Wave energy converters: Impact on the biosphere
What scientists found when they watched wave machines for harm
What this tab covers Effects on human, animal, plant, fungal and microbial life and on whole ecosystems: in the short term (construction and early years), medium term (operating life) and long term (decommissioning and legacy).Monitoring of single devices and small arrays has found no significant harm, and scientists now treat noise, electromagnetic fields and habitat change as low risk at this scale. Effects of large arrays are unknown.
Life-cycle greenhouse gas emissions (ocean energy) 17 g CO2e/kWh (range 5.6-28)6 Observed entanglements of marine animals None recorded7 Risk status, noise and EMF, small numbers of devices Considered retired (2024 review)7Effects over time
| Life affected | Short term | Medium term | Long term |
|---|---|---|---|
| Humans25 | Offshore installation is hazardous marine work; space is taken from fishing. | No visual impact for submerged devices; possible new marine jobs in coastal communities. | Little evidence of effect. |
| Animals72 | Construction noise and vessel traffic. | Operational noise not likely to harm marine species for small numbers of devices; entanglement in moorings theoretical, never observed; buoys attract fish and seabirds. | Little evidence of effect. |
| Plants72 | Anchors and cables disturb small patches of seabed. | Hulls are colonised by algae (biofouling). | Little evidence of effect. |
| Fungi and soil life7 | Little evidence of effect. | Little evidence of effect. | Little evidence of effect. |
| Ecosystems27 | Small footprint of anchors and cables. | Large arrays would lower wave height at the coast, which could alter beaches and sediment; not detectable for small numbers of devices. | Unknown for commercial arrays. |
How the effects are reduced
Impacts are reduced by careful siting away from sensitive habitat and migration routes, taut moorings to cut entanglement risk, buried or armoured cables, and staged 'deploy and monitor' consents that expand arrays only after monitoring. An IEC technical specification for measuring device noise is being standardised.
Sources
- Wave Energy: Technology Brief IRENA, 2014
- Innovation Outlook: Ocean Energy Technologies IRENA (copy hosted by PNNL Tethys), 2020
- Climate Change 2014: Mitigation, Annex III Technology-specific cost and performance parameters, Table A.III.2 IPCC AR5 Working Group III, 2014
- OES-Environmental 2024 State of the Science Report, Chapter 11: Summary and Path Forward PNNL / Ocean Energy Systems, 2024