Energy Lines
April 2013
The official publication for members of Flint Energies
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Go for the green...power, that is
reen power is electric energy produced by renewable, more environmentally friendly sources, limiting the impact on air, water and natural resources. Typical technologies used to create green power are solar, wind, geothermal, biomass and low-impact hydropower. Biomass includes landfill gas and agricultural wastes. Potential green power sources in Georgia are primarily biomass and solar.
Green Power EMC. This represents approximately 3 million Georgians who now have the power to help the environment by using clean, green energy. To date, Green Power EMC has generated 125 million kilowatt-hours (kWh) of green energy, providing the same environmental benefits as taking 125,000 cars off Georgia’s roads, or planting 176,000 acres in trees.
An idea conceived in 2001 and operational by 2003, Green Power EMC was launched as the first renewable energy program in Georgia and is now one of the largest renewable energy programs in the southeastern United States.
Currently, Green Power EMC generates our green power from two landfill gas-to-electricity facilities, a low-impact hydro facility, one wood waste biomass plant and our Sun Power for Schools program. Further, we maintain ongoing research projects for both solar and wind power.
Today, 39 of Georgia’s memberowned electric cooperatives, including Flint Energies, have signed on with
Like the electric cooperatives that join us in supplying cleaner, greener energy to an environmentally conscious
customer base, Green Power EMC is a nonprofit corporation devoted to serving our member-owners. The two landfill gas-to-electricity projects utilized by Green Power EMC produce a combined five megawatts of electricity, enough to power more than 3,000 Georgia homes each year. In Georgia, Green Power EMC uses low-impact hydro produced at Tallassee Shoals Hydroelectric Project. Located on the Middle Oconee River, the 2.3-megawatt facility is owned and operated by the Fall Line Hydro Co., Inc., and licensed by the Federal Energy Regulatory Commission (FERC). The Tallassee Shoals Project was the first hydropower facility in Georgia to earn certification from the Low Impact Hydropower Institute, which was awarded in July 2004, and the 12th nationwide to earn this distinction. Continued on page 26H
Green Power EMC teamed with odor elimination manufacturer Clean Control Corp. and solar project developer First Century Energy to build a 150-kilowatt solar facility in Warner Robins, Ga. The facility will provide 4.7 million kWh of solar energy to the power grid over its projected 25-year lifetime. April 2013
Every Day in USA is Armed Forces Appreciation Day
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Biomass:
iomass consists of any biological material that can be burned as fuel to produce electricity, and it’s everywhere. A quick drive down a country road provides a virtual tour of this renewable energy resource: trees, grasses, crops, livestock waste and even landfill gas. Recent advances in technology have made it possible to use tried-and-true biomass in more efficient ways.
Today, the U.S. boasts almost 11,000 MW of biomass-generating capacity, making it the third-largest source of renewable energy, behind hydropower and wind. The Houston County landfill’s gas-to-electricity project is an example of biomass.
How it works
The basic premise behind this power source is simple. Burning actual biomass feedstock or the gases produced by decomposition of organic material—in whatever form— creates steam, which then spins a turbine and generates electricity. Given the wide variety of biomass resources available, questions on what to burn and in what manner can be answered in a number of ways: • Direct-fired systems: This remains
An abundant renewable fuel
the most straightforward, time-tested means of producing electricity with biomass. Quite simply, material (like wood “slash” from timbering operations) gets shoveled into a boiler to produce heat and steam. Residual heat from the process can be piped off to heat buildings or reused in other ways, increasing plant efficiencies. • Co-fired systems: This method adds biomass to existing fossil fuel plants, mixing wood chips with coal, for example. In this way, fossil fuel plants can lower emissions while maintaining the same electrical output. • Gasification: Slightly more complex, this process converts biomass to a gas through superheating. The resulting synthetic gas (syngas) can be burned in a conventional boiler or used as a substitute for natural gas. • Pyrolysis: This techy term describes changing solid biomass into a different form. If biomass is superheated in an area void of oxygen, it will not catch fire, but will instead liquefy. The resulting oil can be burned to generate electricity or used in making plastics, adhesives and other products.
• Anaerobic digestion: Instead of burning biomass as fuel, this method amounts to piling up waste and waiting. As the name implies, bacteria (anaerobes) literally digest molecules in waste—be it livestock manure or garbage—and produce methane as a byproduct. The gas is then captured and burned to make electricity. Leftover material, in many cases, can be used as compost.
The future of biomass
Biomass has come a long way from putting a log on a fire. Applications continue to develop, many of which involve converting biomass to other forms to supplement petroleum use. New sources of electricity and fuel production are being researched every day, and soon waste such as corn stover (stalks, leaves and husks) and wheat straw will be added to the mix. Non-food crops, such as trees and grasses, are also being researched for their energy-producing potential, especially in liquid form. For more information on the future of biomass and current uses, visit the U.S. Department of Energy National Renewable Energy Lab at www.nrel.gov, and search for “learn biomass.”
Sugar cane is being studied as a possible biomass crop. One of its great advantages is a short rotation; plants regrow after each harvest, allowing multiple harvests without having to replant.
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GEORGIA MAGAZINE
Hydropower: Time-tested renewable energy
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ou may not realize it, but a rush of water likely helps keep your lights on every day. Like many electric cooperatives around the country, Flint Energies draws on hydroelectric power to keep electricity reliable, safe and affordable. Energy from flowing water has been harnessed and used for more than 2,000 years. Ancient Greeks developed the first water wheels and used them to grind wheat into flour. In the 1880s, converting a rush of water into electricity became a reality in the United States. The breakthrough quickly swept the nation, and within a decade, 200 U.S. plants were using water power for some or all generation. Today, hydropower provides about 80,000 MW of capacity in the United States and accounts for 86 percent of all renewable, carbonfree electricity used by co-ops. It’s inexpensive, pollution free and has been supplying electricity to rural areas since the formation of electric co-ops in the mid-1930s. But how does it work? Simply, hydropower converts the natural energy in moving water to mechanical energy. A water wheel, which can be attached to a mill, becomes a basic means to that end. If that water wheel (or its modernday equivalent, a turbine) is attached to a generator, electricity results. With highly efficient turbine generators doing the job formerly performed by waterwheels, electricity can be turned out in a number of ways: • Impoundment: When most people think of hydropower, dams come to mind. By plugging a river and amassing water in a reservoir, its flow (and the resulting electricity) can be better controlled and generated as needed. • Diversion: Water is channeled away from a river, typically near natural falls, down to generators April 2013
Above, a fish ladder near the Bonneville Dam on the Columbia River enables fish to swim upstream and around dams by leaping up a series of low steps. Right, turbine shafts in the Hoover Dam generate, on average, about 4 billion kilowatthours of power each year—enough to serve 1.3 million people.
at the falls’ base. This can be done without any visible impact to the natural course of a river. In fact, this kind of generation was used to bring electricity to Buffalo, N.Y., from Niagara Falls in the late 1800s. • Pumped storage: This method essentially uses off-peak electricity to make electricity for use during times of high consumption. Two reservoirs are filled, one typically uphill from the other, with an electric pump/ generator in between. At night, when demand is low and electricity is less expensive, water from the lower reservoir gets pumped uphill. During the day, when demand for power increases, that water is released down through the generator to make electricity. More than 600 electric co-ops across the country purchase power from 134 federally owned and operated dams, most of which were built between the late 1930s and early 1960s. Despite the incredible importance of these resources, maintenance of the oldtimers has lagged in recent years and created room for improvement.
Every Day in USA is Armed Forces Appreciation Day
Electric co-ops are making efforts to address this problem, advocating that the government set aside funds to repair and maintain dams and the turbines inside them. Researchers are also looking to create more efficient and environmentally sound (i.e. fish-friendly) ways of generating hydropower. Careful studies of aquatic environments have given dam operators a better idea of how to simulate a natural river downstream. More unique environmental protection solutions, such as fish ladders (a concept first developed in the 1600s), are also being researched and put into action. This push for increased maintenance and technology development will ensure that hydropower remains a reliable and affordable renewable resource for decades to come.
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The brighter side of sunshine
here’s nothing new under the sun—not even the sun. For thousands of years, humans have harnessed solar energy to accomplish daily tasks. From starting fires to heating water, the sun powers our society. The latest wave of solar technology focuses on generating electricity. Some solar power systems span acres, while others are no bigger than a postage stamp. At the end of 2009, America’s cumulative solar capacity reached 2,108 MW, ranking it fourth in the world behind powerhouses like Germany, Spain and Japan. Last year, the largest area of growth involved photovoltaic (PV) installations, jumping 38 percent. Solar water heating grew by 10 percent. Pushing this trend are falling prices for solar equipment due in part to federal tax credits. Flint Energies has been harnessing
the sun since 2006 on a small-scale basis, with trial projects at Huntington Middle School in Warner Robins. “Although solar power remains more expensive and less reliable than more traditional forms of power generation, we’re excited about this technology’s potential,” reports Marian Douglas, Manager of Public Relations at Flint Energies.
How it works
Solar power plants harness basic premises such as reflective heating to create steam, or use advanced materials to convert sunlight directly into electricity. Whatever the method, all operate under one major condition: the sun must be shining to make things work. There are two primary methods of harnessing the sun: concentrating solar power (also known as solar thermal energy) and photovoltaics.
Concentrating solar power
The earliest way to convert sunlight into power grew from a basic concept: if you can spin a turbine, you can generate electricity. As a result, solar energy focused to heat water and create steam does just that, creating a power plant that can, if properly operated, deliver electric power year-round. This high-temperature technology exists in a variety of forms.
A transparent thin film barrier used to protect flat panel TVs from moisture could become the basis for flexible solar panels that would be installed on roofs like shingles. 26D
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• Trough systems: Long pipes, filled with synthetic oil or other liquids, are placed just above mirrored troughs tilted toward the sun. Continued on page 26G
Learn more about solar energy Find Solar
Interested in installing a solar PV system at your home, but are unsure of the expense? This tool takes your home’s location, energy use and state and federal incentives into account to calculate potential costs and benefits. It also provides an estimate of how much time is needed before your investment pays off, which often will make or break a PV system’s feasibility. www.findsolar.com
U.S. Department of Energy
The Office of Energy Efficiency and Renewable Energy, part of the U.S. Department of Energy, offers excellent sources of information on solar energy, from frequently asked questions to information on the federal Solar America Initiative. A comprehensive Solar Timeline tracks the renewable resource from ancient use to future applications. www.eere.energy.gov/solar
National Renewable
Energy Laboratory The National Renewable Energy Laboratory (NREL) fine-tunes the performance of solar power technologies and researches new ways to harness the sun’s energy. Check this site for industry news, programs and in-depth information on specific technologies. www.nrel.gov/solar/
GEORGIA MAGAZINE
Making wind
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ind energy has been used to improve quality of life for thousands of years. Rudimentary windmills were pumping water in Asia and grinding grain in the Middle East as early as 200 B.C. Wind turbines were first used to generate electricity in Denmark as far back as 1890, and multi-bladed mills became a symbol of rural America in the early 1900s. With recent advances in technology, this driving force has been channeled by electric cooperatives and other utilities into electricity. Last year, enough wind was harnessed to power almost 10 million American homes (roughly 35,000 MW). With help from tax credits and federal funding, wind power costs have dropped from 80 cents per kWh in 1980 to 8 cents per kWh in 2009. (In comparison, the cost for electricity from coal-fired power plants averages 3.6 cents per kWh; nuclear power, roughly 2.1 cents per kWh; and natural gas, 7 cents per kWh.) As the generation becomes more affordable, wind power plants in some parts of the country—often called wind farms—are now as common as weather-beaten windmills of the past.
How to harness wind
Wind power follows a basic premise: if you can turn a generator, you can produce electricity. Turbines convert the natural energy of wind into mechanical energy by attaching
April 2013
Grand Forks, N.D.-based Minnkota Power Cooperative draws 139.5 MW from the Landon Wind Energy Center.
giant, wind-catching blades to a generator. When wind blows through the blades, they spin and generate power.
Pros and cons
Wind turbines come in a variety of forms. The most common are horizontal-axis varieties, which look like a large pinwheel or fan. These typically sport three blades, although some have two, facing into the wind. Some small turbines that can be erected in a backyard to produce less than 100 kW, while their larger cousins tower hundreds of feet over the horizon, capable of generating more than 3.5 MW of power.
Some parts of America seem customfit for wind power. Over the last three years, two Alaska cooperatives―Kodiak Electric Association and Alaska Village Electric Cooperative―have been named Wind Cooperative of the Year, an award sponsored by DOE and the National Rural Electric Cooperative Association, the Arlington, Va.-based service organization representing the nation’s more than 900 consumer-owned, not-for-profit electric cooperatives, public power districts and public utility districts.
Another configuration puts blades on a vertical-axis to resemble an eggbeater held upright. This less common variation, dubbed the Darrieus turbine after a French inventor, follows the same basic turbine principles.
The 2009 honoree, Kodiak Electric, uses wind to meet 9 percent of its power requirements. By harnessing wind when possible, the co-op saved more than 800,000 gallons of diesel fuel in 2010.
The U.S. Department of Energy (DOE)’s Office of Energy Efficiency and Renewable Energy provides a step-by-step look at how wind turbines tap potential energy at www.eere.energy.gov/ wind/wind_how.html.
But wind doesn’t blow everywhere, and rarely does so around the clock. Even in areas with strong wind resources, an active wind turbine typically only generates 20 percent to 30 percent of its “capacity factor”—the
Every Day in USA is Armed Forces Appreciation Day
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Geothermal: Energy from the ground up
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eothermal energy—created from Earth’s natural heat—has been used by many cultures for thousands of years to cook and bathe. But modern technology has unlocked new ways to harness geothermal potential: producing electricity using hot water and steam locked below the surface; and heating and cooling buildings.
• Flash steam: The most common, these plants pump water boasting temperatures greater than 360 degrees Fahrenheit under high pressure to generation equipment. The steam is separated from the water and used to make electricity; leftover water and condensed steam are channeled back into the reservoir.
America leads the world in geothermal power production, with about 3,080 megawatts of capacity from more than 70 power plants, according to the Geothermal Energy Association, the national trade association for geothermal development companies. Western states boast the most geothermal energy.
• Binary cycle: Uses moderate- to low-temperature groundwater or steam. In a binary cycle system, hot water is pumped from a well and passes through a heat exchanger, where it warms a secondary fluid boasting a lower boiling point than water. This causes the secondary fluid to flash to vapor, which in turn drives a turbine. The secondary fluid then condenses and returns to the loop system; the water gets pumped back into the well.
How it works
Typical fossil-fuel burning and nuclear power plants heat water to boiling to create steam. The steam then turns a turbine, which generates electricity. Geothermal power stations essentially cut out the middle man, piping naturally heated water (which is changed into steam) or naturally occurring steam into a plant to spin turbines. Three different types of geothermal generation exist; the choice depends on the state of the hydrothermal fluid (whether steam or water) and its temperature.
Other uses
Geothermal energy offers an array of benefits beyond electricity generation. In some cases, hot water can be piped directly into systems to heat buildings, greenhouses and fish farms. Some cities run hot water under roads and sidewalks during winter to melt snow and ice.
Geothermal heat pumps rely on energy from the ground—the top 10 feet of earth remains a relatively constant 50 to 60 degrees Fahrenheit temperature year-round—to move heat into and out of a building, providing winter heating and summer cooling. Also called ground-source heat pumps, these appliances come in two types: a groundwater (open-loop) system uses well water; an earth-coupled (closed-loop) model moves a water and antifreeze solution through underground pipes to disperse heat. While geothermal heat pumps generally operate more efficiently than their air-source cousins, they are more expensive upfront. A federal tax credit equal to 30 percent of the cost for materials and installation, with no limit on total project expenses, applies to geothermal heat pumps through December 31, 2016. A full list of geothermal heat pump requirements, along with a product list, can be found at www.energy star.gov/taxcredits. To see if other rebates are available in your state, check the Database of State Incentives for Renewables and Efficiency at www.dsireusa.org.
• Dry steam: The first type of geothermal power plants built, these facilities use steam from a geothermal reservoir (pulled from wells) and route it directly through turbines to create electricity.
A geothermal heat pump might not always be the best option in every situation. Contact Flint Energies to determine whether a geothermal heat pump is the right choice for you. Sources: U.S. Department of Energy, National Renewable Energy Laboratory, Geothermal Energy Association, International Ground Source Heat Pump Association
Geothermal power stations pipe naturally heated water (which is changed into steam) or naturally occurring steam into a plant to spin turbines. 26F
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GEORGIA MAGAZINE
SUNSHINE
Continued from page 26D Heat is concentrated on the pipes, which pump the resulting hot liquid to a steam generating plant nearby. • Dish-engine system: Several small mirrors are fashioned into a large dish, focused on a central arm and engine. The end product looks very similar to a satellite dish. Inside the engine, collected heat builds pressure and drives pistons, which then turn a generator to produce electricity. Large fields of dishes can be programmed to follow the sun throughout the day. • Power tower: These large-scale reflecting plants direct sunlight to a central tower using hundreds of flat, angled mirrors called “heliostats.” The tower contains a liquid that quickly absorbs heat, which then produces steam and generates electricity. Researchers recently have been using molten salt as the heatcapturing liquid, since it retains heat long after the sun has set.
Photovoltaics
Photovoltaic materials directly convert light into electrical energy without need for turbines, generators, or other mechanical assistance. When a PV system absorbs sunlight, energy passes on to electrons. The energized electrons break free and, in the right conditions, join an electric current—which can then power your home. PV systems are most commonly made up of dark, flat panels installed on roofs. Smaller versions can operate individual lights or remote machines (such as pumps), while larger applications power buildings or supply electricity to the grid. New, more flexible panels are on the way. Scientists at the U.S. Department of Energy Pacific Northwest National
April 2013
Laboratory think a transparent thin film barrier used to protect flat panel TVs from moisture could become the basis for flexible solar panels that would be installed on roofs like shingles. The flexible rooftop solar panels–called building-integrated photovoltaics, or BIPVs–could replace today’s boxy solar panels that are made with rigid glass or silicon and mounted on thick metal frames. The flexible solar shingles would be less expensive to install than current panels and made to last 25 years.
The bottom line
Sunlight may look like an easy way to generate electricity, especially in remote areas without easy access to transmission lines. But there are drawbacks. The sun only shines for a set number of hours daily, and cloudy or overcast conditions can wreak havoc on solar power production. Without an effective way to store electricity for nighttime and cloudy day use, a solar system’s effectiveness remains limited. Cost has been a long-standing barrier, though the outlook in that area looks brighter. Researchers at the U.S. Department of Energy Lawrence Berkeley National Laboratory released a study in late 2009 showing PV installation costs over the last decade had dropped more than 30 percent—and more than 4 percent of the drop occurred in 2008 alone. Solar power can serve as an excellent supplement to an existing grid. As costs continue to drop, you may want to research the long-term benefits of adding a system to your home. To learn more, call 1.800.342.3616 or visit www.flintenergies.com. Sources: Solar Energy Industries Association, Lawrence Berkeley National Laboratory, U.S. Department of Energy
Every Day in USA is Armed Forces Appreciation Day
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Continued from page 26E total electricity it could generate operating around the clock. A 2010 National Renewable Energy Laboratory (NREL) survey found less than 1 percent of land in states like Alabama, Kentucky and Georgia windy enough to achieve at least 30 percent capacity factor. Because it’s temperamental, wind can’t be relied on as a steady source of energy. Instead, think of wind as a “fuel displacer,” allowing baseload power plants that rely on fossil fuels like coal and natural gas to burn less when wind blows. Moving energy from a wind farm to homes also raises difficulties. Transmission infrastructure may not be available in areas where the wind blows best, and building new transmission lines takes time, money and a lengthy governmental approval process. Before turbines go up, studies must be done to judge the wind’s variability in a given area. And although the sight of a tall, white wind tower may not be as intrusive as other types of power plants, environmental and economic impacts must be assessed. Will the turbine disrupt bird or bat migratory patterns? Will shipping routes be affected by an offshore wind farm? Although great strides have been made in recent years and more wind turbines are built daily, making wind work as a reliable, affordable energy source will take time. To learn more about wind power’s potential, visit the American Wind Energy Association at www.awea.org or NREL’s wind section, www.nrel.gov/wind. Sources: U.S. Department of Energy, American Wind Energy Association, National Renewable Energy Laboratory
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Meet
Flint Energies:
Terrance Searcy
Working with you
Member Services Technician Reynolds
Featured Business
GREEN POWER
Continued from page 26A
The Wing Shack
Butler, Ga. 478.862.3629 Hours: Thursday-Saturday 5 p.m.-9 p.m. Rupert the Rooster says bring your Co-op Connections Card and receive 10 percent off a 10-piece order of wings (limit two)!
Spring festival time is here Perry Dogwood Festival Perry, April 13-14 www.perrydogwoodfestival.com Lane Southern Orchards’ Spring Fling Fort Valley, April 20 www.lanesouthernorchards.com Georgia Strawberry Festival Reynolds, April 26-27 www.ga-strawberry.org
Celebrate
Earth Day April 22 will once again be recognized as Earth Day across the world. This year’s Earth Day theme is The Face of Climate Change. If you are interested in pledging to do a green act in honor of Earth Day, please visit act.earthday.org. At Flint, we will plant a tree at one of our offices as our green act and will once again offer a special treat to those members who visit any of our offices that day. What will you do to celebrate Earth Day?
Georgia JugFest Knoxville, May 15 www.gajugfest.com Georgia Peach Festival Byron and Fort Valley, June 1-8
www.worldslargestpeachcobbler.com
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Converting wood waste into electricity is an abundant resource in Georgia, including landfill gas-toelectric projects. The Rabun Gap Plant uses woody waste from Georgia’s forestry industry as the primary fuel source in a conventional boiler for the generation of steam to power a steam turbine electric generator. This plant produces 16.3 MW of green energy, is green-e certified and has been on-line since January 2010. Green Power EMC’s Sun Power for Schools program, operating in 33 middle and high schools throughout the state, educates students about renewable energy and its impact on the environment while providing energy from the sun. The first site went on-line in August 2005. In addition, our first large-scale solar project is on the roof of a Rooker industrial building in Athens. It is composed of 125kw of Suniva panels delivering energy to Green Power EMC through an interconnection provided by Jackson EMC. This project has been on-line since September 2010. While the nation’s greatest wind resources are found in the western states, some areas in North Georgia may lend themselves to wind-toelectricity generation. Green Power EMC in 2007 moved into the second phase of a wind assessment project launched in 2005 when, working with Airtricity, it gathered wind data over a period of 18 months from a meteorological tower installed near the upper reservoir of Oglethorpe Power Corp.’s Rocky Mountain Pumped Storage Hydroelectric Plant in Floyd County. GEORGIA MAGAZINE
