molten carbonate fuel cells. These major development goals for fuel cells and gas turbines apply to systems fueled with either natural gas or coal-generated gas. No special considerations for coal-derived fuel gas appear necessary at this time, beyond those described above for the coal program.
To use coal, both fuel cell and gas turbine systems depend on coal gasification technology; both can accept methane and light hydrocarbons in the fuel gas. As discussed in Chapter 6, coal gasification results in a loss of five to 10 percentage points in overall power generation efficiency compared to natural gas. Development of maximally efficient gasification technology is thus essential for future high-efficiency utilization of coal for both fuel cell and gas turbine systems.
The use of topping cycles—as in fuel cells, gas turbines, and MHD generators—to achieve efficiencies higher than those attainable in the simple steam Rankine cycle (approximately 42 percent) has been adopted worldwide and is the major focus of the ongoing DOE program on advanced technologies for electricity generation. Advances in gas turbine and fuel cell technologies have essentially closed the original efficiency gap that stimulated a large worldwide effort on MHD during the 1960s and 1970s. Over the past decade, this MHD effort has been greatly reduced. Within the DOE FE Advanced Clean/Efficient Power Systems Program, no further funds are allocated for MHD, except for closeout of the proof-of-concept study. EPACT Section 1311 recommends (and the committee concurs) that an integrated documentation of the results of the extensive proof-of-concept work should be prepared, to capture the "lessons learned" and to establish a reference point for any possible development of MHD systems in the future.
Environmental control requirements for coal-based power plants are expected to become increasingly stringent in response to more demanding federal, state, and local requirements. In the near-term, new control requirements for nitrogen oxides (NOx) and air toxics are anticipated, along with new ambient standards for fine particulates. Over the longer term, significant reductions in CO2 and solid wastes may be needed.
DOE's strategic objectives for conventional air pollutants (SO2, NOx, and particulates) express future goals relative to the 1979 federal New Source Performance Standards (NSPS) for coal-fired power plants (see Table 10-2). These emissions goals apply to advanced power systems in groups 2 and 3. DOE's goals