Windletter by SiG Coop - The rising challenges of wind energy grid integration
The consultancy firm SiG offers us a first-hand insight into how they are tackling the current challenges of network integration.
Hello everyone and welcome to a new issue of Windletter. I'm Sergio Fernández Munguía (@Sergio_FerMun) and here we discuss the latest news in the wind power sector from a different perspective. If you're not subscribed to the newsletter, you can do so here.
Today’s edition is sponsored by SiG Coop (Simulation Integration Grid Compliance), an independent electrical engineering consultancy specialising in simulation and grid integration of renewable generation plants. A company at the forefront of technical knowledge that, as you will see, has a rather particular story.
It is a real pleasure for Windletter to have SiG as a sponsor of this edition. Regular readers know that whenever we discuss grid integration in these pages, the subject tends to be more complex than it first appears. SiG lives right at the heart of that complexity.
To give us a first-hand account of how the consultancy sees the current challenges of grid integration, and how SiG can help developers and OEMs, we spoke with Xabier Barón, head of operations at the consultancy.
⚡ Grid integration: the bottleneck that never makes the headlines
We have spent years talking about the cost of wind energy, installation records, new turbine models… But there is a topic that comes up with increasing frequency in sector conversations and rarely makes the front page (except when there is a blackout): grid integration.
What happens when an electricity system designed to run on large synchronous generators (thermal, hydro, nuclear plants) starts filling up with renewable generation based on power electronics? Grid management starts to get complicated.
The inertia and flexibility that large rotating generators used to provide diminishes. Frequency and voltage stability becomes dependent on inverters and how they are programmed to respond. And grid operators start demanding things that nobody asked for ten years ago.
In Europe, the grid connection of new generation installations is governed by the RfG (EU Regulation 2016/631). Each country has transposed it with its own peculiarities: the minimum requirements are common, but implementation details vary from one grid operator to another. What is expected on the near horizon is the RfG 2.0: ACER submitted its proposal to the European Commission in December 2023, although the Commission has not yet communicated an adoption timeline.
Meanwhile, other markets are ahead (driven by necessity): Australia with AEMO and Texas with ERCOT have been operating with significantly more demanding grid codes for years. What is standard today in Melbourne or Austin is, more often than not and accounting for each grid’s own characteristics, what will arrive in Europe within a few years.
🔬 Simulate before you connect: what SiG actually does
SiG Coop is an independent consultancy based in Navarra (with a presence in Melbourne) specializing in simulation and grid integration of all types of renewable and storage plants. Its team is made up of senior engineers with over 20 years of experience, most of them coming from wind turbine and power electronics manufacturers, which gives them a perspective that few consultancies have: they know the technology from the inside.
What does simulating the grid integration of a wind farm actually mean? It means building a mathematical model of the plant (turbines, inverters, transformers, lines) and reproducing its electrical behaviour under different grid conditions before the plant exists. Or, for plants already in operation, simulating what happens when something changes: the grid code, the system topology, the arrival of neighbouring plants.
The SiG team works with the main platforms in the sector: PSCAD, DigSilent, PSSE, EMTP-RV, Matlab, etc. Models fall into two main types: RMS (standard detail models) and EMT (high-precision models, capable of capturing phenomena that RMS models cannot).
Their clients cover the entire value chain: developers, EPCs, plant owners and manufacturers. Among them are names such as Iberdrola, Nordex and Ingeteam.
The models for manufacturers segment is perhaps the most distinctive and least visible part of SiG’s business. When an OEM wants to enter a new market, it needs a model of its technology validated against that market’s grid operator. It is a market entry requirement, not optional. Xabier distinguishes two types of needs:
The first are auxiliary: studies the manufacturer must present to its client as part of the contract, independent dimensioning validations, or updates of legacy models for products no longer in the catalogue but still running in operational plants.
The second is the technical core: demonstrating that a turbine or inverter model meets what AEMO, REE, FINGRID or ERCOT requires to connect to their grid.
“We have seen other consultancies take months to get through these technical processes when we have completed the tests successfully in 3 or 4 weeks”, Xabier explains. An advantage he attributes directly to the team’s background in manufacturing and the experience accumulated in the most demanding markets.
🇦🇺 Australia: the desert that forges consultants
In 2018, SiG entered the Australian market alongside a Spanish photovoltaic inverter manufacturer. What they found on arrival was a grid code of a rigour they had not seen before.
Australia operates with one of the strictest standards in the world: if you connect your technology to the Australian grid, you have to demonstrate with very high precision how it will behave under adverse conditions. This involves the comparative analysis between RMS and EMT models that is not yet standard in other markets, and batteries of simulation cases that would be unusual or even disproportionate in Europe.
“The number of cases to analyse in Australia meant we had to automate a large part of the analysis from very early on”, Xabier explains. “It is such a challenging environment that it forges the skills needed to deliver an agile, highly professional service. The desert of grid integration forges the toughest consultants, just like Arrakis.“
The Australian experience has been an accelerated school that SiG has since applied in other markets. Because what AEMO demands today tends to appear in other grid codes with a lag of several years. Texas (ERCOT) is one example. Europe, by all indications, will be the next.
🌐 Grid forming: the paradigm shift that is already here (even if the regulation is lagging behind)
There is a concept that has been circulating through the sector with increasing frequency and decreasing clarity for a couple of years: grid forming. We took the opportunity to ask Xabier about it.
The simplest way to understand it is this: traditional synchronous generators “create” the grid, setting the frequency and voltage reference. Conventional wind and solar plants, connected via inverters, simply “follow” that reference (they are grid following). As synchronous generators disappear from the system, someone has to create the grid. Grid forming is the ability of an inverter to do exactly that: behave, in electrical terms, as if it were a synchronous generator.
The technology to do so exists. What does not yet exist, at least in Europe, is clear regulation that mandates, defines and certifies it in a homogeneous way. SiG participated in 2022 in a pilot test in Australia related to grid forming, on a pumped storage project.
Since then, grid forming has featured increasingly in their work: model analysis for clients who want to stay ahead of the regulatory game, and participation in 2025 in what they describe as the first official Black Start study for the first projects of Spain’s PERTE storage programme.
“I would venture to say that the adaptation challenge is not so much technological as regulatory. Quality technology does not need particularly demanding adaptations; the real challenge is at the regulatory level. Establishing clear standards and harmonising grid code requirements is something Europe needs to advance on, and it benefits everyone“, Xabier tells us.
🤝 A consultancy that does not fit the usual mould
There is something about SiG that does not quite fit the typical pattern of an international technical consultancy: they are a cooperative. The owners are the workers and strategic decisions are made democratically: one person, one vote.
The practical consequence is that employees do not need or feel the urge to change companies every two years, as is common in the sector. In an industry where senior specialist turnover is high, that is a concrete competitive advantage: accumulated knowledge does not walk out the door.
“We are proud to be part of the social economy and proud to be a cooperative. A not insignificant part of our success has come precisely from living by these values”, Xabier acknowledges. And he adds, with candour: “It is not all plain sailing. The work of caring for people is more intense, and major decisions are more complex to make. But in our experience, the benefits win by a mile.”
Being a different kind of company also allows them to take on projects that a conventional consultancy would rarely consider. The most striking to date: the creation of an Escape Room set inside a wind turbine.
The first version is designed for remote control operators at control centres, as a training tool for decision-making under pressure. A version for the general public is coming soon, and we will have more details in due course. “We don’t have much time left in the year for our little acts of madness, but we try to be different and do different things that create value… and have fun doing it”, Xabier says.
📬 Want to know more about SiG?
If you would like to know more about SiG and their simulation and grid integration services, you can get in touch through:
Email: info@sigcoop.com
Their website
Their LinkedIn page
You are on time to meet them in WindEurope! Feel free to mention that you come from Windletter 🙂.
If this is not relevant to you but you know someone it could help, feel free to forward this email. We would be enormously grateful.
Thank you very much for reading Windletter. If you liked it, I invite you to subscribe, give it a ❤️, forward it by email, share it on social media, or recommend it to other people.
See you in the next one!