Coal

Why should utilities consider converting existing coal-fired plants to burn gas? We explore the rationale for fuel switching, some of the options available for the conversion of coal-fired units, technical considerations related to conversion, and some of the financial considerations that will impact the final decision.

Companies continue to increase the size of carbon capture and sequestration test projects. Mitsubishi Heavy Industries (MHI) has launched operation of what it calls the world’s largest demonstration of carbon capture on a pulverized coal plant.

Kansas City Power & Light (KCP&L) began engaging stakeholders in 2003 to develop consensus on a regional energy plan designed to balance customers’ desire for low electricity costs with system reliability needs and environmental requirements. The culmination of that plan was the completion of Iatan 2, which entered service in August 2010. For executing an innovative energy plan that reduced overall fleet emissions, ensuring the region’s future electricity supply, and completing an approximately $2 billion project in time for the summer 2010 peak load by using innovative contracting and project controls, KCP&L’s Iatan 2 is awarded POWER’s 2011 Plant of the Year Award.

Cycling your steam power plant is inevitable, so now is the time to learn how to minimize equipment damage and assess the true costs of cycling. Whether cycling is required by the grid operator because of renewable integration or other factors, you must be proactive about updating operating processes and upgrade equipment so the transition to cycling operation goes smoothly.

As coal-fired power plants increasingly operate in cycling modes, many plants are confronting the potential for higher levels of component damage and degraded performance of environmental control equipment. Generators and EPRI are working together to find ways to mitigate the effects of cycling operation and to manage the transition of formerly baseload plants to flexible operation.

It may seem counterintuitive, but the strategic coupling of simple- and combined- cycle technologies with renewable generation could establish the conditions necessary for adding more renewable megawatts to transmission grids around the world.

Underground coal gasification (UCG) is the gasification of coal in-situ, which involves drilling boreholes into the coal and injecting water/air or water/oxygen mixtures. It combines an extraction process and a conversion process into one step, producing a high-quality, affordable synthetic gas, which can be used for power generation. Still in the early stage of commercialization, UCG is poised to become a future major contributor to the energy mix in countries around the world.

After the 2008 incident involving the failure of a large surface impoundment containing wet coal ash, the EPA began investigating all coal-fired power plants employing this wet coal ash management method. Now a new dry ash management technology offers coal-fired power plants an environmentally suitable alternative for handling coal ash that also increases energy efficiency.

If you needed additional proof that the power industry is changing, the ELECTRIC POWER keynote and panel discussions over the past few years have provided it—top-of-mind issues have been significantly different each year. For the 2011 keynote speaker and panelists, the challenges of reliability, regulatory compliance, financing, and getting the fuel mix right took center stage. In the wake of Japan’s nuclear crisis, safety also featured prominently.

In today’s solid-fueled power plant, managing emissions and moving materials more defines the task than the traditional work of making megawatts. That’s the message that emerged from the coal and solid fuels track at this year’s ELECTRIC POWER.

The international policy framework regulating the emissions of greenhouse gases from industrial and utility boilers is in flux. Meanwhile, most boiler owners are evaluating potential strategies for when, not if, more stringent emissions reduction regulations are put in place. One of the most attractive compliance options is the cofiring of biomass in existing coal-fired boilers.

In surprising findings, given the state’s often-contentious relationship with the Environmental Protection Agency, a study released May 11 by the Texas grid operator concludes that a suite of looming EPA rules to reduce conventional and hazardous air pollution from power plants and to tighten power plant cooling water regulations likely would not force the retirement of any Texas coal plants.

In a wide-ranging speech on U.S. electricity policy, Southern Co. Chairman, President, and Chief Executive Officer Thomas Fanning said that coal is "under attack" by the federal government, that natural gas may not be the panacea seen by some utilities facing environmental constraints on their coal plants, and that federal proposals to sharply reduce utility hazardous air pollution have unreasonable compliance deadlines that should be extended.

Even as Senate energy leaders gear up to re-introduce widely supported legislation to create the Clean Energy Deployment Administration, they have acknowledged that the bill faces a heightened problem this term: the need to find nearly $10 billion in offsets to pay for the new green energy financing authority at a time of overwhelming concern about the federal debt.

Spain has served as both exemplar and scapegoat when it comes to renewable energy policy. Though power policy must necessarily accommodate specific national resources and goals, Spain’s experience as an early and eager adopter of renewable energy technologies and subsidies is a cautionary tale of how the best intentions can have unintended consequences.

Utilities struggling to meet renewable portfolio standards requirements have studied the conversion of existing coal-fired boilers to burn biomass. The results of those studies have been mixed, although test burns continue; the results of one such test are included. Overall, the market is tending toward smaller biomass projects, and the low price of natural gas is perhaps the biggest reason utility-scale projects are now few and far between.

Balancing the rising energy needs of a globally expanding population (most of which lives in poverty) against the need to reduce increases in atmospheric emissions is a monumental problem. What role can clean coal technologies play?

The question concerning coal plant retirements forced by looming regulatory rules, low gas prices, and moribund load growth has changed from “Why?” to “How many plants?” Many highly detailed analyses and reports have been written on the subject by superbly qualified analysts. This approach to estimating potential plant closures is much more qualitative, and much easier to understand. However, the results closely align: About 50 GW are threatened.

Increasing regulatory requirements and a focus on reducing carbon emissions in the U.S. have significantly reduced the number of new coal-fired plants under development compared with past years. In addition, projected capital costs for new coal-fired plants have risen sharply in the past year, while those for natural gas combined-cycle and combustion turbines have stayed relatively flat. In order to keep coal a viable energy source, many countries, including the U.S., are seeking ways to improve plant efficiency while reducing carbon emissions.

The challenges of using Powder River Basin (PRB) coal are as significant as the rewards. The subbituminous coal contains lower amounts of sulfur dioxide than bituminous coal but can be prone to combustible dust explosions if it is not properly managed. To eliminate such hazards, plant personnel need to establish best practices for the safe operation and maintenance of PRB coal-handling and -storage systems based on best available technologies.

In Part III of this three-part report, we look at plant- and fleet-level metrics used to determine compensation. As expected from this EUCG-sponsored benchmarking survey, there is broad use of quantifiable metrics to set portions of compensation, but the metrics selected vary substantially across the surveyed utilities. More surprising was the number of utilities that used no performance metrics as part of their employee compensation packages.

The People’s Republic of China’s Congress approved a much-anticipated draft of the country’s 12th Five-Year Plan (2011–2015) on March 14. Along with key objectives that included boosting its gross domestic product (GDP) by 7% annually on average, the country for the first time in a five-year plan established targets to tackle climate change. It plans to reduce carbon dioxide emissions per unit of GDP by 17% from 2010 levels by 2015 and to reduce energy consumption per unit of GDP by 16% from 2010 levels by 2015.

Subsidized by the Dutch government, a number of Dutch utilities, the European Membrane Institute at the University of Twente, and Dutch consulting firm KEMA have, for over a decade, been testing membrane technology that promises to directly convert water vapor from power and other industrial plants’ flue gases into drinking water. The technology could provide a new source of large volumes of potable water.

If coal is to be a viable long-term fuel for a significant percentage of electricity generation, research and development is needed to increase thermal efficiency, demonstrate cost-effective and secure carbon dioxide capture and storage, further improve emission controls, and reduce water demands.

The U.S. Environmental Protection Agency is developing a number of new regulations for the power sector governing air emissions, cooling water intake structures, and coal combustion waste disposal methods. Combined, these regulations have the potential to drive as much as 40% of existing coal-fired generating units to retire in the next 10 years, representing about 51 GW.

One of the largest returns on investment a plant can achieve is the improved condenser performance that results from an effective condenser tube cleaning. Perhaps it is time to reevaluate your choice of cleaning technologies, establish an optimal cleaning schedule, and add routine air and water in-leakage surveys to your plant’s maintenance schedule.

Bayer in February brought online a pilot plant at Chempark Leverkusen, Germany, to recycle carbon dioxide (CO₂) scrubbed from the flue gas of a 1,000-MW RWE lignite-fired unit and convert it into a raw material and petroleum substitute for plastic manufacturing. The Bayer facility (Figure 4) essentially produces a chemical precursor into which CO₂ is incorporated and then processed into polyurethanes that are used for many everyday items.

Because refractory is out of sight inside the gas flow path of a steam generator and its auxiliaries, it’s also often out of mind. That is, until the refractory fails and causes a forced outage.

Biomass cofiring has the potential to cut emissions from coal-fueled generation without substantially increasing costs or infrastructure investments. Research shows that when implemented at relatively low biomass-to-coal ratios, energy consumption, solid waste generation, and emissions are all reduced. However, mixing biomass and coal does create some challenges that must be addressed.

Efficient boiler operation requires boiler auxiliary equipment to operate in harmony. In this third and last installment of our Power 101 series, we examine ways to decrease the auxiliary power requirements of boiler auxiliaries.