Top Plant: Montoir-de-Bretagne Combined Cycle Plant, Montoir-de-Bretagne, France

Courtesy: GE Energy

Owner/operator: GDF SUEZ

The 435-MW Montoir-de-Bretagne gas-fired power plant is ramping up Gallic generation in the Loire-Atlantique region of western France. The plant’s innovative natural gas combined cycle technology offers high efficiency and low emissions.

Located near the Loire River in an area of western France known for its fresh seafood and vineyards, the new Montoir-de-Bretagne gas-fired power plant is a welcome addition to the region. The plant, which was inaugurated in April this year after going into service late last year, will produce 2,200 GWh of electricity annually. The 435-MW plant operates at 58% efficiency, Jean-Sébastien Erb, senior project manager of power plant systems for General Electric Co., told POWER in July.

GDF SUEZ, the French multinational energy company, owns and operates the plant, which cost close to €300 million ($427 million). With the added generation from this new facility, GDF SUEZ is now able to provide more electricity to the South Brittany region, especially during peak demand periods such as the winter months.

The French Electric Power Industry

France, which has a population of more than 65 million, is a leader among European nations, and abundant, reliable electricity is essential to the country’s continued success. France relies on nuclear power to produce about 77% of its electricity, hydro supplies approximately 14%, and the remainder, less than 9%, is produced by fossil fuels.

France produces approximately 574.8 GWh annually and consumes about 433.4 GWh. The country exports approximately 5,869 GWh and imports about 1,068 GWh (all 2008 estimates).

France is in the midst of transitioning from a prosperous economy that has featured extensive government ownership and intervention to one that relies more on market mechanisms. In 2007, the French electricity market was opened to competition.

GDF SUEZ operates in the fields of electricity generation and distribution, natural gas, and renewable energy. Currently, it controls 78 GW and is the second-largest producer of electricity in France. Initially, GDF SUEZ was formed by the merger of Gaz de France and SUEZ on July 22, 2008. GDF SUEZ is organized into six business lines, including Energy France, the unit that supplies natural gas and electricity to residential, commercial, and industrial customers throughout France.

Électricité de France S.A. (EDF) is the largest electric utility company in France. Headquartered in Paris and with approximately €65.2 billion ($93.2 billion) in revenues in 2010, EDF operates a diverse portfolio of more than 120,000 MW of generation capacity in Europe, Latin America, Asia, the Middle East, and Africa. EDF is one of the world’s largest producers of electricity. In 2003, it produced 22% of the European Union’s electricity, primarily from nuclear power.

The transmission network in France is composed of two different systems. Reseau de Transport d’Electrique (RTE) manages a high-voltage and very high voltage transmission system, which totals approximately 100,000 kilometers (km, 62,127 miles) of transmission lines. In addition, a low- and medium-voltage distribution system (1,200,000 km of lines) is maintained by ErDF (Électricité Réseau Distribution France), formerly known as EDF-Gaz de France Distribution. It was spun off from EDF-Gaz de France Distribution in 2008 as part of the process of totally separating the activities of EDF and GDF SUEZ.

Solving Construction Challenges

The Montoir-de-Bretagne power plant is the result of over two years of construction. Spanish-based general contractor Tecnicas Reunidas provided engineering, procurement, and construction services.

Erb pointed out that the contract was challenging due to construction issues involving operational and environmental constraints. The project also involved the first installation in France of the new GE 9FB gas turbine for GDF SUEZ (Figure 1).

1. The French connection. The GE 109FB combined cycle system, which includes a Frame 9FB gas turbine, was installed at the Montoir-de-Bretagne power plant. It was manufactured at GE’s European gas turbine headquarters in Belfort, France, and then shipped to the Montoir de Bretagne site in late 2008 for on-site assembly. Courtesy: GE Energy

“Regarding the construction challenges, the area where the plant is located is very crumbly and marshy (close to the Loire River),” Erb said. “More than 950 piles (28 m long for 50% of them) had to be installed in the ground to allow the first civil works activities. Moreover, this is a seismic area as well as a restricted area (it is a SEVESO explosive area due to the neighborhood of the Terminal Méthanier de Montoir, a liquefied natural gas terminal), and constraints were numerous and very important.”

The GE project team also had to deal with environmental regulations related to the plant’s construction. As part of the project requirements, they coordinated with the Ministry of Economy, Finance, and Industry, which is responsible for energy.

“This area is subject to environmental restrictions (fauna and flora),” Erb explained. “Local authorities keep strict watch over the effluents (mainly in the Loire River), the far field noise level, and the emissions. All of them were strictly respected and all contractual performance requirements (subject to liquidated damages) were reached by GE.”

Facility Highlights

The GE 109FB combined cycle system includes a Frame 9FB gas turbine—one of the world’s most advanced air-cooled 50-hertz gas turbines—plus a high-efficiency advanced technology (HEAT) steam turbine and associated 450H generators. The 9FB gas turbine technology was designed to meet GDF SUEZ’s requirements for greater operating flexibility, including improved turndown capability, greater fuel flexibility, and faster start-ups, to meet fluctuating demands for electricity.

The 9FB for the GDF SUEZ project was manufactured at GE’s European gas turbine headquarters in Belfort, France, and then shipped to the plant site in late 2008. Addressing the growing need for cleaner power, the 9FB is equipped with GE’s advanced, dry low–nitrogen oxides (NOx) combustion system, which limits NOx emissions to 25 parts per million or less.

“The 9FB gas turbine is very flexible and offers a quick answer to the electricity market’s fluctuations,” Erb said. “In 1 hour and 15 minutes, the unit can go from 0 to 435 MW and in 10 minutes from 250 MW to 435 MW.”

Other equipment installed at the plant included, but was not limited to, the following:

  • Heat recovery steam generator and boiler (Doosan, Korea)
  • Condenser (Foster-Wheeler, Spain)
  • Distributed control system (GE, U.S.)
  • Steam turbine (GE, U.S.)
  • Generator (GE, U.S.)
  • Main transformer (Hyundai, Korea)

Of the personnel who work at the plant now that it is operational, Erb said that “GE had a contractual obligation to ‘optimize’ the number of GDF SUEZ people operating the plant.” Currently, two persons (one in the control room and one on site) must operate the plant continuously. In addition, the maintenance team is composed of five people, each with a specific area of expertise.

Future Impact of the New Plant

Erb believes the additional electricity supplied by the GDF SUEZ power plant will have a positive impact on the Loire-Atlantique region’s economic growth. “This new power plant will supply the equivalent of 450,000 homes with electricity and will consolidate the supply of electricity to all the western area and particularly the region of St. Nazaire,” he said. “It is a determining factor for securing new enterprises to settle in this area.”

Angela Neville, JD, is POWER’s senior editor.