We are pleased to share a new open-access publication associated with the SHY Project, now available on Zenodo:
“Analysis of weather windows and impacts of time to repair on device availability (at two Wavepiston deployment sites)”.
In wave energy, performance is not only about how much energy a device can capture—it is also about how often it is actually available to operate. Offshore, that availability is strongly influenced by a very practical constraint: when you can safely access the device to perform maintenance.
This paper focuses on that real-world challenge by analysing how weather windows (periods when sea conditions allow safe access) and time to repair combine to affect overall device availability, considering realistic operation & maintenance (O&M) constraints.
What are “weather windows” and why do they matter?
A weather window is a time interval when conditions—primarily significant wave height (and, in some cases, wind)—are mild enough for vessels and technicians to reach the device and carry out an intervention safely. If there is no suitable window, even a minor fault may lead to longer downtime, simply because the repair must wait.
What does the study analyse?
The work performs a weather-window analysis using metocean data and applies it to two candidate Wavepiston deployment sites. It estimates accessibility and waiting times between intervention opportunities, and explores how operational constraints can change outcomes. A key aspect considered is that offshore interventions are often limited to daylight hours—a “good” weather window may not be usable if it does not overlap sufficiently with daylight.
Key findings
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Availability depends on access, not only failures. Downtime is driven not just by repair duration, but also by the waiting time until conditions allow access.
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Operational thresholds can strongly change accessibility. Adjusting criteria such as Hs limits can significantly affect how frequently and how long safe access windows occur—shaping the overall O&M strategy.
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Daylight constraints matter. Restricting interventions to daylight hours can reduce the number of usable windows, impacting waiting times and availability estimates.
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Better O&M planning supports higher real-world energy output. Robust accessibility and waiting-time estimates help improve maintenance planning, logistics, and reliability targets—especially relevant for technologies moving from development into demonstration.
Read the full paper (open access)
Zenodo record: https://zenodo.org/records/18631384
DOI: https://doi.org/10.5281/zenodo.18631384