Renewable energy currently accounts for about 10% of U.S. total energy production according to the U.S. Department of Energy. Biomass is the largest source of renewable energy in the United States. Approximately 53% of all domestic renewable energy comes from biomass sources represented by biofuels, landfill gas, biogenic municipal solid waste, wood and wood-derived fuels, and other biomass such as switchgrass. Much of the impetus for the contribution of biomass sources and technologies to the national energy picture originated in a federal law originally viewed as a natural gas conservation measure, the Public Utility Regulatory Policies Act of 1978 (PURPA). A market was created for firms outside of the electric utility industry with a preference or opportunity for producing energy from alternative fuels, especially for qualifying small power facilities that could use biomass, waste, or other renewable resources (including wind, solar energy, and water). Investments and advances in combustion turbine technology preceded the growth of cogeneration. Nowadays, combined heat and power turbine-generator sets are a mainstay of several industries and industrial applications. The pulp and paper industry dominates the cogeneration sector today fueled largely by biomass from wood wastes. State governments have generally led the way in deploying other renewable energy technologies. Picking up where federal research and development dollars left off, states are using the concept of a Renewable Portfolio Standard (RPS) to create a market for renewable energy via mandatory goals. RPS requirements oblige electric utilities to provide electricity from renewable energy sources in increasing amounts over a specified period of years. Through February 2009, RPS requirements or goals have been established in 29 states plus the District of Columbia. A major argument that has been advanced for a national renewable energy (or electricity) standard is that it would encourage increased use of renewable energy. Thus far, two bills have been introduced in the 111 th Congress that would amend PURPA. The American Renewable Energy Act, H.R. 890 , would establish a renewable electricity standard (RES). In the Senate, a renewable electricity standard was introduced in S. 433 . Senator Bingaman had previously released a draft bill to discuss a federal renewable portfolio standard on February 11, 2009. With biomass representing the most widely used (and ostensibly the least expensive) renewable energy resource in the United States, its potential use in meeting RES requirements is key to the success of any RES that may be enacted. Much of the debate over an RES revolves around whether there is a need for a federal requirement for renewable energy use by electric providers and whether the momentum in the states is truly moving the use of renewable energy forward. The Production Tax Credit and the Investment Tax Credit have been used by the federal government to support renewable energy. Recent consideration has also been given to implementing a federal "Feed-in Tariff" (FIT) law. Feed-in Tariffs are incentive structures for generating renewable electricity usually at above-market rates for a set number of years, reducing the payback period and adding certainty to the return on the investment. The successful deployment of renewable energy in Europe is often credited to FIT provisions. Arguments in favor of an RES usually involve impacts on the environment, and reducing dependence on fossil fuels. Historically, most electric power has come from base-load generation in large, central station plants using fossil fuels (principally coal) as the source of energy. When burned, fossil fuels emit pollutants such as sulfur dioxide and nitrogen oxides which are subject to environmental controls to limit their release to the air. Combustion of fossil fuels also produces the greenhouse gas carbon dioxide. Generating electricity from renewable resources emits far less of such pollutants. Many consider carbon dioxide emissions from biomass sources as practically neutral, because biomass sources take in carbon dioxide during their growing cycle and release it when burned. Renewable energy is seen as a way to reduce fossil fuel use, and with growing awareness of the potential impacts of climate change, the role of renewable energy in reducing carbon emissions has garnered increasing public support. But renewable energy technologies (with the exception of basic biomass combustion) are relatively newly developed and costlier than fossil fuels to produce electricity. Federal support for research and development is believed by many policymakers to be crucial in making renewable energy technologies more cost-competitive. A federal RES mandate and consistent, long-term financial incentives are also seen by supporters as necessary to increase renewable electricity generation to attain the goals of cleaner energy and greater energy security. Arguments against the need for a national RES have been made in the past that this is a matter for state or regional self-determination. Some states have moved forward with their own RES programs envisioning either an economic benefit or environmental imperative, or both. States may argue that a federal mandate could override existing state programs which may have involved years of negotiations among local interests to set goals and timetables. Grants, guaranteed loans and tax incentives from the federal government may be viewed by such parties as the best ways for the federal government to encourage renewable energy growth. In regions where the quality or availability of renewable resources may be in question, as for example, in the Southeast, some states are concerned that the current RES proposals would subject them to federal penalties. A "Renewable Electricity Deployment Fund," proposed in H.R. 890 , would return amounts collected from penalties for noncompliance or alternative compliance payments to retail electricity suppliers that have submitted renewable energy credits (REC) for compliance. Unless some balancing mechanism is in place, such as the Bingaman discussion draft proposal to return federal penalties to those states with less renewable energy resources to specifically develop such resources, southeastern states and electric utilities fear that they will become net purchasers of RECs, which will result in a "transfer of wealth" to the sunny and wind-rich states of the Southwest and Midwest, respectively. Given the identified concerns over biomass supplies in the southeastern states and the pivotal role the region will likely have in a federal RES debate, issues in this region will be used as the focus of this report. Investments in energy production in the southeastern United States have long favored base load technologies due to increasing economies of scale from large generation units. The electricity industry in the region is still largely subject to traditional rate regulation, and power generation projects historically have been approved by state regulatory commissions which have endeavored to maintain a favorable, low cost business climate. Relatively low electricity prices have thus resulted in the region. New, renewable energy technologies have not been adopted to the extent seen in other regions of the United States thus far, largely because of cost and operational variability. When considered from a regional perspective, the southeastern United States does not have the high quality wind and solar resources which exist in other regions of the country. Although offshore wind in the region may have promise for southeastern coastal states, there are no commercially operating offshore wind farms anywhere in the United States. However, renewable energy from biomass is the exception. The region is home to 44% of the nation's total energy from woody biomass and a significant portion of other biomass types. Not all biomass is recognized as "eligible" to meet federal RES requirements due to differences in federal legislation and tax provisions defining biomass. These definitions have varied over time with changes in the law and regulations, reflecting policy goals and technological change. The definition of biomass would be critical to determining which technologies and processes would be available to meet possible RES requirements. The next section discusses current and future possible sources of biomass and technologies for renewable energy. Figure 1 shows various types of biomass resources in the United States by annual tonnage per square kilometer available in individual counties. The agricultural resources of the Midwest and the forest-based resources of the Southeast feature prominently. Biomass is possibly mankind's oldest source of energy. Since the time of the first nomadic hunter-gatherer societies, wood has been collected for cooking fires and heating. The use of cellulosic fiber from trees to make paper is a primary use of wood, rivaling other forest product uses such as lumber for buildings and furniture products. Today, most wood used as fuel for thermal processes or power generation actually is waste from the harvesting and processing of trees by the forest products industry (i.e., tree bark, branches and stumps, wood chips, sawdust, and lignin). Thus, wood waste may be burned in biomass boilers specifically for "hog fuel" (basically wood waste other than lignin) to produce steam for process uses and electricity generation. The pulp and paper industry has another wood waste fuel source in "black liquor," a by-product of the pulping process. Inorganic chemicals are used to dissolve the lignin holding together wood fibers, thus making the cellulosic fibers available for the manufacture of paper products. The inorganic chemicals are recovered in a "recovery boiler" and reconstituted for reuse, while the organic lignin is burned, generating heat for steam production. These recovery and biomass boilers are responsible for most of the energy generated by the forest products (biomass) sector, either as steam heat for process uses, or electricity generated for on-site use. Electricity not used on-site to power equipment may be made available for sale on the grid. The harvest of food and other crops often leaves behind a mass of stover (i.e., stalks, leaves and other plant remnants). In past years, much of this material was either plowed under to reconstitute the soil, left for livestock forage, or was gathered to make straw. But nowadays, possibilities for use include collection of a portion of this material for burning in a biomass boiler, producing steam for electricity, or processing into biofuels (see below) such as cellulosic ethanol, as technologies and new processes are developed. Crops grown specifically for energy production are sometimes called "bioenergy crops" or "biomass crops." Biocrops are fast-growing (sometimes hybridized) species dedicated to producing energy (electricity or liquid fuels) from all or part of the resulting plant.