Cheaper Energy by Going to Waste
With energy costs spiraling ever upward, it might be difficult to believe that the US contains a nearly inexhaustible supply of fuel that is not only underused, but is also often wasted.
Getting fuel is relatively simple; it's usually located in uninhabited sites (but not in pristine wilderness areas), and each American family and business helps create this energy source every single day. What's this amazing fuel? Garbage or—to be more precise—methane, a combustible gas naturally produced in landfill sites as the waste materials decompose.
Using methane as energy solves another problem because untreated, "escaped" methane pollutes the air.
To create awareness of the problem and promote the use of this wasted resource, the United States Environmental Protection Agency (EPA) created the Landfill Methane Outreach Program (LMOP) in 1994. Using landfill gas to generate energy reduces dependency on fossil fuels while decreasing emissions of nitrous oxide; sulfur dioxide, a primary contributor to acid rain; and carbon dioxide, the heat-trapping gas that contributes to global warming. According to EPA, approximately 60% of America's solid waste is disposed of in more than 2,100 landfills; over 330 of those recycle the methane gas they produce to generate heat or electricity, but over 500 landfills flare or burn the gas to get rid of it.
"There are many reasons to control this gas," says Chris Voell, manager of LMOP. "From a regulatory standpoint, there are safety concerns: It can be an explosion hazard and an odor nuisance. Methane is also a potent greenhouse gas—23 times more potent than carbon dioxide. Released methane is a pollutant, and for that reason EPA and the states have regulations to control this gas."
Until recently, all landfill owners had to do was contain and eliminate methane. "Once a landfill reaches a point when the owner has to put in a collection system, a well field is a simple system of horizontal and vertical pipes, which are usually put in while the landfill is being built," Voell explains. "Drill pipes are placed into the landfill to siphon off the gas—it's an art to decide how many wells one will need on the site. The methane doesn't take long to be produced. The site doesn't have to be capped for methane production to start; it's an ongoing process.
"Now the default method of controlling methane is to collect the gas in a well field and burn it off. There are still hundreds of flares in use all over the country. When it burns, methane leaves only carbon dioxide and water."
It became evident, though, that merely flaring this energy source was a waste. Voell continues, "[LMOP] was started because we realized methane is a greenhouse gas but not a regulated [one], so starting a program to voluntarily work on gases would lessen pollution while [lowering] uses of other fossil fuels.
"There's a multitude of end-use processes methane can serve. About two-thirds of current methane users make electricity with it by burning the gas in a turbine, making electrons to add to the grid. Of course some ask, ‘When a utility can produce a kilowatt-hour with coal at a half-cent, why do it with methane at four cents a kilowatt-hour?' Right now that's a concern, but there's only so much coal underground. We can—and do—make methane inexpensively all the time.
"The other one-third [using methane] are direct-use projects. The gas is piped to a particular end user to replace some other fuel source. The end user has to retrofit boilers, et cetera, to use methane, but that's not a huge transition because natural gas is 90% or more methane anyway. If one's converting fuel oil or coal burners to a methane burner, that's not cheap, but those costs are easily offset by long-term savings. These programs make sense on their own merit."
BMW's turbines are painted red to call attention to their unique function.
Federal funding or tax credits might encourage users to convert. "Right now," Voell points out, "there's only two sources of funding: [One is] Section 29 of the IRS code, [which allots] tax credits to private entities, can reduce methane's cost to about 1.5¢ per kilowatt-hour produced, [and] has helped get a lot of projects on-line in the 1990s. There's also the Renewable Energy Production Incentive, a pool of funds available to government entities that actually run landfills. There are a multitude of programs available at the state level—tax incentives, long-term loans, grants, et cetera—but at the federal level, this is mostly a congressional exercise; the Department of Energy isn't really in it that much. We are telling Congress about methane's potential, and [Congress is] debating a whole new energy bill, so it's difficult to say where the legislation will end up. There are proposals to keep current incentives alive, but with budgets on all government levels up in the air, who knows?"
BMW's South Carolina Plant Saves Fuel and Clears the Air
There are companies now using methane, however, and they're pleased with the results. "BMW Manufacturing Corporation in Spartanburg, South Carolina, uses its methane both in generating electricity and in direct use," Voell says. "Methane is piped from Palmetto Landfill, 9.5 miles away, to BMW, where the company uses it to make electricity and hot water. We've had a couple of combined projects, but at this point in time, BMW's the largest. [The company is] reaping not only environmental savings but also economic savings."
Gary Weinreich, BMW's environmental manager, concurs. "Adapting to methane didn't take much of retrofit. When we installed this plant 10 years ago, we put in four gas turbines patterned after European design for cogeneration—to make both electricity and hot water used in a heat exchanger to heat our building. Just with this setup, we were increasing our efficiency; if you just make [electricity or just make hot water], efficiency is at 30% or so; do both, [and] you're running at 60% efficiency. Methane conversion wasn't difficult to do; it only required some equipment changes."
Although BMW strives to be an environment-friendly company, the idea for the methane project didn't originate in-house. "Reps from EPA's [LMOP} came to visit us in early 1999," Weinreich explains. "They said we were an excellent candidate for such a program because we had a landfill less than 10 miles away. So we looked into it, performed cost studies, et cetera. When we sat down with those in the power center [the internal BMW department], they quickly embraced the project."
BMW's pipeline is the longest ever built for landfill gas; most are 3–6 mi. in length. Construction on the project began in July 2002 and was completed in December 2002.
Many partners were needed to complete the project, which went on-line in March 2003. "The project moved very fast. The one difficulty we had was finding a partner experienced in such ventures; good thing we found Ameresco Energy Services, which designed, built, and owns the pipeline and the gas-processing and gas-compression facilities, as well as manages the overall operations of the project. The project cost about $12 million. Ameresco purchases the gas from Waste Management Inc., the landfill's owner; they clean and compress the methane and transport it through the pipeline to our plant. Ameresco charges us by use-rate on a [British-thermal-unit] basis—it's like getting a utility company's power bill—and the cost is significantly less than it would be if we were using fossil fuels.
"The state was onboard too. South Carolina's Energy Office helped us with the permits needed, and Sonny DuBose of the South Carolina Energy Office lined up the folks at [the South Carolina Department of Transportation] to find a route for the pipeline that avoided private property and remained on the state highway's right of way," Weinreich adds, calling the project an "environment-improvement opportunity." Adhering to ISO 14001 environment management standards, BMW is the only worldwide car manufacturer whose plants prioritize such demands. "From the corporate level and at the US plant, we're constantly looking for environmental upgrades. The home office in Germany is thinking about setting goals for using green energy in other facilities."
BMW's project is unique in many ways; the methane is "scrubbed" at the landfill, and excess water is removed by using a dehydration system that brings the gas to a dew-point level that BMW specifies. These steps assure BMW that it gets very-high-quality gas—which is crucial because water in the gas can damage the turbine equipment. In addition, BMW runs unique pressures through its system; other systems run 8–12 lb. of pressure, but BMW compresses its gas up to 145 lb. of pressure.
When the methane conversion went on-line in April 2003, EPA Administrator Christine Todd Whitman participated in the dedication festivities. "This is a win-win for everyone. It avoids the need to burn methane; yields significant amounts of clean energy; and—by avoiding 55,000 tons of carbon dioxide emissions each year—results in cleaner, healthier air for everyone to breathe," Whitman says.
Also on hand was Helmut Leube, president of BMW Manufacturing Corporation. He adds, "This project allows BMW to take a wasted source of energy and use it to generate electricity, which benefits the environment and area residents through lower emissions. BMW wants to do whatever it can to make upstate South Carolina a better place to live."
The methane project fulfills a little more than 25% of BMW's total energy needs, which doesn't sound like much until Weinreich points out that "that's the equivalent to heating 15,000 homes per year—and we're actively looking for more uses for methane." It's also projected that BMW's landfill gas-to-energy project will save the company more than $1 million per year, while also reducing carbon dioxide emissions equivalent to removing 61,000 automobiles from US highways each year. Does BMW ever foresee going off of the electric grid entirely? "Not as it stands now. Maybe the most we could get from methane would be only 40% of our needs—but that's still better than being 100% dependent on the grid."
Unstable natural-gas pricing was a factor in BMW's decision. According to the agreements, BMW's landfill gas-to-energy project will provide a guaranteed supply of gas at a guaranteed price for the next 20 years—a rare boon to any company trying to improve its bottom line. Traditionally, natural gas costs $3.50–$4.00 per decatherm; in early 2003, prices rose as high as $10.30 per decatherm. BMW uses an average of 106,000 decatherms per month, but by using landfill gas, the most BMW will pay in the 20-yr. term of its contract is $4.00 per decatherm—resulting in projected savings of at least $20 million.
The arrangement is also good for the landfill owners, as Waste Management Inc. knows; the company has been developing landfill gas-to-energy projects for more than 15 years and currently supplies landfill gas to 69 gas-to-energy projects in 21 states. Waste Management estimates its various landfill gas projects have helped reduce greenhouse gas emissions by 50%.
"This landfill has been in place since 1979—it takes some time for the gas to generate—and we've collected and flared methane since 1990. It's a win-win for everybody: for us, for the client, and for the environment," notes David Pepper, district manager of Waste Management's 196-ac. Palmetto Landfill. "BMW gets the methane cheaper than natural gas, [the methane] burns very well, and we eliminate wasting this fuel source at our plants."
As the landfill grows, containing mostly commercial rather than residential waste, Waste Management will add more wells. "There's a possibility to add electricity back to the grid, as we can generate a little more than BMW can use right now," Pepper adds.
Landfills aren't used forever; each site is given a limit for a set volume of trash. The Palmetto site has a 16 million-ton capacity, and it's estimated that capacity will be reached in three or four years. The microorganisms that generate methane gas should continue to do so, however, well beyond the 20 years of BMW's agreement.
The State's Stake
Not content to rest on his success with the BMW project, Sonny DuBose has several more methane projects heating up. "When I first heard about it from [Ameresco's] Jerry Leone, I thought it an awesome opportunity; we built some critical contacts with state and county agencies and worked to make it happen—it's a classic example of how we all need to work together to make a better tomorrow. We have at least three more such LMOP projects in the works, and three more may be coming up. We're also spreading the word to neighboring states, so who knows how many projects are in the pipeline?"
As an example, DuBose noted that Santee Cooper, the source of power for the state's 20 electric cooperatives, recently agreed to cooperate on similar ventures. South Carolina's Anderson County Regional Landfill and Santee Cooper will build a $7 million methane power plant to produce 5.5 MW of electricity—enough to supply 3,000 homes. In February 2003, Santee Cooper agreed with Allied Waste to construct a $6 million, 5-MW generating station at Lee County Landfill near Bishopville, SC, and the company also signed a letter of intent to develop the Northeast Landfill site in nearby Richland County. In October 2001, Santee Cooper dedicated its 3.3-MW Horry County Landfill Gas Station. Most projects should come on-line during 2004.
Although South Carolina appears to be ahead in the "methane game," Chris Voell has hopes for many more such projects throughout the nation. "My responsibilities cover 26 states; I have a database of landfills, and we'll help them develop methane projects."
Author's Bio: Janis Keating is a frequent contributor to Forester Media, Inc. publications.