DS3 Programme

Our Delivering a Secure Sustainable Electricity System (DS3) programme seeks to address the challenge of integrating world-leading levels of renewable generation onto our power system.

What is the DS3 Programme?

Delivering a Secure Sustainable Electricity System

In response to binding national and European targets, SONI, as part of EirGrid Group, began a multi-year programme, “Delivering a Secure, Sustainable Electricity System” (DS3).

In keeping with United Kingdom and wider European policy, Northern Ireland had a target to achieve 40% of its electricity consumption from renewable sources by 2020. 

The aim of the DS3 Programme was to meet the challenges of operating the electricity system in a secure manner while achieving this 2020 renewable electricity target.

Synchronous v non-synchronous generation

There are two types of electricity generation: synchronous generation and non-synchronous generation. Synchronous generation can produce the same amount of electricity all the time if instructed to do so. It is reliable and predictable and, therefore, easy to bring onto the grid. Fossil fuels such as coal, oil and gas are a type of synchronous generation.

Non-synchronous generation produces a different amount of electricity depending on the energy available. It does not produce the same amount of electricity all of the time. This makes it less reliable, and more difficult to bring onto the grid. Most renewable forms of energy, such as wind and solar, are types of non-synchronous generation. This is because the amount of wind and light is always changing and therefore they cannot produce power predictably.

Meeting 2020 renewable electricity targets

The 2020 renewable electricity target meant that we were required to increase the allowable amount of non-synchronous generation on Northern Ireland’s power system in a safe and secure manner. The aim of the DS3 Programme was to meet this challenge.

By 2018 the DS3 programme had enabled SONI as the TSO (Transmission System Operator) in Northern Ireland and EirGrid as the TSO in Ireland, to increase instantaneous levels of renewable generation on the system from 50% to 65%. This was a world-first. In 2021, we increased this further to 70% and in March 2022 we reached the DS3 goal of 75%. This milestone has been ten years in the making since the launch of the DS3 Programme and Northern Ireland is a global leader when it comes to the integration of renewable energy and we thank all stakeholders who have been involved. These increases have enabled very high levels of renewable energy. 

But we are not stopping here… we are now working to gradually increase the limit over the coming years to 95%!

These increases in the SNSP limit are a key part of the developments required to allow us to achieve a Northern Ireland’s clean energy targets and the journey to net zero. For more information on our future plans see here.

The DS3 programme has bought together numerous important strands of work to facilitate Northern Ireland and Ireland's ambition to produce 40% of electricity from renewable sources by 2020. This exciting and challenging programme is built on three pillars, each vital to its success. These are:

  • System Performance
  • System Policies
  • System Tools

Across these three pillars we are fundamentally reviewing how we do things across the electricity industry to ensure policies, incentives, standards and tools are fit for purpose in a system with world-leading levels of renewables.

For more on the DS3 Programme, read our information brochure here.

The programme involves many different stakeholders, including the Distribution Network Owners (DNOs), Regulatory Authorities, Conventional Generators and Renewable Generators, as well as Government Departments.

As part of this programme, we have established an Advisory Council to ensure that the views of industry are well represented. Read more information here.

Whilst the main objective of DS3 was met in 2020, the 75% non-synchronous trial is ongoing and the final system tools are now coming onstream in the control rooms. Meanwhile a new set of targets have been set for 2030, and the operational roadmap from our new Shaping Our Electricity Future programme will take over from DS3.

Additional information on DS3 can be found in the library section of this website.


One of the key areas in the DS3 Programme is System Services. We want to make sure that the system operates securely and efficiently, while facilitating higher levels of renewable energy. To achieve this aim, we are working to obtain a range of services from as wide a pool of generators and market participants as possible. This includes the development of financial incentives for better plant performance. This should mean savings for the consumer and an increase in the levels of renewable energy we can accommodate at any given time.

We produce a quarterly update on the System Services Implementation Project Plan. Read the most recent update here.

Providing Units can apply to contract with SONI to provide System Services. For a unit to receive a contract to provide System Services they are required to demonstrate their capabilities through the compliance and testing processes in advance of contracting. Further information on System Services testing and compliance requirements can be found here

DS3 System Services Interim Arrangements Procurement

SONI and EirGrid have published the outcome of the procurement for the DS3 System Services Interim Arrangements. This includes a summary of successful tenderers and the services for which they have been contracted for both Northern Ireland and Ireland. Eleven system services were procured from service providers in Ireland and Northern Ireland under the DS3 System Services procurement process, with separate framework agreements for each jurisdiction. The Interim Arrangements became effective on 1 October 2016.

SONI and EirGrid have also published a summary of the contracted volumes for the DS3 System Services Interim Arrangements together with the forecast expenditure for the Interim Arrangements period (1 October 2016 to 30 September 2017). Since the publication of the summary of the contracted volumes the Interim Arrangements period has been extended until the 30 April 2018. The contracted volumes remain the same for this period.

The aim of DS3 System Services is to put in place the correct structure, level and type of service in order to ensure that the system can operate securely with higher levels of non-synchronous renewable generation (up to 75% instantaneous penetration).

August 2018 Update:

Volume Uncapped Phase 1 and Phase 2 Update:

Volume Uncapped Phase 1 arrangements (11 services) went live on May 1st 2018. Volume Uncapped Phase 2 arrangements (FFR services) are scheduled to go live on October 1st 2018.

The TSOs intend to hold an industry feedback session following the conclusion of the Phase 2 procurement process to gather learnings from the Phase 1 and 2 processes (including procurement, testing and performance monitoring) to incorporate in future gates of the Qualification System.

In addition the TSOs intend to consult on the Volume Uncapped contractual arrangements prior to the next gate of the Qualification System, with a view to improving clarity in the terms and conditions of the arrangements.

Such consultation will include issues that have been raised to date by industry such as the inclusion of termination clauses based on plant closure provisions of the Grid Code or derogation from the notice provisions thereunder; clarification of wording describing performance assessment of Providing Units; clarification of business processes in the Protocol document.


All published compliance procedures and reports can be found here – this includes:

An updated DSU application form

Updated Signals specification document 

A Guidance Document 


DS3 Advisory Council

The DS3 Advisory Council was established in 2011 to provide a forum to discuss issues which may impact on the success of DS3. The Council consists of experts from across the power industry. This includes representatives from academia and industry across Northern Ireland, Ireland and Europe. Meetings are held approximately every four months and links to documents from these meetings are available here

DS3 Consultations and Publications

Links to DS3 Consultations and Publications are available here