We all want to leave the next generations a world worth living in. Therefore, we must decarbonize immediately and decisively to mitigate climate change. If we are forced to use fossil fuels in certain applications, we must do so efficiently. And if we already have renewable energy sources on the grid, we must avoid curtailments.

  • ELWA Power-To-Heat systems have been developed to make a valuable contribution to decarbonization as a highly efficient technology in the field of sector coupling.
  • ELWA Power-To-Heat systems can be perfectly combined with heat pumps, combined heat and power plants, battery systems and large thermal storage units. We will be happy to advise you on how the various technologies can be perfectly combined.

ELWA P2H Advantages

  • Safety concept for 24 / 7 fully automated operation
  • Low maintenance & individually replaceable heating elements
  • Preventive maintenance & remote maintenance
  • Modular concept for very high system power
  • Powerful control system for extremely fast response times
  • Suitable for primary and secondary control power (PRL & SRL)
  • Control of additional system components possible

P2H MLB (modular load bank)

Modular system consisting of three units with a total capacity of 4.7 MW. This plant is

integrated into a concept with a battery system and a large thermal storage. The

municipality of Fuchstal (Germany) operates its own wind farm and uses this system to

store surplus electricity in the battery bank or, via the ELWA P2H system, in the thermal

storage tank, from which the local district heating network can be served. Thus,

shutdowns of the wind power plants can be avoided.



The maximum power in a single heater is currently 1 MW at 400 VAC and 1.68 MW at 690 VAC. For higher powers, multiple heaters connected in series are used. The total power of the system is theoretically not limited. With our modular system MLB, we can reasonably cover outputs up to the high 2-digit MW range. With the modular system, the heater and switchgear are delivered ready for operation on a common mounting frame. This considerably reduces on-site expenses.

See table below for common plant sizes.

We combine the switchgears with our heaters for liquids and gases in order to cover the most different temperature ranges and operating conditions. If your process involves higher temperature ranges, for example up to 800 °C for air heating, please contact us.

Operating temperatures

Water / Steam 220 °C
Thermal oil 300 °C
Operating pressures

As standard we can supply systems up to 16 bar, higher operating pressures are available on request.

All projects realized by ELWA so far were applications on AC networks in the low voltage range. Theoretically, direct currents can also be switched and converted into heat in the heating elements. However, this requires a considerable effort especially at low voltages because of the high currents to be handled. Also theoretically, medium voltage systems can be realized – in all cases considered so far, however, a realization in the low voltage range was more economical and, above all, technically more sensible.

We can handle all voltages from 230 to 690 VAC with our standard radiators. If still possible in the project planning phase, we recommend to provide 690 VAC for the Power To Heat system. This allows a significant cost saving compared to lower voltages. The switched currents are significantly lower and we can dimension both the switchgear and the heaters smaller. Or looked at the other way around: We get higher power at the same currents through the switchgear and the heater.

In addition to the usual mains frequencies 50 & 60 Hz, we can also process fixed/variable frequencies of approx. 20 to 75 Hz. The adaptation is done by using special switching elements and fuses.

Due to the very low latency of our plants during power control, the plants are technically suitable for both secondary and primary control power. For the use as control power a prequalification of the plant has to be carried out. Since the systems monitor themselves and also send timely messages on recommended maintenance work, handling in the Redispatch 2.0 environment is facilitated.

Plant safety in accordance with DIN EN 12828:2013-04 is ensured by both electronic and hydraulic components. Safety-relevant actions are carried out by a safety switching device and possibly supplemented by further measures in the PLC control system. Errors are logged in the PLC and can then be read out by ELWA either locally via the display or via the remote maintenance router.

P2H MLB (modular load bank)

ELWA P2H with 22 MW system power as precise counterload for gas turbines. The

system can represent any load profiles for the turbine test benches and provide heat for

the building heating of the property. Variable voltages and frequencies can be handled.

Performance data

P2H SLB individual systems (complete systems)
ELWA P2H SLB systems are tested and ready for operation on delivery. The switchgear and heater are mounted on a common frame. The entire sensor system and safety technology is pre-installed.
P2H SLB power kW → 50 100 150 250 500 750 1000 1250 1500
operating voltage 400 VAC
690 VAC

P2H SLB-PM individual systems (complete systems)
ELWA P2H SLB-PM systems are based on the SLB systems, supplemented with a circulation pump and mixing valve to achieve precise flow temperatures with power-controlled operation.
P2H SLB-PM power kW → 50 100 150 250 500 750 1000 1250 1500
operating voltage 400 VAC
690 VAC

P2H CLB individual systems (decentralized system)
ELWA CLB systems are primarily used when switchgear and heaters have to be installed separately for structural reasons.
P2H CLB power kW → 50 100 150 250 500 750 1000 1250 1500
operating voltage 400 VAC
690 VAC

P2H MLB modular system
The ELWA P2H MLB system was developed to be able to cover large capacities flexibly. The systems can be expanded at any time and are particularly suitable for high-availability systems due to their distributed controls and individually operable components.
P2H MLB power kW → 50 100 150 250 500 750 1000 1250 1500
operating voltage 400 VAC
690 VAC

P2H MOD individual system design
Under ELWA P2H MOD we summarize all projects in which we can apply our decades of experience in the development of complex systems in shipbuilding, power plant construction and industry. For our customers, we manufacture systems for the reliable supply of thermal processes with water or thermal oil as the heat transfer medium. We design decentralized or centralized switchgear and work together with proven manufacturers of pumps and heat exchangers to develop customized solutions.