Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal
To keep global surface warming below 1.5°C by 2100, the portfolio of cost-effective CDR technologies must expand. To evaluate the potential of macroalgae CDR, we developed a kelp aquaculture bio-techno-economic model in which large quantities of kelp would be farmed at an offshore site, transported...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-08-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2022.966304/full |
| _version_ | 1811339348492156928 |
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| author | Struan Coleman Tobias Dewhurst David W. Fredriksson Adam T. St. Gelais Kelly L. Cole Michael MacNicoll Eric Laufer Damian C. Brady Damian C. Brady |
| author_facet | Struan Coleman Tobias Dewhurst David W. Fredriksson Adam T. St. Gelais Kelly L. Cole Michael MacNicoll Eric Laufer Damian C. Brady Damian C. Brady |
| author_sort | Struan Coleman |
| collection | DOAJ |
| description | To keep global surface warming below 1.5°C by 2100, the portfolio of cost-effective CDR technologies must expand. To evaluate the potential of macroalgae CDR, we developed a kelp aquaculture bio-techno-economic model in which large quantities of kelp would be farmed at an offshore site, transported to a deep water “sink site”, and then deposited below the sequestration horizon (1,000 m). We estimated the costs and associated emissions of nursery production, permitting, farm construction, ocean cultivation, biomass transport, and Monitoring, Reporting, and Verification (MRV) for a 1,000 acre (405 ha) “baseline” project located in the Gulf of Maine, USA. The baseline kelp CDR model applies current systems of kelp cultivation to deep water (100 m) exposed sites using best available modeling methods. We calculated the levelized unit costs of CO2eq sequestration (LCOC; $ tCO2eq-1). Under baseline assumptions, LCOC was $17,048 tCO2eq-1. Despite annually sequestering 628 tCO2eq within kelp biomass at the sink site, the project was only able to net 244 C credits (tCO2eq) each year, a true sequestration “additionality” rate (AR) of 39% (i.e., the ratio of net C credits produced to gross C sequestered within kelp biomass). As a result of optimizing 18 key parameters for which we identified a range within the literature, LCOC fell to $1,257 tCO2eq-1 and AR increased to 91%, demonstrating that substantial cost reductions could be achieved through process improvement and decarbonization of production supply chains. Kelp CDR may be limited by high production costs and energy intensive operations, as well as MRV uncertainty. To resolve these challenges, R&D must (1) de-risk farm designs that maximize lease space, (2) automate the seeding and harvest processes, (3) leverage selective breeding to increase yields, (4) assess the cost-benefit of gametophyte nursery culture as both a platform for selective breeding and driver of operating cost reductions, (5) decarbonize equipment supply chains, energy usage, and ocean cultivation by sourcing electricity from renewables and employing low GHG impact materials with long lifespans, and (6) develop low-cost and accurate MRV techniques for ocean-based CDR. |
| first_indexed | 2024-04-13T18:25:01Z |
| format | Article |
| id | doaj.art-f4f9b1b73139409a940f65afec67c3f6 |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-04-13T18:25:01Z |
| publishDate | 2022-08-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-f4f9b1b73139409a940f65afec67c3f62022-12-22T02:35:18ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452022-08-01910.3389/fmars.2022.966304966304Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removalStruan Coleman0Tobias Dewhurst1David W. Fredriksson2Adam T. St. Gelais3Kelly L. Cole4Michael MacNicoll5Eric Laufer6Damian C. Brady7Damian C. Brady8School of Marine Sciences, Darling Marine Center, University of Maine, Walpole, ME, United StatesKelson Marine Co., Portland, ME, United StatesDepartment of Naval Architecture and Ocean Engineering, United States Naval Academy, Annapolis, MD, United StatesAquaculture Research Institute, Darling Marine Center, University of Maine, Walpole, ME, United StatesDepartment of Civil and Environmental Engineering, University of Maine, Orono, ME, United StatesKelson Marine Co., Portland, ME, United StatesConscience Bay Research, LLC New York, NY, United StatesSchool of Marine Sciences, Darling Marine Center, University of Maine, Walpole, ME, United StatesAquaculture Research Institute, Darling Marine Center, University of Maine, Walpole, ME, United StatesTo keep global surface warming below 1.5°C by 2100, the portfolio of cost-effective CDR technologies must expand. To evaluate the potential of macroalgae CDR, we developed a kelp aquaculture bio-techno-economic model in which large quantities of kelp would be farmed at an offshore site, transported to a deep water “sink site”, and then deposited below the sequestration horizon (1,000 m). We estimated the costs and associated emissions of nursery production, permitting, farm construction, ocean cultivation, biomass transport, and Monitoring, Reporting, and Verification (MRV) for a 1,000 acre (405 ha) “baseline” project located in the Gulf of Maine, USA. The baseline kelp CDR model applies current systems of kelp cultivation to deep water (100 m) exposed sites using best available modeling methods. We calculated the levelized unit costs of CO2eq sequestration (LCOC; $ tCO2eq-1). Under baseline assumptions, LCOC was $17,048 tCO2eq-1. Despite annually sequestering 628 tCO2eq within kelp biomass at the sink site, the project was only able to net 244 C credits (tCO2eq) each year, a true sequestration “additionality” rate (AR) of 39% (i.e., the ratio of net C credits produced to gross C sequestered within kelp biomass). As a result of optimizing 18 key parameters for which we identified a range within the literature, LCOC fell to $1,257 tCO2eq-1 and AR increased to 91%, demonstrating that substantial cost reductions could be achieved through process improvement and decarbonization of production supply chains. Kelp CDR may be limited by high production costs and energy intensive operations, as well as MRV uncertainty. To resolve these challenges, R&D must (1) de-risk farm designs that maximize lease space, (2) automate the seeding and harvest processes, (3) leverage selective breeding to increase yields, (4) assess the cost-benefit of gametophyte nursery culture as both a platform for selective breeding and driver of operating cost reductions, (5) decarbonize equipment supply chains, energy usage, and ocean cultivation by sourcing electricity from renewables and employing low GHG impact materials with long lifespans, and (6) develop low-cost and accurate MRV techniques for ocean-based CDR.https://www.frontiersin.org/articles/10.3389/fmars.2022.966304/fullkelp aquaculturelevelized cost analysisCarbon Dioxide Removal (CDR)CDR MonitoringReportingand Verification (MRV) |
| spellingShingle | Struan Coleman Tobias Dewhurst David W. Fredriksson Adam T. St. Gelais Kelly L. Cole Michael MacNicoll Eric Laufer Damian C. Brady Damian C. Brady Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal Frontiers in Marine Science kelp aquaculture levelized cost analysis Carbon Dioxide Removal (CDR) CDR Monitoring Reporting and Verification (MRV) |
| title | Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| title_full | Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| title_fullStr | Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| title_full_unstemmed | Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| title_short | Quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| title_sort | quantifying baseline costs and cataloging potential optimization strategies for kelp aquaculture carbon dioxide removal |
| topic | kelp aquaculture levelized cost analysis Carbon Dioxide Removal (CDR) CDR Monitoring Reporting and Verification (MRV) |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2022.966304/full |
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