VPS(TM) Liquid Air Energy Storage (LAES) - Technology Overview
A cost-effective, “bulk” electric power storage solution is necessary for wind power and other intermittent renewable power sources to reach their full potential as part of the world’s power generation portfolio by turning this intermittent power into dispatchable ("firm") baseload power. Similarly, widespread large-scale power storage would allow today’s baseload power plants (utilizing coal, natural gas or nuclear fuels) to consume less fuel per kWh of peak-period power by storing “surplus” power generated at these plants during off-peak periods. Expansion Energy's patented “VPS(TM) Cycle” liquid air energy storage (LAES) technology allows off-peak electric power from any source (including wind and other renewable sources as well as fossil fuel or nuclear sources) to be stored cost-effectively at multi-megawatt scales and released as 100% firm power during the peak demand period, when power is more valuable.
The VPS Cycle's energy storage medium is safe, environmentally benign liquid air (L-Air), which is produced from the original power source during off-peak periods. The L-Air is stored in safe, low-pressure cryogenic containers.
In addition to energy storage applications, the VPS Cycle can be deployed as a next-generation, waterless combined-cycle power production system, which has far higher thermal efficiency than standard combined-cycle power plants (CCPPs). Because VPS can be cost-effectively deployed at scales much smaller than standard CCPPs and can ramp up or down quickly, the VPS Cycle can be classified as a "Combined Cycle Peaking Plant"--a breakthrough for the industry.
Expansion Energy has designed Utility-Scale (20 to 100's of MW) field-erected versions of VPS and modular, factory-built Commercial-Scale (5 to 20 MW) versions of VPS.
In addition to stand-alone "greenfield" deployments of the VPS Cycle, existing simple-cycle gas-fired power plants ("peakers") can be retrofitted with VPS technology to convert them into “daily duty” baseload power storage plants + next-generation combined-cycle plants—making them far more valuable assets than the under-utilized peakers they are today.
Similarly, VPS can be integrated into existing combined-cycle gas-fired power plants to add power storage to the CCPP's capabilities, and to substantially raise their peak period power output, to increase their efficiency and to lower their Heat Rate to levels unattainable by standard combined-cycle technology.
Deploying VPS for "behind-the-meter" CHP/co-generation applications at industrial facilities where high-grade waste heat is available is a major opportunity worldwide, saving industrial power consumers substantial amounts of money by generating low-cost power on site, and potentially providing them with additional revenues by selling surplus power to the grid.
By utilizing high-grade waste heat (whether from industrial sources or from GT peaker plants), the VPS Cycle can achieve extraordinarily low Heat Rates of less than 2,000 BTU/kWH (versus 10,000-12,000 BTU/kWH for typical simple-cycle peaker plants and 6,600-7,700 BTU/kWH for most existing combined-cycle plants). Stated differently, VPS plants can generate > 3 X more power from a given amount of natural gas than a simple-cycle plant, and up to 2 X more power than a combined-cycle plant.
Key features and benefits of the VPS Cycle technology include:
VPS components are 100% commercially available (“off-the-shelf”)
“Round-trip efficiency” (RTE) can exceed 90%
4 to 10+ hours of power release capacity — daily cycling, at a constant release rate
Low capital cost per kWh of daily storage & release capacity: $150-$300/kWh
Can be deployed virtually anywhere above-ground
Substantially reduces grid congestion and line losses if sited near load centers
Ultra-high BTU conversion efficiency (far higher than combined-cycle power plants)
Fast start — less than 20 minutes to reach full outflow capacity
100% man-made (no reliance on special geology) — reliable, predictable, replicable
Expected useful life of 25-40 years
For more detail on the VPS Cycle technology, please download the PowerPoint overview through the link below.