Renewable energy packs a powerful punch. More solar energy hits the Earth's surface in one hour than is used by the entire global energy system in a year. In the U.S., Great Plains and East Coast off-shore wind could provide enough energy to meet the entire country's need. As nations seek ways to address energy security, air pollution, and climate change, they look to renewable resources such as solar, wind, and geothermal.
Now, researchers Mark Jacobson of Stanford and Mark Delucchi of U.C. Davis have calculated that it is possible to meet 100 percent of world energy demand using only energy from clean sources by 2050. They say we can do it -- and, what's more, we can do it using only off-the-shelf technology.
Jacobson and Delucchi did their projections based on only existing technologies that have no climate-disrupting-emissions and "low impacts on wildlife, water pollution, and land." Making the dramatic transition to using only such technology, they suggest, would require a combination of strategic policies and massively ramped-up manufacturing along the lines of retooling the auto sector to produce aircraft during World War II, only much bigger. Other studies, most famously by Robert Socolow and Stephen Pacala, have shown similar results.
Take wind energy, for example. Jacobson and Delucchi's vision calls for production of approximately 3.8 million five-megawatt wind turbines to supply 50 percent of global power demand. They envision a similar scenario for various types of solar, and the rest from geothermal, wave, tidal, and hydro-power.
And let's not forget transportation. Jacobson and Delucchi assert that this oil-dependent sector could be replaced by renewable electricity or hydrogen. To smooth out differences in supply and demand, they suggest a few key management practices, including decentralized storage, updating the transmission system, and combining wind and solar to offset their intermittent nature.
What's the greatest obstacle to realizing their vision? According to Jacobson and Delucchi, it is not technological or even economic, but social and political. As they point out, "current energy markets, institutions, and policies have been developed to support the production and use of fossil fuels."
Some countries are making great strides, though. More than 100 countries have adopted policies to spur expansion of renewable energy. Germany is expected to generate nearly 40 percent of its electricity from renewable energy by 2020. In 2009, for the second year in a row, both the United States and Europe added more new electric power from renewables than from conventional sources such as coal -- but a federal clean-energy program is necessary to take it to the next level.
Clean-energy advocates in the U.S. have prioritized the goals of required renewable energy targets, energy efficiency measures, and an end to the $10 billion in U.S. subsidies to dirty fuels, but these policies are up against relentless opposition from those who benefit from the status quo. If demand remains steady, policies to systematically shutter old, polluting power plants are essential to creating a strong market for clean energy.
As costs come down for renewables, we are waking up to the true costs of dependence on dirty energy: how it leaves our lives and communities in ruins. From extraction to combustion to waste disposal, hidden costs burden society in the form of health problems, irreversible environmental damage, and even premature death. Harvard Medical School analysts say coal alone generates as much as $523 billion per year in burdens to society, which is more than twice the total amount of electric utility revenue in 2009.
While experts will debate the details, the important message is that yes, we can break free from dirty energy sources of the past -- and we must move quickly. Success will require leadership, vision, and commitment to our health, security, and the future of the planet.
Lyndsay Moseley is a federal policy representative with Sierra Club's Beyond Coal campaign.