How to turn gas guzzlers into green machines

How much gasoline could US citizens save by driving around in light-weight hybrid vehicles? Up to half what they currently use, say scientists at MIT.

The US consumes about 140 billion gallons of gasoline each year. A team of researchers led by John Heywood has completed a five-year assessment of what can be done to slash that and save fuel for the nation.

They looked at how gas and diesel engines, as well as hybrid electric cars and plug-in cars, are likely to evolve between now and 2035. They also assessed what can reasonably be expected from new fuels such as hydrogen and biofuels.

"Improvements" in cars in recent years have largely focused on increasing performance, driven by the demand for ever-larger and more powerful cars. As a result, no significant fuel consumption gains have been realised over the past 25 years, says the team.

They call for car manufacturers to focus efforts on improving fuel savings over performance.

Lighten the load

A seemingly simple way of reducing the amount of fuel used by cars without a big change in consumer preferences would be to produce lighter cars. Heywood's team estimate that the average US car 25 years from now could feasibly weigh between 20% and 35% less without compromising on security and convenience. This alone would cut fuel consumption by between 12% and 20%.

Looking to what types of cars could push petroleum cars off the roads in 15 to 30 years, the team see the greatest potential in hybrid electric and plug-in hybrid electric cars – with batteries that can be topped up from the grid.

Whereas current spark-ignition cars use on average 8.9 litres of gasoline to travel 100 kilometres, more efficient equivalents could consume just 5.5 litres by 2035, while hybrids and plug-in hybrids would consume 3.1 and 2.2 litres respectively.

The team calculate what this would mean in terms of carbon dioxide emissions. On average, current "conventional" cars in the US emit 277 grams of CO₂ per km travelled. In 2035, their equivalents could chuck out just 178g per km. Hybrids and plug-in hybrids, meanwhile, are projected to emit just 109g.

The price tag

There will be a price to pay though: the hybrids will cost between $2500 and $5900 more than their contemporary petrol-only equivalents. Heywood says the government may have to step in to help with the transition.

Despite the hurdles, he and his team estimate that by improving fuel efficiency over the next 15 years and bringing in "radically different" cars including hybrids and possibly fuel cell cars in the next 30, it should be possible to slash the amount of fuel guzzled by the gas-guzzling nation by 30% to 50% by 2035.

The team points out that the biggest change can come from the drivers themselves. "We have got to get out of the habit of thinking that we only need to focus on improving the technology, that we can invent our way out of this situation," says Heywood.

"Transitioning from our current situation onto a path with declining fuel consumption and emissions, even in the developed world, will take several decades – much longer than we had hoped or realised," he says. "We've got to start now."

Reference: On the road in 2035, 2008

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Kangaroo Farming Could Reduce Global Warming

Written by Ariel Schwartz

What if you could drastically reduce greenhouse gases just by changing your eating habits?

According to a new study by the University of New South Wales, farming kangaroos instead of sheep or cattle could lower national greenhouse gases in Australia by 3 percent a year.

Methane from burps and farts of cows and sheep is an often overlooked contributor to global warming, but it accounts for 67% of Australia’s agricultural sector methane emissions. It also contributes 11% of Australia’s total emissions. In contrast, kangaroos barely produce any methane.

Of course, changing an entire nation’s eating habits isn’t easy. Australia sells relatively little kangaroo meat for consumption compared to other types of meat, and then there’s the issue of kangaroos being a national icon. But Australia produces 1.5 of the world’s carbon emissions, so drastic steps certainly shouldn’t be out of the question. If the farming project actually takes off, the authors of the University of South Wales study estimate that rangelands could support 240 million kangaroos—and only 175 million kangaroos are needed to produce the same amount of meat currently harvested from rangelands.

Fortunately for those of us living outside of Australia, other countries are embarking on similar projects to reduce methane by farming low-emissions animals. Examples include springbok in South Africa, red deer in the UK, and bison in the United States. With CO2 emissions from other industries showing no signs of slowing down, eating a red deer burger doesn’t sound so bad.

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Geothermal power tapping its potential

By Stevenson Swanson |Chicago Tribune correspondent

NEW YORK — When a historic seminary in the heart of Manhattan went searching for a way to cut its energy costs in an environmentally friendly way, it didn't turn to the heavens for sun or wind power but sought salvation in an unlikely direction for a religious institution. It looked underground.

Tapping the energy stored in the Earth, the General Theological Seminary, the oldest Episcopal seminary in America, is in the midst of a multiyear effort to construct the largest geothermal project on the East Coast. When completed, 20 wells reaching depths of at least 1,500 feet will supply water to heat and cool the seminary's 275,000 square feet of space.

The institution—built on land donated by Clement Clark Moore, who wrote "The Night Before Christmas"—is hardly alone in seeing the potential for geothermal power. From large power plants in the West that produce electricity to a hospital in the Chicago suburb of Elgin to homeowners looking to save money on their utility bills, geothermal power is experiencing steady but largely unnoticed growth in America.

Seeking alternatives

Say "alternative energy" and the images that spring to mind are probably huge wind turbines spinning above a farm field, or a vast array of solar panels.

But rising energy prices are bringing other unconventional energy sources to the fore, especially geothermal energy, which relies on the relatively straightforward principle that the temperature of the Earth below a certain level stays more or less constant. And the technology does not require high-visibility equipment like wind power or still-evolving methods for storing solar power efficiently.

"Drilling a hole is drilling a hole," said Maureen Burnley, head of finance and operations at the seminary, which was founded in 1817. "The technology is really simple. And the wells and the water and the Earth will be there forever."

Geothermal power is used in all 50 states, according to the Department of Energy's National Renewable Energy Laboratory.

Heat from the Earth's core radiates toward the surface, warming subterranean rocks and groundwater. Through deep holes, pumps bring hot water to the surface, where it can be used to generate electricity. Or it can be used in a heat pump, which transfers heat from the water to the air inside a building in the winter and reverses that process in the summer, when the air temperature is higher than the water temperature.

The renewable energy laboratory estimates that if all the heat trapped up to 2 miles under the U.S. were tapped, it could generate enough electricity to meet all of the country's power needs for 30,000 years.

"It's ubiquitous," said Karl Gawell, executive director of the Geothermal Energy Association, a Washington-based trade group. "It's a huge resource. But it's a largely untapped resource."

Currently, geothermal power plants account for about half a percent of the total U.S. electricity generation, providing power to an estimated 3 million households.

But that is likely to double in the next few years, with 103 new geothermal plants either under construction or planned in 13 states, predominantly in the western half of the country, where geological conditions are more favorable for large geothermal operations.

Heat pumps supply heating and cooling to about 600,000 U.S. households, according to the geothermal association, with an additional 50,000 households being added annually.

Growing presence

Institutions also are finding that geothermal systems can make sense. The entire Idaho Capitol complex uses geothermal climate control, and the new Sherman Hospital in Elgin will use a geothermal system consisting of about 150 miles of plastic pipe resting on the bottom of a 15-acre lake.

The hang-up that has prevented this seemingly inexhaustible energy source from finding widespread acceptance has been the initial cost of the system, especially deep drilling. A typical geothermal power plant costs three to four times more to build than a plant that burns natural gas, Gawell said.

But after the plant is paid for, it is much cheaper to run because the fuel—warm groundwater—costs virtually nothing.

"It's like deciding between two cars, one that costs $10,000 and one that costs $35,000," he said. "But the $35,000 car comes with a lifetime supply of gas. Now that energy prices are high, people are beginning to think about what they pay for fuel."

When the seminary's geothermal system is completed, the final cost is likely to be more than $20 million, said the seminary's Burnley. But heating oil prices have risen dramatically in the last five years, from 90 cents to $2.80 a gallon, she said.

And the new system will allow buildings that were stiflingly hot in summer to be used for the seminary's expanding summer programs. Plus, the system will reduce the seminary's carbon footprint by an estimated 1,400 tons of emissions annually.

"It's about stewardship of the campus," Burnley said. "And it's about stewardship of the planet."

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