Electricity is 16% cheaper than the European average, and gas is 8% more expensive: in France, an electric steam boiler is cost-effective below a specific price ratio. Here’s how to calculate it for your small business.
In France, it’s often said that nuclear power makes electrification a no-brainer. The reality is more nuanced and can be summed up in a single figure: the ratio between what you pay for a MWh of electricity and what you pay for a MWh of gas. Below a certain threshold, producing steam with electricity costs less than producing it with gas. Above that threshold, it doesn’t. This article explains that threshold, the French average, and the factors that influence the outcome for a small business.
The starting point: a real French advantage, but one that’s insufficient on its own
According to statistics from the French ministry (SDES), French companies paid an average of 148.8 €/MWh (excluding VAT) for electricity in 2025, 16% less than the European Union average. At the same time, their natural gas cost 65.7 €/MWh PCS, 8% more than the European average.
No major neighboring industrialized country combines such competitive electricity prices with such expensive natural gas. But the average ratio remains around 2.3: a MWh of electricity still costs more than twice as much as a MWh of natural gas.
The threshold: between 1.2 and 1.7, depending on your current boiler
An electric resistance boiler converts about 99% of the electricity into steam. A gas boiler loses energy through flue gases, blowdowns, shutdowns, and startups. Furthermore, gas is billed based on PCS, while efficiency ratings are reported in PCI, resulting in a difference of about 10 %.
The formula is simple:
Threshold = 0.99 ÷ (actual PCI efficiency of your gas boiler × 0.90)
| Actual Efficiency of the Gas Boiler (PCI) | Typical scenario | Threshold ratio |
|---|---|---|
| 90% | New boiler, stable output | 1.22 |
| 85% | Proper boiler, variable load | 1.29 |
| 75% | Old or oversized boiler | 1.47 |
| 65% | Intermittent demand, short cycles, long steam network | 1.69 |
If your electricity-to-gas ratio is below your threshold, each metric ton of steam costs less when using the electric boiler.
Calculate your ratio in two minutes
- Take your most recent electricity bill: total amount (excluding VAT) ÷ MWh consumed.
- Do the same with your gas bill (in MWh PCS).
- Divide the first number by the second.
For an SME, the published order of magnitude figures are approximately 205 €/MWh for electricity (20 to 499 MWh/year) and €86/MWh PCS for gas (278 to 2,778 MWh/year), which is a ratio of about 2.4. Let’s be honest: at that level, in a boiler room operating continuously, gas is still cheaper per MWh. The question is what lowers your ratio or raises your threshold.
Five factors that change the calculation
- Actual performance, not the rating on the nameplate. An SME that needs steam for a few hours a day is operating its gas boiler far from its optimal operating point. Measure the gas consumed and the steam actually used: the ratio is usually around 1.5–1.7.
- The reduced excise tax on electricity. The standard excise tax rate is 26.35 €/MWh for businesses, compared to 16.66 €/MWh for natural gas. However, depending on your level of electricity intensity, the excise tax on electricity can drop to 5.50 or even 3.00 €/MWh—a reduction of up to 20 €/MWh.
- The times when electricity is cheap. The wholesale price varies greatly throughout the day and week: in October 2026, on some Sundays it averaged about 26 €/MWh, while on several weekdays it exceeded 200 €/MWh. An electric boiler starts up in minutes and is regulated in stages: with the right contract, you can generate power when the price per MWh is lowest.
- Gas price volatility. In August 2026, wholesale gas prices averaged 61.5 €/MWh, compared with 31.6 €/MWh a year earlier. The French regulator (CRE) notes that this increase was only very partially passed on to French electricity prices. A ratio calculated today can be reversed in a single quarter.
- The investment. No burner, no chimney, no gas line, no combustion control. And starting in September 2026, the CEE IND-UT-141 subsidy will cover part of the installation cost, with a subsidy of nearly ×3 for low-power systems. We explain it here: France Pays to Electrify Your Industry (IND-UT-141).
Cases in which the utility company is already profitable today
- Plant without a gas line, powered by propane or diesel.
- Small or intermittent demands: cleaning, sterilization, batch cooking, laboratory.
- New installation or expansion: no boiler room needs to be built; the boiler is installed next to the process.
- Clean steam for food, cosmetics, or pharmaceutical applications.
- Photovoltaic self-consumption with surplus power during the day.
Frequently Asked Questions
Is an electric steam boiler cost-effective in France in 2026?
Yes, when your electricity-to-gas price ratio is below your threshold, which ranges from 1.2 to 1.7 depending on the actual efficiency of your gas boiler. CEE subsidies, the reduced excise tax, and time-of-use pricing bring that threshold closer.
How much power does an SME need?
Most SMEs’ needs range from a few kW to 180 kW, or up to about 250 kg/h of steam. This is the range covered by our NGV line.
Do you need to upgrade the electrical service?
It depends on the contracted power and the available margin. That’s the first thing we check in a study.
Your ratio, calculated for free
Send us your two most recent electricity and gas bills and your steam requirements: we’ll calculate your ratio, your threshold, and the appropriate sizing. Giconmes has been manufacturing electric steam boilers since 1957.