Energy Conservation Opportunity Fund Act of 2008 or the ECO Fund Act of 2008 - Establishes in the Treasury an Alternative Energy Sources State Revolving Fund.
Directs the Secretary of Housing and Urban Development to use amounts in the Fund to provide loans to states and Indian tribes to provide incentives to owners of single family and multifamily housing, commercial properties, and public buildings to provide: (1) renewable energy sources, such as wind, wave, solar, biomass, or geothermal energy, for such structures; (2) energy efficiency and energy conserving improvements and features for such structures; or (3) infrastructure related to the delivery of electricity and hot water for structures lacking such amenities.