Carbon-aware electricity pricing, measured daily on 38 grids

71 pointsposted 6 hours ago
by High-Five

59 Comments

boshomi

4 hours ago

Here is an analysis from Germany: Quarter-hourly spot prices compared to the share of renewable energy generation in total generation. A higher share of renewables puts massive downward pressure on the spot market electricity price.

https://www.energy-charts.info/charts/price_scatter/chart.ht...

Since price elasticity for electricity is very high, the market cap decreases by approximately €150,000 for every additional GWh of renewable energy production. A single additional offshore wind turbine with an annual output of 60 GWh reduces the combined revenue of all electricity producers by about €9 million per year that it is in operation.

Blocking wind power and solar projects only serves to secure the profits of monopolists and oligopolists in the electricity market, but causes massive harm to the economy.

jstimpfle

2 hours ago

This is interesting, but now explain why Germany has both the highest electricity prices in Europe as well as a relatively high CO2 footprint from electricity? Germany is buying not only nuclear but also coal energy from neighbouring countries.

Will this be fixed at some point or is the German model not actually as good as you imply?

throwaway473825

2 hours ago

The main reason why electricity is expensive in Germany is because it's taxed to oblivion. Even when wholesale prices are negative, electricity costs about three times as much as gas.

Now you might ask why electricity is taxed to oblivion. Some don't like nuclear or coal. Some prefer oil or gas. In the end, there's a majority that wants electricity to be expensive.

sfn42

an hour ago

Nuclear does not produce CO2. Nuclear energy is green energy.

High-Five

3 hours ago

Good link. Germany is the case where it works cleanly — more renewables, lower price, lower carbon, all moving the same direction.

leonidasrup

2 hours ago

No amount of solar panels will generate electricity without sun light. Also the amount sun light can shrink quite a lot in winter months at high latitudes and under cloud cover.

No amount of wind turbines will generate electricity without wind, or to be more precise:

Cut-in speed: 3–4 m/s (12–15 km/h) to begin spinning and producing power.

Cut-out / Stop speed: Above 25 m/s (90 km/h) where brakes are applied to prevent mechanical damage

Germany has to have backups, currently quite expensive, for all this times of missing renewables production.

boshomi

2 hours ago

The apparent volatility of electricity generation from a single wind turbine is negligible, because what counts is the wind and PV output over large areas. Due to regular weather fronts, electricity output from wind and PV in Europe is surprisingly stable; when there is less sunshine, there is more wind. In 2025, for example, the weekly electricity output from wind and solar PV was 14.0 TWh, with no week falling below 10.5 TWh. If more wind power were installed in Eastern Europe, the curves would flatten out even further.

https://www.energy-charts.info/charts/energy/chart.htm?l=de&...

leonidasrup

an hour ago

Yes, single wind turbine is negligible, what counts is the wind and PV output over extremely large areas because weather fronts are correlated over hundreds of km. Of course night/day cycle is correlated over whole Europe with few hours shift.

So in 100% renewables Europe scenario, you have build multiples of renewable production in each region.

You build enough renewables in Western Europe to power the whole Europe, you build enough renewables in Central Europe to power the whole Europe and you build enough renewables in Eastern Europe to power the whole Europe and build electric grid to transfer 2/3s of electricity produced in each region into other regions.

Can it be done? Yes, but it will be very expensive.

Many renewable energy modelers often ignore realities and costs of physical electric grid and model whole continent as copper plate which can transfer infinite amount of electricity from each to point to any other point.

For more realistic scenarios German government is looking into power-to-gas energy storage systems, where you convert renewable electricity to hydrogen, ammonia or ethanol and store it underground. There are also plans to import large part of these gases/liquids from other countries, so no energy independence in the future.

https://www.bundeswirtschaftsministerium.de/Redaktion/EN/Pre...

https://www.cleanenergywire.org/news/germany-revise-hydrogen...

flaburgan

2 hours ago

I think the point is, if you can decide when to consume electricity then you will do it when it's the cheapest, so let's put the cheapest when the low carbon sources are available. So the website is taking into account that renewables are not always available, that's exactly its point.

And the backup source for Germany is the nuclear electricity from France. The grid is at the European scale.

Havoc

3 hours ago

Mine is just flat pricing but I do try to align it.

UK has big variations in carbon intensity depending on how solar & wind is doing, so easy enough to make a small effort to align discretionary things like washing machine with that

There is also a very nice dashboard for UK grid that shows clearly what's going on at any point in time.

https://grid.iamkate.com/

High-Five

2 hours ago

That dashboard is great. The UK is probably the best case for this in Europe. Moving the washing machine is basically what my model assumes, except it assumes everyone does it every day. NESO publishes a carbon intensity API, so the UK is an easy one to add. On the list.

HexPhantom

5 hours ago

The harder question is probably whether dynamic pricing changes behavior without mostly becoming a penalty for people who have less flexibility in when they use electricity

bee_rider

2 hours ago

There should be a penalty for having less flexibility in consuming electricity. That’s how the market incentivizes us to figure out how to be flexible in our consumption.

We should probably also subsidize the conversion, for people who look at the incentives, want to become more flexible, but don’t have the money.

And we might have to handle some special cases—maybe hospitals, for example—where reliable power is an important social good. But these should be rare.

silon42

an hour ago

For households in Europe, there are some incentives to switch to heat pumps for heating... for best efficiency (and longevity), usually a heat pump needs to run at lower power constantly without switching off much.

And since the heat pump will be the biggest total consumer in a household (in winter), there is not a huge opportunity for flexibility.

bee_rider

a minute ago

This seems like a sort of complex trade-off (taking your word for it that they do run more efficiently when run continuously). We’d still probably prefer to run them on renewable energy and defer them when running on non-renewables, because the inefficiently consuming a plentiful resource that is not very damaging to produce, is better than efficiently consuming one that is destructive to produce.

But if we have multiple tasks with multiple levels of defer-ability (either due to efficiency benefits or due to people just wanting to run their dishwashers at a time convenient to them), it could be more complicated. But working out trade offs like this is what the market is for, right?

zacmps

3 hours ago

I've long thought there should be a standard mechanism for back pressure for loads that can defer their usage.

For example dishwashers, overnight battery charging, car charging, etc should be able to receive scheduling data from the grid to determine the best time to run.

Users could of course be given a choice whether to use grid scheduling in exchange for lower prices or not.

bee_rider

2 hours ago

This sort of thing was called “smartgrid” but it doesn’t seem to have caught on. Maybe we could lean into modern buzzwords.

The electricity distribution system is a big sparse graph. If they are allowed to pass signals back and forth, don’t look too close, and maybe we can call it an AI enhanced grid. Then we can call this sort of ability to schedule appliances based on those signals “closed loop AI enhanced green appliances” or something similarly buzzwordy.

jaapz

6 hours ago

In my country (for people with a so called "dynamic pricing" contract) the price of electricity already drops significantly when we have a load of green energy (wind, solar). I guess this is just a side effect of not having a well-balanced grid. But still that's already kind of a CO2-based pricing - although not directly

HexPhantom

4 hours ago

This is what makes me wonder how much additional benefit an explicit carbon signal actually buys you over normal dynamic pricing

Zeebrommer

5 hours ago

Mostly yes, but it works the other direction as well: a fossil power station may not want to completely shut down because it expects more demand later in the day, and offer a few hours of low cost electricity to stay in the merit order.

Maxion

4 hours ago

A lot of fossil power stations cant shut down for a few hours, they have to keep themselves on.

Gigachad

4 hours ago

Coal mostly. This is why coal is largely being phased out for natural gas which can cycle on and off as needed.

flaburgan

2 hours ago

The idea is interesting but unfortunately most of the people don't know the electricity price even now without this mechanism. This should be displayed on top of every washing machine everywhere to make it works

bethekidyouwant

an hour ago

Dryer? Are washing machines expensive to run?

flaburgan

43 minutes ago

Dryers are even worst but they are very uncommon in France where I live. Washing machines are bad because they have to warm the water.

maelito

5 hours ago

On the long-term, the French option of just running a low-carbon grid remains the obvious solution.

the_why_of_y

4 hours ago

Spending 19 billion € over 18 years to build 1.65GW Flamanville 3 is not quite obvious to me.

https://en.wikipedia.org/wiki/EPR_(nuclear_reactor)#Flamanvi...

Edit: compare this with China: they added 315 GW of Solar capacity in a single year (2025; see page 34 of the PDF).

https://www.irena.org/Publications/2026/Mar/Renewable-capaci...

(You can't compare nameplate capacity directly, but it can be safely assumed that 2 orders of magnitude more is ... actually more)

leonidasrup

3 hours ago

French nuclear supply chain atrophied quite lot in the last 30 years. Don't forget that even in France, president Hollande promised in 2014 to the voters to slash nuclear's contribution of power generation by 2025.

https://spectrum.ieee.org/renewables-up-nuclear-down-in-fren...

It was only when Russia started invasion in 2022, that the politicians in France started to change their opinion.

If you want build a nuclear power plant you go to nuclear supplier with uninterrupted experience in building nuclear power plants, like South Korea, China or Russia.

The South Koreans build Barakah nuclear power plant 5600 MWe for $32bn.

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

https://www.powermag.com/uaes-first-reactor-gets-go-ahead/

otherme123

an hour ago

> French nuclear supply chain atrophied quite lot in the last 30 years.

Because today it makes no economic sense. Supply chain for horse carts is also very atrophied.

>The South Koreans build Barakah nuclear power plant 5600 MWe for $32bn.

Still very expensive. Flamanville is an extreme when things go really bad, but 175 MWe for 1 bn is also very high. 1 bn buys ~1 GW of solar, ~1 GW of onshore wind, or ~3 GW of battery capacity. You should only build new nuclear either to get a better mix in the grid (up to 5% is the nuclear lobby recommendation), or because you have no sun and no wind.

leonidasrup

29 minutes ago

What would you need to replace a 1 GW nuclear power plant with 98% capacity factor?

Probably 1 GW solar power plant, together with 1 GW onshore wind and 1 GW of gas power plant. Then you have to also pay the natural gas to compensate for times of low solar + wind production. You can build battery storage to decrease the natural gas consumption, but how much battery storage do you have to build and how much can you reduce the natural gas consumption strongly depends latitude and local weather patterns.

https://solarbatteryatlas.electrotech-revolution.com/deploym...

BenoitP

an hour ago

France exports about 60TWh of electricity yearly for about 4B€.

Flamanville running at 100% generates 32TWh. It is amortized in 9 years. I'd say it's doing pretty okay even with its ballooning cost.

HexPhantom

5 hours ago

Sure, but I don't think the two ideas are really in conflict. A low-carbon grid should absolutely be the end goal, but even a mostly clean grid has hours that are cleaner than others

jarvist

4 hours ago

These approaches always measure the wrong thing though - the average carbon cost of electricity.

What you need to know is the marginal carbon cost, which will be much less variable as almost all dispatchable generation is fossil.

So yes, you should avoiding adding load when there is a severe supply crunch and the marginal power is generated by gas peaker plants (often gas turbine based), and use power when renewable generation is otherwise being curtailed, but most of the time the grid is firmly in the middle regime with a fairly average marginal cost.

_bent

3 hours ago

They are in conflict, because you can spend the same Euro only once. You could build a lot of batteries, solar panels and wind turbines for the cost of one nuclear plant

ZeroGravitas

2 hours ago

France has been offering lower prices at night to make the most of their nuclear since the 1960s.

Australia used similar tech to make the most of baseload coal overnight since the 1950s.

It's just a good idea, and should be used to get cheaper cleaner power in grids today too.

otherme123

an hour ago

It is not even an "idea". Is the consequence of nuclear power being so difficult to modulate to consumption. You give it for free by night, hoping that at least some people consumes, because the country is sleeping.

Solar energy aligns so much better, peaking its production when the consumption is high, going to zero when the consumption gets low, except for the diner time. In Spain we get really low prices (sometimes near 0) in the middle of the day, you don't have to plan or incentivize night consumption.

boshomi

4 hours ago

Not really. Nuclear power requires massive subsidies. In Germany, the "De Height" wind farm was completed in August. Sixty-four 15-MW turbines generate about 4 TWh of electricity annually, which is sold entirely on the open market without any EEG funding.

The market for baseload electricity has disappeared in Germany, as renewables push the residual load to zero or below for almost the entire year:

https://www.energy-charts.info/charts/power/chart.htm?c=DE&l...

The base load is an imaginary line passing through the troughs of the residual load curve.

djantje

3 hours ago

Yes, but then when the wind doesn't blow, you miss upto 960MW of capacity, you can choose how to fill that; solar, coal, gas, waterpower, diesel, nuclear.

And the question is, are those wind turbines without subsidy?

Here in the Netherlands some big energy users like Aldel already have stopped, those big users are also good in up and down scaling energy usage on demand, and also those products have to come from somewhere else now, so in the end the question is about energy and availability.

Some (or a lot of) subsidies can be justified.

boshomi

2 hours ago

A single wind turbine or a single PV module obviously provides only variable amounts of electricity. However, this is not the case for many PV modules and wind turbines spread across the entire continent. Wind and PV complement each other very well in Europe because of regular weather fronts; when there is little wind, there is more sunshine.

https://www.energy-charts.info/charts/energy/chart.htm?l=de&...

In Europe, the average weekly electricity generation in 2025 was 14.0 TWh, and no week fell below 10.2 TWh. In 2026, the average output was about 15.5 TWh, and so far, no week has fallen below 12.5 TWh.

Of course, batteries are needed for short-term storage, but with the creation of excess capacity in wind and solar power, the troughs below the load curve become narrower and shallower, drastically reducing the need for storage.

leonidasrup

2 hours ago

> when the wind doesn't blow

During day hours and with clear weather it's solar.

Currently at night in Germany it's: imports from other countries + coal power plants + gas power plants + little bit of hydro/biomass.

The plan for coming decade is to replace coal power plants with new subsidized gas power plants.

https://table.media/en/europe/news/gas-fired-power-plants-eu...

well_ackshually

2 hours ago

So, relying on others to fix your mess + catastrophic emissions + catastrophic but less so emissions + something pretty much at full capacity.

Archelaos

4 hours ago

Yep. Poisoning the planet with nuclear wast for a million years. 40,000 generations of our children will be happy and thankful.

leonidasrup

3 hours ago

Germany is currently operating the world biggest permanent storage for dangerous waste UTD Herfa-Neurode. Contains at least 690,000 tons of waste containing dioxins and furans, 220,000 tons of waste containing mercury, 127,000 tons of waste containing cyanide, and 83,000 tons of toxic waste containing arsenic. Nuclear waste is currently excluded, but I think it would not make a difference, especially because after about 400 years most dangerous fission products (Caesium-137, Strontium-90, and Iodine-131) decay away and only Plutonium and minor actinides stays. Mercury, arsenic, dioxins and furans stay forever.

https://de.wikipedia.org/wiki/Untertagedeponie_Herfa-Neurode

https://radioactivity.eu.com/articles/radioactive_waste/acti...

We learned quite lot about underground migration of plutonium over millennia because we studied the remnants of the natural nuclear fission reactor which nature run about approximately 1.7 billion years ago in Oklo, Gabon.

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

"Plutonium has moved less than ten feet from where it was formed almost two billion years ago contained in the sedimentary rocks that kept them from being dissolved or spread by groundwater."

http://large.stanford.edu/courses/2018/ph241/voigt2/

vikramkr

3 hours ago

I mean yeah. Nuclear waste is much safer than fossil fuel waste - deaths caused, radioactivity, etc

calinet6

4 hours ago

Man, I am so tired of reading slop.

Retr0id

3 hours ago

At this point I can tell fairly reliably from titles alone, "measured daily on 38 grids" is not the kind of thing a human would write in this context.

High-Five

3 hours ago

English is not my mother language. Yes, I polished. My prefered one was Carbon-aware electricity pricing but seemed so general.

axus

2 hours ago

Write it in your mother language, and then ask the AI to translate it; and post both

Retr0id

3 hours ago

I'm not commenting on the word choice or phrasing, but the choice of which information to include.

zeristor

6 hours ago

I’ve been thinking about this the CO₂ usage could be part of the price. I had toyed with having a two dimensional price, the price alongside the CO₂ usage, but I guess that way madness lies.

High-Five

6 hours ago

Hey guys, A small site that checks, every day, whether making electricity cheaper when the grid is clean would actually cut CO₂.

It reads yesterday's generation mix from ENTSO-E and the EIA, works out the carbon intensity hour by hour, and compares a normal tariff against two carbon-aware ones.

It started for Switzerland, which turned out to be a good place to start for an odd reason. Swiss electricity is already very clean — about 34 gCO₂/kWh — and yet it's one of the best grids in the set at 2.4%, because it imports from dirtier neighbours and its carbon intensity swings through the day. Louisville, at 741 g/kWh, gets 0.01%: it burns coal at the same rate around the clock, so there's no cleaner hour to move into.

Across 38 grids, the correlation between the saving and how dirty a grid is comes out slightly negative. With how much it varies, it's 0.91. Being dirty doesn't help at all — being uneven is the whole thing.

Fair warning: the demand response is a model rather than measured behaviour, and it uses average carbon intensity, not marginal. Happy to hear your thoughts.

Maxion

4 hours ago

Proportional decrease is not as useful in a climate change sense than actual decrease in co2 emissions. A grid that is highly sustainable with lots of wind and solar, but fossil peaker plants will have a lot more potential co2 savings in this model. It essentially makes dirty grids look cleaner.

addag

5 hours ago

Is it assumed that the total consumption remains the same (i.e there is an increase in consumption in clean energy when there is a decrease in less clean ones)?

Otherwise, there would be an obvious solution which is to increase the price all the time to reduce demand and thus reduce CO2 consumption, but it is impractical politically.

rconti

an hour ago

I had the same question but about price (and its related impact on consumption, which is your question) -- are we assuming total spent / total consumed are held constant?

It wasn't stated in the website and I didn't see anything about it from skimming the github. I didn't read the thesis, though :D

floodle

4 hours ago

How are you modelling how demand changes in response to price changes?

a115ltd

5 hours ago

Nice. On Octopus Agile in GB the price already tracks the mix (roughly 2.2x day-ahead wholesale), so the carbon-aware tariff exists in the wild.

What bounds the response is not willingness but plumbing: which import/export products the supplier lets you pair, and the export limit on a single-phase connection (about 3.7 kW). I reconstructed a 200 kWh home battery on the published half-hourly rates for June to August: the exact optimum moves 50 to 60 kWh a day, and the connection is a bigger lever than the software by a factor of two to three.