What's the biggest renewable power source in the U.S.?

(Photo of turbines inside Hoover Dam from Flickr and photographer Mike Chen aka MetalMan)


It’s not wind or solar. It’s hydropower, which accounts for 7% of our electric power, and two-thirds of U.S. renewable energy today. The Obama Administration thinks hydro can play a bigger role in weaning us off fossil fuels, with their carbon footprint, and producing clean-tech jobs.

The Energy and Interior departments and the Army Corps of Engineers are eyeing ways to increase hydropower without harming the environment – most specifically migrating fish.

"I think that hydropower in the past was developed in a way that didn't protect local environments as it could have," said Energy Sec. Steven Chu. "We now know better how to design turbines that are kinder to fish."

"This is taking a look at existing facilities and low-impact hydro,” said Interior Sec. Ken Salazar. “This is an examination of what we can do with hydropower that does not necessitate the building of new dams."

The U.S. has 79,000 dams, but only 2,200 of them produce electricity.

The three departments will develop a strategy that would not only maximize efficiency at hydropower dams and put turbines in some dams that don’t produce power now, but also would look into new technologies, like putting turbines in major rivers and water pipelines.

And then there’s also the ocean. Wave action is just beginning to be seen as a powerful source of energy.

Clean tech jobs
There would be more than twice as many jobs in developing ocean power as in inland hydro, according to a recent report by Navigant Consulting.

Hydropower could provide a half-million to 1.4 million jobs, dependant upon the U.S. having an renewable energy standard of 10% to 25%, Navigant said.

Hydropower has the potential to produce 16,000 to 25,000 more megawatts of power, Chu has said. Navigant raises that to between 25,000 and 60,000 by 2025 if there’s an RES.

One good thing about hydro is its storage ability, something wind and solar are struggling with.

The federal government owns about half the existing hydropower dams, according to Linda Ciocci of the National Hydropower Assn. She said there need to be strong incentives to drive more private investment.

Most facilities are in the West, as well as in Tennessee and Pennsylvania. But Navigant said expansion can bring hydro jobs to all regions of the country.

Also involved is the Federal Energy Regulatory Commission, which has 9 pending applications for new nonfederal projects.

(Sources: ClimateWire Landletter, E&E Daily)

Provocative NASA study puts road traffic ahead of power plants as cause of climate change near-term

(Picture of auto traffic from Flickr and photographer Lynac)

A new study from NASA’s Goddard Institute for Space Studies says tailpipe emissions will cause the most global warming over the next decade. Next comes heating homes by burning wood and cow dung in poor countries. Third is methane from cows.

Electric power is further down the list, though it will be the prime source of warming by century’s end, the study predicts. The provocative study, by a team led by NASA’s Nadine Unger, was published this month in the Proceedings of the National Academy of Sciences.

Policy implications
Does this mean we should turn away from fighting the coal industry and focus more on electric cars, high-speed rail and aid to third-world countries? Possibly. We may have a little more time than we thought to shut off coal – as far as global warming is concerned.

But this is just one study. It will need to be confirmed by others.

And the reason behind the findings is troubling. It all has to do with the release of aerosols that block the incoming sunlight and have a temporary cooling effect. Tailpipe emissions don’t have much of those, while coal-fired plants do. Some aerosols, such as sulfates and organic carbon, have a very short-term cooling effect (they are rained down in just a few days), while greenhouse gases stay aloft for decades.

Of course this is a double-edged sword. Aerosols have a known harmful effect on human health and on the environment. That’s why industrialized countries have been phasing them out.

A choice we don’t want to make
Do we have to choose between climate change and our health? Unger says, “no,” that we need to phase out unhealthy aerosols, but that an immediate focus on transportation will give us the biggest bang for our buck in the next decade.

A sound way to proceed is by attacking all sources – tailpipes, burning of wood and dung, cattle-produced methane AND power plants. If we can remove many of the sources of greenhouse gases, we won’t need unhealthy particles in the air to block out the sun.

To read about the study and see graphs go to NASA’s Web site.

See Q&A with Unger. (Caution: Don’t be biased by her picture. She’s a pretty blonde.)

If you want to read the study abstract.

(Sources: NASA, Proceedings of the National Academy of Sciences, fastcompany.com)