Clean spark spread calculator: live German and Dutch power, your gas and carbon marks
Today's and tomorrow's day-ahead power prices, hour by hour, priced against the gas and carbon marks you type in. A GB version adds the Carbon Price Support. The method is set out in full below.
On Thu 24 Sep 2026, German day-ahead power averages €138.12/MWh across the day (Bundesnetzagentur | SMARD.de). At that price a gas plant running at the standard 49.13% efficiency breaks even if the gas it burns, plus the carbon that gas emits, costs no more than €67.86 per MWh of gas. Above that, its clean spark spread is negative. Dutch day-ahead power averages €155.59/MWh, a break-even budget of €76.44.
Tomorrow's auction (Fri 25 Sep 2026) has cleared: Germany €176.63/MWh, a budget of €86.78; the Netherlands €167.94/MWh, a budget of €82.51. Whether the clean spark spread is positive depends on gas and carbon prices, which exchanges license and this page does not print. Type your own marks below and the calculator prices every hour.
The spread by hour, today and tomorrow
Reference plant 49.13% efficient (gross CV) · 0.18404 tCO2 per MWh of gas · 0.3746 tCO2 per MWh of power · enter both marks to price the spread
HOUR BY HOUR TABLE · GERMANY
| Day | Hour | Power €/MWh | Budget €/MWh gas |
|---|---|---|---|
| 2026-09-24 | 00:00 | 130.37 | 64.05 |
| 2026-09-24 | 01:00 | 118.87 | 58.40 |
| 2026-09-24 | 02:00 | 114.51 | 56.26 |
| 2026-09-24 | 03:00 | 107.03 | 52.59 |
| 2026-09-24 | 04:00 | 107.32 | 52.73 |
| 2026-09-24 | 05:00 | 121.70 | 59.79 |
| 2026-09-24 | 06:00 | 147.81 | 72.62 |
| 2026-09-24 | 07:00 | 168.01 | 82.55 |
| 2026-09-24 | 08:00 | 173.76 | 85.37 |
| 2026-09-24 | 09:00 | 152.41 | 74.88 |
| 2026-09-24 | 10:00 | 111.73 | 54.89 |
| 2026-09-24 | 11:00 | 68.41 | 33.61 |
| 2026-09-24 | 12:00 | 16.00 | 7.86 |
| 2026-09-24 | 13:00 | 11.60 | 5.70 |
| 2026-09-24 | 14:00 | 19.69 | 9.67 |
| 2026-09-24 | 15:00 | 75.88 | 37.28 |
| 2026-09-24 | 16:00 | 117.68 | 57.81 |
| 2026-09-24 | 17:00 | 180.03 | 88.45 |
| 2026-09-24 | 18:00 | 226.04 | 111.05 |
| 2026-09-24 | 19:00 | 267.32 | 131.34 |
| 2026-09-24 | 20:00 | 260.00 | 127.74 |
| 2026-09-24 | 21:00 | 225.82 | 110.95 |
| 2026-09-24 | 22:00 | 204.87 | 100.65 |
| 2026-09-24 | 23:00 | 188.01 | 92.37 |
| 2026-09-25 | 00:00 | 181.94 | 89.39 |
| 2026-09-25 | 01:00 | 172.17 | 84.59 |
| 2026-09-25 | 02:00 | 165.64 | 81.38 |
| 2026-09-25 | 03:00 | 167.12 | 82.10 |
| 2026-09-25 | 04:00 | 169.71 | 83.38 |
| 2026-09-25 | 05:00 | 187.91 | 92.32 |
| 2026-09-25 | 06:00 | 235.27 | 115.59 |
| 2026-09-25 | 07:00 | 261.40 | 128.43 |
| 2026-09-25 | 08:00 | 249.74 | 122.70 |
| 2026-09-25 | 09:00 | 196.24 | 96.41 |
| 2026-09-25 | 10:00 | 158.54 | 77.89 |
| 2026-09-25 | 11:00 | 108.41 | 53.26 |
| 2026-09-25 | 12:00 | 60.19 | 29.57 |
| 2026-09-25 | 13:00 | 30.11 | 14.79 |
| 2026-09-25 | 14:00 | 39.89 | 19.60 |
| 2026-09-25 | 15:00 | 87.04 | 42.76 |
| 2026-09-25 | 16:00 | 154.52 | 75.91 |
| 2026-09-25 | 17:00 | 199.00 | 97.77 |
| 2026-09-25 | 18:00 | 241.43 | 118.61 |
| 2026-09-25 | 19:00 | 303.43 | 149.07 |
| 2026-09-25 | 20:00 | 252.17 | 123.89 |
| 2026-09-25 | 21:00 | 224.17 | 110.14 |
| 2026-09-25 | 22:00 | 206.35 | 101.38 |
| 2026-09-25 | 23:00 | 186.76 | 91.76 |
Cyan: what each day's baseload day-ahead price paid a 49.13% plant per MWh of gas, gas and carbon together. Enter marks to draw your own cost line across it.
What is live, what is yours, and why
A clean spark spread needs three prices. Only the power price is published under a licence that lets us show it, so the gas and carbon legs are always your marks. We checked each candidate source's terms on 24 Sep 2026.
| Leg | On this page | Source and credit | Why |
|---|---|---|---|
| Power, Germany-Luxembourg and Netherlands | Live day-ahead auction, quarter-hours averaged into hours | Bundesnetzagentur | SMARD.de, licensed CC BY 4.0. Changed by Voltstack: averaged into hours and daily means, break-even budgets derived. | SMARD publishes its market data for free reuse with attribution. |
| Power, Great Britain | Your mark | None | The GB day-ahead auction runs on Nord Pool's N2EX, whose terms need its written consent to republish prices. |
| Gas, Germany and Netherlands | Your mark, per MWh (gross CV) | None | TTF prices belong to ICE Endex and the German hub price to EEX. Official alternatives either pass on those exchange prices or need written consent. |
| Gas, Great Britain | Your mark, pence per therm or £/MWh | None | NBP quotes are licensed. National Gas's System Average Price needs its written consent to reproduce. |
| Carbon, EU | Your EU allowance mark, per tonne | None | Secondary allowance prices are EEX and ICE data. Auction results are periodic and cannot stand in for a daily price. |
| Carbon, Great Britain | Your UK allowance mark, plus Carbon Price Support of £18/t added for you | CPS rate: DESNZ guidance. Contains public sector information licensed under the Open Government Licence v3.0. | UK allowance auction results sit behind ICE's click-through terms; the CPS rate is a published tax rate. |
| Reference plant | 49.13% efficiency, 0.18404 tCO2 per MWh of gas, both gross CV | ICIS European Daily Electricity Markets methodology, 28 Jan 2020, p.18 | The convention traded spark spreads use. See the method below. |
What is a clean spark spread?
The spark spread is what a gas-fired power plant earns for turning gas into electricity: the price of one MWh of power minus the cost of the gas burned to make it. The clean spark spread also takes off the cost of the carbon allowances the plant has to surrender for that gas. It is a gross margin. Operating costs, start-ups, network charges and the capital cost of the plant all come out of it, so a plant needs the clean spark spread well above zero, not just above it.
Traders watch it because it tells you when gas plants run. When the clean spark spread is positive, a gas plant makes money on the next MWh and will generate; when it turns negative, it would rather sit idle. Gas plants set the European power price in many hours, which is why power prices track gas. When wind and solar cover demand, the price falls below what a gas plant needs and its spread goes negative.
How to calculate the clean spark spread
with the standard plant: power - 2.0354 x gas - 0.3746 x carbon
The gas price is per MWh of gas, the carbon price per tonne of CO2, and the result per MWh of power. 2.0354 is the heat rate, the MWh of gas a 49.13% plant burns for each MWh of power. 0.3746 is the tonnes of CO2 it emits per MWh of power, which is 0.18404 tonnes per MWh of gas divided by the efficiency.
Power at €100.00/MWh, gas at €40.00/MWh, carbon at €80.00 a tonne.
gas cost €40.00 / 0.4913 = €81.42 · carbon cost €80.00 x 0.3746 = €29.97
spark spread €100.00 - €81.42 = +€18.58 · clean spark spread +€18.58 - €29.97 = -€11.38
The plant makes €18.58 on the gas alone and loses €11.38 once it pays for carbon, so it stays off. Its break-even power price at these marks is €111.38/MWh.
The break-even budget shown above
Run the formula backwards and the power price tells you the most a plant can spend. Multiply the power price by 0.4913 and you get the money one MWh of power pays per MWh of gas burned. If gas plus the carbon that gas emits (0.18404 t, so carbon price x 0.18404) costs less than that, the clean spark spread is positive. This budget needs no gas or carbon price, which is why the page can show it live. It is a ceiling for gas and carbon together, not a gas price.
What is the clean spark spread in the UK?
The formula is the same, in pounds, with two GB twists. GB gas trades in pence per therm, so divide by 2.93071 to get pounds per MWh. And a GB generator pays for carbon twice: it surrenders UK allowances and also pays the Carbon Price Support, a tax on fuel for power generation that HM Treasury holds at £18 per tonne of CO2. The CPS alone costs a 49.13% plant £6.74 per MWh of power, which is one reason GB gas plants need a higher power price than continental ones to run.
power £120.00/MWh · gas 100p/therm = £34.12/MWh · allowances at £50.00 a tonne
gas cost £69.45 · carbon (£50.00 + £18.00) x 0.3746 = £25.47 · clean spark spread +£25.08
The GB tab of the calculator takes all three prices as your marks, because none of them is licensed for us to republish.
What is a spark spread hedge?
A spark spread hedge locks in a gas plant's margin by trading all three legs for the same delivery period at once: sell the power forward, buy the gas the plant will burn (2.0354 MWh per MWh of power at the reference efficiency) and buy the allowances it will need (0.3746 t per MWh). Whatever prices do next, gains and losses on the three legs offset and the plant keeps the spread it locked. Generators use it to secure running margins a season or a year ahead. Traders run it the other way to take a view on the spread without owning a plant.
The ratios are why the efficiency convention matters. A desk that hedges a newer plant running at 55% (gross) with 49.13% ratios buys about 12% more gas than the plant will burn.
How the numbers are built
- Power. Day-ahead auction prices for the Germany-Luxembourg and Netherlands bidding zones, read from SMARD (series 4169 and 256). The auction clears in quarter-hours; each hour is the mean of its four. Baseload is the mean of a day's hours. Peak is 08:00 to 20:00 local time on every day, weekends included, whereas exchange peak products run Monday to Friday only. Days are local days, so the October clock change gives a 25-hour day.
- Reference plant. 49.13% efficiency and 0.18404 tCO2 per MWh of gas, both on a gross calorific value basis, as set out in the ICIS European Daily Electricity Markets methodology (28 Jan 2020, p.18). That gives a heat rate of 2.0354 and a carbon intensity of 0.3746 t per MWh of power.
- Why not 0.202. The widely quoted 0.202 t per MWh is the IPCC default for natural gas on a net calorific value basis. European gas trades per MWh of gross calorific value, so the efficiency and the emission factor have to be gross as well. Pairing 0.202 with a gross-basis 49.13% overstates the carbon leg by about 10%.
- Great Britain. Carbon Price Support of £18 per tonne is added to your UK allowance mark. Gas typed in pence per therm is divided by 2.93071 to give pounds per MWh.
- Your marks. Applied flat to every hour, and on the history chart to every past day. That line shows which days your marks would have cleared; it is not a history of gas or carbon prices. Marks live in the page address after the # sign. Browsers do not send that part to a server, so we never see them.
- What the spread leaves out. Variable operating costs, start-up costs, network charges, capacity payments and each plant's own heat rate. It is a benchmark for a standard plant, not any one plant's margin.
- Refresh. The page rebuilds every 15 minutes. The next day's auction clears around midday CET and shows here once SMARD publishes it.
Quick answers
What is the German clean spark spread today?
We can give you the power side and the break-even, not the spread itself. On Thu 24 Sep 2026, German day-ahead power averages €138.12/MWh across the day (Bundesnetzagentur | SMARD.de). At that price a gas plant running at the standard 49.13% efficiency breaks even if the gas it burns, plus the carbon that gas emits, costs no more than €67.86 per MWh of gas. Above that, its clean spark spread is negative. Dutch day-ahead power averages €155.59/MWh, a break-even budget of €76.44. Whether the spread is positive depends on the gas and carbon prices you use. Exchange quotes for both are licensed, so this page does not print them; type your own marks into the calculator and it prices every hour of today and tomorrow.
What is a clean spark spread?
The clean spark spread is the gross margin of a gas-fired power plant: the price of one MWh of electricity minus the cost of the gas burned to make it and the cost of the carbon allowances that gas requires. It leaves out operating, start-up and capital costs, so a plant needs it comfortably above zero to cover those.
How do you calculate the clean spark spread?
Clean spark spread = power price - gas price / efficiency - carbon price x emission factor / efficiency. With the market convention of 49.13% efficiency and 0.18404 tCO2 per MWh of gas (both on a gross calorific value basis), that is power - 2.0354 x gas - 0.3746 x carbon. Hypothetical example: power at €100.00, gas at €40.00 and carbon at €80.00 a tonne give €100.00 - €81.42 - €29.97 = -€11.38/MWh.
What is the clean spark spread in the UK?
The same formula in pounds, with two GB twists. Gas is quoted in pence per therm, so divide by 2.93071 to get pounds per MWh. And a GB generator pays for carbon twice: it surrenders UK allowances and also pays the Carbon Price Support, a tax held at £18 per tonne of CO2. The CPS alone costs a 49.13% plant £6.74 per MWh of power.
What is a spark spread hedge?
A spark spread hedge locks in a gas plant's margin by trading all three legs for the same delivery period at once: sell the power forward, buy the gas the plant will burn (2.0354 MWh per MWh of power at the reference efficiency) and buy the carbon allowances it will need (0.3746 t per MWh). Later price moves then offset across the legs and the plant keeps the spread it locked.
Why does this page not show TTF or EUA prices?
The Dutch TTF and German THE gas prices and EU and UK carbon allowance prices are exchange data owned by ICE and EEX, and their licences do not let us republish them. The day-ahead power price is published by the German regulator's SMARD platform under an open licence, so that part is live. The gas and carbon legs are your marks, kept in the page address after the # sign, which browsers never send to a server.
Free to reproduce with credit
You may quote any figure on this page with a credit to Voltstack and a link here. The power prices must also carry the SMARD credit below. Suggested citation:
German day-ahead power averaged €138.12/MWh on 24 Sep 2026, which pays a 49.13% efficient gas plant up to €67.86 per MWh of gas for gas and carbon together. Source: Voltstack Intelligence, Clean Spark Spread Calculator; power data Bundesnetzagentur | SMARD.de (CC BY 4.0). https://voltstack.energy/clean-spark-spread
The calculator's CSV holds the hourly power prices and break-even budgets for today and tomorrow and a year of daily baseload, plus your spread columns when you have entered marks.
Run this spread on your own marks, on a live desk
The Voltstack workspace keeps your gas and carbon marks next to live day-ahead power for the European zones it covers and reprices the clean spark spread as the auction prints. The free trial starts with a sign-up; there is nothing to install.
More European energy research
Disclaimer: This calculator is produced by Voltstack Intelligence for information only and is not investment advice. Power prices come from SMARD and may be revised there. Spreads are computed on marks you enter, for a standard reference plant, and are not any plant's actual margin. Corrections to research@voltstack.energy.
Sources: Bundesnetzagentur | SMARD.de (day-ahead prices, CC BY 4.0); ICIS European Daily Electricity Markets methodology (plant convention); DESNZ and HMRC via gov.uk (Carbon Price Support, Open Government Licence v3.0).