​​Connecting Renewables

Connecting Renewables

ESB Networks is committed to playing a leading role in enabling Ireland’s transition to a low carbon energy future, powered by clean electricity.
Each year sees more renewable energy sources connected to the electricity network to support the goal of minimising the amount of carbon produced. By 2030, it has been forecast that ESB Networks will have connected over 8GW of renewable generation.

​Supporting new technologies

Our key challenge is to support the efficient transition of these new technologies onto the electricity network while maintaining the current levels of resilience and security of network.

To date large-scale onshore windfarms have provided the main source of renewable generation. Over recent years we have also seen new Distributed Energy Resources (DER) apply for and connect to our network. These new technologies include grid-scale solar Photo Voltaic (PV), Combined Heat and Power (CHP) and biomass. These technologies are now developing market momentum.

We aim to examine the impact of increased connection of non-domestic DER and renewables on our future electricity system, and establish how our planning standards and policies need to evolve to support their connection, in the most economic method possible. 

As we connect more DER such as renewables and energy storage onto our distribution network we need to ensure this is done in the most cost effective way while maintaining a safe, secure and stable system. This can only be done by first determining what capacity is available on our network.

The DistriHost project is developing a set of tools that will evaluate the capacity on our network to host renewables and DER. This is the amount of DER that can be accommodated without adversely impacting power quality or reliability under current network configurations and without required infrastructure upgrades. The hosting capacity will consider DER connection without allowing voltage/flicker violations, protection mal-operation, thermal overloads or decreased safety, reliability and power quality. 

Key deliverable(s) -

  • Equip our network planners with tools to quickly visualise and understand the impact of DER across our distribution network. This will be done by utilising EPRI’s hosting capacity method to analyse large numbers of MV feeders. The tools developed will enable areas of the distribution system to be easily identified where there is capacity available to connect renewables. This will aid network planners in network investments to quickly evaluate the Least Cost Technically Acceptable (LCTA) connection method to connect DER to our system.

Renewable generators’ access to the distribution network is informed by our models of how our system behaves at its limits, these limits are based on minimum demand and maximum generation. However, due to the intermittent nature of renewable generation, much of the time the system operates well within the aforementioned limits. Active Network Management (ANM) will allow generators to consider variable access options and take advantage of the intermittent output characteristic of renewable generation.

To explore the variable access options open to renewable generators we will deploy an ANM system to two existing distribution connected windfarms (7.5 MW & 10.5 MW MECs), fundamental to this is the provision of access to a newly constructed 38kV circuit to both windfarms. Access to this new circuit would allow both windfarms to remain connected to the distribution system during fault conditions or for planned works such as annual maintenance programmes and capital works programmes, both scenarios would result in a generator outage today.

Key deliverable(s) -

  • Deliver an Active Network Management solution, where we will employ operational flexibility to both windfarms associated with the trial, while adhering to mandatory planning and operational security limits, while imposing minimal constraint on either of the associated windfarms. 
  • Learning about the practical implementation of variable network access systems and processes in Ireland. 

UCD, with funding from Enterprise Ireland, has developed a device which modulates the reactive power produced by a windfarm and can be programmed to minimise losses on a designated circuit of the distribution network to which it is connected. This can be immediately adjacent to the windfarm in question or a designated circuit further upstream. 

We are supporting the development of this device and are facilitating the search for a suitable site on which to trial it. The current regulatory framework and calculation methodologies in Ireland do not currently incentivise the use of this device by windfarm owners.

Key deliverable(s) -

  • Understand how such a losses based objective function, may or may not work with other competing objectives such as voltage control. 
  • Inform what regulatory or process changes, if any, would be required in the event that this approach was adopted. 

Currently, windfarm connections are deterministically assessed on the basis that they will never cause breaches of our current planning and security standards. In order to assess the impact of windfarms on the network, we will use big data and probabilistic analysis to develop a deeper understanding of the performance of windfarms under various conditions and not only when there is (i) maximum demand on the system, (ii) maximum generation and (iii) when the connection point voltage is at its maximum. 

Key deliverable(s) -

  • The analysis will be used to inform any revision of our planning and security standards and may offer insights into ways of providing increased flexibility when connecting customers to the system. This prudent approach of using the analysis to inform revisions of the planning and security of supply standards should reduce the risk of unintended consequences and should contribute to ensuring the system as a whole continues to be reliable, safe, secure, economic and efficient for the benefit of all customers. 

Our forecasts indicate that solar PV based generation will become a major part of Ireland’s energy system with much of it connected directly to the distribution network. By 2030, it is predicted that ESB Networks will have connected over 2,400MW of solar PV based generation. In order to develop our understanding of the impact that this technology will have on our networks we have deployed a state-of-the-art monitoring system on the MV/LV substation upstream of Nenagh Leisure Centre which has 45kW of PV installed, consisting of 180 panels, on the rooftop of their building. 

Key deliverable(s) -

  • Evaluate the output and efficiencies of a number of solar installations nationwide in an effort to ensure the electrical system is ready and optimised to accommodate this form of decentralised renewable energy in the future.

The current issue of the Distribution System Security and Planning Standards (DSSPS) was approved by the CER in January 2015 (following a consultative process) and plays a major role in the development of a safe, secure, reliable, economic and efficient distribution network in Ireland. 

In common with most DSOs across the world, our Planning Standard is primarily deterministic based, and is largely focused around ensuring sufficient capacity is available to meet the ‘peak demand’ and/or ‘peak generation’ in a manner and timeframe consistent with the needs of our customers. The standard is also ‘risk based’ to such an extent that connections at higher voltages serving a larger amount of load receive a higher level of security. The control and operation system we have in place at present to manage the distribution network essentially aligns to this philosophy.

Technological advancements allowing ESB Networks to move towards a more active management system with more flexible and dynamic tools at our disposal, together with the many changes affecting the overall energy system at present, including the large-scale deployment of non-network technologies such as Demand Side Response (DSR), electrification of transport and energy storage and the changing role of the customer are key drivers that have given rise to the need for ESB Networks to fundamentally and holistically review the Planning Standards within a broad stakeholder engagement forum to determine the best outcome for all users (current and future) of the distribution system.

The review will consist of two distinct phases. Phase 1 is a comprehensive research, analysis and modelling engagement and consultation process. There will be no preconceived ideas about what changes are required. The changes arising from the review may range from a modification and update of the current arrangements, development of a completely new approach starting from first principles, through to recommending removal of any deterministic planning standard, relying instead on regulatory incentives and other legislation to motivate efficient network design. 

The essential task of Phase 1 is to research and develop a range of options for the overall approach to structure and detail the appropriate level of network planning and security standards and then to propose how such options can be evaluated, particularly in light of the advancements ESB Networks will be making towards a more active management system. There will be significant engagement with key stakeholder groups to inform the process. We will ensure that the principle of non-discriminatory access to the distribution system is maintained and that the options being considered will continue to provide for a safe, secure, reliable, economic and efficient distribution system in the new future environment. The research will consider the outputs from the review, trials, pilots and projects that will be carried out as part of the connection renewables roadmap and, where appropriate, other roadmaps. We will then evaluate the options and recommend the most appropriate approach that should be taken forward into Phase 2. 

Phase 2 will take forward the recommendations settled upon in Phase 1 and begin the process of bringing these changes into business as usual. A smooth transition plan is essential to ensure the integrity of the system is maintained. This will include any necessary revisions of our Distribution System Security and Planning Standards document and, if necessary in other related policy or standards documentation; submission of the revised documents as appropriate for CER review and approval; implementation of the new planning standards in line with a more active management system; a communications plan throughout the process but in particular around the roll-out of any changes to key stakeholder groups.

Key deliverable(s) -

  • Phase 1: Research and develop a range of options for the overall approach to structure and detail the appropriate level of network planning and security standards and then to propose how such options can be evaluated.
  • Phase 2: Evaluate the recommendations settled upon in Phase 1 and begin the process of bringing these changes into business as usual.