Egypt’s use of mazut fuel oil in power stations has soared to a five-year high as the country works to increase natural gas exports, according to data seen by Reuters. Figures from the Egyptian Electric Utility and Consumer Protection Regulatory Agency (Egyptera) showed that mazut accounted for almost 21% of all fuel used by power stations in October, the highest since September 2017 when it registered 22.8%.

That’s not all: Data from the Joint Organisations Data Initiative shows that demand for mazut rose to 135k barrels per day in September, the highest since June 2018.

Why are we burning more mazut? To help ease a shortage of foreign currency. Egypt had significantly reduced its use of mazut in recent years but has increased consumption following a decision in August to begin rationing the amount of natural gas used in local power plants. The government wants to make more natural gas available for export, which will bring more hard currency into the country as officials wrestle with the country’s external position.

Cheap… Burning mazut is four times less expensive than burning natural gas priced at the European TTF benchmark, Eugene Lindell, head of refined products at energy consultancy FGE, told the newswire. Refinitiv data shows that Egypt has significantly upped its purchase of discounted Russian fuel oil, enabling it to make “massive” savings, he said.

…but environmentally-costly: Mazut is a low-quality, high-sulfur fuel oil that generates more air pollution when burned than other types of oil.