CAES
London 12th September 2016
this presentation
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Introduction.
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Bridging the pressure gap.
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Recent CAES work in Australia.
Tony Kitchener
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40 years as compressor designer, manufacturer, inventor
& company director.
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Sold &/or licensed IP to major compressor makers in
Denmark, Germany, Korea, USA, Australia, Belgium,
China & Japan.
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Director & board member responsible for R&D of Ateliers
Francois world’s largest maker of 40bar oil free
compressors for PET bottle blowing.
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Director of specialist compressor innovation company
SVW Pty Ltd.
Compressor packages
Bridging the pressure gap
Recip
3 stage oil free
40 bar 550kw 55m3/min
Turbo
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ghh 6 stage turbo
Screw
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Two stage screw air end
How high? How big?
It’s all about the the
crosshead.
Rings
Oil free, 230 bar pressure difference.
8000 hrs
Hydraulic booster
With the lot.
High efficiency pumps
Liquid pressure supported
seals
Linde Ionic compressor
Accidentally inventing the
diesel engine
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The higher the air pressure the lower the auto
ignition temperature of lubricating oil.
Foaming
The Raleigh Taylor instability
Expander
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Ultra super critical
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280bar 600C
Reciprocating expander
cryogenic practice.
Conclusion
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No obvious compressor or expander limit to the
pressure you might be tempted to approach.
Recent CAES work in
Australia.
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Australia. Sunny, lots of space.
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Europe & former parts of Europe. Less sun. Less
space.
Raygen CPV
Raygen CPV
Cost of solar heat
Glasspoint.
Cost
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5 kwhrs / m2 / day = 1825 kw hrs / year.
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5% interest.
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heliostat @ $100 / m2
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70% collection eff.
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100*.05 / (1825 * 0.7) = 0.4 c/ mj = $ 4/mmbtu
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Glasspoint quote $4/mmbtu
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If compressor / expander 83 % efficient you need 5 mj/kwhr of solar heat to get
an electrical round trip of 1.
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that is elec power in = elec power out.
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So solar heat to get CAES round trip of 1 costs 2 c/kwhr.
CAES after the meter
Compressors use a lot of
power.
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If compressors were a country they would have the same electrical demand as
Spain & Turkey & Italy combined.
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Roughly 1/3 of all electric power is generated for industry and 10% of that is used
for compressors.
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Compressors use around 3% of global electricity. Germany generates 2.6%
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AF makes 100MW of compressors per year.
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Most factories have a compressor.
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More than 350-500,000 air compressors sold each year. 80% < 40kw.
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There are around 5,000,000 factories in the world. 2,000,000 in China.
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Most factories have roofs.
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Most factories only work during day.
The off load problem
Many solutions
Solar Caes after the meter.
3 stage logic
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3 stages of compression
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60% time to 6 bar @ 100 whr/m3
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10% time to 36 bar @ 200 whr/ m3
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30% time to 216 bar @ 300 whr/m3
Power needed
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low press work = 0.6 x 100 = 60 whr/m3
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med press work = 0.1 x 150 = 15
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high press work= 0.3 x 250 = 75
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overall = 150 whrs/ m3
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1kwhr from solar panels will compress 6.6 m3.
Solar CAES.
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Solar power
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$1500 / kw PV
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1500 kwhrs/ yr / kw
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5% interest.
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$75 x 100/1500 = 5c/kwhr
@6.6 m3 / kwhr = 0.75 c/ m3 power cost.
Overall efficiency of current art
with storage before the meter.
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Wind 1000 watt hrs
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after transmission to large CAES or pumped storage (3%) 970 whrs
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dispatch from large CAES or pumped storage (70%) 660 whrs
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arrive at end user (5%) 625 whrs
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compress at average efficiency of 125 wh/m3 @ 7 bar
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net 5m3 @ of air for 1 kwhr output from wind mill.
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If factory electricity cost 15c/kwhr then power cost for compressed
air 1.875 c/ m3
Storage is relatively cheap
and off the shelf.
High pressure bottles &
skids.
Relative vessel and energy
storage costs.
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18 bar LPG vessels $300/m3 = $ 300 / kwhr
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40 bar vessels $750 / m3 = $220 / kwhr
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200 bar G cylinders $1000/ m3 = $100 / kwhr
Summary
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Solar CAES viable now for factories in sunnier
places where factory power prices >15c/kwhr.
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100% reduction in CO2.
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Cheaper than mains powered compressed air.
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Payback 4 to 6 years.
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SVW building prototype for Australian application.