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Compressed air energy storage

Compressed Air Energy Storage

Longtime storage - thermal mechanical storage solutions

Thermal mechanical long-term storage is an innovative energy storage technology that utilizes thermodynamics to store electrical energy as thermal energy for extended periods. 

Siemens Energy Compressed air energy storage (CAES) is a comprehensive, proven, grid-scale energy storage solution. We support projects from conceptual design through commercial operation and beyond. Our CAES solution includes all the associated above ground systems, plant engineering, procurement, construction, installation, start-up services and long term service support.

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Latest news

Corre Energy launches global collaboration with Siemens Energy for multiday CAES to address rising market demand

Corre Energy, a leader in the design, development and commercialisation of long duration energy storage (LDES), and Siemens Energy, have launched a global collaboration for the deployment of multiday CAES. This allows Corre Energy to accelerate the international roll-out of major integrated renewable energy infrastructure projects which underpin the global energy transition.

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Long-duration power storage: cost-effective and at grid-scale

As renewable power generation from wind and solar grows in its contribution to the world’s energy mix, utilities will need to balance the generation variability of these sustainable resources with demandfluctuations. Power-generation operators can use compressed air energy storage (CAES) technology for a reliable, cost-effective, and long-duration energy storage solution at grid scale. 

Siemens Energy CAES improves utilization of renewable energy resources by absorbing GW-hours of energy that would otherwise be curtailed and provides grid balancing and reserve services with lower fuel usage and carbon footprint than other controllable resources.

Cycle Overview - Diabatic and Adiabatic Cycles

Diabatic CAES Cycle Schematic: D-CAES

Diabatic storage units dissipate part of the compression heat into the atmosphere with intercoolers. The air must be reheated to be returned to the CAES cycle. Energy and ancillary services with low fuel consumption provide best efficiency.

Adiabatic CAES Cycle Schematic: A-CAES

The adiabetic CAES cycle stores energy in form of pressure in a cavern, while compression heat is stored in a thermal storage. For re-electrification both forms of energy are being utilized. No additional fuel is needed to heat up the released air. 

 

CO₂ and NOx emission free CAES

  • Electricity, preferable from renewable sources, is used for the air compression, which heats the air in the same time.  
  • The compressed air is stored in existing caverns, e.g. in emptied salt caverns, mines, re-used gas pipes, etc. Worldwide many of these storage options exist.
  • Via the thermal storage and heat exchanger the decharge cycle is activated. An expander (turbine) driven generator converts this cycle back in electricity.
a-CAES emissionfree compressed air energy storage

Proven components packaged for a new market

CAES expansion train
Expansion Train

Flexible and efficient power generation with 90 percent turndown of rated output

  • 160 MW and 140MW design output 
  • 90 percent turndown 
  • 20 percent ramp rate per minute
  • 10 minute start-up to reach full generation
  • Dual re-heat recuperator
  • H2 co-firing

 

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Compressor Train

Flexible and efficient load absorption with 30 percent turndown of rated output

  • Up to 120 MW per compression train
  • 30 percent turndown
  • 30 percent ramp rate per minute
  • 4 minute start-up to reach full load

 

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  • Integrally-geared compressors
  • Gearbox
CAES compression train
Plant solutions
Plant Solutions

One of the most important challenges today is the decarbonization of the global economy. The key to meeting this challenge is to consistently expand renewable energy sources and integrate them in developed industry, energy, and mobility infrastructures.

 

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Benefits

Responds quickly

Responds quickly - Designed to be started and brought to full load in less than 10 minutes, eliminating the need for intermediate-load plants and providing a cost-effective way to meet spinning reserve requirements. 

Excellent load-following capability and exceptional part-load efficiency

CAES generation also has excellent load-following capability and exceptional part-load efficiency. 

Full compression in less than five minutes

Full compression can be available in less than five minutes to quickly absorb load rather than reducing your base load generation.

Flexible cycling options

Flexible cycling options - The CAES plant allows for independent operation of the compression and expansion systems, allowing for simultaneous load absorption and balancing.

Generation efficiency

Generation efficiency - Relatively flat heat rate across all operating ranges, thus overall generation efficiency is near the same at 10 percent as it is at 100 percent.

Days of storage

Days of storage - The intermittency of renewables coupled with unpredictable weather patterns means the reality of long periods where balancing is paramount to absorbing renewables. 

Compressor bundle
Large Air Compressors

The compressor portfolio of Siemens offers efficiency and reliability on a long-term basis. It's made to meet customers’ needs in any industry.

Industrial Steam turbine

As a market leader for industrial steam turbines, we offer a comprehensive range of reliable and versatile steam turbines for the power output range from 2 to 250 MW. Our industrial steam turbines are designed for easy constructability, fast start-up and economical operation.

Generator

Reliable generators from 0.3 up to 2,235 MVA - the perfect solution wherever power has to be generated quickly, reliably and efficiently

Modular Thermal Storage

Siemens Energy has launched the "Future of Storage" initiative. The aim of the initiative is to bundle knowledge and build an ecosystem of technology partners in order to offer energy storage solutions tailored to customers' needs. 

Applications

CAES is the ideal solution for energy and ancillary services including:

  • Load leveling / balancing
  • Ramping regulation
  • Frequency oscillation
  • Transmission optimization
  • VAR support

Performance Summary

Power OutputSystem FlowLHV Heat RateLHV Fuel Usage
MWlbm / sBTU / kWhlbm / s
16031738558.5
10522638815.6
8519939064.6
6516839403.5
5014739802.7
3511640351.9
208742081.2
167342540.9