Can sewage plants export energy? Consider the following example?
The only thing you are missing for your equation is the KW per m3 for methane. Take the amount of gas (2000 m3/h) multiply by the percent of methane (65%) and multiply by the eefficiency of the energy transfer (40%) and multiply by the KW/m3 for methane (should be listed in your text book) to get the power output per hour. Then figure out how many hours per month you could produce this and how much this would have cost you at 12c/KWh. Edit: Biogas composed of 65% methane yields 650 Btu per cubic foot (5,857 kcal/cubic meter). Which equals 0.001163 KW So the 2000m³/h equals 2.326 KW/h but at 40% efficiency that would only be about 0.93 KWh which would be worth about 11¢ per hour. So no it would not have enough energy to export.
