Gas

Growing hothouse tomatoes might not be the first application that comes to mind for a natural gas–fueled combustion engine, but that’s exactly what an innovative grower in Southern California is doing, with some help from General Electric (GE).

Relatively simple upgrades to legacy turbine systems can yield big payoffs in efficiency and reduced maintenance.

The fate of coal-fired generation remains fluid as owners weigh environmental rules, the effect of low natural gas prices, and the shifting cost of investing in emissions control technology. An analysis of generating unit data suggests that smaller, older, less-efficient, and less-frequently dispatched assets are most vulnerable to retirements. Recently accelerated retirement dates for some units indicate that economic factors are a more important determining factor than pending environmental mandates

As part of the University of Iowa Research Park’s efforts to promote renewable energy use, the new campus power plant’s engine generators are designed to operate primarily on landfill gas when the pipeline from the Iowa City Landfill is completed, with natural gas as a secondary fuel source. To make it more efficient, the plant’s waste heat recovery system captures waste heat from the gas engine generator’s cooling and exhaust systems to produce hot water for heating, or chilled water for cooling, campus facilities.

Droughts, unreliable gas imports, and protests against proposed projects have hampered the Chilean power sector and its largest economic driver, the copper-mining industry. Recent policies designed to foster more reliable supplies are a move in the right direction, but remaining obstacles are formidable.

The natural gas and electricity industries have entered into an increasingly codependent relationship as coal-fired electricity gives way to natural gas–fired generation. Both industries are firmly committed to providing reliable service, although each goes about its business in different ways. Utilities, regulators, and stakeholders are searching for ways to align interests and expectations.

Plentiful supplies of low-cost natural gas have changed unit dispatch orders across the U.S., led to thermal stress–induced maintenance issues at cycling coal plants, and resulted in management challenges at coal and gas units alike. This scenario is unlikely to change so long as gas holds its competitive edge over coal.

The widespread transition from coal to natural gas for new generation is exemplified by the morphing fleets of some of the biggest U.S. generators. Figures show the amount of power generated by each company using coal (top) and natural gas (bottom). Sources: POWER, NextEra, Duke Energy, Tennessee Valley Authority (TVA), Southern Co., American Electric Power […]

Several major power plants around the world began operations over the past months.

The 1,309-MW Claus C power plant showcases the successful repowering of an existing steam power plant by upgrading it and adding a highly efficient combined cycle plant that doubles the original plant’s power output for just a 35% increase in fuel consumption. In addition, the newly retrofitted plant is cutting CO2 emissions by 40% compared with a simple-cycle gas-fired plant of equal capacity.

The Dutch utility Eneco and the Danish energy group DONG Energy recently collaborated in building the 870-MW Enecogen Power Station that has a thermal efficiency above 59% and is designed for maximum operational flexibility. As part of Eneco’s strategy to lower emissions across its fleet, the combined cycle plant is designed to quickly compensate for intermittent power produced by the utility’s wind turbines.

Glow Energy’s 382-MW Glow Phase 5 power plant in Thailand exceeded early expectations by packing into a tightly constrained space more capacity than anyone thought possible. The plant’s engineering feat earns it recognition as a POWER Top Plant for 2012.

The Tennessee Valley Authority (TVA) is known for its large fleet of coal-fired plants. With TVA’s renewed emphasis on nuclear power and gas-fired generation, the organization will soon fulfill its new goal: “to be one of the nation’s leading providers of low-cost cleaner energy by 2020.” Construction of the 880-MW John Sevier Combined Cycle Plant puts TVA one step closer to achieving that goal.

Faced with the need to begin generating its own power after decades of relying on larger regional suppliers, and impending renewable portfolio standard requirements, the Lea County Electrical Cooperative had to get creative. Its choice of a highly flexible gas-fired engine plant that will work together with a nearby wind farm makes this a POWER Top Plant.

Set to begin commercial operation on Sept. 17, 2012, the 280-MW Lodi Energy Center is the first “fast-start” combined cycle power plant in the U.S. The advantages of the gas turbine’s shorter startup capabilities are reduced fuel costs, lower emissions, and the versatility to effectively partner with intermittent renewable energy sources. The new power plant is located next to the city of Lodi’s municipal wastewater treatment plant and uses its treated wastewater for cooling purposes.

A new gas-fired power generation technology that uses an oxyfuel, high-pressure, supercritical carbon dioxide cycle and produces pipeline-ready carbon dioxide for sequestration or use in enhanced oil recovery (EOR), without reducing plant efficiency, garnered the interest of three new partners in June.

The environmental push for renewables and mandates to force them into existence are rightly facing some serious headwinds. The American Renewable Energy Production Tax Credit Extension Act of 2011 foundered in Congress, and more states are experiencing significant power rate increases to cover renewable energy production costs. While renewables are generally not ready for prime time in large quantity on today’s power grid, that doesn’t mean environment concerns ought to be trashed, especially when a more effective off-the-shelf solution is available.

The second of Georgia Power’s three natural gas combined cycle units at Plant McDonough-Atkinson in Smyrna, Ga., came online on April 26 (Figure 7). The first unit at the plant became operational in December 2011, and the third unit, currently under construction, is expected to come online in November 2012, increasing the plant’s capacity from […]

India’s long-term annual economic growth rate is projected at over 7%, and the country is investing in its hydroelectric, nuclear, and renewable resources. However, the primary fuel used to produce electricity remains coal, and the government has ambitious plans to significantly increase coal-fired capacity. Those plans have been challenged by a number of unexpected factors that threaten to stifle India’s economic growth. India’s long-term annual economic growth rate is projected at over 7%, and the country is investing in its hydroelectric, nuclear, and renewable resources. However, the primary fuel used to produce electricity remains coal, and the government has ambitious plans to significantly increase coal-fired capacity. Those plans have been challenged by a number of unexpected factors that threaten to stifle India’s economic growth.

A West Coast combined cycle plant that uses reclaimed water found that cycling 300 times a year caused disruptions to the plant’s cooling water chemical treatment program. The solution was a performance-based monitoring and control system that uses available plant operating data plus algorithms to measure corrosion rates and fouling factors, which in turn allows the plant to trim chemical feed rates so they correlate with a specified corrosion rate, rather than a suggested chemical residual.

Panelists at the ELECTRIC POWER Keynote and Roundtable Discussion in Baltimore in May wrestled with a range of issues. But despite calls for a “balanced portfolio,” an “all-of-the-above” energy strategy, and predictions of “more changes in the next 10 years than in the last 100,” the focus of attention appears to be the decidedly mundane displacement of coal by natural gas.

A diverse range of speakers reviewed the state of gas-fired generation at ELECTRIC POWER, but there was one constant: flexibility

Combined cycle power plants use fuels and other materials that can cause fires or explosions in the combustion turbine, ducting, or heat recovery steam generator. Purging that equipment with ambient air to displace residual combustible gases before starting is a normal safety practice. But when plants are cycled, the disadvantages of purging often outweigh the advantages.

Large circles represent technical reserves and small (blue) circles represent potential reserves of shale gas, both in trillion cubic feet. Bars on the right represent each region’s existing natural gas–fired generation in 2008 (yellow) and the amount projected for 2035 (blue) in TWh. OECD = Organisation for Economic Co-operation and Development. Data source: Energy Information […]

Massive offshore shale gas reserves exceeding 1,000 trillion cubic feet (tcf) discovered in the UK in April could catapult that country to the top ranks of global producers.

A model of Switzerland’s energy future to 2050 that abides with the country’s post-Fukushima decision not to build any new nuclear power plants suggests the phase-out could cost nearly $33 billion.

The Tennessee Valley Authority (TVA) has begun commercial operation of the natural gas–fired 880-MW John Sevier Combined Cycle Plant, located near Rogersville, Tenn.

In March, Cambridge Energy Research Associates hosted its 30th annual CERAWeek, a conference that is renowned for high-profile attendees from around the world.

Dr. Daniel Yergin, chairman of IHS Cambridge Energy Research Associates, is a Pulitzer Prize–winning author; leading authority on energy, international politics, and economics; and a recipient of the United States Energy Award for “lifelong achievements in energy and the promotion of international understanding.” He recently spoke with POWER about his latest book—and more.