Archive for November, 2010

Optimizing Wind Farms – lessons learned at Altamont Pass

November 28, 2010 Leave a comment

Altamont Pass, California

Altamont Pass is perhaps a classic example of how unexpected consequences can make a “green” project quickly turn brown. East of San Francisco on I-580, Altamont pass is home to very strong winds – ideal for wind turbines that use this wind to generate electricity. Also along this pass is an established migration route for many birds, including several types of raptors.  In 2004, the California Energy Commission found that up to 1,300 raptors are killed each year in Altamont.

While I could spend this blog post on criticizing the engineers behind the Altamont Pass wind farm that results in the death of more than 4,000 birds, including 70 golden eagles each year, the truth is that this farm has taught us a lot about optimum wind farm designs.

For instance, we now know that large wind turbines are optimally spaced when they are 15 rotor-diameters apart, more than double today’s commonly used 7 rotor-diameter spacing. According to Dr. Charles Meneveau at Johns Hopkins, who has developed an algorithm for optimizing wind turbine spacing, the greater spacing allows for optimum wind flow along the wind farm (closer spacing “muddies” the flow of the wind). This spacing might also dramatically decrease the number of bird kills in the area. It might also lower the cost of electricity generated in these wind farms.

Dr. Meneveau’s work, combined with other research being done throughout the world, are taking the mistakes we have made in the past, to help us optimize our future wind farm designs. The results –  lower cost renewables and reduced environmental impacts.


Where is the wind (power)?

November 27, 2010 Leave a comment

Wind power capacity in the United States has increased dramatically over the past decade – but where is this wind capacity being installed?

Scientific American: Power from pondscum

November 26, 2010 Leave a comment

Favorite story of the day – David Wogan’s blog post on Scientific American’s guest blog.

In the discussion of alternative energy and fuels, algae have been bubbling to the top of the proverbial feedstock pool. Algae, the little green guys responsible for everything from making your Dairy Queen Blizzard solid to forming the basis of our current fossil fuels, are being looked at long and hard by some of the nation’s top researchers and decision-makers as a source for next-generation biofuels.

Titled “Power from pondscum: algal biofuels,” David’s post discusses what algae-for-biofuels could mean for the US.

David is currently a graduate research assistant in the Webber Energy Group at the University of Texas at Austin. A dual-degree student in Mechanical Engineering and Public Affairs, David has spent his time studying the potential for algae to supply our transportation fuel needs. In his work, David has developed a model that incorporates solar, water, and carbon dioxide resources to determine the potential for algae growth by region.

The Daily Wogan: Austin EMS to use solar-powered ambulances

November 24, 2010 Leave a comment

Yesterday, The Daily Wogan published a blog post about several new ambulances in the Austin EMS fleet that will use solar panels to power critical on-board equipment. These panels will allow EMTs to shut down their engines while they wait for their next call. This will not only save fuel ($$) but reduce their environmental impact.  As reported by the Austin American Statesman on Sunday:

EMS officials said calculations show the switch will reduce gas consumption by several hundred gallons per unit, save gas money — up to $4,000 a year per ambulance — and decrease emissions.

“It is huge for us and the city as well,” Assistant EMS Director James Shamard said. “This is one of those times when we were able to maintain our medical equipment while at the same time do a little better for the environment.”

Officials said the agency is among the first nationally to begin using solar energy to help power ambulances. At a statewide EMS conference in Austin today, they will unveil one of two units that have the solar panels.

Very cool.

Returns on Energy Investments – EROI and EIR

November 23, 2010 3 comments

Dr. Carey King, a research associate at the Jackson School of Geosciences at The University of Texas at Austin and member of the Webber Energy Group, has spent the past couple of years studying a metric called Energy Return on Energy Invested (EROI). In his work, he strives to define what EROI includes and what it means – with the hope of allowing us to compare the efficiency of the different energy sources that we currently, or might soon, rely upon to power our lives.

In Dr. King’s November 10th publication in Environmental Research Letters he introduces discusses EROI in terms of another interesting dimension, called the Energy Intensity Ratio (EIR), that brings economics into the mix. As written by Dr. King…


Dr. Carey King

In this letter I compare two measures of energy quality, energy return on energy invested (EROI) and energy intensity ratio (EIR) for the fossil fuel consumption and production of the United States. All other characteristics being equal, a fuel or energy system with a higher EROI or EIR is of better quality because more energy is provided to society. I define and calculate the EIR for oil, natural gas, coal, and electricity as measures of the energy intensity (units of energy divided by money) of the energy resource relative to the energy intensity of the overall economy. EIR measures based upon various unit prices for energy (e.g.  $/Btu of a barrel of oil) as well as total expenditures on energy supplies (e.g. total dollars spent on petroleum) indicate net energy at different points in the supply chain of the overall energy system. The results indicate that EIR is an easily calculated and effective proxy for EROI for US oil, gas, coal, and electricity. The EIR correlates well with previous EROI calculations, but adds additional information on energy resource quality within the supply chain. Furthermore, the EIR and EROI of oil and gas as well as coal were all in decline for two time periods within the last 40 years, and both time periods preceded economic recessions.

Energy Return on Energy Invested (EROI)

The concept of Energy Return on Energy Invested (EROI) seems fairly clear – to get energy, we (generally) have to use energy. The EROI is a measurement of how much energy we use to get the energy we want.

For example: The gasoline that we use to power our vehicles (usually via a spark-ignition engine) is first pumped out of the ground as crude oil. This oil is then transported to refineries and then processed into gasoline (or diesel + a bunch of other refined petroleum products). This gasoline is then piped and trucked to gas stations, and then pumped into our cars. At every step, we use energy to get our gasoline a step closer to what we want – gasoline in our tank that can be used to take us where we want to go.

Calculating the energy return on energy invested (EROI) for the process above shows us that we get more energy out of our gasoline than we put into it to get it to our cars. This is one of the reasons that we like traditional gasoline – lots of power out for little amounts of energy in. It is also one of the arguments against corn-based ethanol, which requires a lot of energy in for arguably less energy out.

Energy Intensity Ratio (EIR)

The Energy Intensity Ratio (EIR) is the energy intensity of an energy resource, divided by the economic energy intensity (energy per unit of GDP) of a country. A low economic energy intensity means that a high amount of economic value can be realized for a very small amount of energy.

To learn more, you can check out Dr. King’s publication for free here.

Wasted Food, Wasted Energy

November 22, 2010 1 comment

On the 8th, I mentioned research done by Dr. Michael Webber and former Webber Energy Group member Amanda Cuellar on the energy we waste when we waste food.  This work is now featured on the UT Austin main website in the article titled “Eat Your Leftovers: How America’s Wasted Food Could Power Switzerland for a Year.”

If you find some time this afternoon, I would recommend checking out this article on UT’s website – found here. It is a very nice summary of the research and its potential implications.

Food waste and energy in America by food group, percent of food energy wasted and total energy lost

Food & Energy Waste in America - by Cuellar and Webber

Pecan Street Project – Request for Information

November 20, 2010 1 comment

This week, the Pecan Street Project (PSP) released its draft Request for Information (RFI). They are asking for comments from interested parties until December 3rd. Over the following week, the folks at the PSP will review all of the comments they receive and will update the draft RFI to its final state, which will be released on or about December 10th.

Before the comment deadline, PSP will hold a conference call at 3pm on November 29th (see the draft RFI for more details).