# Ocean waves: Impact on nature

Tiny land footprint, but what about marine life?

Source page: https://www.materialinsights.org/energy/e_waves/nature/

What this tab covers What taking energy from this source does to land, water, air and climate, wildlife and ecosystems, with life-cycle emissions and land use where measured.

Wave energy devices have low life-cycle emissions (IPCC AR5 median 17 g CO2e/kWh for pre-commercial ocean technologies) and almost no land footprint. Their likely effects are local: changes to waves reaching the shore, interaction with marine life, and exclusion of other sea users.
 Life-cycle emissions 17 (median) g CO2e/kWh^[7](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) Life-cycle, IPCC AR5 category 'ocean (tidal and wave)', listed among pre-commercial technologies; range 5.6 to 28. Few devices have been studied, and NREL's harmonisation project did not publish a harmonised ocean median.

#### Effects on nature

| Area | Effect | Size | How it is reduced |
|---|---|---|---|
| **Climate** | Emissions from steel and concrete structures, installation and maintenance vessels.^[7](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) | IPCC AR5 ocean energy (wave and tidal, pre-commercial): median 17, range 5.6 to 28 g CO2e/kWh. | Longer device lives; integrate into breakwaters to share structures. |
| **Coast and seabed** | Arrays remove energy, so waves behind them are smaller, which can change sediment transport and shoreline erosion.^[6](https://www.energy.gov/sites/prod/files/2021/02/f82/78773_3.pdf) | The US assessment assumes arrays deplete waves to 8 kW/m as they pass through. | Siting and spacing studies; this effect can also protect coasts. |
| **Marine life** | Possible collision, entanglement in moorings, underwater noise and habitat change around devices.^[3](https://html.rhhz.net/jmsa/html/20250104.htm) | Not yet quantified at commercial scale; risk-assessment tools such as WEC-ERA map pressures for different converter types. | Environmental risk assessment and monitoring before scale-up. |
| **Land and shoreline** | Most devices are offshore; shoreline plants can be built into existing harbour walls.^[3](https://html.rhhz.net/jmsa/html/20250104.htm) | Mutriku's 14 units are housed in a breakwater. | Use of existing coastal structures. |

Because so few wave devices have operated for long, their environmental effects are known mainly from small demonstrations and models. Emissions are low, there is no fuel and no air pollution, and land use is negligible. The effects that matter are at sea: arrays calm the water in their lee, which could alter beaches and sediment, and moorings, cables and noise interact with fish, seabirds and marine mammals. Exclusion zones can also displace fishing and shipping.

#### Sources

1. [Review of Wave Energy Resource Characterisation, Metrics, and Global Assessments (Ramos-Marin and Guedes Soares, Journal of Marine Science and Application 24, 53-75)](https://html.rhhz.net/jmsa/html/20250104.htm) Springer / Harbin Engineering University, 2025
2. [Marine Energy in the United States: An Overview of Opportunities (Kilcher, Fogarty and Lawson, NREL/TP-5700-78773)](https://www.energy.gov/sites/prod/files/2021/02/f82/78773_3.pdf) National Renewable Energy Laboratory / US DOE, 2021
3. [Climate Change 2014: Mitigation, Annex III Technology-specific cost and performance parameters (Schlömer et al.), Table A.III.2, p. 1335](https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7) IPCC AR5 Working Group III, 2014

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_waves/index.md)
- [Overview](https://www.materialinsights.org/energy/e_waves/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_waves/correlation/index.md)
- [How energy resides](https://www.materialinsights.org/energy/e_waves/resides/index.md)
- [Abundance](https://www.materialinsights.org/energy/e_waves/abundance/index.md)
- [Fluctuation in time](https://www.materialinsights.org/energy/e_waves/time/index.md)
- [Across the Earth](https://www.materialinsights.org/energy/e_waves/geography/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_waves/links/index.md)