In a 2021 interview with the BBC, the royal was challenged about his car-related carbon footprint. He explained that his beloved Aston Martin—his favorite car, which he has owned for more than 50 years—had been converted to run on a “surplus of English white wine and whey from the cheese process.” The type of biofuel he refers to is called E85; it’s composed of 85 percent bioethanol and 15 percent unleaded petrol. The bioethanol in E85 can come from different sources, but in the case of what fuels King Charles III’s Aston Martin, it comes from surplus wine and the alcoholic extraction from fermented whey.
The king has earned some praise for using this newer energy source, but he has also faced criticism. While it’s clear he recognizes the importance of developing energy sources that don’t rely on fossil fuels, critics are not so quick to embrace his choice as the way forward. Biofuel—even when made from food waste—is considered a “niche” energy source that is not scalable for availability to the masses. Experts are quick to point out that using land and resources to produce fuel could lead to massive global food insecurity.
While most of the cars currently used on his estates are electric, King Charles III has voiced concerns about electric cars being unaffordable for many, the impacts of the battery materials required to run them, and how they would be recycled.
King Charles III has a history of supporting environmental and conservation issues and for raising the alarm on climate change. His personal efforts at reducing his own carbon footprint don’t stop at a car that runs on biofuel: They also include switching to biomass boilers at his Birkhall home and installing solar panels at Clarence House. He also makes time to campaign for the use of wool (it’s a fully biodegradable material), has a large organic vegetable garden at his estate at Highgrove, and makes the environment an important part of his mandate as monarch.
However, in his 2021 BBC interview, King Charles III acknowledged that “no one person can solve the problem,” and that everyone must do their part to help the environment. Not everyone needs to drive a car thar runs on wine and cheese, but he suggests people lower their consumption of meat and dairy products, reduce waste, and plant more trees.