Policy interactions and underperforming emission trading markets in China.

Emission trading is considered to be cost-effective environmental economic instrument for pollution control. However, the ex post analysis of emission trading program found that cost savings have been smaller and the trades fewer than might have been expected at the outset of the program. Besides policy design issues, pre-existing environmental regulations were considered to have a significant impact on the performance of the emission trading market in China. Taking the Jiangsu sulfur dioxide (SO2) market as a case study, this research examined the impact of policy interactions on the performance of the emission trading market. The results showed that cost savings associated with the Jiangsu SO2 emission trading market in the absence of any policy interactions were CNY 549 million or 12.5% of total pollution control costs. However, policy interactions generally had significant impacts on the emission trading system; the lone exception was current pollution levy system. When the model accounted for all four kinds of policy interactions, the total pollution control cost savings from the emission trading market fell to CNY 39.7 million or 1.36% of total pollution control costs. The impact of policy interactions would reduce 92.8% of cost savings brought by emission trading program.

Implications of near-term coal power plant retirement for SO2 and NOX and life cycle GHG emissions.

Regulations monitoring SO(2), NO(X), mercury, and other metal emissions in the U.S. will likely result in coal plant retirement in the near-term. Life cycle assessment studies have previously estimated the environmental benefits of displacing coal with natural gas for electricity generation, by comparing systems that consist of individual natural gas and coal power plants. However, such system comparisons may not be appropriate to analyze impacts of coal plant retirement in existing power fleets. To meet this limitation, simplified economic dispatch models for PJM, MISO, and ERCOT regions are developed in this study to examine changes in regional power plant dispatch that occur when coal power plants are retired. These models estimate the order in which existing power plants are dispatched to meet electricity demand based on short-run marginal costs, with cheaper plants being dispatched first. Five scenarios of coal plant retirement are considered: retiring top CO(2) emitters, top NO(X) emitters, top SO(2) emitters, small and inefficient plants, and old and inefficient plants. Changes in fuel use, life cycle greenhouse gas emissions (including uncertainty), and SO(2) and NO(X) emissions are estimated. Life cycle GHG emissions were found to decrease by less than 4% in almost all scenarios modeled. In addition, changes in marginal damage costs due to SO(2), and NO(X) emissions are estimated using the county level marginal damage costs reported in the Air Pollution Emissions Experiments and Policy (APEEP) model, which are a proxy for measuring regional impacts of SO(2) and NO(X) emissions. Results suggest that location specific parameters should be considered within environmental policy frameworks targeting coal plant retirement, to account for regional variability in the benefits of reducing the impact of SO(2) and NO(X) emissions.

The high-resolution estimation of sulfur dioxide (SO2) concentration, health effect and monetary costs in Beijing.

Severe air pollution episodes with high SO2 loading have been frequently observed during the last decades in Beijing and have caused a noticeable damage to human health. To advance the spatiotemporal prediction of SO2 exposure in Beijing, we developed the monthly land use regression (LUR) models using daily SO2 concentration data collected from 34 monitoring stations during 2016 and 7 categories of potential independent variables (socio-economic factors, traffic and transport, emission source, land use, meteorological data, building morphology and Geographic location) in Beijing. The average adjusted R2 of 12 final LUR models was 0.62, and the root-mean-squared error (RMSE) was 4.12 µg/m3. The LOOCV R2 and RMSE of LUR models reached 0.56 and 5.43 µg/m3, respectively, suggesting that the LUR models achieved the satisfactory performance. The prediction results suggested that the average SO2 level in Beijing was 11.06 µg/m3 with the highest one up to 22.49 µg/m3 but the lowest one down to 3.86 µg/m3. The SO2 exposure showed strong spatial heterogeneity, which was much higher in the southern area than that in the northern in Beijing. The mortality and morbidity due to the excessive SO2 concentration were estimated to be 73 (95% CI:(38-125)) and 27854 (95% CI:(13852-41659)) cases per year in Beijing, leading to economic cost of 35.76 (95% CI:(16.45-54.06)) and 441.47 (95% CI:(318.31-562.04)) million RMB Yuan in 2016, respectively. This study clarified the intra- and inter-regional transport modeling of the SO2 pollution in Beijing and supplied an important support for the future air-quality and public health management strategies.

Uncertainty and variability in health-related damages from coal-fired power plants in the United States.

The health-related damages associated with emissions from coal-fired power plants can vary greatly across facilities as a function of plant, site, and population characteristics, but the degree of variability and the contributing factors have not been formally evaluated. In this study, we modeled the monetized damages associated with 407 coal-fired power plants in the United States, focusing on premature mortality from fine particulate matter (PM(2.5)). We applied a reduced-form chemistry-transport model accounting for primary PM(2.5) emissions and the influence of sulfur dioxide (SO(2)) and nitrogen oxide (NO(x)) emissions on secondary particulate formation. Outputs were linked with a concentration-response function for PM(2.5)-related mortality that incorporated nonlinearities and model uncertainty. We valued mortality with a value of statistical life approach, characterizing and propagating uncertainties in all model elements. At the median of the plant-specific uncertainty distributions, damages across plants ranged from $30,000 to $500,000 per ton of PM(2.5), $6,000 to $50,000 per ton of SO(2), $500 to $15,000 per ton of NO(x), and $0.02 to $1.57 per kilowatt-hour of electricity generated. Variability in damages per ton of emissions was almost entirely explained by population exposure per unit emissions (intake fraction), which itself was related to atmospheric conditions and the population size at various distances from the power plant. Variability in damages per kilowatt-hour was highly correlated with SO(2) emissions, related to fuel and control technology characteristics, but was also correlated with atmospheric conditions and population size at various distances. Our findings emphasize that control strategies that consider variability in damages across facilities would yield more efficient outcomes.

Economics of an integrated approach to control SO2, NOX, HCl, and particulate emissions from power plants.

An integrated approach for the simultaneous reduction of major combustion-generated pollutants from power plants is presented along with a simplified economic analysis. With this technology, the synergistic effects of high-temperature sorbent/coal or sorbent/natural gas injection and high-temperature flue gas filtration are exploited. Calcium-based (or Na-based, etc.) sorbents are sprayed in the post-flame zone of a furnace, where they react with S- and Cl-containing gases to form stable salts of Ca (or Na, etc.). The partially reacted sorbent is then collected in a high-temperature ceramic filter, which is placed downstream of the sorbent injection point, where it further reacts for a prolonged period of time. With this technique, both the likelihood of contact and the length of time of contact between the solid sorbent particles and the gaseous pollutants increase, because reaction takes place both in the furnace upstream of the filter and inside the filter itself. Hence, the sorbent utilization increases significantly. Several pollutants, such as SO2, H2S, HCl, and particulate (soot, ash, and tar), may be partially removed from the effluent. The organic content of the sorbents (or blends) also pyrolyzes and reduces NOx. Unburned carbon in the ash may be completely oxidized in the filter. The filter is cleaned periodically with aerodynamic regeneration (back pulsing) without interrupting furnace operation. The effectiveness of this technique has been shown in laboratory-scale experiments using either rather costly carboxylic salts of Ca or low- to moderate-cost blends of limestone, lime, or sodium bicarbonate with coal fines. Injection occurred in the furnace at 1150 degrees C, while the filter was maintained at 600 degrees C. Results showed that 65 or 40% SO2 removal was obtained with calcium formate or a limestone/coal blend, respectively, at an entering calcium-to-sulfur molar ratio of 2. A sodium bicarbonate/coal blend resulted in 78% SO2 removal at a sodium-to-sulfur molar ratio of 2. HCl removal efficiencies have been shown to be higher than those for SO2. NOx reductions of 40% have been observed with a fuel (coal)-to-air equivalence ratio, phi, around 2. The filter has been shown to be 97-99% efficient in removing PM2.5 particulates. Calculations herein show that this integrated sorbent/filter method is cost-effective, in comparison with current technologies, on both capital cost ($/kW) and levelized cost ($/ton pollutant removed) bases, if a limestone/coal mixture is used as the sorbent for fossil fuel plants. Capital costs for the filter/sorbent combination are estimated to be in the range of $61-$105/kW for a new plant. Because current technologies are designed for removing one pollutant at a time, both their cost and space requirements are higher than those of this integrated technique. At the minimum projected removal efficiencies for HCl/SO2/NOx of about 40%, the levelized costs are projected to be $203-$261/ton of combined pollutant SO2/HCl/NOx and particulates removed from coal-fired power plants.

Modeling the effects of changes in new source review on national SO2 and NOx emissions from electricity-generating units.

The Clean Air Act establishes New Source Review (NSR) programs that apply to construction or modification of major stationary sources. In 2002 and 2003, EPA revised its rules to narrow NSR's coverage of renovations. Congress mandated a National Research Council study of the revisions' impacts. In that study, we used an electricity-sector model to explore possible effects of the equipment replacement provision (ERP), the principal NSR change directed at power plants. We find that, assuming implementation of the Clean Air Interstate Rule (CAIR), tight enforcement of the prerevision NSR rules would likely lead to no or limited decreases in national emissions compared to policies such as ERP. However, emissions might shift forward in time because the previous NSR rules would depress allowance prices, discouraging banking and encouraging allowance use. Only under the most aggressive prerevision NSR enforcement scenario, in which essentially all coal capacity is compelled to retrofit controls by 2020, do NOx emissions fall below ERP levels. Even then, total 2007-2020 SO2 emissions are unaffected. Further decreases in national emissions could be accomplished more cheaply by tighter emissions caps than through NSR because caps provide incentives for efficient operating strategies, such as fuel switching, as well as retrofits.

The shadow price of substitutable sulfur in the US electric power plant: a distance function approach.

Given restrictions on sulfur dioxide emissions, a feasible long-run response could involve either an investment in improving boiler fuel-efficiency or a shift to a production process that is effective in removing sulfur dioxide. To allow for the possibility of substitution between sulfur and productive capital, we measure the shadow price of sulfur dioxide as the opportunity cost of lowering sulfur emissions in terms of forgone capital. The input distance function is estimated with data from 51 coal-fired US power units operating between 1977 and 1986. The indirect Morishima elasticities of substitution indicate that the substitutability of capital for sulfur is relatively high. The overall weighted average estimate of the shadow price of sulfur is -0.076 dollars per pound in constant 1976 dollars.

Cost-effective control of SO2 emissions in Asia.

Despite recent efforts to limit the growth of SO(2) emissions in Asia, the negative environmental effects of sulphur emissions are likely to further increase in the future. This paper presents an extension of the RAINS-Asia integrated assessment model for acidification in Asia with an optimisation routine that can be used to identify cost-effective emission control strategies that achieve environmental targets for ambient SO(2) concentrations and sulphur deposition at least costs. Example scenarios developed with this optimisation module demonstrate a potential for significant cost savings in Asia, if emission controls are allocated to those sources that have the largest environmental impact and are cheapest to control. It is shown that strategies that simultaneously address harmful population exposure and the risk of vegetation damage from acid deposition result in the most cost-effective use of resources spent for emission controls.

Estimating the benefits of pollution reduction on agricultural yields: Taiwan's air pollution emission fees program.

Taiwan's implementation of the 1997 Air Pollution Emissions Fees Program will conceivably lead to long-term reductions in pollution emissions. The purpose of this paper is to estimate the benefits to Taiwan from the expected reduction in crop losses as a direct result of such a decrease in air pollution. We employ a demand-supply framework for rice production to estimate the change in social welfare resulting from changes in the concentration of certain pollutants in the atmosphere. Our empirical results show that, in the year 1997, social welfare increments resulting from the decline in sulfur dioxide concentrations in the atmosphere ranged between US dollars 946200 and US dollars 2435800. Meanwhile, during the same period, the increase in social welfare due to the decline in the ozone concentration in the atmosphere ranged between US dollars 838100 and US dollars 1927000. The average benefit from the reduction in both sulfur dioxide and ozone concentrations is calculated to be between US dollars 2.67 and US dollars 6.86 per acre (for sulfur dioxide), and from US dollars 2.36 to US dollars 5.43 per acre (for ozone).