Tonteg synchronous condenser project

Welcome to the information page for our proposed Tonteg synchronous condenser project.

Conrad Energy is proposing to develop a synchronous condenser facility with associated infrastructure, access and landscaping on land to the south-east of Pound Farm, Tonteg, CF38 1SU.

This site has been carefully chosen for its potential to install a synchronous condenser facility to connect to the National Grid Upper Boat Substation. This technology is able to adjust conditions on the electricity transmission grid, either dynamically absorbing or supplying reactive power as needed to adjust the grid’s voltage. There is no combustion in a synchronous condenser, no emissions including carbon emissions, and no generation or storage of power onsite.

The location of the project is shown below or can be viewed on what3words’ interactive map here ///retain.cabinet.cornfield

Net zero Wales

National Grid Electricity System Operator (ESO) is the electricity system operator for Great Britain. They are responsible for moving electricity around the country second by second, ensuring the right amount of electricity is where it’s needed, when it’s needed.

Recent changes in decarbonisation, decentralisation and digitalisation are driving significant change across the electricity network, impacting how National Grid operate the system now and into the future. By 2030 it is expected there will be 40GW of offshore wind and 17GW of interconnection, both of which will present operability challenges. They must upgrade and prepare the grid network for the transition to renewable energy.

Wales is committed to an energy target of net zero by 2050, which can only be achieved by increasing the amount of renewable electricity generation.
At present, National Grid incurs substantial costs managing renewable energy generation due to the lack of infrastructure available to stabilise the network. This is a direct result of the decommissioning of traditional coal-fired power stations and the fast growth of renewable energy technologies like wind and solar power. In response to this, the National Grid Electricity System Operator, is developing an initiative called the Stability Pathfinder to stabilise the generation of renewable electricity within the grid, which will nationally save consumers up to £128 million over six years.

The Stability Pathfinder Phase 3 programme defines five ‘regions of need’, namely: North-East England, East of England, South Coast, South-West England, and South Wales. Within each region, National Grid have identified Grid Supply Points which have capacity to house such a connection without the need for significant modifications which would contribute substantial time and cost to the projects, further delaying the transition to renewable generation and achieving net zero targets. Upper Boat Substation has the identified required capacity and lies in close proximity to land at Pound Farm’s northern boundary, hence the location for this proposed development.


The proposed development is located on land to the south-east of Pound Farm. The southern boundary of the site is defined by Pound Farm Lane, whilst the northern boundary abuts the Merthyr Line of the railway network and Upper Boat Substation. Approximately 1km to the east of the site is the Treforest Industrial Estate. Pontypridd is located approximately 2.5 miles north-west of the site.

The site has been carefully selected, driven first and foremost by its requirement to be close to an available identified Grid Supply Point. As part of a detailed feasibility process Conrad Energy have identified Upper Boat Substation as a Grid Supply Point with such capability. The Grid Supply Points are primarily defined by National Grid’s regions of need as well as sufficient available land which is able to deliver a technically and economically viable point of connection. As part of the site selection process environmental and technical constraints as well as planning policy have been considered, including the following:

  • Physical constraints (i.e. topography and ground conditions);
  • Statutory and planning policy designations at the site and surroundings including any landscape policy considerations, heritage assets and designations; ecological designated sites; agricultural land quality; flood risk; landscape character; and proximity to visual receptors; public rights of way; highways; and access considerations.

A suite of technical surveys have been carried out to confirm that the land would be suitable for the proposed use, please see the planning documents for more information and to access these reports.

Project key facts

  • Synchronous condensers provide short-circuit power, inertia and dynamic reactive power to the transmission grid network. They are key to integrating renewable generation onto the network and transitioning away from fossil fuels, helping reach net zero targets.
  • Deployment of this technology and further grid stability services across the UK will save consumers up to £128 million over six years.
  • The site location has been selected due to the proximity to the National Grid Upper Boat Substation whilst factoring in residential and ecological sensitivities. Due to the land take required for the development the site is unable to be located within the Treforest Industrial Estate.
  • Through landscape enhancement measures the development has been demonstrated to achieve a Biodiversity Net Gain for habitats (1.84%) and hedgerows (10.74%) in accordance with Natural England’s (NE) latest BNG metric (The Biodiversity Metric 3.1 Auditing and accounting for Biodiversity Calculator Tool, 2022).
  • Access to the site will be via a newly created junction off of Pound Farm Lane which will require the removal of a small section of hedgerow. Once operational visits to the site are expected to be infrequent and for maintenance purposely only.
  • This application is supported by technical reports covering protection, mitigation and enhancement measures relating to ecology, noise, landscape and visual, flood risk, heritage, arboriculture, geotechnical and construction impacts.
  • The development is fully reversible, with an operational period of circa 40 years. The site would be fully restored to its existing condition on cessation of operations.

Proposed landscape strategy

Indicative project timeline

August 2022

Planning submission

Q4 2022

Planning decision expected and agreement with National Grid

Q3 2023

Construction start

Q4 2024/Q1 2025

Site operation

Tell us what you think

We’d like to hear your feedback to help us shape our plans. If you have any questions please get in touch.

Initial comments to be received by 2 September

Post: Tonteg c/o Conrad Energy, Suites D&E Windrush Court, Blacklands Way, Abingdon, OX14 1SY

or fill in the form below:

    Has this website been helpful in understanding our proposal?*

    With regards to the Tonteg project proposal on this page are you:*