Generation, Renewable Energy, Solar

Solar steam augmentation: A sensible alternative to PV

Issue 5 and Volume 91.

by John Robbins, AREVA Solar

After years of being poised for rapid growth, the opportunities for concentrated solar power (CSP) are multiplying fast. Analysts expect that over the next decade there will be a 20-fold increase in CSP generation, with several factors driving the increased interest.

Rendering of Sundt Solar Power Booster Project

Some solar power producers are benefitting because solar’s cost is better understood. Traditionally measured cost of solar power production has decreased, but analysts are increasingly factoring in volatile fuel prices, impact to the grid and the environmental costs of such things as land use, water use and fossil fuel emissions.

CSP offers tremendous opportunities for local industrial development in a fragile economy. Many solar steam generators are made with standard materials and can be rapidly deployed using low-cost, locally-sourced manufacturing processes and materials.

Increased investment from global energy leaders, including Alstom, AREVA, Bechtel and General Electric (GE), removes barriers and builds trust. CSP companies can now reliably offer the full package of necessary services and guarantees, from technology leadership to engineering, procurement and construction services to operation and management expertise.

CSP technologies are mature, with more than 1 gigawatt (GW) of installed capacity, and many having undergone rigorous proof-of-concept testing in real-life situations.

Perhaps most importantly, demand continues to grow as utilities are pressured to reduce emissions in the near term without significant capital investment. CSP technologies effectively addresses these concerns, offering cost-effective and quick-to-market opportunities for utilities to increase the fossil-fuel plant output without added emissions, or reduce emissions while keeping plant output the same. Since CSP provides solar electricity to the grid that is far more stable than photo-volatic (PV), it enhances grid reliability and can be an important, cost-effective solution for the industry in bridging the carbon gap.

The Advantages of Solar Steam Augmentation

Power augmentation is when utilities integrate CSP boosters into the steam cycle of existing fossil fuel, geothermal and biomass-powered plants. Utilities choose CSP because they need to either cleanly boost power plant output to meet increased demand or offset fossil fuel consumption and reduce emissions. Either way, power augmentation with CSP delivers a number of additional benefits.

  1. Electrical output from a solar steam augmentation project is more stable than electricity from a PV plant because thermal inertia of the steam enhances grid reliability.
  2. Boosters can often be built on land that power companies already own and control. For those companies that face land constraints, compact linear fresnel reflector (CLFR) technology is the most land-efficient solar solution.
  3. Existing infrastructure can be leveraged to levelize electricity costs, allowing CSP technology to compete with similar sized PV plants, depending upon the CSP technology used.
  4. Incremental investment allows power plant operators to maximize the value of existing plant assets without major capital expenses or long lead-times, such as those typically associated with building a new power plant.
  5. Incremental solar power from solar steam augmentation qualifies for environmental credits, meets renewable portfolio standards (RPS) or both, thus increasing the value of this investment.

Real World Proof

In 2010, Florida Power and Light went online with a 75MW trough CSP booster to work with a 1,200 MW combined cycle power plant near Indiantown, Fla. In 2011, Abengoa brought two 20 MW trough CSP boosters online at new gas-fired, combined-cycle power plants in Morocco and Algeria. Together these projects generate more than 240GWhe per year of solar energy, while reducing greenhouse gas emissions by more than 121,000 tons per year.

Success builds on success. Tucson Electric Power (TEP) has a booster project slated to go online in early 2014, a partnership with AREVA Solar that will provide a 5 MW solar addition to TEP’s gas and coal-fired, 400 MW H. Wilson Sundt Generating Station in Tucson. The project will allow Sundt’s dual-fueled Unit 4 to reliably produce an additional 5 MW or the same amount of electricity during peak daylight periods, while reducing the use of up to 3,600 tons of coal per year or up to 46 million cubic feet of natural gas.

AREVA Solar also has begun construction on a 44 MW solar thermal addition to CS Energy’s existing 750 MW coal-fired Kogan Creek Power Station in South West Queensland, Australia. When it becomes operational in 2014, that booster will avert 35,600 tons of CO2 emissions each year and will be the world’s largest coal and solar augmentation project. The projects, and others like it, will create local construction, operations, and maintenance jobs while sourcing local materials and manufacturing.

The Time to Leap Forward is Now

These projects provide compelling evidence that solar augmentation using CSP technology offers utilities a cost-effective, reliable strategy to quickly boost capacity, meet sustainability goals and renewable portfolio standards, and reduce fuel, emissions, and operations and maintenance costs.

As CSP providers deliver those benefits, they will be making a dramatic and long overdue stride forward for the CSP industry.

Author

John Robbins is senior director of North American Sales at AREVA Solar. He has more than 20 years in the industry working for Alstom Power Inc., Solar Turbines Inc. and General Electric. He received his Bachelors of Science in Mechanical Engineering at Oregon State University and earned a Juris Doctorate from American University.

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