How much can Renewables really do?

How much of our need for power could we actually satisfy with renewable energy in America?

Today, renewables account for less than 10% of our electricity supply, most of that in the form of large-scale hydro;  (check out the National Academies web site here).  But many studies have been done in recent years, either on specific technologies or renewables in general, to indicate how much they could contribute to our energy demand.  Scott Sklar of the Stella Group  has assembled and interpreted some of these studies, and the menu of potential clean energy contributions is very impressive.  We would be more impressed if a side order of political will were available to actually bring these solutions to the table.  Absent that, what you see below may just be an a la carte listing of missed opportunities.

We hope that’s not the case.

Energy Self-Reliant States

“All 36 states with either renewable energy goals or renewable energy mandates could meet them by relying on in-state renewable fuels.  64% could be self-sufficient in electricity from in-state renewables; another 14% could generate 75% of their electricity from homegrown fuels.  Indeed, the nation may be able to achieve a significant degree of energy independence by harnessing the most decentralized of all renewable resources: solar energy.  More than 40 states plus the District of Columbia could generate 25% of their electricity just with rooftop PV. In fact, these data may be conservative.  The report does not, for example, estimate the potential for ground photovoltaic arrays – although it does estimate the amount of land needed in each state to be self-sufficient relying on solar – even though common sense suggests that this should dwarf the rooftop potential….. It is at the local level that new technologies like smart grids, electric vehicles, distributed storage, and rooftop solar will have their major impact.”

from Energy Self-Reliant States
published by the Institute for Local Self-Reliance
October 2009, updated May 2010

Geothermal

Geothermal could meet 10% of U.S. needs by 2050.

from The Future of Geothermal Energy
MIT study
Jan 22, 2007

Biomass

Biomass power could result in 17%-28% of total U.S. electric generation by 2020.

National Renewable Energy Laboratory
January 16, 2006
Nuclear Information and Resource Service

Concentrating Solar Thermal Power

“Another study, published in Scientific American in January 2008, proposes using CSP and PV plants to produce 69% of U.S. electricity and 35% of total U.S. energy, including transportation, by 2050.”

Plan B Updates
Jonathan Dorn
Earth Policy Institute
July 22, 2008

Distributed Solar (PV/solar thermal)

According to a Navigant/Energy Foundation 2005 market study, using only roof space (per census) and using average amounts of shading, tilt, etc., there is a maximum technical potential in the US of 1,037,519 MWp, which would represent almost 33% of total electricity US usage MWh for MWh.

Technical Potential of PV in the US
Navigant/Energy Foundation
2005

Water Energy

“Several studies conclude that upgrading existing dam turbines, installing free-flow hydropower (no dams or diversions) tidal, wave and ocean currents and thermal could produce 10% of US energy.”

The Role of Advanced Hydropower and Ocean Energy in Upcoming Energy Legislation
EESI, EPRI, NHA, OREC

Waste Heat (Combined Heat-and-Power (CHP) power plants)

According to ACEEE, EPA and DOE, 8 % of US electricity could easily be produced by CHP.

Combined Heat and Power: Capturing Wasted Energy
American Council for an Energy-Efficient Economy

Wind

A new analysis by the U.S. Department of Energy (released 5/08) finds that wind can be a major contributor to the country’s energy mix, supplying up to 20% of electricity by 2030.

www.20percentwind.org