Producing electricity generates a lot of waste heat – “lost” energy that is a byproduct of providing useful power. As Scientific American notes, “For every one unit of energy that is converted into electricity in power plants today, two units of energy are thrown away.” Similarly, running large refining and chemical operations to create the products consumers rely upon generates tremendous amounts of excess heat.
To ExxonMobil engineers, that lost heat offers opportunity: What if we captured the heat produced at our facilities and recycle it for further use?
One approach we use to capture this lost heat is called cogeneration, and we’ve employed it at more than 100 installations at more than 30 locations across the globe.
With cogeneration we capture the waste heat and utilize it for our manufacturing processes, resulting in a reduced need for boilers, not to mention the fuel that goes with those boilers.
Because cogeneration is so obviously energy efficient, its use leads to cost savings as well as reduced greenhouse gas emissions. In fact, ExxonMobil’s cogeneration plants reduce greenhouse gas emissions by more than 6 million metric tons a year.
Over the past decade, we have added more than 1,000 megawatts of cogeneration capacity, and now have interests in approximately 5,500 megawatts overall. That’s equivalent to the energy needed to power 2.5 million U.S. homes.
There’s more to come. Last year we began construction of a new 84-megawatt cogeneration facility at our Singapore refinery and chemical complex, which will bring total capacity to over 440 megawatts.
To get a better sense of the use of cogeneration at ExxonMobil facilities, check out this recent Energy Factor story on operations at our Baytown refinery and chemical complex.