I calculate that only about 3.5 cubic ft of natural gas burned gives the same heat as one kilowatt-Hr of electricity. One kilowatt-Hr of electricity is the equivalent of one to two batteries going from full charge to complete discharge. Specify, this is equivalent to a 12 volt 83 amp-hr battery or a 6 volt 166 amp-hr battery going from full charge to full discharge.
Capturing the gas, storing it and regulating the pressure so as to be able to be used in current products is not a technology issue. Compressor, storage bottles, and regulators exist now. The only real issue is how to produce gas efficiently and how to not let oxygen mix with it until it is needed to burn. If too much air or oxygen is mixed then it could become dangerously explosive. In this case we could possibly use needle valves and one way check valves to keep a potential explosive mix from feeding back to the storage containers.
It is interesting to note the cost of natural gas in my area to produce the same amount of energy as electricity is about 20% of the cost of electricity. For producing the same energy 1 kilo-watt-hr = 3,414 BTU = .03414 Therms = 3.414 Cubic Ft of natural gas at .333 lb/sqin. Note: 1 Therm = 100 Cubic ft = 100,000 BTU. Technical data of the previous two lines came from a call to my gas company.
Offered by Mike.