Great British Grid: what faster grid connections could mean for compliance testing

Great British Grid: what faster grid connections could mean for compliance testing

Summary. On 29 September 2026 the Prime Minister, Andy Burnham, announced plans for Great British Grid, a publicly owned company inside Great British Energy that will invest in and compete for transmission connection projects. The aim is faster grid connections. For manufacturers and developers of inverters, battery storage, chargers and other grid-connected equipment, a faster connection date can bring the compliance programme forward too. Evidence against Engineering Recommendations G98 and G99 in Great Britain, and against the grid codes of any export markets, may become the critical path. This post covers what was announced, why connections are a bottleneck, and what a grid-connection test bench involves.

What was announced?

In his first Labour Party conference speech as Prime Minister, in Liverpool on 29 September, Andy Burnham set out plans for a new publicly owned company, Great British Grid (GB Grid). Based on Labour's statements and early coverage:

  • GB Grid will sit within Great British Energy and be funded from GB Energy's existing budget.
  • It will invest in, and compete for, transmission connection projects alongside the three private companies that own and run the transmission network in Great Britain.
  • It's intended to make it easier for businesses waiting for a connection to finance and build high-voltage connection infrastructure themselves, with GB Grid supporting and possibly co-investing.
  • It forms part of a wider goal to bring UK energy costs into line with other European countries within ten years.

Full details of the body haven't been published yet, so timescales and remit may change as the plans develop.

Why are grid connections a bottleneck?

The National Audit Office (NAO) published Upgrading the electricity transmission network on 11 September 2026. Its findings explain why connections are now a political priority:

  • The queue is growing. The number of projects waiting to connect has grown significantly and delays are increasing. The share of projects offered a connection at the time they wanted fell from around 64% in 2019-20 to around 16% in 2023-24.
  • The grid needs a lot of new capacity. Ofgem estimates that transmission owners may need to spend up to around £70 billion between 2025 and 2031, quadrupling the current rate of investment.
  • Constraint costs are rising. Payments to generators to turn up or down, to manage the network's physical limits, rose from £0.6 billion in 2018-19 to £1.9 billion in 2025-26 (2024 prices). The NAO says they could reach £6.6 billion to £7.8 billion in 2030 if grid upgrades are not accelerated.
  • The targets are demanding. The government's Clean Power 2030 target is for clean sources to supply at least 95% of Great Britain's electricity by the end of 2030, up from 73% in 2025. The Department for Energy Security and Net Zero estimates this needs installed generating capacity to rise from 111 GW in 2024 to between 204 and 231 GW by 2030.

Connections matter on the demand side too. The NAO notes a growing focus on connecting energy-intensive projects such as data centres, and GB Grid is being positioned to help large power users such as manufacturing sites and EV charging infrastructure connect sooner.

What could faster connections mean for equipment makers?

If GB Grid, the wider connections reform and self-build options shorten the wait for a connection, projects may move from "waiting" to "building" with less warning. For the equipment that connects to the network, that can compress the time available to produce compliance evidence.

That applies to:

  • inverter manufacturers preparing type-test evidence for new PV, battery or hybrid products
  • battery energy storage system integrators proving that a power conversion system behaves as the connection agreement requires
  • EV charger and V2G developers whose bidirectional chargers export to the network
  • developers and EPCs who need compliance evidence for each power park module before energisation
  • test houses and university labs facing more demand for grid-code testing

None of this is certain yet, and the timetable will depend on how the plans are implemented. But teams that already have a repeatable in-house test method are likely to be better placed than those who book test-house time only once a connection date is fixed.

What does grid-connection testing involve in Great Britain?

In Great Britain, generation connecting to distribution networks is covered by Engineering Recommendations published by the Energy Networks Association:

  • G98 covers fully type-tested micro-generators (up to 16 A per phase) connecting in parallel with public low-voltage distribution networks.
  • G99 covers generation above the G98 limits, with requirements that scale by power park module type.

Depending on the equipment and its type, testing can include:

  • Loss-of-mains protection: the unit has to detect islanding and disconnect, including rate of change of frequency (RoCoF) behaviour. IEC 62116 describes a common islanding-prevention test procedure for utility-interconnected PV inverters.
  • Over and under voltage and frequency protection: trip settings and timings checked against the required values.
  • Fault ride-through: for larger power park modules, staying connected through defined voltage dips.
  • Frequency response and reactive power capability: behaviour as frequency and voltage move.
  • Power quality: harmonic emissions and flicker, which in these recommendations refer to the IEC 61000-3 series, such as IEC 61000-3-2 and IEC 61000-3-12 for harmonics and IEC 61000-3-3 and IEC 61000-3-11 for flicker.

For export markets the list changes. EN 50549-1 and EN 50549-2 apply in Europe, and IEEE 1547.1-2020 and UL 1741 SB for the North American market. Check the current edition of each document and your network operator's requirements before you fix a test plan.

What goes on the test bench?

A grid-connection bench recreates the network, the energy source and the measurement point, so a device can be taken through each test repeatably:

  1. A grid emulator in place of the mains. It applies voltage and frequency steps, dips, phase jumps, harmonics and islanding conditions, and absorbs the power the device under test exports. Regenerative, four-quadrant units return that energy to the building supply instead of burning it as heat. See our grid emulators from Cinergia and Pacific Power Source.
  2. A DC source for the input side: a solar array simulator for PV inverters, or a bidirectional DC supply that can emulate a battery for storage and V2G products. See our bidirectional DC power supplies.
  3. A load: an RLC load for anti-islanding tests, where the balanced resonant case is the hardest to detect, or a regenerative load for converters.
  4. Measurement: a power analyser at the point of common coupling, and a harmonics and flicker test system where power quality evidence is needed to the IEC 61000-3 series. Our harmonics and flicker testing article goes into more detail.

Our anti-islanding testing guide covers how the bench fits together for islanding tests, and our power hardware-in-the-loop article covers linking an emulator to a real-time grid model.

Rent or buy?

If a connection date moves forward, the time to buy, install and commission a bench may not be there. Renting a grid emulator or DC source can cover a certification campaign or a short project, and it lets you prove a test method before you commit to a purchase. Every grid emulator line we supply can be rented as well as bought. See rentals.

Getting ready

The details of GB Grid are still to come, but the direction is clear: faster connections, with more of the work on the applicant's side. If your products or projects will need grid-code evidence in the next year or two, now is a good time to check that your test method is ready.

Tell us your equipment rating, target markets and timescale, and we'll support you in choosing an appropriate test set-up.

Contact us

Sources

No items found.

No items found.