Abstract
Sustainable production of algae will depend on understanding trade-offs at the energy-water nexus. Algal biofuels promise to improve the environmental sustainability profile of renewable energy along most dimensions. In this assessment of potential US freshwater production, we assumed sustainable production along the carbon dimension by simulating placement of open ponds away from high-carbon-stock lands (forest, grassland, and wetland) and near sources of waste CO2. Along the water dimension, we quantified trade-offs between water scarcity and production for an 'upstream' indicator (measuring minimum water supply) and a 'downstream' indicator (measuring impacts on rivers). For the upstream indicator, we developed a visualization tool to evaluate algae production for different thresholds for water surplus. We hypothesized that maintaining a minimum seasonal water surplus would also protect river habitat for aquatic biota. Our study confirmed that ensuring surplus water also reduced the duration of low-flow events, but only above a threshold. We also observed a trade-offbetween algal production and the duration of low-flow events in streams. These results can help to guide the choice of basin-specific sustainability targets to avoid conflicts with competing water users at this energy-water nexus. Where conflicts emerge, alternative water sources or enclosed photobioreactors may be needed for algae cultivation.
| Original language | English |
|---|---|
| Article number | 836 |
| Journal | Water (Switzerland) |
| Volume | 11 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2019 |
Funding
Funding: We thank Department of Energy’s (DOE) Bioenergy Technologies Office and Devinn Lambert, program manager for funding this work. Part of this this research, carried out at the Jet Propulsion Laboratory, California Institute of Technology, was under a contract with the National Aeronautics and Space Administration, copyright 2018 California Institute of Technology. We greatly appreciate Andre Coleman and MarkWigmosta (PNNL) for their collaboration in this research, which included providing BAT simulation results for our analysis. This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the US DOE. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). We appreciate a collegial review by Teresa Mathews and reviews by two anonymous reviewers. We thank Department of Energy's (DOE) Bioenergy Technologies Office and Devinn Lambert, program manager for funding this work. Part of this this research, carried out at the Jet Propulsion Laboratory, California Institute of Technology, was under a contract with the National Aeronautics and Space Administration, copyright 2018 California Institute of Technology.
| Funders | Funder number |
|---|---|
| Department of Energy’s | |
| U.S. Department of Energy | |
| National Aeronautics and Space Administration | |
| California Institute of Technology | |
| Bioenergy Technologies Office |
Keywords
- Algal biofuels
- Bioenergy
- Energy-water nexus
- Instream flow
- Sustainability indicators
- Trade-offs
- Visualization
- Water allocation
- Water scarcity
- Water temperature
