|Title:||United States methane emissions by type of waste management system/industrial process in percentages for 2011|
|Source:||Public Utilities Fortnightly|
Start of full article - but without data
U.S. METHANE EMISSIONS ([TONS)
Nearly one-third of U,S. methane emissions come from waste.
Wastewater treatment X% Petroleum systems X% Manure management X% Coal mining XX% Landfills XX% Livestock enteric fermentation XX% Natural gas systems XX% Other X%
Note: Table made from pie chart.
The average American generates X.X pounds of trash per day. Rather than simply disposing of this trash, along with other types of waste such as agricultural refuse and sewage, we can instead use it beneficially as a clean energy resource. Technologies already exist that could turn our waste into an energy fuel, solving our disposal dilemmas and energy needs simultaneously. In fact, waste in America is projected to have an energy potential of approximately XX to XX GW, which would amount to XX to XX percent of non-hydro renewable U.S. generation capacity.
While waste as an energy source has often been underappreciated--and as a result, under-utilized--certain characteristics make waste an attractive source of fuel for energy production. Power plants burning waste fuels have baseload characteristics, and their levelized cost of energy generation is competitive with plants burning fossil fuels. There's also significant potential for carbon abatement through avoiding emissions of methane, a gas with XX times the greenhouse gas impact of carbon. Additionally, technologies to produce energy from waste are mature and infrastructure development is largely de-risked by public policy financial support.
All of these characteristics make waste an attractive source of fuel for utilities looking to diversify their portfolios and build carbon abatement backstops and capabilities in case a future carbon regime is implemented.
Disposing America's Waste
Waste disposal is big business. The U.S. spends $XX billion every year to landfill more than half of the XXX million tons of municipal solid waste it generates. However, disposal options are becoming less available. Due in large part to EPA emission regulations forcing out small landfill operators who couldn't afford compliance measures, the number of landfills in America has shrunk from almost X,XXX to X,XXX since 1988. As generation of waste continues to increase with population and economic growth, landfills have ballooned in size, tripling over this same period. Current remaining landfill capacity is projected to last another XX years, down from XX years in 1991. While new capacity will be created, it's expected to come from expansions on current sites, since permitting new landfills has become increasingly difficult.
With fewer but larger landfills, waste increasingly needs to travel longer distances from pickup to disposal. As the number of landfills decreases and transportation costs increase, the costs of landfill disposal will rise. Some U.S. municipalities, such as Del Norte, North Carolina and San Francisco, California, have abandoned landfilling as a disposal option all together and set zero landfill goals, much as Europe has done in recent years.
The need for disposal options, however, won't disappear altogether. Although recycling has increased, especially of paper and plastics, there haven't been dramatic improvements in recent years. From 1970 to 2000, recycling rates improved by X percent a year, but in the last decade they have only improved by X percent a year. About XX percent of MSW is recycled, while XX percent of the population has access to curbside and XX percent has access to drop-off collection programs. Last year, XX percent of municipal solid waste still required disposal.
Waste is also a large environmental dilemma. Landfills contribute XX percent of U.S. methane production, while other waste streams, such as manure management and wastewater treatment, contribute X percent and X percent, respectively (see Figure X). Since methane has XX times the global warming potential of carbon dioxide, waste sources emit the equivalent of XX coal plants--or XX million passenger cars--in greenhouse gases.
In addition to global warming concerns, disposal of waste can have other environmental impacts. The Food and Agriculture Organization of the United Nations reports that livestock waste has caused a host of environmental problems, including leaching of nitrates and pathogens into groundwater; oversupply of nutrients that damage soil fertility; destruction of fragile ecosystems such as wetlands, mangrove swamps and coral reefs; and eutrophication of nearby water sources, whereby rivers and streams are essentially starved of oxygen by runoff. There have also been instances in the past of landfill seepage into groundwater, causing contamination. And of course landfills can create odor problems that affect land use, and complicate options for siting disposal locations.
Garbage as a Clean Fuel
While waste is generally perceived as a nuisance, it has hidden value as an energy fuel. One ton of municipal solid waste can produce XXX kWh of electricity through incineration. Alternatively, if the trash is dumped in a landfill, the methane gas created as the organic materials decompose can be captured and harnessed for energy use. Methane gas is also created by the decomposition of livestock and human waste and can be captured from these sources. The technology for these three processes already exists (see Figure X). Although such waste fuels currently provide only XX percent of non-hydro U.S. renewable energy capacity, they offer an attractive opportunity for utilities.
The prospects for waste-to-energy development depends in part on regulatory policies, and also on economic and market drivers.
XX states have enacted renewable portfolio standards (RPS), which mandate the use of renewable power for a certain percentage of retail electricity. While short-term targets have been moderate and, in many cases, reflect existing renewable generation capacity, medium-term targets are well above current capacity levels and, in total, XXX TWh of electricity per year of renewables still remains to be sourced to meet 2020 RPS goals. Many of these states struggle to find in-state resources and must purchase renewable power out of state to offset the lack of in-state availability. Waste fuel is considered a renewable energy source in most RPS states. Landfill gas to energy is considered renewable in all states, while waste incineration and anaerobic digestion are excluded in some.
While a carbon regime at the federal level is still uncertain, some regional and state efforts are moving forward. The California Air Resources Board has approved a cap-and-trade system under Assembly Bill XX that will establish the first U.S. market for greenhouse gases and could provide the foundation for other regions or a national regime to follow. Compared to other renewable energy technologies, energy from waste sources can have a more significant impact on carbon reductions. While other renewable energy sources offset greenhouse gas emissions by the avoidance of fossil-fuel based generation, energy from waste sources provides the added benefit of destroying methane that otherwise would be emitted into the air (see "Waste Fuel and Carbon Markets"). In fact, landfill gas energy production is already a common source for the voluntary carbon offset market.
Significant coal-power capacity likely will be phased out with new EPA regulations on air emissions. Although forecasts of expected retirements range from XX to XXX GW, the need for reliable power that will be removed from the system remains. Although wind and solar will continue to be important renewables, the intermittency of these resources won't solve the grid's need for enough baseload power generation for reliability. In comparison, energy from waste can provide continuous power every hour of every day.
The costs for energy from waste sources are very competitive with other clean energy technologies (see Figure X). Much like other renewable energy technologies, the upfront capital expenses make up the majority of the cost. While cost input varies based on location, project size, and materials costs, energy from waste sources undoubtedly offers a cost-competitive renewable option.
Although technologies have existed for quite some time to extract the energy potential from waste sources, significant potential still hasn't been tapped. Several factors indicate that these markets are poised for growth, and participation from mature energy players can help unleash the potential for these technologies.
According to the EPA Landfill Methane Outreach Program, XXX landfills in the U.S. capture landfill gas and utilize it as an energy fuel. While landfill gas is predominately used to produce electricity on-site, it also can be used for heating applications or cleaned and injected directly into natural gas pipelines.
Yet significant landfill resources aren't being exploited. More than XXX landfills remain to be developed with a combined potential to provide over XXX MW of power. There's also significant potential to expand projects already in production. Operating projects might be located on landfills that are increasing in size as more waste is disposed or if projects were undersized to begin with.
Potential for expanding landfill gas projects in the United States exceeds X,XXX MW. California, in particular, has significant potential (see "California Potential").
Unfortunately, LFG projects are small, with the average project producing about X MW, as compared to the average coal plant at over XXX MW and wind farms with XX to XXX MW. The industry is extremely fragmented, with the top XX players owning only XX percent of the market. Small players developing small projects create several challenges that can be mitigated by consolidation. Smaller size increases the transaction costs for utilities to enter into power purchase agreements for renewable energy, and smaller players must be vetted and project risk examined more closely. Large market leaders would mitigate the risk of service interruptions.
A fragmented market also has hindered traction with landfill owners. Although managing the environmental impact of landfill gas is a major concern for landfill owners, in many cases the annual revenue generated by energy sales from these systems is equivalent to what a landfill owner makes in one week in waste disposal fees. These projects are perceived as more of a risk than a major revenue stream. As such, landfill owners seek market leaders with a long operating history and a well-established track record.
Larger landfill-gas-to-energy players would also improve project economics. Larger players have standardized operating procedures, buying power with vendors, and can reduce project specific risk through portfolio management. Overhead can be spread over a large base and larger players can more likely fund projects internally lowering the cost of capital as compared to finding external capital. The small size of landfill gas to energy projects also makes it difficult to take advantage of the tax incentives provided to all renewable energy by the federal government. If the project developer doesn't have the tax appetite to benefit from the incentives, as is often the case, the developer must find a third party to participate as a tax equity investor. However, the transaction costs to set up the correct structures to include tax equity players aren't worth the benefit for such small projects.
Consolidation can improve the ability of the industry to develop projects with landfill owners, develop relationships with offtakers for the energy produced, and improve project economics. There's evidence that industry consolidation is underway as six of the top XX operators are backed by private equity and two of the largest players have explicitly stated their intentions to grow through acquisition.
Big Trouble for Trash Burners
Burning trash before it's even disposed in a landfill is another approach to recovery of energy from trash. There are currently XX U.S. waste incineration plants, which burn municipal solid waste in boilers and recover metals, producing X,XXX MW of power. Areas with high landfill disposal fees have historically been related to more waste incineration development (see Figure X). In other words, areas with the most constrained landfill capacity have introduced waste incineration solutions. However, no new waste incineration plants have been built in the U.S. in more than a decade. Several reasons suggest there will be a revival in waste incineration power production.
Over the years, waste incineration has been met with opposition from environmental groups for the toxins emitted from the incineration process. This negative reputation has made permitting new facilities with this technology difficult. For example, in 1989, Mayor David Dinkins of New York City proposed a waste management plan which included plans for a number of incineration facilities with advanced air pollution control systems. However, when Mayor Rudy Giuliani came into office he scrapped these plans primarily as a result of opposition from environmental organizations that were concerned about emissions. The environmental argument, however, was based on data from the emissions of incinerators in the 1980s, which was before Environmental Protection Agency regulations had been implemented. Recent evidence, in contrast, suggests that a negative environmental reputation is ill-deserved. For instance, Covanta, the largest U.S. operator, uses advanced air pollution control equipment and continuous emissions monitoring systems that operate well below and comply with strict state and federal emission standards XX.X percent of the time. On average, waste incineration plants emit half the sulfur oxide emissions that a coal plant produces and only a little more than a natural gas plant. In terms of nitrogen oxide emissions, waste incineration emits less than either coal or natural gas plants do.
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With increasing regulatory focus on greenhouse gas emissions, waste incineration turns from an environmental problem to an environmental solution. Even though landfill gas collection systems can be installed at landfills to capture the methane produced by trash as it decomposes, organic materials release significant methane even before a landfill gas collection system can be put in place. Waste incineration guarantees to prevent methane release from landfills. For each ton of municipal solid waste processed in a waste incineration plant, X ton of carbon dioxide equivalent emissions is avoided. EPA has stated that waste incineration plants produce electricity with less environmental impact than almost any other source of electricity, and in a 2009 study, identified waste incineration as the most environmentally friendly destination for urban waste that can't be recycled.
Another key reason for the lull in waste-to-energy development has been the 1994 Carbone Supreme Court decision that largely removed the ability for municipalities to legally direct where solid waste should be disposed. Losing control of the waste flow made it very difficult for a waste-to-energy facility to contract all the solid waste in a given geographic area. Consequently, projects absorbed the additional risk of supply shortfalls, and raising debt became significantly more difficult. For example, the city of Camden, N.J., borrowed millions of dollars to build an incinerator, charging towns and businesses high tipping fees to cover the cost of the debt. The Carbone decision, however, ended the guaranteed supply of trash to the Camden incinerator, and since the market opened up to outside competition, tipping fees there dropped from more than $XX per ton to $XX--not enough revenue to pay off the bonds. In late 2010, the country required $XX million from the New Jersey Department of Environmental Protection to escape defaulting on a $XX million final balloon debt payment.
In Harrisburg, Penn., an incinerator originally built in 1972 and shut down in 2003 by the federal government due to noncompliance with air emission regulations underwent a $XXX million revamp and expansion. The city was hoping to use the facility to burn trash from neighboring counties. However, some counties decided not to take their garbage to the incinerator, resulting in an oversized plant with some of the highest tipping fees in the country, and a city that's struggling with an oppressive debt burden.
However, the financial troubles experienced by incinerators in Camden and Harrisburg are less likely to arise on future projects, because the Carbone decision was overturned in 2007 with the Oneida-Herkirner case. Municipalities will once again have the authority to control the flow of the waste in their geographical areas and direct it to their incinerators. Developers of new waste-to-energy facilities, who will be able to contract long-term waste supply in advance, can now take risk out of the project, easing the concerns for potential lenders.
Although waste-to energy doesn't qualify as a renewable energy resource in some states, it appears that the combined benefits of providing both clean power and a waste solution have begun to support growth in this industry.
There's already evidence of a revival in waste incineration. Recent projects that have been approved include a $XXX million Wheelabrator facility in Hawaii, a XX-MW Wheelabrator facility in Maryland, and a Covanta facility in Ontario. SNL Energy reports a development pipeline containing more than XXX MW of waste incineration projects.
European examples have shown that waste incineration is a preferable disposal option. While the U.S. incinerates X percent of its waste, the number is XX percent for Denmark and XX percent for Germany. As a result, Denmark has gotten down to X percent of waste disposed in landfill and X percent in Germany. This was achieved through aggressive landfilling regulations, a landfill allowance trading scheme, and the resulting high landfill fees.
New technology on the rise also might help the comeback for waste incineration. Although still at the demonstration stage in North America, several companies are developing other ways to turn waste into energy, aside from the traditional process used at most waste incineration facilities. Gasification, the most common alternative process, exposes solid waste to extremely high temperatures of up to X,XXX degrees C in an oxygen-limited environment to produce syngas, a flexible energy product, plus water, metals, and vitrified ash byproduct. Other alternative solutions include plasma-arc gasification, which creates a high temperature torch to gasify waste materials; and pyrolysis, which operates similar to gasification, except that the process happens in the absence of oxygen. Today XX gasification facilities, XX pyrolysis facilities, and X plasma-arc commercial facility are operating, but none are located in North America; most are in Japan, with a few located in Europe.
Waste management consulting firm Gershman, Brickner & Bratton estimates that upward of XXX companies are either marketing or developing waste conversion technologies. Unfortunately, some of these new technologies have had trouble in the past in scaling up to commercial scale. For example, the Thermoselect plant in Karlsruhe, Germany, one of the world's largest trash-gasification plants, was forced to close permanently in 2004 after only two years due to operational problems and more than $XXX million in losses. Proposals for commercial development without proven technology have also muddied the picture. For example, Palm Beach Post reported that when St. Lucie County, Fla., asked for proof on the remarkable numbers in a Geoplasma plasma arc proposal, the company couldn't provide it, and the county's hired consultant thus determined that there was no evidence supporting the technological and economic claims.
However, although there have been some stumbles in the past, as alternative combustion technologies mature and winners emerge, commercial viability and technological confidence will take hold.
Wet Waste Prospects