Compressed Air Storage: Difference between revisions
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=Storage Math= | =Storage Math= | ||
*500 gal propane | *500 gal propane tank - 66 cu ft x10 = 660 cu ft. Cost is $1500 + installation, so about $2000. | ||
*250 cu ft is $300 for [[Type K Cylinder]]. | |||
**Advantage here is high modularity, scalability. | |||
**Type K tanks are about 2x less expensive than propane tanks. | |||
=Usage= | |||
*7 cfm for .2 hp at $250 [https://www.ebay.com/itm/New-Air-Drive-Pneumatic-Radial-Piston-14mm-Shaft-Motor-0-2HP-900RPM-Mixer-DIY/271399029996?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D230924%26meid%3Dcadef6bd62dd4e26b2999e183e5f2b18%26pid%3D101195%26rk%3D4%26rkt%3D12%26sd%3D303335987408%26itm%3D271399029996%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganic%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851] | |||
**One type K cylinder at 250 cfm runs this for 35 minutes | |||
=Air Power Cube= | |||
*10 Type K cylinders produce 35 minutes of 2 hp, or 1 hp hour. Not bad. | |||
*Using 700atm storage vessels, we get sufficiency - 10 gal | |||
=Cost= | =Cost= | ||
Latest revision as of 18:03, 3 December 2023
Intro
Taking example calculation at https://en.wikipedia.org/wiki/Compressed_air_energy_storage -
a 500 gallon propane tank stores .75 kWhr of energy when compressed to 200 PSI. Pressure rating of propane tanks is 215 PSI - [1]. Taking efficiency of an air engine - generator to be 50% - we have .4 kWhr. So a 500 gallon tank would get us 0.4 kW hr of usable energy.
See comments below:
Storage Math
- 500 gal propane tank - 66 cu ft x10 = 660 cu ft. Cost is $1500 + installation, so about $2000.
- 250 cu ft is $300 for Type K Cylinder.
- Advantage here is high modularity, scalability.
- Type K tanks are about 2x less expensive than propane tanks.
Usage
- 7 cfm for .2 hp at $250 [2]
- One type K cylinder at 250 cfm runs this for 35 minutes
Air Power Cube
- 10 Type K cylinders produce 35 minutes of 2 hp, or 1 hp hour. Not bad.
- Using 700atm storage vessels, we get sufficiency - 10 gal
Cost
Calculations
For volume of 500 gallons (propane tank) -
E=Pressure x Volume.
=200 PSI x 1.9 cu meters =1,400,000 Pascals x 1.9 cu meters =2.7 million Joules =.75 kW hr
With 60% efficient air engines - this makes it slightly under 1/2 kWhr of energy storage.
For comparison, one motorcycle battery at $20provides a comparable amount of electrical energy storage, making a weak case for compressed air storage on cost considerations.
- However, a motorcycle bat will last you a year, whereas the tank will be unlimited lifetime.
For comparison - if one could generate an average of 50W via wind power, that appears to be an easier route of power generation.
Links
- EPRI head states that air will be cheaper per watt hr store than batteries. - [5]
- Cost Comparison of Energy Storage - [6]