Contact between overhead (OH) lines and wildlife causes considerable disruption to electricity supplies, damage to plant and apparatus resulting in costly repairs as well as causing death or injury to the wildlife making contact.
From figures obtained from the National Fault and Interruptions Reporting Scheme (NAFIRS) and WPD systems it is estimated (pro rata) that it is costing the UK distribution and transmission companies in excess of £10M per annum in terms of the Customer Minutes Lost (CMLs) and Customer Interruptions (CIs) and to carry out repairs. These contacts also cause thousands of wildlife deaths through electrocution or collision.
The scope of the project is to carry out research on the interaction of wildlife with OH lines / structures in order to design, develop and produce a suite of UK and Ireland specific mitigation measures and a risk assessment (RA) Software App which will provide member companies / end users with guidance on the most cost-effective way of minimising wildlife contact.
Conservative estimates suggested that the UK distribution companies experience 1000s of wildlife contacts that damage equipment at a cost of over of £10M per annum. If successful and implemented by member companies it is estimated that UK distribution companies could save in the region of £5M to £8M per annum.
Stage one of the Wildlife Protection project successfully carried out research on the types of wildlife that interact with overhead networks, the impact their interactions have, before moving on to demonstrating existing measures that are available and the standards in place to support these. This confirmed that there are currently no standards in place within the UK that support protection against wildlife interactions, but there is a clear need for schemes to be in place.
Following this, the project went on to design and test measures for mitigation wildlife interactions on the network, including electrical and non-electrical interactions, and those from the ground as well as in the air. This led to the following main conclusions and recommendations:
This project has been able to identify a range of cost-effective wildlife mitigations which can reduce both the likelihood and potential effects of wildlife interaction with HV overhead lines.
The range of wildlife interaction mitigations identified contain both long standing engineering solutions and more modern ecologically based approaches.
The project found that wildlife protection schemes should be clear about which species they are targeting, and the specifics of their interaction modes.
The project has been able to develop a risk assessment app, which can support the selection and justification for implementing wildlife protection schemes.
The approach to wildlife protection schemes needs to become proactive for it to be successful, implemented at construction or asset replacement stages, and would benefit from being supported by a specific national standard document.
A national standard document would remove the need for networks to be guided by manufactures and suppliers of wildlife protection products and devices, whose claims historically have often been unsubstantiated.
Overall the project can be deemed a success, with significant parts being transferred into our BAU processes both during and following the project.
The project produced a number of reports and outputs during its lifecycle including the research phase report, design solutions report, product specification, trial report, risk assessment app and user guide, and a closedown report. These are available on www.westernpower.co.uk/projects/wildlife-protection
The key points of learning from the project have been summarised below. Some points are recommendations at this stage and will be progressed with the ENA Members over the coming months. This is with the aim of policy and training changes.
The accuracy of wildlife / overhead line interaction reporting is not considered to be particularly accurate, as events are not always fully investigated, and it is not always possible to identify a direct root cause of events.
The effects of wildlife interactions with overhead power lines can have a marked effect upon the populations of some wildlife species
Network operators already have a large range of options available to them when seeking to improve network performance/system reliability. Many of these solutions can be used to reduce rates of wildlife interaction and improve the outcomes of wildlife interaction
ENA member organisations do not have established methods or techniques by which they evaluate the effectiveness or value of wildlife interaction mitigation investments
Overhead lines which are supported by pin insulators in a flat horizontal formation present a particularly high risk to large birds and raptors. Structures such as loop poles or transformer poles which support carry-over jumpers are considered to be the most dangerous
The conclusions drawn from research studies are deemed to be credible
Wildlife interactions with HV overhead lines would be considered to be a suitably emotive subject which, if not carefully managed, is likely to generate a high volume of unwanted social media attention, bad publicity and reputational damage directed towards ENA member companies.
Many of the current processes and procedures used by ENA member organisations did not consider wildlife protection as one of the main priorities when engaging in activities involving overhead lines
There does not appear to be an electricity supply industry standard for wildlife protection devices, wildlife protection mitigation schemes, or their application to either electrical transmission or distribution systems in Great Britain
There does not appear to be an electricity industry standard for the design of freestanding transformer poles or cable connected H-poles/Loop poles which takes wildlife interaction into consideration.
The Wildlife Mitigation Evaluation Assessment tool developed as part of this project should provide an appropriate starting point to enable ENA project member organisations to undertake more detailed organisationally specific analysis.
Clear conflicts between the mitigation approaches for different species exist – for example wildfowl and birds of prey
Mitigations identified should be included within any wildlife mitigation decision support tool or ‘app’ which may be developed in future project works.
There was not a UK standard for wildlife protection products designed or intended for use within the utility or high voltage electrical distribution sector
There is an extremely wide range of wildlife products, applications, and materials available, and it has not been possible to identify appropriate product quality or type tests for every product type variant. This makes the task of determining a definitive specification requirement impossible.
The area of wildlife product type testing required further development.
ENA member companies have traditionally been guided by the manufacturers and suppliers of wildlife protection products and devices, whose claims historically have often been unsubstantiated
Wildlife interaction considerations did not feature within the majority of ENA member company’s standard overhead construction specifications, and are therefore unlikely to form part of the primary decision making criteria when making investment decisions