High priority: can a human-robotics hybrid make wind farms safer?

The recent deaths of two workers have focused attention on safety at UK wind farms. Julian Turner talks to Kate Harvey of the Global Offshore Wind Health and Safety Organisation, and David Flynn and Keith Brown, two engineers working on a human-robotics hybrid solution for offshore farms, to find out what can be done to improve safety.

Kate Harvey is general manager at the Global Offshore Wind Health and Safety Organisation (G+). She began her career at RWE npower and worked at Entec UK and SSE, before being seconded to G+.

David Flynn and Keith Brown are associate professors at Heriot-Watt University in Edinburgh, UK. They are part of a consortium of experts working on a £4.5m project to deliver a human-robotics hybrid solution for the maintenance and operation of offshore wind farms.

Julian Turner: What health and safety (HSE) risks are workers exposed to during wind farm construction, maintenance and repair projects?

Kate Harvey: G+ was established in 2011 the wake of a fatal incident at the Greater Gabbard wind farm. Thankfully, the industry suffered no fatalities in 2016, but lifting and manual handling, working at height and in confined spaces, and dropped objects continue to be safety issues.

Some offshore wind projects also include a lot of onshore civil work. Companies don’t tend to work to the same standards that we insist on offshore and so this is an area where incidents can occur.

Cable laying and sub-section construction can also be risky. Balfour Beatty was fined £2.6m after an employee was killed while carrying out onshore cable works. BB had been warned that the shoring on the cable corridors was inadequate.

JT: Two wind farm workers recently died in separate incidents in Scotland. What needs to be done to ensure that similar tragedies are prevented?

David Flynn & Keith Brown: Offshore infrastructure is inherently complex and yet present sensing solutions are often basic. Current remote condition and process monitoring (CPM) applications target only sub-systems such as gearboxes and generators with sensors suited to such a limited task.

As a result, at present direct human intervention and inspection is often required and maintenance procedures are expensive and potentially dangerous. Avoiding direct human intervention is key to reducing costs and managing safety in the harsh offshore environment.

The project at Heriot-Watt will formulate a multi-physics, knowledge-driven prognostics/diagnostic model of the wind farm. Integrating sub-systems and different physics-based modelling domains (electrical, thermal, mechanical, lifetime/aging) will provide a much improved understanding of what is happening across the farm and integrate disciplines traditionally operated as independent ‘silos’.

Secondly, this knowledge-based model will be validated against real-world and experimental data, and a data-analytics driven model interconnecting performance and diagnostic information from previously isolated sub-systems.

Thirdly, the project will identify complementary advanced sensing methodologies such as automated and robotic inspection to fill in system information gaps, improve the quality of information available and reduce manual on-site inspection. The ultimate goal is an automated diagnostic and prognostic suite of integrated tools in order to better manage windfarm operation and maintenance (O&M).

JT: How can new technologies such as human-robotics hybrids and drones improve safety levels?

KH: G+ runs ‘Safe by Design’ workshops each year covering everything from marine access and transfer to the standardisation of boating landings and lifts on turbines, known as man-riding hoists.

We approached post-graduate students working in the Renewable Energy Marine Structure (REMS) programme at Cranfield University and Oxford University to look at human-free lifting. The students are collating the results of G+ survey on the subject and looking at ways to remove people from lifting operations and automating them.

One of the most recent workshops focused on how future technology could make the use of davit cranes safer with a view to eventually replacing them altogether. G+ members are also working with the specialist drone company Cyberhawk to investigate the use of unmanned aircraft to survey and detect faults on offshore wind infrastructure including the turbine blades.

DF & KB: To further remove human intervention, where possible, robots and automation provide a degree of flexible sensing and intervention. The HOME-Offshore consortium will bring together and consolidate theoretical underpinning research in different subject areas and at different universities.

Currently there are no technologies to undertake a detailed and in-situ assessment of subsea cable integrity. The Heriot-Watt research project will investigate multilayer co-centrical scattering theory for subsea cable structures processing data from a bio-inspired low frequency sonar. The integration of techniques into a streamlined suite of tools within a monitoring framework is a major challenge.

JT: What can offshore wind operators learn from the oil and gas industry when it comes to safety?

KH: The main difference between wind and oil and gas is that we have a greater range of assets out there in the field. The oil industry may have just one platform, but an offshore wind farm comprises hundreds of turbines. People also work at extreme heights and there are more vessel transfers.

However, the wind industry is relatively new compared with oil and gas, which has been around for 70 years, and we are learning from both operators and trade bodies.  For example, G+ is becoming a member of the Dropped Objects Prevention Scheme (DROPS) in order to share data and expertise.

G+ requires its members to provide all of their offshore health and safety data − a big deal for the energy industry – and we collate that into an annual HSE report released into the public domain.

JT: How will improved O&M give the UK a competitive advantage in the offshore energy market?

DF & KB: An improved O&M strategy will reduce costs to UK tax and bill payers by increasing the lifetime of the multi-billion UK offshore asset base. Currently, the O&M of these offshore assets is undertaken in a very primitive manner. Moving to condition-based maintenance where data from appropriate sensors is used in prognostic systems will reduce maintenance costs, increase asset lifetime and reduce the need for personnel working in the hazardous offshore environment. A public demonstration of the research outcomes will take place at Salford Quays in Manchester.

KH: At G+ we engage with over 200 stakeholders in the wind energy supply chain including OEMS and suppliers such as vessel and cable companies, plus trade associations and government bodies.

In the past we have been quite UK-focused, but we have moved into Europe – particularly Denmark and the Netherlands − and our next target is Germany, where the wind industry is very different. After that we plan to engage with the US, Japan and China; ultimately, we want a set of safety good practice guidelines related to wind operation and maintenance that can be rolled out globally.