​Asset Optimisation

Asset Optimisation

ESB Networks manages a network of assets ranging from the 2.3 million meters in every house in Ireland, to the 400kV substations connecting hundreds of megawatts of generation. Developed over decades, these assets are located in all corners of the country, serving the needs of all Irish electricity customers. 

Technological Developments

As these assets age, and as our customers’ needs change over time, we are working to extend our assets’ useful lives, improve their reliability and maximise the capacity they can provide.  Technological developments are creating new opportunities in how ESB Networks manage the assets, improving: 

  • Efficiency
  • Environmental impact
  • Reliability

The Asset Optimisation innovation roadmap is designed to ensure that ESB Networks take value of advances in asset management technologies, materials and practices to develop a network that provides the services customers want.

With the growing relevance of distributed renewable energy sources (DRES) in the generation mix and the increasingly pro-active demand for electricity, power systems and their mode of operation need to evolve. 

ESB Networks is involved with the evolvDSO project, a collaborative project funded by the European Commission and carried out by a consortium of 16 partners coordinated by Enel Distribuzione. 

EvolvDSO is the development of a method and tools for new and evolving Distribution System Operator (DSO) roles on the basis of scenarios which will be driven by different DRES penetration levels, various degrees of technological progress, and differing customer acceptance patterns.

ESB Networks has installed over 2.2 million poles across the LV & MV networks. These poles have traditionally been creosote wooden poles, however the Department of Communications, Climate Action and Environment banned the use of ‘A oil’ poles in 2000 and has only granted permission for the continued use of ‘B oil’ and ‘C oil’ creosote wood poles up to 2021. Therefore there is a requirement for ESB Networks to find an alternative for creosote wood poles.

The project will include examining Fibre Glass Composite Poles (full length Pole and Modular type Poles), Steel Poles, Concrete Poles, Laminate Poles and Hybrid Poles.

Each Pole alternative will be examined under the following headings:

  • Suitability – ability to climb, durability, installation in various terrains (bog, rock, sand, clays etc.), workability, conductivity, life span
  • Manufacturing capabilities – quality assurance, raw material supplies, ability to manufacture in Ireland and capability to supply large quantities of poles on a regular basis
  • Storage & Transportation
  • Costs

Wind stay wire supports are used in ESB Networks to support poles where the foundations are weak and where end poles/angle poles are used. The stay wires are attached to the top portion of the pole and are anchored into the ground using treated wood that is assembled to make up stay blocks.

ESB Networks are encountering a serious problem using treated wood sleepers as stay blocks. The stay blocks are showing signs of rot after being installed in the ground after only 10 years. It is alleged that the fibre glass stay blocks will last a minimum of 70 years (and maybe up to 80 years as they will be buried underground).

For this project, we have purchase eight 3m x 1m Fibre Glass slabs with the view to testing them as stay blocks in the construction of 110kV Poleset Overhead Lines. A large machine, linked through a stay wire to a dynamometer onto the stay rod will be used to apply the loads to the stay rod and Fibre Glass Pad. The dynamometer in turn will be connected to a laptop which will be used to record the loads.

ESB Networks 38kV overhead line network is currently arc suppressed and requires an arc suppression coil (ASC) in associated 110kV Stations to compensate for these faults. This approach is used to improve the continuity of supply in the event of an earth fault. The existing load dominant networks require relatively small ASCs but new windfarm connections (which require long 38kV underground cable connections) substantially increase the size of ASC required. Typically the cost of an ASC is around 20% of the full installed cost due to the complexity and cost of working in a legacy HV station. If further windfarm connections are later made using 38kV cables, further upgrading of the ASCs may be necessary.

In this project ESB Networks will trial an alternative approach, where instead of upgrading the substation ASC following connection of additional 38kV cable connected windfarms, the compensation required will be associated directly with the specific 38kV cable .  

Whilst ESB Networks’ existing overhead networks have recently been largely converted to 20kV and smaller 5kVA units replaced with 15kVA transformers , the LV still continues in operation at 230V. If there is a very extensive increase in the use of heat pumps and electric vehicles in rural areas the available headroom could be used up in little more than a decade. The question then is how would significant extra capacity be provided at optimal costs?

In considering this issue ESB Networks looked at innovative approaches by other utilities and found that in Finland the existing LV system voltage is boosted to close to 1000V to reduce volt drop and avoid reinforcement. In this scenario, when upgrading transformers, ESB Networks could consider the replacement of existing MV/LV transformers with a transformer with an additional 1000V winding. Normal 230V winding would be used for local loads and 1000V for distant ones. The 1000V systems could then be used to increase the capacity of an LV connection by a factor of 2.5 where the connection is distant from the transformer in rural areas where we anticipate we will see rural EV’s and heat pumps and where LV connected generation is anticipated.

In this project we will assess the costs and complexity of this solution and evaluate the capability of this solution to be adopted here in Ireland in areas of LV network that are rural and are looking to connect significant amounts of new low carbon technologies to the network.

Currently line inspections on our Overhead Transmission Lines are carried out manually. To carry out these inspections the lines need to be switched out and then the inspectors are deployed to carry out visual inspections on all structures and equipment associated with the line by climbing the structure.  This leads to long outages and safety risks for staff.

A specification has been produced by ESB Networks called “Specification for the Inspection of Live 38kV, 110kV, 220kV, 275kV and 400kV Overhead Power Lines using Drones – UAVs” and ESB Networks plan to go out to tender with a view to engaging a Service Provider to inspect all Transmission Lines using drones. 

This will lead to an assessment of the capability of drone inspections to potentially provide a low cost, higher quality method of asset inspection, with better scope to apply data analytics and with greater consistency of data. Associated impacts should be improved asset management resulting in lower costs, more focussed maintenance and refurbishment, with greater reliability and safety.

As part of the Smart Network plan, ESB Networks intend on delivering communication services over operational fibre to backhaul information and potentially control secondary substations. To evaluate this, the Smart Networks team in ESB Networks will liaise with regional offices to arrange for ESB Networks Telecom Services division to install communications equipment and thus verify the cost associated with implementing communications via this technique. The fibre will run alongside already existing network equipment that ESB Networks own. The Smart Network applications will then be implemented over these fibre cables.

Network planning is based on taking load readings and then extrapolating their growth over time to assess when Network reinforcements are required. A problem with this system is that the measured loads are temperature dependent so that changes in load from one year to another may be as a result of changes in temperature rather than as a result of actual growth in load.

A correlation between temperature and load for each MV feeder would be required based on SCADA load data and temperature data from Met Eireann. Wind data could also be included. The relationship between load and temperature is also complicated by the thermal inertia of buildings, so that there can be a lag between temperature and load response.

This project will look at a methodology to calculate the load, temperature and weather conditions for each MV Circuit and assess an appropriate temperature correction factor for each. A baseline temperature corresponding to realistic worst case conditions would then be set and all loads temperature corrected to this reference temperature.

Operation of the Network, both Transmission and Distribution, is simplified if it is known in real-time what line capacity is actually available. Line capacity is strongly influenced by wind speed but in a complicated manner. In Germany, Westnetz and EON have found that by using actual wind speed data in a very conservative manner, they can safely increase line ratings in real-time. This approach arose from a comparison of Dynamic Line Rating measurements and theoretical calculations using average wind speeds, where it was found that if a conservative approach were used then the line rating could be increased with little risk of the rating being incorrect.

As the topography of Ireland is different than that in Germany the amount of wind stations required to perform similar calculations could be much greater, and the fact that wind speeds are less consistent geographically in Ireland than in Germany could again make similar calculations significantly more difficult. However the benefits if available are significant in relation to the potential very low cost in achieving them.