Energy audits typically identify information on projects that could address the consumption of fossil fuel and electricity as well as projects that could reduce emissions from other sources, such as leaks in refrigeration equipment. Energy audits also include information on the cost- effectiveness of projects and on the extent to which the projects could reduce emissions. This information can then be used to evaluate and select projects. The audits generally fall into three categories— preliminary, targeted, and comprehensive—and are distinguished by the level of detail and analysis required. Preliminary audits are the least detailed and provide quick evaluations to determine a project’s potential. These audits typically do not provide sufficiently detailed information to justify investments but may prove useful in identifying opportunities for more detailed evaluations. Targeted audits are detailed analyses of specific systems, such as lighting. Comprehensive audits are detailed analyses of all major energy-using systems. Both targeted and comprehensive audits provide sufficiently detailed information to justify investing in projects. Energy-saving projects that fall outside the scope of energy audits include efforts to enhance outreach and education efforts to curtail energy use by building occupants and purchasing high-efficiency appliances. Outreach and education efforts include providing information on how employees can conserve energy, such as AOC’s “how-to guides” that detail cost- effective methods to save energy in the workplace. Efforts to curtail energy use include purchasing energy-efficient computer equipment and appliances, using information available from the Environmental Protection Agency’s Energy Star program or the Federal Energy Management Program (FEMP). Energy Star-qualified and FEMP-designated products meet energy-efficiency guidelines set by the Environmental Protection Agency and the Department of Energy and, in general, represent the top 30 percent most energy-efficient products in their class of products. These products cover a wide range of categories, including appliances and office equipment. According to the Energy Star program, office products that have earned the Energy Star rating use about half as much electricity as standard equipment and generally cost the same as equipment that is not Energy Star qualified. AOC has made some progress toward implementing the two recommendations in our April 2007 report. First, AOC has taken steps to address our recommendation that it develop a schedule for routinely conducting energy audits by developing a prioritized list of buildings for which it plans to conduct comprehensive energy audits (see App. 1). Specifically, AOC is currently undertaking a comprehensive energy audit of the U.S. Capitol Police Buildings and Grounds and obtained a draft submission in May 2008 from the private contractor performing the audit. AOC also plans to use $400,000 of fiscal year 2008 funds to perform comprehensive energy audits of the Capitol Building and the Ford House Office Building, and says it will direct any remaining fiscal year 2008 funds to an audit of the Hart Senate Office Building. Additionally, AOC has contracted with a private firm to conduct a preliminary energy audit of the Senate Office Buildings that could prove useful in identifying opportunities for more comprehensive and targeted evaluations. AOC officials said that they developed the prioritized list of buildings to audit by comparing the amount of energy used per square foot of space in each building (referred to as energy intensity) and then placing the buildings that use relatively higher levels of energy at the top of the list. However, AOC’s prioritized list does not provide information on the energy intensity of each building, an explanation of its prioritization scheme, or cost estimates. Furthermore, AOC has not developed a schedule for routinely conducting audits as we recommended in our April 2007 report. AOC officials said that they cannot complete a more comprehensive schedule because of uncertainty about the extent to which AOC will receive future appropriations to conduct the audits. We believe that developing a more detailed schedule for future audits along with an explanation of its prioritization scheme and cost estimates would assist the Congress in its appropriations decisions and facilitate the completion of additional audits. Second, AOC can do more to fully address the second recommendation in our April 2007 report that it implement selected projects as part of an overall plan to reduce emissions that considers cost-effectiveness, the extent to which the projects reduce emissions, and funding options. In recent years, AOC has undertaken numerous projects throughout the Capitol Hill Complex to reduce energy use and related emissions, but these projects were not identified through the process we recommended. Projects completed or underway include upgrading lighting systems, conducting education and outreach, purchasing energy-efficient equipment and appliances, and installing new windows in the Ford building. Examples of projects in Senate office buildings include upgrading the lighting in 11 offices with daylight and occupancy sensors, installing energy efficiency ceiling tiles in the Hart building, and replacing steam system components. According to AOC, these efforts have already decreased the energy intensity throughout the Capitol Hill Complex. Specifically, AOC said that it decreased its energy intensity—the amount of energy used per square foot of space within a facility—by 6.5 percent in fiscal year 2006 and 6.7 percent in fiscal year 2007. As AOC moves forward with identifying and selecting projects that could decrease energy use and related emissions, it could further respond to our recommendation by developing a plan that identifies the potential benefits and costs of each option based on the results of energy audits. Such a plan could build on AOC’s existing Sustainability Framework Plan and its Comprehensive Emissions Reduction Plan for the Capitol Complex, which identify measures that could lead to improvements in energy efficiency and reductions in greenhouse gas emissions. Complementing these plans with information on projects identified through energy audits would further assist AOC in using the resources devoted to energy efficiency enhancements as effectively as possible. The Senate has three primary options for decreasing greenhouse gas emissions and related environmental impacts associated with its operations. These include (1) implementing additional projects to decrease the demand for electricity and steam derived from fossil fuel; (2) adjusting the Capitol Power Plant’s fuel mix to rely more heavily on natural gas, which produces smaller quantities of greenhouse gas emissions for each unit of energy input than the coal and oil also burned in the plant; and (3) purchasing renewable electricity or carbon offsets from external providers. Each option involves economic and environmental tradeoffs and the first option is likely to be the most cost-effective because the projects could lead to recurring cost savings through reductions in energy expenditures. Regarding the first option, as we reported in April 2007, conducting energy audits would assist AOC in addressing the largest sources of emissions because the audits would help identify cost-effective energy-efficiency projects. In general, energy projects are deemed cost-effective if it is determined through an energy audit that they will generate sufficient savings to pay for their capital costs. These projects may require up-front capital investments that the Senate could finance through direct appropriations or contracts with utility or energy service companies, under which the company initially pays for the work and the Senate later repays the company with the resulting savings. Until AOC exhausts its opportunities for identifying energy-efficiency projects that will pay for themselves over a reasonable time horizon, this option is likely to be more cost-effective than the second two options, both of which would involve recurring expenditures. In pursuing energy audits, AOC faces a significant challenge collecting reliable data on the baseline level of energy use within each Senate office building. Such data would help identify inefficient systems and provide a baseline against which AOC could measure potential or actual energy- efficiency improvements. First, while AOC has meters that track electricity use in each building, the meters that track the steam and chilled water used by each building no longer work or provide unreliable data. AOC officials said that they have purchased but not installed new meters to track the use of chilled water and are evaluating options for acquiring new steam meters. Installing these meters and collecting reliable data would enhance any efforts to identify potential energy saving measures. Second, AOC does not have submeters within each building to track the electricity use within different sections of each building. Such submetering would further assist in targeting aspects of the Senate buildings’ operations that consume relatively high quantities of energy. AOC said that it plans to install submeters for electricity, chilled water, and steam by February 2009. A second option for decreasing greenhouse gas emissions would involve directing AOC to further adjust the fuel mix at the Capitol Power Plant to rely more heavily on the combustion of natural gas in generating steam for space heating. The plant currently produces steam using a combination of seven boilers—two that primarily burn coal, but could also burn natural gas, and five boilers that burn fuel oil or natural gas. The total capacity of these boilers is over 40 percent higher than the maximum capacity required at any given time, and the plant has the flexibility to switch among the three fuels or burn a combination of fuels. The percentage of energy input from each fuel has varied from year to year, with an average fuel mix of 43 percent natural gas, 47 percent coal, and 10 percent fuel oil between 2001 and 2007. In June 2007, the Chief Administrative Officer of the House of Representatives released the Green the Capitol Initiative, which directed AOC to operate the plant with natural gas instead of coal to meet the needs of the House. The House Appropriations Committee subsequently directed GAO to determine the expected increase in natural gas use for House operations and the associated costs at the power plant that would result from the initiative. In May 2008, we reported that the fuel-switching directive should lead to a 38 percent increase in natural gas use over the average annual quantity consumed between 2001 and 2007. We also estimated that the fuel switching should cost about $1.4 million in fiscal year 2008 and could range from between $1.0 and $1.8 million depending on actual fuel costs, among other factors. We also estimated that the costs would range from between $4.7 million and $8.3 million over the 2008 through 2012 period, depending on fuel prices, the plant’s output, and other factors.