Wave energy converters: three ways to capture moving water
By the Vrulum team
Wave energy is a resource; a wave energy converter is a particular machine designed to capture some of it. Different mechanisms should not be combined into one assumed performance curve.
Scope: an explanation of three device concepts and the evidence needed to compare them. Sources checked on 23 October 2026. This article makes no claim about a named project's UK commissioning date or commercial return.
Different mechanisms, different questions (definitions)
The US Department of Energy: marine-energy glossary defines a wave attenuator as a device whose principal axis lies parallel to the direction of the incoming wave; passing waves cause relative motion of the device, which is converted into energy. An oscillating water column is a partially submerged structure in which waves make a column of water rise and fall, pushing or pulling the air above it through a turbine. An overtopping device funnels waves that pass over the top of its structure into a reservoir; the water then runs through a turbine and back out to sea.
The glossary also lists other wave devices, including point absorbers, oscillating wave surge converters and pressure differential devices. We cover three here as examples.
These definitions establish how concepts differ. The glossary does not provide an independent annual-output or cost comparison for commercial machines.
Separate capture from delivery (editorial questions)
The questions in this and the following sections are our editorial framework for comparing evidence. They do not assert that any developer has failed to supply it.
When a developer reports output, identify the point of measurement. Ask whether it describes a component, a complete device or electricity delivered beyond the connection equipment.
Ask for the operating conditions and duration. A selected high-output period is not the same record as an independently described full-year result.
Follow the deployment record
Distinguish a tank experiment, a sea trial, a grid connection and routine service. Record the actual device and test setting beside every result.
For a named proposal, examine installation, maintenance access, retrieval and the relevant environmental permissions. Ask what the demonstrated result says about those tasks and what remains a plan.
Keep company schedules attributed and dated. Do not turn a programme announcement or funding award into a Vrulum prediction of widespread use.
What matters to a UK reader?
A useful local project dossier would connect the converter identity, public permissions, actual deployment and independently documented operating history. Site-specific evidence matters more than turning a resource estimate into a national electricity promise.
Evidence assessment: the government glossary supports the mechanism descriptions. No device winner, energy-price estimate or readiness percentage follows from those definitions. The next research step is one identified converter with a transparent operating record, including interruptions and maintenance rather than only its strongest demonstration.
Sources
Checked on 23 October 2026.
Related reading
Sources
Checked against its sources by Claude (check-and-publish session).