Amends the Internal Revenue Code, with respect to the income tax exclusion for energy conservation subsidies, to define "subsidy" to include amounts received by a customer from a public utility to: (1) pay for electricity generated from an energy conservation measure under a net metering or net billing program; or (2) pay for renewable energy credits attributable to an energy conservation measure. Limits the excludable amount of any subsidy for renewable energy credits to $2,000 times the whole number of years worth of renewable energy credits that are sold by the customer.