Requirements of a scalable approach to decarbonizing the world

National debate about a green economy has so far mostly ignored a key issue: Practical strategies to decrease carbon use must work within the existing, multi-trillion-dollar energy infrastructure. This investment includes, for instance, 115,000 gas stations, 2.4 million miles of fuel pipeline and 275 million vehicles. Fortunately, we can build a decarbonized society on this infrastructure by continuing to plug in clean energy sources.

Two largely independent, multi-trillion-dollar production and distribution systems dominate world energy today, bringing electricity to homes and businesses and providing hydrocarbon fuels for transportation and other purposes. To be practical, a low-carbon economy must use these two systems, electricity and hydrocarbons, because they are simply too embedded in society to replace.

The existing electricity system requires investment and modernization, but it fundamentally works. We are already plugging in power from renewable resources such as solar, and this system can become greener by adding more low-carbon energy. This can come from more renewable energy, or by capturing the carbon dioxide from hydrocarbon sources.

Similarly, the hydrocarbon fuel system can become greener by replacing naturally occurring fuels with manufactured, renewable hydrocarbons. Synthetic hydrocarbons can be used to produce gasoline, jet fuel or natural gas to power existing vehicles, aircraft or HVAC systems. In contrast, the “hydrogen economy” has limited practicality, not for technical reasons, but because it requires building out a new infrastructure.

{mosads}Synthetic fuels and renewable electricity can be used alongside energy produced by traditional means, allowing them to be seamlessly added to existing distribution systems incrementally. That makes the pipelines, gas stations and vehicles — and the people behind them — part of the solution, creating potential supporters whose jobs and economic interests are preserved in a decarbonized world.

Massive reductions in carbon emissions with minimal societal disruption require these three steps:

1. Invest in electric power, increasingly from low-carbon energy sources. Growing the use of electricity is a powerful way to utilize low-carbon energy sources by building on an enormous existing infrastructure. We can simply add power from renewable sources into the electric grid. However, policymakers should avoid setting artificial electrification goals, such as a mandated phase out of internal combustion engines in favor of electric vehicles — leave that to the market.

2. Reduce the costs and risks of carbon capture and storage. Capturing carbon dioxide from hydrocarbon combustion is viable and scalable, as significant commercial facilities have shown, but financial risks to investors must be lowered. Carbon capture is the only way the owners of hydrocarbons can participate in a decarbonized society. 

3. Promote renewable “drop-in” fuels. Systems requiring massive up-front replacement costs, such as hydrogen, should be avoided in favor of renewable hydrocarbons that can be incrementally deployed. Leveraging existing hydrocarbon industries could allow hydrocarbon fuels to follow the lead of renewable electricity, dropping new sources into existing infrastructure.

Low-carbon solutions must integrate into existing systems, be scalable, and be incrementally deployable. This decarbonization strategy could engage a broad political constituency while minimizing economic disruption. Doing so will leave a cleaner planet for our children and grandchildren.

Tim Lieuwen is the David S. Lewis Jr. professor and the executive director of the Strategic Energy Institute at Georgia Tech. He is a member of the National Academy of Engineering.