- Columbia marine geophysicist suggests that offshore wind turbines could be paired with carbon capture technology to help reduce carbon dioxide levels in the atmosphere
- Proposal says that excess wind energy could be used to sequester carbon, creating a net reduction in carbon and reducing costs
- Offshore sites offer certain advances, though technological uncertainties remain
Summary by Dirk Langeveld
Growth is ramping up in the offshore wind industry, with several installations planned off the East Coast and the White House setting a goal of 30 gigawatts of new capacity by 2030. While these facilities are designed to provide clean and renewable energy, a Columbia University professor is suggesting that they could play a greater role in combatting climate change if they are paired with carbon capture technology.
David Goldberg, a marine geophysicist and deputy director of Columbia’s Lamont-Doherty Earth Observatory, has done extensive research into offshore sequestration options for carbon dioxide. Goldberg says that while reducing greenhouse gas emissions is an important strategy, it will also be necessary to remove existing carbon dioxide from the atmosphere to address climate change.
Sequestering carbon involves locking it away so it will not escape back into the atmosphere, including in geologic deposits such as basalt where chemical reactions will cause gaseous carbon dioxide to calcify into a solid mineral. The National Energy Technology Laboratory says offshore storage may prove easier than onshore storage, and offer an alternative to onshore storage in areas where this capacity is limited.
Goldberg suggests that pairing offshore wind turbines with carbon capture technology would allow carbon sequestration in subsea natural reservoirs. This process would also help reduce the costs of carbon capture since it would minimize the need for extensive pipelines.
The technology currently available for carbon capture pulls carbon dioxide from the air using filters or liquid mediums, then uses energy to release the carbon to storage and start over. The energy source used in the process must be carbon-free in order to achieve a net reduction in carbon dioxide.
Goldberg says that offshore wind turbines might provide an ideal option, since excess energy produced on days when the turbines create more electricity than what is needed could go toward carbon capture. He says that New York’s goal of establishing 9 gigawatts of offshore energy by 2035 would deliver 27.5 terawatt-hours of energy a year, estimating that 825 megawatt-hours would be excess energy that could be used to sequester about half a million tons of carbon dioxide a year.
Improvements in carbon capture technology would be necessary to fully realize this potential. The systems assume high utilization rates, with greater challenges in powering the systems when surplus wind is not available. Carbon capture technology would also need to be capable of withstanding the harsher conditions in a marine environment.
However, Goldberg recommends that interested parties begin planning now to potentially incorporate carbon capture into offshore wind installations. This work would include surveying for potential storage sites, environmental monitoring processes, and establishing approval processes.
A workshop on accelerating the capture and offshore storage of carbon dioxide, held by Columbia in October 2020, determined that offshore storage offers benefits such as avoiding potential contamination of freshwater and simpler jurisdictions than onshore sites. The report from the workshop also concluded that other renewable power sources could be used at offshore sites, including solar, tidal, or wave power.
However, the report also cited technological challenges with offshore platforms despite significant advances in the field. These include uncertainties about depth capacity, longevity, size, and long-term maintenance requirements.