Stories tagged renewable energy

Apr
18
2007

Solar cells reduce your electric bill, but they are also very expensive to buy and install.  Are they worth it?: Photo by clownfish from www.flickr.com
Solar cells reduce your electric bill, but they are also very expensive to buy and install. Are they worth it?: Photo by clownfish from www.flickr.com

Some people are installing solar panels on their homes. These panels generate electricity from sunlight. Using the panels will lower your electric bill, and reduce demand from power plants (which often burn coal).
But, are they worth it?

On April 15, the San Francisco Chronicle said yes. They looked at the costs of buying and installing the panels, and weighed it against the benefits (which include getting a tax rebate). They found that, over 25 to 30 years, the average home would save about $33,000.

So, solar panels are a good idea, right? Not so fast! On April 14, the NY Times reported that solar panels never pay for themselves. Even accounting for electrical savings and tax rebates, they are so expensive that you never make your money back.

Well, the two articles can’t both be right. Right? Well, actually, they both seem correct -- but they are based on two very different scenarios:

  1. Different tax rebates in the two states.
  2. More sunshine in California, making the panels more useful.
  3. The panels are almost twice as expensive in NY than in SF.
  4. The NY Times assumed that, if you didn’t spend the money on panels, you’d put it in the bank or otherwise invest it, where it can earn money for you. The SF Chronicle did not take this into account.

So, whether or not solar panels are a good financial investment depends on a lot of factors. Whether they are good for the environment is much easier to answer – they produce electricity without pollution.

In the future, the debate may be moot – scientists are working on new types of solar cells that use nanotechnology, which may bring the costs way down.

Mar
06
2007

Minnesota's Renewable Energy Standard (RES) set high.

High standard set by Minnesota: MN State Government
High standard set by Minnesota: MN State Government
Minnesota passed legislation (S.F. 4) that requires Minnesota's largest utility, Xcel Energy, to secure 30 percent of its electricity from renewable sources by 2020, while other utilities’ target is 20 percent by 2025. The state average of 25 percent renewable energy by 2020 is the most aggressive in the nation.

"I just think this is a landmark moment for our state," Pawlenty told about 150 lawmakers, environmentalists, utility representatives and academics at the St. Paul campus of the University of Minnesota.
The legislation is expected to produce thousands of new jobs and billions of dollars in new investments over the next couple of decades. (Feb 22/07) Pioneer Press

Renewable Energy Standard wins by a landslide

Minnesota's Senate voted 61-4 and the House of Representatives voted 123-10 which shows the overwhelming support for mandating renewable energy production.

"Right now, Minnesota imports more electricity than any other state. We need to keep more of our money at home," said the bill's sponsor, Rep. Aaron Peterson, DFL-Appleton.

It has been estimated that, when implemented, the use of renewable energy under the bill will save consumers and businesses as much as $500 million a year. StarTribune

Renewable energy cost worries refuted

Passage of the RES was aided by the results of a recent study released by the Minnesota Public Utilities Commission. The study found that utilities could use wind power to generate up to 25 percent of their energy mix without a significant impact on energy costs. (gov. news release)

Dec
08
2006


Prairie grasses: This experimental plot contains four species of prairie plants. The nearby plots, going clockwise, contain eight species, four species, and 16 species. (Photo courtesy David Tilman, University of Minnesota)

Scientists at our very own U of M have made some exciting new discoveries about the prospect of using biofuels for energy! They found that planting a diverse mix of native prairie species is more efficient than corn or soybeans, even on degraded soil. Amazingly, their most diverse plots, with 18 different species, produced 238% more bioenergy than the plots with only 1 species.

While there is still a lot of research needed to make this system useable on a wide scale, these findings are encouraging for a few reasons. Unlike all of our other forms of fuel, including corn ethanol or biodiesel from soy beans, the native plants actually absorb more carbon from the atmosphere than is released when used for fuel. Because of the vast root network associated with prairie plants (which allow them to withstand Minnesota’s hot and dry summers), much carbon is stored below ground and is not harvested for fuel. Also, these environmentally friendly crops can be grown on land that is unusable for traditional food crops. They do not need to be fertilized, a benefit to growing a native species, and thus can be grown in nutrient poor areas. Fertilizer runoff from traditional agriculture is a big contributor to water quality problems. Additionally, because native prairie species are perennial crops, they can help prevent erosion. For much of the year, particularly during the rainy months in the spring, corn or soybean fields are bare. This leaves the ground vulnerable to soil loss. Planting a native mix, particularly on steep slopes or along riverbanks, which are less suitable to traditional crops anyway, could mitigate many environmental issues. Plus, we could increase the amount of prairie habitat for native wildlife!

For more information on sustainable agriculture and the latest research check out Sustainable Agriculture Research and Education and the Minnesota Institute for Sustainable Agriculture.

Nov
11
2006

Hydrogen from soybean oil
Hydrogen from soybean oil

Homegrown fuel

Many consider hydrogen to be a perfect fuel. The waste product produced when it is burned is water. Hydrogen is a component contained in a variety of materials but figuring out how to cheaply extract that hydrogen is what one scientist refers to as the Holy Grail of 21st century energy.

U of Mn scientist, Lanny Schmidt, extracts hydrogen from biofuels

Lanny Schmidt, a Regents professor at the University of Minnesota, has invented such a process. It will produce hydrogen from renewable fuels like ethanol, sugar water, or soybean oil.

The reactor is deceptively simple in design. At the top is an automotive fuel injector that vaporizes and mixes the ethanol-water fuel. The vaporized fuel is injected into a tube that contains a porous plug coated with the catalyst. As the fuel passes through the plug, the carbon in the ethanol is burned, but the hydrogen is not. What emerges is mostly carbon dioxide, burnt carbon, and hydrogen gas. The reaction takes only 5 to 50 milliseconds and produces none of the flames and soot that usually accompany ethanol combustion. The reactor needs a small amount of heat to get going, but once it does, it sustains the reaction at more than 700 degrees C. University of MN

Minimize transportation costs

Also, his device is small and portable One of the thorniest economic problems of making biofuel from cornstalks or sawdust has been the cost of transporting the bulky materials to a distant factory. With Schmidt's invention, you wouldn't have to — the "factory" could be located on a farm or at a sawmill.

Electricity without powerlines

Converting biofuels into electricity requires fuel cells which generate electricty from hydrogen. Schmidt imagines a 1 kilowatt unit about the size of a washing machine where the electricity comes from a fuel cell powered by hydrogen, derived from ethanol or other biofuels. This could allow developing countries to eliminate the need for expensive powerlines into rural areas.

Sources: Pioneer Press and MPR

Joe, from the Energista website, reported on yesterdays Renewable Energy Workshop sponsored by the U of MN Electrical Engineering Department.