Related loss is 9.9% with natural gas and 15.4% with hydrogen. Solution is to reheat combined cycle Rankine steam below atmospheric pressure – for example 0.7 bar instead of the current 20 bar. In optimal solution there is no other Rankine reheating. Reheating utilizes close to 30% of the condensing energy of the water vapour in combustion gases by increasing Rankine cycle vapour content from 90% to 100%. The rest is utilised by evaporating secondary Rankine cycle water below 1 bar.Reheating is made to about 550-600 K final temperature with splitted combustion gases mass flow in low temperature area heat-exchanger – parallel to main low temperature heat-exchanger, where water preheating occurs. About 2/3 of combustion gases mass flow is enough for water preheating and rest 1/3 is nearly exactly enough for steam reheating. The invention may appear to contradict the Carnot theory because average temperature where heat is brought into the cycle is lower. But the Carnot theory excludes utilization of the heat of condensation of water vapour from combustion gases.


Also current combined cycle Rankine mass flow is smaller cause heat-exchanger exergy losses (related to temperature differences) are bigger or alternatively little higher gas turbine pressure ratio can be used. This means directly higher pure gas turbine efficiency. As a result calculations with temperatures, turbine efficiencies, pressure losses etc. used in commercial CCGT enables world record CCGT electric efficiency 68% (presently 2024 about 64,4%). Figure 10 of US12000335 gives about 60% CHP (Combined Heat and Power) electric efficiency. There are not yet official studies in June 2024 even if also according to patent examination efficiency increase.


This kind of CCGT may nearly double power generation profit with especially hydrogen as a fuel. Better efficiency means 100.000.000 $ money save in ten years (600 MW unit)  With 95 euros CO2 tax/ ton money save is 170.000.000 $. Compared to 15-20 years old CCGT power plant possible money save may be nearly 500.000.000$. Then old power plants can be used as free reserve power for example in cold winter days solving problem related to renewable wind power (variable power generation). Related to that problem Systematic Power has also two innovations for electricity storage. The other is renewable hydrogen manufacturing related and other non-hydrogen solution. Better one offers probably world´s lowest electricity storage price even if both are very competitive. Systematic Power has also many other innovations not listed here.


Below link to US12,000,335 patent. Also other countries applied/patent coming.

US12,000,335 B2

Below link to wikipedia : combined cycle article. Added text with heading ”Combined cycle advanced Rankine subatmospheric reheating”

Combined cycle power plant – Wikipedia


This invention is 30% more energy efficient compared to present hybrid car engines. This means 2.5-3 litre/ 100 km fuel consumption without taking extra energy from battery. Efficiency is about 53% with 585 Celsius exhaust gas valve temperature.  Advantage is high torque because of electric powertrain. Electric powertrain has typically 50-100 % higher torque and so extra 30% power from same engine  may give possible 50% extra torgue.  This is important because Atkinson type engine typically has a bit lower torque. In some applications there is no need for gearing (no gearing losses). Smaller, cheaper and  lighter main engine give same total power because of extra generated power.  CO2 taxes are also lower and it’s easy for manufacturers to reach EU CO2 reducing requirements. Engine is flexible with part load and variable RPM and there are also much less particles compared with present engines. This is cause volume flow (at 0.2 bar) is 4-5 times larger. There isn’t typical turbo lag with this naturally aspirated engine. Driving range is also 30% longer and ethanol application has zero CO2 emissions and so lower global CO2 compared with 100% EV’s.


Diesel power plant/marine advanced ETC (Electric Turbo Compounding) system has 55% electric efficiency. With natural gas CHP electric efficiency may be 55-57% because of higher maximum temperature. Invention is based with simultaneous Atkinson cycle and exhaust gas expansion in two ETC (Electric Turbo Compounding) inverted Brayton cycle turbines to appr. 0.2 bar after second turbine. Exhaust gases are compressed to 1 atm with 2 stage compression resulting with simultaneous Atkinson cycle to lower min pressure of system and so more work is got with higher efficiency. This is triple more efficient than present ETC systems and generated electricity is utilisized. Free calculations available if You ask  (53% eff. ) are made for non-diesel hybrid car application. Two stage fuel injection is useful in diesel application. Note that also normal present diesel can be used if little natural gas is fed with air. Much heat is generated and CHP electric efficiency is World Record 55-57%. Diesel is useful in balancing wind power. This invention has high part load efficiency and quick start up. Also efficiency is high with 1-10 MW size plant. In winter ETC unit may generate 10% more extra power because compressor power need is lower. In summer power need is also low because water vapour formed during combustion is condensed and pressurized with pump with minimal energy.


Below US patent application. DE, GB and FI also exists.

US10,830,108 B2