Status and Potential of Sustainable Energy Technologies to Meet U.S. Energy Needs
Over the past 40 years, since the 1973 Arab oil embargo, renewable energy and energy-efficient technologies have slowly emerged to become major players in the nation's energy mix. While virtually every analysis envisions continued expansion, projections range widely as to the impact on U.S. energy production and consumption to be played by sustainable energy technologies over the next 40 years. Some foresee modest growth while others, including the author, suggest that energy efficiency investments could cut energy consumption by half or more, while renewable energy sources could satisfy 80-100% of remaining supply needs.
According to the U.S. Energy Information Administration (EIA), in 2012 the United States is expected to consume roughly 96-97 quadrillion Btu's (Quads) of primary energy, a level that has more or less held steady for the past 15 years. Of that, about 9.1 quads (9.5%) will come from renewable energy sources (biomass/biofuels - 4.6%, hydropower - 3.1%, wind - 1.4%, geothermal - 0.2%, solar - 0.2%).
The nation's energy consumption takes the form of electrical generation, transportation fuels, thermal (heating buildings), and chemical & industrial feedstocks. In the electrical generation sector, which accounts for a bit over 40% of energy consumption, renewable energy sources during the first eight months of 2012 contributed 12.2% (hydropower - 7.0%, wind - 3.3%, biomass - 1.4%, geothermal - 0.4%, solar - 0.1%). In the transportation sector, which consumes another 28% of the nation's primary energy, renewables (primarily biofuels) now account for 4.3% of liquid fuels. In the space heating sector, renewable sources in the form of solar thermal, geothermal heat pumps, and biomass also contribute a small but hard-to-quantify share of the energy consumed.
These numbers confirm that renewable energy sources are now a significant, though still quite modest, contributor to the nation's overall energy production and consumption. What may be more important than their current status, though, are their recent growth rates and what that may suggest about their potential for both the near-term and longer-term.
Over the first term of the Obama Administration, while the nation's overall energy production from all sources grew by roughly 8%, non-hydro renewables grew by 33%. Particularly dramatic growth rates were experienced by wind (249%), solar (238%), and biofuels (44%). In the electricity generation sector alone, while overall production from all energy sources during the first eight months of 2012 dropped by 1.6% compared to the same period in 2011, net electrical generation from solar photovoltaics and solar thermal increased by133%, from wind by 17.7%, from geothermal by 8.8%, and from biomass by 1.5%.
Further, according to the Federal Energy Regulatory Commission, during the first eleven months of 2012, 47 percent of all new electrical generating capacity in the U.S. came from renewable energy sources (biomass, geothermal, solar, water and wind). In the month of September, 100% of all new electrical generating capacity came from just wind and solar sources.
How rapidly renewables will grow in future years and the share they will comprise of the nation's energy mix depend heavily on a combination of public policy -- tax, R&D, mandates, procurement, land use and other regulation, transmission and other infrastructure -- and philosophy, including the priority given to addressing climate change, nuclear waste, and other environmental concerns.
On the conservative end, EIA's just-released "Annual Energy Outlook 2013" says the share of electricity generation from renewables will grow only to 16% by 2040. It also forecasts that biofuels will provide a mere 5.8% of the liquid fuels market by 2040. On the other hand, according to Pike Research's recent study, "Smart Energy Annual Report 2012," North America will add more than 400 GW of renewable capacity from 2012 through 2015 alone. The National Renewable Energy Laboratory's new "Renewable Electricity Futures Study," which looks at a broader range of renewable technologies and at a longer timeframe, shows that the U.S. could generate 80% of its electricity from renewable energy by 2050.
Another way to view the nearer-term potential of renewables to meet U.S. energy needs is to compare how this country presently stacks up against others. The non-profit organization Wind-Works reports that on a per-capita basis, Germany now has 20 times more solar than the U.S., while Italy has 14 times more and Denmark has nearly five times more. Though the U.S. has the most installed geothermal generating capacity in the world, Iceland has nearly 200 times more geothermal capacity per capita. German farmers operate nearly 200 times more biogas capacity per capita than do American farmers, while Austria operates 60 times more.
In addition, dozens - if not hundreds - of recent U.S. and international studies have documented the very large near- and longer-term potential of individual renewable energy technologies. For example:
- With solar photovoltaic (PV) installations climbing and costs continuing to fall, cumulative PV generating capacity could surpass 1 million megawatts in 2020, according to the Earth Policy Institute. (Current world electricity generating capacity from all sources is only five times that, or 5 million megawatts.) In its "Solar Heating and Cooling Technology Roadmap," the International Energy Agency says almost a sixth of the world's low-temperature heating and cooling energy could come from solar power by 2050 - a 25-fold increase.
- The Global Wind Energy Council says wind power could supply up to 12% of global electricity by 2020. The U.S. Department of Energy said in a 2008 study that wind energy could supply 20% of the nation's electricity needs by 2030. A report by the Center for American Progress indicates that more than 4,000 GW could be generated from U.S. offshore wind; by comparison, offshore oil resources extracted over 20 years are estimated to amount to 18 GW equivalent. Another study by Stanford University engineers found that placing wind turbines off the East Coast could meet the entire demand for electricity from Florida to Maine.
- The Geothermal Energy Association reports that 147 geothermal projects are now in development in the United States. The 59 in Nevada alone have a combined potential capacity of 2,000 MW. According to a study recently released by a multi-disciplinary research group at MIT, market changes and an investment of $800 million to $1 billion over 15 years could bring more than 100 GW of geothermal energy to the U.S. grid by 2050. In addition, ground-source geothermal heat pumps now make up 5% of the total domestic heating, ventilation, and air conditioning markets with an estimated 100,000 new units being added annually.
- A new Union of Concerned Scientists study, "The Promise of Biomass," shows nearly 680 million tons of biomass could be made available for fuel and electricity on an annual basis by 2030. That is enough for 54 billion gallons of non-food, cellulosic ethanol, quadruple the amount of corn ethanol produced nationwide in 2010, or enough electricity to meet one-fifth of nationwide demand. Researchers at the University of California-Berkeley's Energy Biosciences Institute say biofuels could account for 30% (i.e., a four-fold increase) of the liquid motor fuels in the U.S. by 2037. In its study "Renewable Biogas," Pike Research predicts a doubling of the global biogas market (now about 14.5 GW of installed distributed and grid-scale generation) by 2022.
- The National Hydropower Association notes that only 3% of the nation's 80,000 dams currently generate electricity. Nearly 9000 MW of new capacity could be added by modernizing existing hydropower facilities. Globally, the International Energy Agency's "Technology Roadmap: Hydropower" says hydroelectricity production could be doubled by 2050. Newly emerging water power technologies such as tidal and wave have great longer-term potential. The Electric Power Research Institute, for example, estimates that coastal energy could yield 2,610 terawatt-hours of electricity per year.
Coupling Renewables with Energy Efficiency
The share of the nation's energy mix to be supplied by renewable energy sources could be greatly increased if their growth were accompanied by a corresponding decrease in energy consumption. This could be achieved through a combination of energy efficiency improvements, common sense energy conservation efforts, and modest lifestyle changes. For most end-use sectors (i.e., buildings, appliances, lighting, transportation, industry, utilities), study after study has suggested that savings of up to 20% are cost-effective and well within research technically. Other analyses, though, have indicated that far greater savings are also achievable. For example:
- In a comprehensive assessment of cost-effective domestic energy efficiency opportunities, McKinsey & Company identified potential ten-year savings of $1.2 trillion in U.S. utility bills alone. MacArthur laureate David Goldstein believes that aggressive efficiency improvements could drive domestic energy consumption down by more than 80% within four decades, and that $10 trillion in associated savings is likely a gross underestimate.
- Although only about 7-8% of the nation's electricity generation capacity presently comes from installed combined heat and power (CHP) installations, CHP facilities have the ability to nearly double the efficiency of power plants fueled by fossil fuels, which typically run with an efficiency in the ballpark of 33%. A recent analysis by the American Council for an Energy-Efficient Economy suggests that CHP could replace up to 100% of retiring coal plant capacity in states across the country. President Obama recently signed an Executive Order calling for action in the deployment of 40 GW of new CHP capacity in the U.S. by 2020 - an increase of 50% compared with today.
- The Union of Concerned Scientists has outlined a plan by which the United States could cut its projected oil use in half over 20 years, relying on the Obama Administration's recently announced new fuel efficiency standards for cars, light trucks, and commercial trucks coupled with improved efficiencies in residential heating oil use, greatly expanded reliance on electric vehicles, and efficiency upgrades by planes, trains, and ships.
Drawbacks and Challenges
Beyond political opposition by fossil fuel and nuclear competitors and their allies, the greatest challenges to the rapid expansion of renewable energy technologies include institutional problems (e.g., land-use restrictions, lack of adequate transmission facilities), financing for project construction, economic cost concerns, and perceived environmental impacts.
Regarding the last, like any other supply-side option, renewable energy technologies can be accompanied by a range of environmental consequences that potentially include impacts on wildlife, agricultural, and wilderness areas; visual and noise pollution; greenhouse gas and/or other emissions; water use; and food vs. fuel concerns, among others. The nature and extent of the environmental impacts associated with a given renewable energy project will be influenced by its type, size, design, and location. Careful advance least-cost planning should help minimize, if not mitigate, most impacts. Moreover, whatever impacts may be identified will, in most instances, be less hazardous than those that would be posed by fossil fuel or nuclear alternatives.
As for the economic costs associated with renewable energy sources, those concerns are rapidly fading as many technologies are now cost-competitive and/or are experiencing rapid price drops that should enable them to achieve grid-parity within the next few years.
Because of the wide variation in governmental subsidies and institutional incentives offered to competing energy sources, as well as the failure to incorporate environmental and social costs, it is difficult to provide a generally agreed-upon economic comparison of renewables versus fossil fuels or nuclear power. Nonetheless, the trend line over the past four decades, and particularly during the past five years, has been one of sharp price reductions for all renewable energy technologies while the costs for oil, coal, and nuclear power have risen. Thus, while there are variations based on geographical region, size, and design, most renewable energy sources are now cost-competitive - or soon will be - with fossil fuels and nuclear power. Biomass, geothermal, and hydropower can now often provide base-load electricity thatis cheaper than their non-renewable competitors. Wind-generated electricity, though intermittent, is also cost-competitive in many locales while solar, already competitive or cheaper in specific off-grid applications, is frequently projected to be cost-competitive with conventional sources within five years.
Furthermore, the apparent economy of fossil fuels disappears when you take into account the extensive subsidies and loan guarantees provided by taxpayers to the oil, natural gas and nuclear industries; the waivers those industries are given on pollution abatement, and the costs imposed on health, food production, water supply and infrastructure associated with climate change.
Thus, the real challenge in the years ahead is to find the political will to tap the mix of renewable resources and energy-efficient technologies that could facilitate the rapid phase-out of both nuclear power and fossil fuels.
The views expressed in these essays are those of their respective authors and do not necessarily reflect the views of Physicians for Social Responsibility.
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