The pressure to reduce emissions, contain energy costs and gain resilience has prompted many industries to rethink their thermal generation model.
One of the most efficient and flexible solutions is the hybrid steam system, which combines a high-efficiency electric boiler with a conventional gas boiler. By intelligently managing the sources, this system can adapt to changing conditions, take advantage of dynamic energy prices and significantly reduce the carbon footprint.
In this article we explain how this system works and analyze two operating scenarios: one with PV integration and one without, based solely on hourly energy prices.
What is a hybrid steam system?
A hybrid steam generation system integrates:
- Electric boiler (99% efficiency): ideal to take advantage of renewable or economical electricity.
- Gas boiler (81% efficiency): backup to cover demand when electricity is not viable.
Both boilers operate in coordination through an advanced control system that selects in real time the optimal energy source based on price, availability and thermal requirements. This ensures efficiency and continuity without manual intervention.
Scenario 1: Electric boiler + photovoltaic plant
In this scenario, a 3.69 MWp solar photovoltaic plant is installed to supply the electric boiler during daytime hours. The gas boiler only comes on line when demand exceeds renewable production. This configuration is designed to maximize solar self-consumption and minimize the use of fossil fuels.
Main benefits
- More than 59% of the steam generated with solar electricity.
- Partial energy autonomy: less exposure to energy markets.
- Generation of Energy Saving Certificates (CAE) for efficiency improvements.
- Reduction in the cost per ton of steam.
Environmental impact
- Emissions reduction: 777 tCO₂/year avoided.
- +19,000 tCO₂ avoided during the 25-year life of the system.
- Significant reduction in natural gas consumption (>60%).
System profitability
- Estimated IRR: 15.4%.
- VAN: 2.320.960 €.
- Amortization period: 7 years
- Total CAPEX: €2,886,118.40 (with 25% subsidy)
- Cost of electricity (self-generated): 0 €/kWh (margin)
- Gas cost: 0.06598 €/kWh
- Grid electricity (where applicable): 0.0736 €/kWh
Scenario 2: Electric boiler without photovoltaic, hourly price activation
In this case, no solar plant is installed. The hybrid system takes advantage of fluctuations in the market price of electricity. The electric boiler is activated only when the hourly price of electricity falls below the cost of gas. The rest of the time, the gas boiler guarantees the supply.
This strategy allows obtaining efficiency without the need for initial investment in renewable generation.
Main benefits
- Operational flexibility: use of electricity only during economically advantageous hours.
- Energy savings: thanks to the superior efficiency of the electric boiler.
- No investment in PV plant: the grid infrastructure is used.
- Dynamic optimization: cost reduction without compromising production.
Environmental impact
- Reduction of gas consumption, especially during electricity off-peak hours.
- Avoided emissions similar to PV scenario if electrical activation is frequent (~60% of the time).
- Contribution to decarbonization without the need for onsite renewables.
System profitability
- Estimated IRR: 8-10% (dependent on hourly volatility)
- NPV: lower than PV scenario but no need for large CAPEX
- Payback period: 4 to 6 years (only for electric boiler)
- Approximate CAPEX: ~560,000 € (hybrid boiler only)
- Cost of electricity (from grid): 0.0736 €/kWh
- Gas cost: 0.06598 €/kWh
- Average savings per ton of steam produced with electricity: 18% energy, equivalent to ~29 €/tonGI_20250620_01_BRAS DEL…
Conclusion
The implementation of a hybrid steam system represents a strategic decision for industries seeking to advance sustainability without compromising productivity. Whether through its own renewable generation or by taking advantage of the dynamics of the electricity market, this technology:
- Reduces carbon footprint
- Increases operational efficiency
- Improves energy resilience
- Optimizes thermal costs
Choosing the best scenario depends on the context of each plant, but in both cases, the combination of electricity and gas represents a solid opportunity to transform the industrial energy model. Contact us and we will help you design the optimal solution for your facility.