Analyses of projects implemented in Asia, Africa, and Brazil show that the gas-to-wire model provides energy security and expansion of the natural gas network.
Experts from the Research Centre for Innovation in Greenhouse Gases (RCGI) analyzed eight projects that use natural gas as an electrical power source and concluded that the model can play a vital role in the nation’s energy security. Another benefit is stimulation of the growth of the natural gas network, which is a more advantageous energy source than coal and oil derivatives, in terms of emissions of greenhouse gases and pollutants.
The RCGI headquarters are in the University of São Paulo (USP) and it receives funding from FAPESP and Shell. The article A review of gas-to-wire (GtW) projects worldwide: State-of-the-art and developments was published in March in the prestigious Energy Policy journal.
“The gas-to-wire model allows natural gas to be transformed into electrical power through a vertical process in which all phases are carried out by the same company or consortium,” says Thiago Brito, one of the authors of the article and a post-doctoral student at the University of São Paulo. “This system integrates all stages of the energy chain, from the exploration of natural gas to the generation and commercialization of electrical power.”
According to Brito, this model is usually adopted in countries that have not developed a gas distribution system. “The company or the consortium detects a natural gas reserve, usually located in a remote, hard-to-reach area. Due to the lack of local infrastructure, the investor builds its own infrastructure, including a thermoelectric plant that will basically be supplied by gas from that particular reserve. The project is designed right from the start according to the gas-to-wire (GtW) concept, which can also be called reservoir-to-wire [or reservoir-to-electrical-grid] or gas-to-power. These are different terminologies for the same concept,” he explains.
INNOVATIVE PROJECT – Three of the eight projects analyzed are in Brazil; the others in Asia and Africa. One of them is the Parnaíba Complex, in the State of Maranhão, owned by the Brazilian company Eneva. The project was launched in 2013 and is responsible for 11% of the nation’s gas-fired thermal capacity. It was the first wellhead project in Brazil, that is, GtW plants located next to the gas reservoir. This is a unique project in Brazil for taking advantage of onshore natural gas reserves, since most Brazilian gas reserves are located offshore, especially in the pre-salt region. “In addition to being unique, it is innovative, having broken down several barriers, a major one being the lack of infrastructure for the flow of gas to the consumer, thus providing the nation with low-cost energy security, while mitigating environmental impacts and contributing to local populations,” states Ciro Beltrão, another author of the study.
He adds that another initiative is the Azulão-Ocelot Series, which also belongs to Eneva and went into operation in 2021. In this case, the natural gas extracted from the Azulão field, in the Amazon, is used to generate electricity in the State of Roraima. Without access to the Brazilian electrical power grid, Roraima obtained 100% of its energy from thermoelectric plants powered by diesel oil, which is responsible for elevated levels of greenhouse gas emissions. “Although it is a fossil energy source, natural gas emits less greenhouse gases and pollutants than coal and oil derivatives,” says Brito. He notes that in the case of Roraima there was also the factor of instability. “Since diesel oil was purchased from Venezuela, the political and economic turmoil in that country in recent years ended up compromising the supply of the product.”
Currently, natural gas is transported by trucks with cryogenic tanks that leave the Azulão field and travel about 1,100 kilometers to the Jaguatirica thermoelectric plant in Boa Vista, Roraima. The complex is estimated to have the capacity for generating enough electrical power to supply more than half of the State of Roraima. “In fact, from an economic and environmental point of view, the ideal is for the thermoelectric plant to be close to the gas reserve. However, our article dispels the belief that this is the rule for the gas-to-wire model. In most of the projects studied, the distance exceeded 100 kilometers, since the gas can be transported to the plant via pipelines or trucks, for example.”
Finally, the researchers also looked into the Marlim Azul project, which will likely begin operations in 2023, in the city of Macaé, Rio de Janeiro. As a result of the partnership between Shell and Mitsubishi Hitachi Power Systems, with Pátria Investimentos subsequently joining, the project should generate 565 megawatts, which is power enough to meet the demand of a population of 2.5 million people. Brito enthusiastically states that “Marlim Azul is expected to show that natural gas from the Brazilian pre-salt region, which did not have options for outlets to consumers, can add value via the production of electrical power.”
ANCHOR PROJECT – The oldest project analyzed by the RCGI’s researchers is the Malampaya Deep Water gas-condensate reservoir, in the Philippines, which is a joint venture of Shell, Chevron Texaco, and the Philippine National Oil Company (PNOC). The enterprise began its operations in 2002 and supplies about 13% of the electrical power demand of the Asian country. The gas is extracted offshore, on a Shell oil platform, and sent to a thermoelectric plant 500 kilometers away, in the city of Batangas. The project achieved economic competitiveness by linking the price of gas to fluctuations in the value of petroleum.
Although successful, the Philippine project will likely close, this year, due to depleted gas reserves. Therefore, for the thermoelectric plant to continue operating, a different network must be built to transport gas and biogas from other locations. “In my opinion, that is positive, because it helps to expand the country’s gas network. Of course, this gas can be used for other purposes, such as fuel for vehicles. It is not by chance that the gas-to-wire model can be considered an anchor project, because it can inspire and enable the creation of other projects in the energy sector that take advantage of the original infrastructure,” Brito concludes.