by non-intermittent power sources. 4. You have to pay for the intermittent power generation as well as the backup power generation. 5. Cost of providing power goes up because your capitol costs have increased.

From the article you linked:

>Generators were “gaming” the system: using their power in concentrated markets to create artificial scarcity of supply and so force prices up.

It is not so much physics and math (which of course do not apply in australia), but politics. The line costs are also separated from supply costs (which is why more than 50% of my bill is not actually for power). The scale of the price gouging outweighes anything physics could throw at the costs. In SA they have had spot pricing of -1k to +14k inside of the 30min pricing window.

Your comments do not reflect reality, are poorly researched and contradict the op's entirely true statement.

Prices are not high due to renewables. You'll have to show that this is the case to make that argument.

AFAIK it's a combination of massively overbuilding the networks (due to privatisation and crappy/most likely corrupt energy regulator allowing companies to decide to overbuild while taking huge profits) plus a whole heap of coal and gas stations being quite decrepit and nearing end of life, with associated high costs of maintenance.

Renewable energy isn't really in the picture.

To add to this, a massive battery array was installed in South Australia in conjunction with Tesla which helped even out power distribution capacity in the event of drops in power output caused by coal/gas plants struggling during heatwaves, which otherwise would have caused blackouts.

I can't make sense of the sequence you've laid out but what do does capital cost have to do with daily (or even momentary) fluctuations in price?

Also, energy prices can be higher on average than elsewhere and dip to zero in some circumstances.

To deal with the inherent fluctuations in renewable energy sources, you have 2 options: 1) Storage, and right now while there is a lot of R&D into large-scale energy storage, there aren't really any great solutions yet, and 2) Non-renewable backup, e.g. natural gas plants. Since it's easy to have cloudy or windless conditions for days or weeks on end, your backup plants basically need to be able to run at full capacity if you want to prevent blackouts.

Thus, with renewable sources, you need to have the capital investments of both the renewable plant and the backup plant(s).

This does not answer my question.

The identifying characteristic of capital cost is: does not change over small time intervals, it is fixed up front and amortized over the lifetime of the asset.

This article and OP are talking about price spikes which are a symptom of short term (days, hours, minutes) market dynamics.

The reason that prices spike has nothing to do with capital cost and everything to do with short term demand/supply fluctuations.

Fair enough. You were focused on the short term spikes and I jumped to the larger issue of a reliable grid that had backup power.

The connection in my mind is that if you shift your mix of generation plants towards renewables then you have less ability to respond to outages of any kind. Could be cloudy days, windless days, failed transmission lines, and so on.

The advantage of a coal/gas/hydro/nuclear plants is that you can control the amount of power they are producing. That isn't true with wind/solar. You certainly can't turn them up and I think (but I'm not sure) it is difficult to shed power that they generate (i.e. turn them down).

Those price spikes are last ditch attempts to purchase power to meet demand before moving to brown/blackouts. Just another side-effect of not having an appropriate mix of generation capacity.

The argument is that in order to be able to deal with the higher short-term variability inherent with renewables you have higher up front capital costs.

>there is a lot of R&D into large-scale energy storage, there aren't really any great solutions yet

Re#1: Storing water in a reservoir behind a set of generators is a pretty good solution.

R&D isn't needed. Energy storage is not rocket science or necessarily expensive. You just use excess energy to lift something high ... pump it or railroad it uphill, or stack it. Reverse to power generators. Of course that's just a boring, cheap, low-tech, well-proven solution.

Re#2: Of course if you try rewewables in the wrong place, you get unsatisfying results. With a big enough reservoir,'days or weeks' isn't hard ... and so you don't need backup plants. Even then, while costs of backup plant fuels are high. renewable fuel costs are nearly zero. At the right sites, the average costs are at least competitive.

FWIW, the proposed costs for doing what you recommend with Hoover Dam is $3 billion:


Couple this with water shortages exacerbated by global warming and hydrostatic storage is by no means a panacea.

Isn’t less AC used when cloudy, meaning less than full capacity needed? Presumably some industrial uses can adapt with changing supply as well. If the biggest peak usage is in wintertime the AC thing may not apply, but I don’t think that is the case in Australia.

There is a third option and that is demand management. Just turn off the load when the price is high. This can work for things like domestic water heating, space heating if coupled with modest amounts of heat storage, charging electric vehicles when the price is low.

We need to use all of them.

Wholesale electricity price spikes happen in Australia too. For example, spot prices in Victoria hit $14,500/Mwh in January this year: https://www.aer.gov.au/communication/wholesale-electricity-p...

It is simple supply and demand. Electricity generation at any given point in time must be sufficient to meet demand for electricity, otherwise blackouts occur. When you introduce intermittent generation sources into the market, like solar and wind, it becomes more difficult for this matching to occur as generation output is weather dependent. Consequently, you get times in the wholesale market where a confluence of factors momentarily drive up wholesale prices: wind stops blowing, sun stops shining and demand spikes due to it being the middle of a hot summer day (e.g. middle of the day in January, which is summer in Australia, so everyone turns on their A/C). Prices shoot up until it entices other generators to make up the shortfall (e.g. gas turbine operators).

As i posted in other comment, the high spot process are entirely manufactured. The reason for the 14k spot price is because that is the cap. The energy suppliers have been gaming the market. Restricting demand for short periods in order to push up the price over the spot price period. This is entirely political (ie. Failure of regulation) and not at all about supply and demand.

Renewables mean lots of BOTH for a simple reason: supply and demand.

When the wind is blowing and the sun is shining, renewables can provide lots of power no matter what the live price is. (The cost of renewables is 100% installation, 0% operation. Any price above 0 is good as far as a wind turbine is concerned.)

When the wind is not blowing and the sun is not shining, no price signal is going to change that. What the price signal DOES do, however, is incentivize a response on the demand side.

Renewables are less stable than fossil fuels, that results in too much supply at times, and too little at others. These are facts not FUD.

"The road to a world powered by renewable energy is littered with unintended consequences"

Yes, entirely unlike a world powered buy fossil fuels, which has provided no surprises whatsoever and continues to go off without a hitch.

Pretty sure you’re being sarcastic.

idk, the consequences have really only been a surprise to people who are willfully ignorant. Can't argue the going off without a hitch though.

edit: I interpreted the comment as sarcastic, and responded to the opposite of the explicit as implied by the sarcastic comment. Kind of forgot that it was written that way and thus that it could be interpreted to mean I might be saying it has gone off without a hitch.

mmmm lead

Yes, renewable energy like wind and solar are intermittent, so we will need to invest (a lot) more into energy storage. So far storage has been expensive and need to drop a lot, so it can reach mainstream [1].

[1] https://www.pv-magazine.com/2019/08/12/new-us-study-finds-re...

Storage is one part of it. Flexible demand and load-shifting is another, and something that's getting more feasible with automation and better coordination with markets.

Yes, we can definitely incentivize people to change their energy usage habits as well. EVs will come very handy if/when their charging schedule can be centrally managed (thru automaker car networks or smart chargers).

Looks cool but I just don't see this ever getting to grid scale unless it could be integrated into natural geography like a shear cliff face to give it much greater capacity and throw. Especially with days or weeks of storage like we'd need to cover 2-3 standard deviations of renewable output.

1. The energy overhead seems quite significant - as the concrete barrels don't really drop. 2. What guarantees non-collapse in case of winds (and ignoring floods)? 3. Does this really scale? I mean, concrete is more dense than water, but I think it's only... what, twice the density?

Not the person you responded to, but you correctly identified some of the serious flaws in this idea. They claim to be using commercially available crane technology, but existing cranes are generally not designed to operate in high winds, so they seem like a poor match for wind energy. According to [0] tower cranes are typically limited to operating in wind speeds of 20m/s or less, where as wind turbines[1] top out at ~35m/s. That would mean when the turbines are at peak production (i.e, when you want to be 'charging' your storage) wind speeds would be too high for co-located concrete block storage to work.

The design also seems to have quite poor power density; their website[2] shows a single tower in front of fields of turbines, but they only quote a power output of 4-8MW - the equivalent of 1-2 large turbines - so in reality you'd need dozens of them for a single installation.

[0] https://www.cranes.org.nz/uploads/2/0/5/7/20572552/wind4.pdf [1] https://www.enercon.de/fileadmin/Redakteur/Medien-Portal/bro... [2] https://energyvault.com/

The diagram seems a bit silly. They say the concrete weights are the most expensive part of the system. So many of those blocks go through a small elevation change (or none, in the case of those on the bottom layer).

Most "gravity" batteries don't consider the cost of the weight. So far the only two types of viable gravity based energy storage systems are pumped hydro storage and hydraulic hydro storage since both take their weights from the surrounding environment.

I will admit that the crane idea is at least fixing the flaw of most gravity batteries requiring a separate generator per weight. Doubling the length of the crane arm increases the capacity 4-fold.

Sometimes, a greener grid means you will be struck by lightning. It's true! If the power cables move from one place to another, a lightning strike could hit you instead of some power cables.

Also, sometimes a greener grid means you will fail to win the lottery. A news item about the grid may distract you from putting down the correct numbers!

IIRC the 40% renewables in California only work because we can page from British Columbia's hydro reserves when we have a shortfall and then sell it back for cheap to let them recover.

I'm not sure you can go much higher right now without building more dams or retrofitting more of them for pumped storage and there's been enough opposition to recent hydro expansions to make it seem nonviable for the path to 100.

Renewables in CA are difficult because when the sun sets, electricity demand is high, but there's no source of solar power to the west.

(And coastal wind in CA is hard since the costal shelf drops much deeper than on the East Coast.)

Why would it be more during night? It's much cooler at night compared to the day when AC is used at most buildings.

The solar ramp-down is faster than the AC ramp-down. If you have a dumb thermostat, it runs the AC a fraction of the time which is a function of the outside temperature. However, the temperature stays elevated some hours after sunset, but the solar supply drops off quickly some hours before sunset. Solar supply is pretty well matched to AC demand except for a big mismatch a few hours around sunset.

Consider California. Currently, this mismatch is taken up by fossil fuel plants and imports, but the solar demand drops off so fast that they have real difficulty in ramping up as needed. Batteries are a major part of the solution, but another part is improved transmission of wind from states to the east. This will cost less than you might think.

California might use 800GWh daily; and yes, installing 800GWh of battery capacity would be prohibitively expensive. However, the wind picks up in the evening just a few hours after the sun goes down, so the batteries really just need to shift some excess power from midday to the evening. When I last calculated this, the additional transmission + batteries would cost around $40 billion.

Interestingly, smart thermostats can make this worse: devices with a home/away mode allow the house to warm up when no one is inside because the owner doesn't want to pay for cooling that they won't enjoy. However, as all of these owners return home after work and school, this creates a demand spike; also, the AC units on these houses, which have been allowed to warm up, now need to run far longer into the evening. Really, the home/away feature is a little bit of a hack: the real goal is to minimize cost with some constraints on the temperature, and the utility ought to pay owners to shift their demand forward from evening to midday. This is like getting paid to store energy temporarily.

So some combination of demand shifting---either with smart-er thermostats or batteries---adding other generation sources like wind, and some additional transmission, mean that California really can get to 100%. It will not be free, but it seems like the cost is less than $100 billion.

Now in Texas, the situation is somewhat reversed. There is too much wind generation, and not enough solar, but the upshot is similar.

Peak usage is in the evening after work until bed time. People get home, turn on heat or cooling, cook dinner, watch TV, and so on. Peak solar is in the middle of the day. There is quite a bit of overlap (especially with A/C), but it doesn't correlate perfectly.

Isn't some of this due to Texas' Amish approach to the national grids? What I mean by that is that Texas has little interconnection with the rest of the country. Like the Amish, they mostly only use electricity they make themselves [1].

Unlike most of the rest of the country, this means that when demand is much higher than local capacity they can't import from other states, and when demand is lower than capacity they can't export the excess. So they get big price swings.

[1] It's largely a myth that the Amish do not use electricity. What the Amish avoid is tying their infrastructure too closely to the outside. Tying into the grid would be too close, but they generally are OK with electricity generated locally by solar panels, windmills, or gas powered generators.


> Clean energy advocates point to batteries as a solution to renewables’ intermittent nature

Not just batteries, but an efficient grid that uses all the resources in an optimal manner. This was always the goal in creating microgrids, to be able to not rely on the main grid unless required, and when required the main grid would be able to perhaps use another microgrid's resources.

I'm pretty sure, the conditions that would lead one's switch to main grid would be similar to everyone resulting overloading the main grid which pretty much the article is alluding to. It matter diddly squat if I save 5c an hour if I have to pay $1000 / hour during over load

When controlled through TCP/IP, every air conditioner, ice maker or refrigerator can function as a battery.

Low tech magazine has a good writeup on energy stability and security as it relates to green energy: https://solar.lowtechmagazine.com/2018/12/keeping-some-of-th...

That's a pretty big incentive to try and bring in new sources of greener power, isn't it?

It’s also a great incentive to upgrade your infrastructure and upgrade buildings. I’m noticing a lot of office buildings in my area have switched to white rubber roof seals instead of black asphalt.

sound like texas is doing it wrong tbh

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