Power producers invest for a mixed fuel future

1st February 2013

South American power producers are investing heavily in new technology, both to enable them to swap quickly between different fossil fuels and to improve their hydropower performance. Sean Ottewell reports.

Finnish company Wärtsilä, a leading supplier of flexible power plants and services for the decentralised power generation market, has received contracts from three Brazilian independent power producers (IPPs) to provide conversions for their generating stations.

The conversions will enable them to attain fuel flexibility and switch from heavy fuel oil (HFO) to gas operation.

The combined value of the three contracts is in excess of Euro 48 million and represent the biggest project of its kind ever undertaken by Wärtsilä Services. The converted plants are expected to be fully operational in October 2010.

Alternative fuels

When the conversions are completed, the power plants will be fully compliant with the stipulated flexibility requirements, allowing the fuel to be switched instantly from liquid to gas, or vice versa. The customers will have a choice of alternative fuels for environmental as well as for redundancy reasons, and will be able to take advantage of lowest fuel cost options.

In addition to the engine conversions, the scope of the contracts includes the installation of the main gas fuel system equipment and the gas compressor units, and the modification of the control and electrical systems. The electrical output from the plants will remain the same whether they run on HFO or gas.

Furthermore, the fuel sharing system allows the engines to run on gas and liquid fuel in different proportions.

This will optimise the operation of the plants according to the availability of the fuels.

The three customers are Geradora de Energia do Amazonas, Companhia Energética Manauara, and Rio Amazonas Energia), all with power plants located in Manaus city, Brazil.

All three plants were delivered by Wärtsilä in 2006, with each being pre-designed to facilitate this conversion.

The three power plants each have five Wärtsilä 18V46 engines (Fig.1), and the total power output is more than 85MW per plant. The Finnish company currently operates and maintains all three plants under contract and has a total of close to 1800MW of generating capacity installed, on order or under construction in Brazil.

Commenting on the implications of these conversions, Tomas Hakala, president of Wärtsilä in Latin America, said: "These combined plant conversions represent the biggest project of its kind ever undertaken by Wärtsilä Services. The size and scope of the project, together with the fact that the work is to be carried out at three separate sites, means that it is an interesting challenge. However, it is a challenge that Wärtsilä is more than capable of meeting and we anticipate that the converted plants will be fully operational on schedule in October 2010."

Fuel cost options

The customers all indicated a desire to be able to use all possible fuel alternatives in the future, for environmental as well as for redundancy reasons, and to take advantage of lowest fuel cost options. The key driver, however, has been the anticipated availability of natural gas to the region in 2010.

The gas conversions will be carried out one engine at the time, in all three power plants concurrently. Wärtsilä in Brazil has set up a project management organisation to best organise the human and parts logistics to ensure the delivery meets the contractual terms. Moreover, the company says it maintains the same guarantee of availability in the service agreements, both before and after the gas conversion.

Meanwhile, in Uruguay, the company has won a contract supply equipment and engineering for a new 80MW baseload power plant for the state electrical utility UTE. The value of the order is approximately EUR35million. The UTE Uruguay plant will supply electricity to the national grid.

The plant is to be located within the existing Central Batelle power plant field in the capital Montevideo. The Finish company is to deliver eight previously used 12V46 engines that it has fully overhauled and reconditioned. This order represents Wärtsilä's first power plant installation in Uruguay, a country where some 70 per cent of the electricity is supplied by hydropower.

Wärtsilä was also awarded an operations and maintenance (O&M) agreement for two years with a further two years extension option.

The new power plant is expected to be fully operational by the end of October 2009. The engines will initially be run on HFO, but will later be converted to gas and HFO dual-fuel capability, and will run mainly on gas.

Wärtsilä's says its ability to supply the equipment and engineering services within the very tight schedule stipulated was a key factor in the company winning, along with the fuel flexibility of its engines.

"This order is the result of the very good understanding of the customer's needs and the fact that we are able to supply fully reconditioned engines. The engines are not only rebuilt to as-new condition, but they are also ready to be converted at a later stage from HFO to gas operation. The technical and engineering support is also critical to this installation as the brown field location is particularly challenging with very limited space available," explains Alberto Fernandez, business development manager for Uruguay and Argentina, Wärtsilä Power Plants.

Brazilian hydro too

Alstom Hydro, which currently has a 35 per cent share of Brazil's hydropower market, has further strengthened its presence in the country by winning a contract worth over EUR300 million to supply part of the equipment for the Jirau hydropower plant.

The contract includes Bulb-type turbines and generators. Bulb units are especially suitable for low head and run-of-river hydropower schemes such as Jirau and Santo Ant-nio.

These units are highly efficient as they are fully submerged in the water and thus able to handle significant variations in water discharge, as is the case for the Amazon region.

Located 135km from the city of Porto Velho in northern Brazil, the Jirau hydropower plant will generate up to 3300MW and will start in operation in 2012

The Jirau contract follows an earlier contract won by Alstom Hydro in 2008 to supply equipment to the 3150MW Santo Antonio hydropower plant. Both projects form part of Brazil's infrastructure development scheme, the Madeira River projects.

The contract was signed between Alstom Hydro, as leader of an equipment manufacturing consortium, and Jirau project investor Energia Sustent´vel do Brasil.

The Alstom-led consortium will design, manufacture and supply a total of 28x75MW Bulb type generating units, out of which Alstom Hydro is responsible for supplying 10 turbines and 17 generators, as well as all of the 28 speed governors, monitoring systems, bus bars and surge/neutral devices; this represents around 48 per cent of this contract.

The contract scope also includes supervision of erection and commissioning. Most of the equipment will be produced in Brazil, notably the turbines and generators manufactured at Alstom Hydro's Taubaté factory.

"This new contract further strengthens Alstom Hydro's presence and leadership in the Brazilian hydropower market where it built hydropower plants for over 50 years," said Philippe Joubert, Alstom executive vice president and president, power systems. "The Madeira River projects count among Brazil's most important infrastructure development schemes and will play a key role in the country's economic development over the next decade. Winning the trust of Energia Sustent´vel do Brasil for this project confirms a worldwide acknowledgement of Alstom's superior technology in hydropower," he added.


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