Geothermal Organic rankine cycle systems
In only 6 years we achieved the second largest ORC binary geothermal fleet worldwide
In only 6 years we achieved the second largest ORC binary geothermal fleet worldwide
Geothermal resources are one of the most secure and stable among renewables for reliable base-load energy production. Today the total installed capacity worldwide is 15,6 GW, with USA, Philippines, Indonesia and Turkey leading the way.
Growing demand for electrical power production from geothermal resources at medium-low temperatures has created a promising and evolving market for ORCs that have proven to be the best power generating solution in these cases.
With our patented Radial Outflow Turbine technology, EXERGY offer efficient and tailor-made Organic Rankine Cycle (ORC) geothermal binary power plants and today counts approximately 450 MWe of geothermal power installed or under construction in its portfolio.
EXERGY’s geothermal ORC systems can be applied in diverse resource conditions:
EXERGY’s ORC systems are available from small 1 MW modular units to tailor-made plants up to 50 MW.
Thanks to the simpler design and specific configuration of the ROT technology our ORC geothermal plants can offer several advantages:
EXERGY’s geothermal ORC systems can be applied in diverse resource conditions:
Binary geothermal power plants have the possibility to feature multi-pressure-level cycle systems. This cycle configuration offers a significant increase in the power output and in the cycle efficiency. Technologically advanced multi-pressure-level geothermal binary systems traditionally available on the market require at least one turbine per pressure level. The EXERGY Radial Outflow Turbine, thanks to its unique single disk and multi-stage configuration, allows multiple pressure level cycles to be expanded on a single-disk overhung turbine.
The geothermal fluid flows through the first sequence of HIGH pressure heat exchangers, transferring heat to the organic fluid. This organic fluid vaporizes and flows into the HIGH pressure turbine Inlet. Then the geothermal fluid flows through the second sequence of LOW pressure heat exchangers, vaporizing the organic fluid, which is then admitted into the LOW pressure turbine Inlet. The EXERGY Radial Outflow Turbine (ROT), fed by HIGH and LOW pressure organic fluids, drives a generator to produce electrical power. The geothermal fluid is then re-injected back into the ground and the cycle continues.
Some geothermal binary plants, downstream the ORC cycle, release exhaust non-condensable gases at high pressure and temperature no longer usable in the ORC cycle. EXERGY has designed and developed the NCG expander unit in order to utilise this residual gas flow with the maximum efficiency, before its discharge into the atmosphere.
The NCG expander is a compact plug-n-play unit, containing a turbine that expands the non-condensable gases exiting the ORC cycle, to produce additional electrical energy. Each NCG unit is designed to improve the plants’ performances and profitability, and at the same time, reduce the environmental impact of the plant. When the NGC is supplied in plants with high NCG volumes it can increase up to 5% the plant’s efficiency.
