Heat2Power‑Applications []

General

The Heat2Power-Technology has the primary goal of generating electricity – not just heat as with classic machines.

• Technological Basis: Further development of the Stirling process into the Heat2Power Engine.
• Efficiency: Higher efficiency through optimized combustion, regenerator, and High-Temperature Thermal Storage.
• Emissions: Significantly lower pollutant emissions compared to diesel or gas engines.
• Flexibility: Utilization of waste heat from industrial processes, flue gases, residues, biogas, or landfill gas.
• Energy Transition: Conversion of surplus power from wind and solar energy into electricity via High-Temperature Thermal Storage.
• Baseload capability: Reliable power supply even during periods of low wind and solar output.
• Substitution: Replacement of inefficient large engines and microturbines, reducing primary energy consumption.

Ship Propulsion

The Heat2Power engine opens up new possibilities for climate-friendly hybrid propulsion at sea and significantly reduces emissions and fuel consumption.

• Emissions: Ships cause around 2% of global CO₂ emissions, as well as significant amounts of NOₓ and particulate matter.
• Hybrid propulsion: The Heat2Power engine delivers electricity to a buffer battery at optimal efficiency.
• Advantages: Silent, low-vibration operation, fewer auxiliary units, no long shaft tunnel required.
• Fuels: Flexible use of H₂, bio-LNG, or diesel – without methane slip.
• Environmental friendliness: External combustion reduces pollutant emissions, often without additional exhaust gas cleaning.
• Passenger ships: Particularly advantageous due to quiet, low-emission operation and high comfort for the Passengers.

Submarines

The Heat2Power-Engine opens up entirely new possibilities for submarine propulsion: It replaces conventional diesel and AIP systems with a single, efficient solution, increasing range, efficiency, and stealth.

• Previous Technology: Conventional submarines use two systems – diesel for surface travel and AIP (usually fuel cells or Stirling engines) for submerged travel.
• Limitations: AIP delivers only a few hundred kW, sufficient for extended underwater stays, but not for long ranges at cruising speed.
• Solution: A single Heat2Power engine replaces both systems and enables full power both above and below the surface.
• Oxygen Supply: 1 kg of diesel requires 0.58 kg of O₂; 1000 liters of diesel require only 1.0 m³ of O₂ at 335 bar – technically easy to achieve.
• Cooling & Efficiency: The expansion of the compressed O₂ produces a significant temperature drop, which is used for cooling and increasing efficiency while simultaneously reducing the heat signature.
• Advantages: Long range, less complexity, silent operation, high efficiency, and smaller footprint.
• Conclusion: The Heat2Power engine makes nuclear submarines obsolete.

Typical design of modern conventional submarines. Here: HDW's U-216 concept with fuel cell AIP.

Steel Works

Enormous amounts of waste heat are generated in steel production, which have so far been insufficiently utilized. The Heat2Power-Engine efficiently harnesses these energy sources and converts them into electricity – a crucial contribution to the energy transition and the reduction of emissions.

• Problem:The supply of waste heat exceeds the demand; turbines operate at low efficiencies.
• Limitations: Turbines require constant heat sources and can only utilize extracted heat (steam/gas).
• Solution: The Heat2Power engine utilizes waste heat directly via recirculating air circuits and Thermal Storage.
• Efficiency: Even heat losses such as wall heat or sensible heat in coke ovens can be used for electricity production.
• Potentials: Converter gas, exhaust gases from electric arc furnaces, blast furnace slag, and cast steel are usable sources.
• Advantages: Higher efficiency, continuous electricity generation, and significant emission reduction.

Thermal Storage

The Heat2Power-Engine in combination with High-Temperature Heat Storage enables efficient intermediate storage and reconversion of energy into electricity. This allows peak loads from renewable energies to be smoothed and a reliable base load to be provided – a key to the energy transition.

• Problem: Wind and solar power are volatile; Peak power is often curtailed or exported at negative prices.
• Solution: High-temperature thermal storage absorbs excess energy and releases it as needed.
• Heat2Power Engine: Reconversion of stored heat into electricity with high efficiency – also suitable for baseload power generation.
• Efficiency: The combination of storage and Heat2Power Engine achieves electrical efficiencies of 50-60%, significantly higher than microturbines (25-30%).
• Flexibility: Hybrid operation is possible – when the storage system is empty, methane or biomass can be used in the short term.
• Superiority over batteries: A High-temperature thermal storage systems offer higher storage capacity per euro, a longer lifespan, and require no critical raw materials such as lithium or cobalt – thus significantly surpassing the overall performance of conventional battery systems.
• Decentralization: Storage engine tandems can be deployed in neighborhood-based systems, e.g., within the framework of combined heat and power (CHP).

Aluminium works

The primary aluminum production process from bauxite generates enormous amounts of waste heat – which has so far remained largely unused. The Heat2Power-Engine offers an efficient solution for recovering this energy and converting it into electricity.

• Problem: Approximately 45% of the electrical energy required is lost as waste heat through the walls of the electrolysis cells.
• Previously: Until now, there were no practical technical solutions for this surface heat.
• Solution: Recirculating air systems can absorb the heat and transfer it directly to the Heat2Power engine.
• Efficiency: Reconverting the waste heat into electricity significantly reduces overall energy consumption and production costs.
• Advantages: Continuous power generation, reduced dependence on external power supplies, contribution to decarbonization.

Waste heat from industrial processes

Large amounts of waste heat are generated in almost all industrial processes – often unused and lost. The Heat2Power-Engine unlocks this potential and transforms it into usable electricity, potentially replacing several conventional power plants.

• Potential: According to Fraunhofer IPM, the use of industrial waste heat in Germany could replace five to ten coal-fired power plants.
• Problem: Only one-third of the energy used is currently utilized; The rest is lost as waste heat.
• Challenge: Waste heat often occurs cyclically and must be temporarily stored or smoothed.
• Solution: Thermal storage absorbs the energy and continuously powers the Heat2Power engine.
• Examples: Heat sources such as converter gas, electric arc furnaces, blast furnace slag, or wall heat can be used directly.
• Advantages: Simple integration, lower costs, and new opportunities to utilize previously untapped heat sources.

Examples of implementation

Continuous electricity generation by a Heat2Power plant in the event of cyclical heat generation.

Waste heat utilization

Periods with waste heat generation: Electricity generation via Heat2Power-System and simultaneous charging of a High-Temperature Thermal Storage System.

After the energy has been transferred to the Heat2Power-Engine or to the High-Temperature Thermal Storage, the circulating gas still has sufficient residual temperature to feed a district heating network or an atmospheric two-zone storage system.

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Periods without waste heat generation: Electricity generation by Heat2Power System through the discharge of a High-Temperature Thermal Storage.

Smoothing of peak power from renewable energy generation

Periods of peak power generation: Excess production is used to charge a High-Temperature Thermal Storage.

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Periods without peak power generation: Electricity generation by Heat2Power System through the discharge of a High-Temperature Thermal Storage.

Landfill and low-level gases

The decomposition of organic waste produces landfill gases with a high methane content. These gases are harmful to the climate and are currently mostly flared off – the heat remains unused. The Heat2Power Engine offers an efficient way to convert this energy into electricity while simultaneously reducing emissions.

• Origin: Landfill gas consists of methane (CH₄), carbon dioxide (CO₂), and other gases such as hydrogen sulfide.
• Problem: With a decreasing methane content (<25%), it is referred to as "low gas"—currently hardly usable for engines or turbines.
• Climate Impact: Methane is 20–25 times more harmful to the climate than CO₂; unburned methane ("methane slip") often escapes into the atmosphere.
• Previous Uses: Flaring or gas engines—both with low efficiency and high methane slip.
• Solution: Feeding of the Heat2Power Engine with landfill or low-grade gases via specially developed burners. ( COSTAIR-burner ).
• Advantages:: Efficient combustion without methane leakage, continuous electricity generation, reduction of greenhouse gases.
• Contribution to the energy transition: : Utilizing previously untapped gas sources as a climate-neutral electricity source.

Cement Plants

Cement production is one of the most energy-intensive industrial processes worldwide and a significant source of CO₂ emissions. Die Heat2Power-Engine bietet hier eine Möglichkeit, die immensen Abwärmemengen effizient zu nutzen und in Strom umzuwandeln.

• Problem: Durchschnittlicher Energiebedarf liegt bei rund 3,14 GJ pro Tonne Zement – mit hohen CO₂‑Emissionen.
• Emissions: Approximately 35% come from fossil fuels, 65% from direct process emissions. (Conversion of CaCO₃ to CaO + CO₂).
• Waste heat: Large quantities are produced on surfaces such as rotary kilns or coolers – which have hardly been used so far.
• Solution: The Heat2Power engine can absorb this surface heat via circulating air systems and convert it into electricity.
• Advantages: Additional energy generation, reduction of external electricity demand, contribution to decarbonization.
• Example: Utilization of primary and secondary air from coolers as well as surface heat of the rotary kiln.

Combined heat and power plants (CHP)

Combined heat and power (CHP) plants utilize residual energy from other processes, but currently generate only a small amount of electricity. The Heat2Power Engine significantly increases electrical efficiency and makes CHP plants an important component of the energy transition.

• Previously: Conventional combined heat and power (CHP) plants generate approximately 30–40% electricity; the remainder is used as heat.
• Problem: The low electricity output is insufficient to meet the requirements of the energy transition.
• Solution: The Heat2Power engine significantly increases the proportion of electrical energy.
• Advantages: Higher efficiency, better utilization of residual energy, and reduced emissions.
• Contribution: A further step towards decarbonization and the efficient use of existing energy sources for the energy transition.

The future

The Heat2Power-Engine opens up entirely new perspectives for a sustainable energy supply. It combines efficiency, climate protection, and economic viability, thus becoming a key component of the energy transition.

• Integration: Can be used in industry, shipping, submarines, power plants, and decentralized applications.
• Flexibility: Can be combined with High-Temperature Thermal Storage, renewable energies, and hybrid operation.
• Climate protection: Reduction of CO₂ emissions and prevention of methane slip.
• Economic efficiency: Higher efficiency, lower operating costs, better use of existing resources.
• Perspective: A step towards an energy supply independent of fossil fuels.
• Contribution: This makes the Heat2Power Engine a key to the energy transition.