Uploaded July 2013 | Updated September 2026, 2 weeks ago
The Power Of Dreams
In 2010, Honda presented the Honda Air concept car at the LA Auto Show.
Compressed air cars are emission-free at the exhaust. Since a compressed air car's source of energy is usually electricity, its total environmental impact depends on how clean the source of this electricity is.
Compressed air has relatively low energy density. Air at 30 MPa (4,500 psi) contains about 50 Wh of energy per liter (and normally weighs 372g per liter). For comparison, a lead--acid battery contains 60-75 Wh/l. A lithium-ion battery contains about 250-620 Wh/l. Gasoline contains about 9411 Wh per liter; however, a typical gasoline engine with 18% efficiency can only recover the equivalent of 1694 Wh/l. The energy density of a compressed air system can be more than doubled if the air is heated prior to expansion.
In order to increase energy density, some systems may use gases that can be liquified or solidified. "CO2 offers far greater compressibility than air when it transitions from gaseous to supercritical form.
The Power Of Dreams
In 2010, Honda presented the Honda Air concept car at the LA Auto Show.
Compressed air cars are emission-free at the exhaust. Since a compressed air car's source of energy is usually electricity, its total environmental impact depends on how clean the source of this electricity is.
Compressed air has relatively low energy density. Air at 30 MPa (4,500 psi) contains about 50 Wh of energy per liter (and normally weighs 372g per liter). For comparison, a lead--acid battery contains 60-75 Wh/l. A lithium-ion battery contains about 250-620 Wh/l. Gasoline contains about 9411 Wh per liter; however, a typical gasoline engine with 18% efficiency can only recover the equivalent of 1694 Wh/l. The energy density of a compressed air system can be more than doubled if the air is heated prior to expansion.
In order to increase energy density, some systems may use gases that can be liquified or solidified. "CO2 offers far greater compressibility than air when it transitions from gaseous to supercritical form.
