To decarbonize by 2040, try renewable natural gas

With the ink barely dried on Connecticut's 2022 legislative session, a few key issues clearly made legislators' priority list — students' mental health and combatting juvenile crime both earned the support of bipartisan majorities and words of affirmation from the governor. But as the clock ticks another year closer to 2040, by which point policymakers want to see carbon-neutral energy, some legislators are entrenched in the same partisan stonewalling, with Democrats advocating for renewables and electrification and Republicans worrying about the costs of implementation.

To break through these age-old barriers, policymakers should consider that sometimes the best way to tackle is a new problem is with the toolbox you already have. Decarbonization can be done with proven, existing technologies that we know work by incrementally infusing natural gas with non-carbon fuel sources, namely, green hydrogen and renewable natural gas, or RNG. Rather than focusing only on solar and wind, Connecticut policymakers should adopt an all-of-the-above approach, because improving, rather than eliminating, natural gas can lower costs and assure investors while playing a key role in a holistic decarbonized framework.

Legislators have already begun to consider the role hydrogen can play in a decarbonized Connecticut; for instance, House Bill 5200 was introduced to create a task force to study how Earth's most abundant element can help reach net-zero energy goals. While hydrogen is currently most often made through separation from methane, which takes a lot of carbon-based energy to do, green hydrogen is made by separating hydrogen from oxygen molecules in water through electrolysis, which can be done using wind or solar power. When hydrogen gas is burned for energy, the main byproduct is water vapor, so from start to finish, hydrogen can be completely carbon-free. It also offers longer energy storage than batteries do, and it's already being used, for example, to power some forklifts.

But like all forms of energy, hydrogen isn't a one-sizefits-all solution. It's highly flammable and prone to leaks because its molecules are so much lighter and smaller than natural gas. This is especially relevant when hydrogen is transported in existing pipelines, which were constructed with different fuels in mind. To compensate for these risks, at least one utility company recommends fuel made of 20 percent hydrogen and 80 percent natural gas, increasing the relative amount of hydrogen over time as storage and transmission technologies improve. Environmental experts are split on this idea: some say incrementalism is positive, while others contend it's just a way for utilities to “greenwash” the continued use of carbonized natural gas.

Thus, while green hydrogen can be an element of decarbonization, it's not alone: renewable natural gas also offers considerable promise to policymakers. RNG transforms the methane biogas produced as a byproduct in landfills and livestock farms into an energy source. Because RNG leaves natural gas in the ground, instead utilizing organic emissions that would be released anyway, the Environmental Protection Agency considers it carbon-neutral, though some environmental groups reject this characterization in favor of cleaner (but weatherdependent) sources like solar and wind. Still, the growth of RNG content in natural gas is already rapidly expanding around the world. Denmark, for example, supplements its wind turbine energy with RNG-infused natural gas. Because RNG utilizes existing natural gas infrastructure, Denmark has been able to increase RNG from 0 percent of natural gas six years to ago to nearly a quarter today.

It's a positive sign that Connecticut policymakers pursued a variety of decarbonization tactics in 2022, including changes to solar energy programs, increasing the number of electric cars on the road, and even beginning to study the role green hydrogen could play in replacing natural gas across the state. But to achieve the ambitious goal of net-zero energy in 18 years, legislators should also look to encourage the use of renewable natural gas and other alternative energy sources that utilize, rather than replace, existing technologies, because an all-of-the-above approach will create a netzero future more quickly and with fewer financial burdens on Connecticut residents.