Last year DTE Energy made an industry-leading commitment to reduce carbon emissions by more than 80 percent by 2050, largely by decreasing greenhouse gas emissions from its coal-fired electric generation plants. The company is now emerging as an industry leader in reducing emissions of another greenhouse gas – methane – by more than 80 percent by 2040.
While methane accounts for about 10 percent of total greenhouse gas emissions, it traps much more planetary heat than carbon dioxide. According to the Intergovernmental Panel on Climate Change, methane warms the planet by 72 times as much as carbon dioxide over a 20-year time period.
DTE is systematically reducing methane leaks from its natural gas operations by replacing miles of aging steel and cast iron pipelines with new, safer air-tight materials as well as through maintenance upgrades at DTE gas compressor stations. Natural gas compressors are industrial pumps that pressurize gas for transmission through gas mains. In 2015, DTE analyzed the 48 compressor units it operates in 10 locations and implemented a plan to reduce fugitive methane emissions from those units by 80 percent over five years.
“We estimate that our methane reduction program will reduce CO2-equivalent emissions by about 16,300 metric tons per year,” said Mark Stiers, president and chief operating officer of DTE Gas. “Using the EPA greenhouse gas calculator, that would be equivalent to greenhouse gas emissions from 3,490 passenger vehicles in one year, or the CO2 emissions from the energy use of 1,760 homes for a year. We’re proud to be taking on methane reduction as part of our climate change solution. In 2016, we cut methane emissions from our compressor station engines by 93 percent from the year before. And last year we nearly doubled the EPA-recommended replacement rate of aging steel and iron pipelines.”
DTE is an active partner in the Environmental Protection Agency’s Methane Challenge Program to reduce methane emissions. While the EPA recommends that Methane Challenge Partners like DTE minimally replace 1.5 percent of older pipeline materials each year, in 2016, DTE replaced 2.8 percent, accelerated the pace to 3.8 percent in 2017 and this year will achieve a 3.9 percent replacement rate. “Replacing our older pipelines with polyethylene tubing and epoxy coated high-strength steel for transmission lines is dramatically reducing methane emissions at an industry-leading pace,” said Stiers.
Much of the nation’s gas distribution system consists of older steel and cast iron pipelines, some as old as 60 years. While these pipelines have provided safe and reliable natural gas for generations, they can rust and, along with underground pressure and movement, small leaks occur, allowing methane to escape into the atmosphere.