Grass is greener in biofuel future

By Jessica Daly Stephen Long amid Miscanthus stalks found to outperform other biofuel sources.
as published via CNN

LONDON, England (CNN) — Researchers in the United States are buoyed by the results of a study which has determined that a giant grass could help the country to meet its steep biofuel targets.

Stephen Long amid Miscanthus stalks found to outperform other biofuel sources.

After successful long-term trials in Europe, a three-year field study of Miscanthus x giganteus by the University of Illinois has revealed that it outperforms traditional biofuel sources, producing more than twice the ethanol per acre than corn or switchgrass, using a quarter of the space.

Crop sciences professor and study leader Dr. Stephen Long told CNN that while there probably isn’t one magic bullet to fix our climate woes, Miscanthus — also known as elephant grass — promises to be one of five or six options that could help the U.S. to reach its target of replacing 30 percent of gasoline use with biofuels by 2030.

“I think it’s important in the biofuels debate that we don’t throw the baby out with the bath water. The idea we use the sun’s energy to grow plants and then make fuels from those plants is essentially a good one,” Dr. Long said.

“It’s been tainted by the fact that the easy way to do it is to just use food crops, but society needs to realize there are big opportunities beyond food crops and beyond the use of crop land.”

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Miscanthus, for instance, is able to grow on land too marginal for crop production, so it doesn’t have to compete with land for food crops. It also doesn’t require major input or fertilization after planting and once established will yield for around 15 years.

Yet even with the success of these trials in the U.S. and the earlier European ones, it could be years before the full potential of Miscanthus is realized.

This is due in part to the fact that it’s much more complex to make cellulosic ethanol — ethanol made from non-food plants — than it is to turn simple food starches found in corn or wheat into ethanol.

In the United Kingdom, Miscanthus is recognized by the Department of Environment, Food and Rural Affairs as an energy crop and it’s currently being used to co-fire the Drax power station in England’s Yorkshire.

Even still, Dr. Geraint Evans from the UK’s National Non-Food Crops Centre said rather than plants like Miscanthus, wheat grain will be used to meet the UK target of replacing five percent of fuel with renewable sources by 2010.

“Miscanthus has the potential to be more efficient, producing between 4,000 and 7,000 liters of fuel per hectare, whereas ethanol made from wheat grain makes about 1900 liters per hectare.”

“Wheat grain-derived ethanol is what we can do today with the technology we have available today. The technology to use Miscanthus is not yet commercially available,” Dr. Evans told CNN.

In addition to the technical hitch, Dr. Evans said a further downside is that even though Miscanthus is a low maintenance crop, it can be costly to plant compared to wheat or rapeseed canola and the first yield wouldn’t occur for at least three years.

In an effort to overcome some of the challenges, Dr. Long now intends to turn his attention to experimenting with the wild Miscanthus used in the U.S. trial.

And if the sort of improvements made to corn in the last 50 years are any indication, Miscanthus could be well be used to fuel the future in a matter of years.


Solar Thermal Power Coming to a Boil

Solar Thermal Power Coming to a Boil

By Jonathan G. Dorn
Earth Policy Institute

After emerging in 2006 from 15 years of hibernation, the solar thermal power industry experienced a surge in 2007, with 100 megawatts of new capacity coming online worldwide. During the 1990s, cheap fossil fuels, combined with a loss of state and federal incentives, put a damper on solar thermal power development. However, recent increases in energy prices, escalating concerns about global climate change, and fresh economic incentives are renewing interest in this technology.

Considering that the energy in sunlight reaching the earth in just 70 minutes is equivalent to annual global energy consumption, the potential for solar power is virtually unlimited. With concentrating solar thermal power (CSP) capacity expected to double every 16 months over the next five years, worldwide installed CSP capacity will reach 6,400 megawatts in 2012—14 times the current capacity. (See data.)

Unlike solar photovoltaics (PVs), which use semiconductors to convert sunlight directly into electricity, CSP plants generate electricity using heat. Much like a magnifying glass, reflectors focus sunlight onto a fluid-filled vessel. The heat absorbed by the fluid is used to generate steam that drives a turbine to produce electricity. Power generation after sunset is possible by storing excess heat in large, insulated tanks filled with molten salt. Since CSP plants require high levels of direct solar radiation to operate efficiently, deserts make ideal locations.

Two big advantages of CSP over conventional power plants are that the electricity generation is clean and carbon-free and, since the sun is the energy source, there are no fuel costs. Energy storage in the form of heat is also significantly cheaper than battery storage of electricity, providing CSP with an economical means to overcome intermittency and deliver dispatchable power.

The United States and Spain are leading the world in the development of solar thermal power, with a combined total of over 5,600 megawatts of new capacity expected to come online by 2012. Representing over 90 percent of the projected new capacity by 2012, the output from these plants would be enough to meet the electrical needs of more than 1.7 million homes.

The largest solar thermal power complex in operation today is the Solar Electricity Generating Station in the Mojave Desert in California. Coming online between 1985 and 1991, the 354-megawatt complex has been producing enough power for 100,000 homes for almost two decades. In June 2007, the 64-megawatt Nevada Solar One plant became the first multi-megawatt commercial CSP plant to come online in the United States in 16 years.

Today, more than a dozen new CSP plants are being planned in the United States, with some 3,100 megawatts expected to come online by 2012. (See data.) Some impressive CSP projects in the planning stages include the 553-megawatt Mojave Solar Park in California, the 500-megawatt Solar One and 300-megawatt Solar Two projects in California, a 300-megawatt facility in Florida, and the 280-megawatt Solana plant in Arizona.

In Spain, the first commercial-scale CSP plant to begin operation outside the United States since the mid-1980s came online in 2007: the 11-megawatt PS10 tower. The tower is part of the 300-megawatt Solúcar Platform, which, when completed in 2013, will contain ten CSP plants and produce enough electricity to supply 153,000 homes while preventing 185,000 tons of carbon dioxide (CO2) emissions annually. All told, more than 60 plants are in the pipeline in Spain, with 2,570 megawatts expected to come online by 2012.

Economic and policy incentives are partly responsible for the renewed interest in CSP. The incentives in the United States include a 30-percent federal Investment Tax Credit (ITC) for solar through the end of 2008, which has good prospects for being extended, and Renewable Portfolio Standards in 26 states. California requires that utilities get 20 percent of their electricity from renewable sources by 2010, and Nevada requires 20 percent by 2015, with at least 5 percent from solar power. The primary incentive in Spain is a feed-in tariff that guarantees that utilities will pay power producers €0.26 (40¢) per kilowatt-hour for electricity generated by CSP plants for 25 years.

In the southwestern United States, the cost of electricity from CSP plants (including the federal ITC) is roughly 13–17¢ per kilowatt-hour, meaning that CSP with thermal storage is competitive today with simple-cycle natural gas-fired power plants. The U.S. Department of Energy aims to reduce CSP costs to 7–10¢ per kilowatt-hour by 2015 and to 5–7¢ per kilowatt-hour by 2020, making CSP competitive with fossil-fuel-based power sources.

Outside the United States and Spain, regulatory incentives in France, Greece, Italy, and Portugal are expected to stimulate the installation of 3,200 megawatts of CSP capacity by 2020. China anticipates building 1,000 megawatts by that time. Other countries developing CSP include Australia, Algeria, Egypt, Iran, Israel, Jordan, Mexico, Morocco, South Africa, and the United Arab Emirates. (See map.)

Using CSP plants to power electric vehicles could further reduce CO2 emissions and provide strategic advantages by relaxing dependence on oil. In Israel, a tender issued by the Ministry for National Infrastructures for the construction of CSP plants and a 19.4¢ per kilowatt-hour feed-in tariff for solar power systems are sparking interest in developing up to 250 megawatts of CSP in the Negev Desert. This would produce enough electricity to run the 100,000 electric cars that Project Better Place, a company focused on building an electric personal transportation system, is planning to put on Israeli roads by the end of 2010.

A study by Ausra, a solar energy company based in California, indicates that over 90 percent of fossil fuel–generated electricity in the United States and the majority of U.S. oil usage for transportation could be eliminated using solar thermal power plants—and for less than it would cost to continue importing oil. The land requirement for the CSP plants would be roughly 15,000 square miles (38,850 square kilometers, the equivalent of 15 percent of the land area of Nevada). While this may sound like a large tract, CSP plants use less land per equivalent electrical output than large hydroelectric dams when flooded land is included, or than coal plants when factoring in land used for coal mining. Another study, published in Scientific American in January 2008, proposes using CSP and PV plants to produce 69 percent of U.S. electricity and 35 percent of total U.S. energy, including transportation, by 2050.

CSP plants on less than 0.3 percent of the desert areas of North Africa and the Middle East could generate enough electricity to meet the needs of these two regions plus the European Union. Realizing this, the Trans-Mediterranean Renewable Energy Cooperation—an initiative of The Club of Rome, the Hamburg Climate Protection Foundation, and the National Energy Research Center of Jordan—conceived the DESERTEC Concept in 2003. This plan to develop a renewable energy network to transmit power to Europe from the Middle East and North Africa calls for 100,000 megawatts of CSP to be built throughout the Middle East and North Africa by 2050. Electricity delivery to Europe would occur via direct current transmission cables across the Mediterranean. Taking the lead in making the concept a reality, Algeria plans to build a 3,000-kilometer cable between the Algerian town of Adrar and the German city of Aachen to export 6,000 megawatts of solar thermal power by 2020.

If the projected annual growth rate of CSP through 2012 is maintained to 2020, global installed CSP capacity would exceed 200,000 megawatts—equivalent to 135 coal-fired power plants. With billions of dollars beginning to flow into the CSP industry and U.S. restrictions on carbon emissions imminent, CSP is primed to reach such capacity.

Copyright © 2008 Earth Policy Institute