net energy return造句

Depending on the ethanol study you read, net energy returns vary from . 7-1.5 units of ethanol per unit of fossil fuel energy consumed.
:: : : I think by'we don't know how'SB meant we currently have no pratical way to do it for a price that would make it worth doing and with actually getting a net energy return.
However, while there may be a positive net energy return at the moment, recent research suggests that the sugarcane plantations are not sustainable in the long run, as they are depleting the soil of nutrients and carbon matter On the other hand, productivity of sugar cane per land area in Brazil has consistently grown over the decades; sugar cane has been shown to be less depleting to the soil than cattle and yearly cultures; and there are many regions in the country where sugar cane has been cultivated for centuries.
It's difficult to find net energy return in a sentence. 用net energy return造句挺难的