Carbon-aware electricity pricing, measured daily on 38 grids

(carbonawarepricing.com)

47 points | by High-Five 3 hours ago

8 comments

  • boshomi 27 minutes 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.

  • jaapz 2 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 1 hour ago
      This is what makes me wonder how much additional benefit an explicit carbon signal actually buys you over normal dynamic pricing
    • Zeebrommer 1 hour 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 1 hour ago
        A lot of fossil power stations cant shut down for a few hours, they have to keep themselves on.
        • Gigachad 38 minutes ago
          Coal mostly. This is why coal is largely being phased out for natural gas which can cycle on and off as needed.
  • maelito 1 hour ago
    On the long-term, the French option of just running a low-carbon grid remains the obvious solution.
    • the_why_of_y 21 minutes 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)

    • HexPhantom 1 hour 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 44 minutes 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.

    • boshomi 17 minutes 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.

    • Archelaos 38 minutes ago
      Yep. Poisoning the planet with nuclear wast for a million years. 40,000 generations of our children will be happy and thankful.
      • vikramkr 15 minutes ago
        I mean yeah. Nuclear waste is much safer than fossil fuel waste - deaths caused, radioactivity, etc
  • HexPhantom 1 hour 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
  • calinet6 50 minutes ago
    Man, I am so tired of reading slop.
  • zeristor 2 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 3 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 1 hour 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 1 hour 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.

    • floodle 59 minutes ago
      How are you modelling how demand changes in response to price changes?
  • a115ltd 1 hour 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.