Coal-fired power plants costs

Table 4. Cost estimates of alternative mitigation technologies in the power generation sector compared to baseline pulverized coal-fired power plant and natural gas Combined Cycle with Gas Turbine (CCGT) power stations and the potential reductions in C02 emissions to 2020 [14]...

Existing capture technologies, however, are not cost-effective when considered in the context of sequestering C02 from power plants. Most power plants and other large point sources use air-fired combustors, a process that exhausts C02 diluted with nitrogen and excess air. Flue gas from coal-fired power plants contains 10%-12% C02 by volume, while flue gas from natural gas combined cycle plants contains only 3%-6% C02. For effective carbon sequestration, the C02 in these exhaust gases must be separated and concentrated. 

NGCC/GTCC, Natural gas combined cycle (often termed gas-turbine combined cycle) PC, Pulverized-coal-fired power plant IGCC, Integrated gasification combined cycle, Oxy-fuel (PC boiler) plant. Flue-gas desulfurization and air particulate control is included in the total cost, but not in the separation unit cost. 

While the development of flue gas clean-up processes has been progressing for many years, a satisfactory process is not yet available. Lime/limestone wet flue gas desulfurization (FGD) scrubber is the most widely used process in the utility industry at present, owing to the fact that it is the most technically developed and generally the most economically attractive. In spite of this, it is expensive and accounts for about 25-35% of the capital and operating costs of a power plant. Techniques for the post combustion control of nitrogen oxides emissions have not been developed as extensively as those for control of sulfur dioxide emissions. Several approaches have been proposed. Among these, ammonia-based selective catalytic reduction (SCR) has received the most attention. But, SCR may not be suitable for U.S. coal-fired power plants because of reliability concerns and other unresolved technical issues (1). These include uncertain catalyst life, water disposal requirements, and the effects of ammonia by-products on plant components downstream from the reactor. The sensitivity of SCR processes to the cost of NH3 is also the subject of some concern. 

The second reason for environmental projections is the significance of control costs. For example, proposed acid rain legislation could cost utilities and their customers billions of dollars. Before this money is spent, it is important to be able to evaluate the effects that controls may have on emissions, on employment, in different regions of the country, and the like. A large share of S02 emissions are from older, dirtier, coal-fired power plants. If these plants are retiring in a few years, it may not make economic sense to spend millions or billions of dollars to retrofit them with controls. On the other hand, if such plants will be operating for many years to come, the benefits may be considered worth the expense. 

When biomass is co-fired with coal (even in small percentages), the alkali metals in biomass ash can alter the properties of the resulting mixed ash. This could have a significant impact on the coal plant s operating and maintenance costs or even operability. The addition of biomass to a coal-fired power plant can also nullify ash sales contracts for coal flyash. Biomass ash components in feedstocks may also reduce the long-term efficiency and effectiveness of certain (selective catalytic reduction, SCR) systems for the selective catalytic reduction ofNOx. 

The purpose of this paper is threefold (1) to describe the pollution problem quantitatively, (2) to summarize our present understanding of comparative coal-cleaning ECTs, and (3) to analyze the impact of coal-cleaning ECT costs on the economic tradeoffs between coal cleaning at (or near) the mine and FGD at the coal-fired power plant. 

The capital cost of STPs is one quarter to a half of that of PV power plant (Table 1). The LEC is defined by the total cost, [(capital cost)x(fixed charge rate) + O M + fuel cost], per annual net electricity production in kWh. It varies depending on the plant scale and solar share. The LEC ranges between 0.05kWh and 0.12/kWh for the STP, and attains 0.4/kWh- l/kWh for PV electricity. Thus, the solar H2 production cost by PV and STP electricity is not comparable in terms of capital cost and LEC. However, the cost of STP electricity is still not competitive with that of a conventional coal-fired power plant. To close the price gap, the solar thermal parabohc trough power plant industry has introduced integrated solar combined cycle systems (ISCCS) which are able to offer a competitive base-load electricity cost of 0.05-0.07/kWh at solar shares of 15-25% [7] (Fig.l). 

The capital cost of nuclear fission will have dropped significantly— especially compared with that of the then-dinosaur-technology coal-fired generation. (As one example, today the capital costs of Advanced Candu Reactors are in the range of 1000 per kilowatt [kW]—about the same as coal-fired plants.) But since the operating cost of a nuclear power plant will always be a small fraction of that for a coal-fired power plant, the energy currencies from nuclear plants will be lower. 

A baghouse is needed at a coal-fired power plant for a design operating period of 20 years. If the unit fails at anytime (bag meltdown), a 45% (of the initial cost) reinvestment cost will result. Two companies submit bids for this particulate control device with the following cost and operating characteristics data ... 

In case of power-generating installations, the allocation of allowances at a level lower than their market development potential creates in practice a strong barrier to development. The purchase of additional allowances to enable higher production in coal-fired power plants means the growth of marginal production costs by more than 50% and cannot be compensated by the higher efficiency of that producer. 

Power from a new coal-fired power plant will cost 5 to 6.4 cents per kWh and 4 to 5.7 cents per kWh for a gas-fired plant, and 4.6 to 6.5 cents per kWh for a nuclear plant, according to UNIPEDE, the European Utility Association. 

A lower cost system is achieved if electricity and steam is generated from a coal-fired power plant and then routed to a high-temperature electrolysis plant for steam decomposition with an overall thermal efficiency of 35 - 38 % (based on 35 % efficiency of electricity production from coal) [55]. 

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