Our latest news and industry insights

Point-on-Wave technology key in providing grid code compliant solution – Fallago Rig Wind Farm

17 Apr 2023

Enspec news

Looking back at a project completed close to a year ago now, it’s important to highlight key innovations and the improvement it can have on the net-zero transition, as well as the overall operations of Wind Farms across the country.

Last year Enspec completed a successful power system project at the Fallago Rig Wind Farm, operated by EDF Renewables UK with 80% assets owned by Hermes Infrastructure.

Enspec’s uniquely designed switching panel uses Point-on-Wave technology to manage a very complex switching and control requirement that will give Fallago Rig the most cost-effective solution to the site’s voltage control requirements. Fallago Rig was already a fully operational wind farm and included a full STATCOM system, which were historically commonly used for UK grid code compliance in wind farms. The original STATCOM cost several million pounds and has worked very hard to support the transmission network voltage since day one of operation. Whilst Obligatory Reactive Power Service (ORPS) payments were accordingly high, inverter failure rates and associated costs were increasing, and enduring support and risk of non-compliance became more of a concern.


Fallago Rig Wind Farm
Pic: Peter Devlin

To solve this issue, ensuring power quality and compliance, Enspec manufactured and commissioned 50MVAr of PoW switched capacitor banks, as part of a hybrid solution, which cost £1.6mil versus another estimated £5.1mil for a new STATCOM system. Enspec’s Point-on-Wave (PoW) system also has nowhere near the maintenance cost, saving EDF £100,000s annually.


“We’ve been incredibly impressed with Enspec’s expertise in not only providing the P-o-W switched capacitor element of the hybrid solution, but also their capacity to identify and mitigate risks associated with adding and switching large capacitor banks onto an existing electrical system in such a manner,” said Rob Mitchell, Senior Electrical Engineer at EDF Renewables.


The solution features Enspec’s expertise in Point-on-Wave (PoW) switching to allow for capacitor bank re-energisations within seconds instead of the traditional 8-10 minutes. The PoW banks will then work in conjunction with the upgraded control software of the Vestas turbines and wind farm controller in a hybrid solution to provide dynamic voltage control in line with Grid Code requirements.”.

Fallago Rig Wind Farm
Pic: Peter Devlin

The capacitor banks also offers greatly reduced transients on energisations; where traditional capacitor banks can pull 1000s of Amps of inrush current, PoW banks are energised with inrush current levels only 1.5-2 times higher than the standard capacitor bank rating. This reduces wear on switches and ensures for limited disturbances on the Wind Farm network.


Enspec applied their established and trusted knowledge in harmonic studies and compliance by carrying out a revised G5/4 harmonic study for the Wind Farm with consideration of the new capacitor banks. This highlighted that normal banks could lead to harmonic resonance and amplification and so guided the design towards a de-tuned type to avoid this phenomenon.


The newly installed voltage support system was confirmed to fully satisfy all criteria. Enspec director, Tim Rastall, said; “Enspec is very grateful for the trust of our long-standing partner EDF Renewables to deliver this significant project for Fallago Rig. We are very proud of our team’s dedication and effort towards the completion of this milestone contract. It is great to see the completed system in operation and delivering the designed grid code compliance support.”


All images have been provided by EDF Renewables.

About Fallago Rig wind farm

Fallago Rig wind farm is situated in Lammermuir Hills in Berwickshire, Scotland. It consists of 48 3MW turbines, with a generating capacity of 144MW. The construction of Fallago Rig, which was commissioned in 2013, saw £3 million invested into the local community and created more than 350 jobs. £240,000 is invested into the community on an annual basis via the wind farm’s community benefit fund.

For more information, go to the Fallago Rig Wind Farm website : https://www.edf-re.uk/our-sites/fallago-rig


About EDF Renewables in the United Kingdom

EDF Renewables UK and Ireland (www.edf-re.uk) is a subsidiary of the EDF Group, one of the world’s largest low carbon electricity companies, and our investment and innovation is reducing costs for consumers and bringing significant benefits for communities. With our operating portfolio of 36 renewable energy sites including battery, onshore and offshore wind (together totalling 1 GW) we are providing much needed affordable, low carbon electricity. We have an expanding portfolio with almost 5 GW of projects in planning and development, including wind, battery and solar PV. Find out more at www.edf-re.uk


About Hermes Infrastructure

Federated Hermes Infrastructure is part of Federated Hermes Limited’s Private Markets Platform, comprising Infrastructure, Real Estate, Private Equity and Private Credit, with an aggregate AUM of c.£20bn USD as at 31 March 2022.  Our infrastructure team manages a £3.1 billion portfolio of infrastructure investments in the UK and Europe, across renewable energy, regulated utilities and transport infrastructure sectors. On behalf of our >1m UK and European pension beneficiaries, we are focussed on investing in long-term, sustainable infrastructure which provides value to all stakeholders. For more information please visit: Hermes Infrastructure (hermesgpeinfrastructure.com)

Join our mailing List

Sign up to our newsletter to receive industry insight, case studies and more

    Interested in: