Compressed Air Energy Storage

• 3kW hr of energy storage at 8 bar requires 65 cubic meters of volume - [1]
• But - if you use high pressure, you can reduce that volume down to 300 bar simply using a $300, 1800W Scuba compressor.
• Scuba compressor on AliExpress - $300 - [2]
• 80 cu ft tanks cost $200. That is 2 cubic meters. They are rated for 3000 psi. Derate to 100 atmospheres.