G99/NI Fast Track Changes
From 1 May 2026, NIE Networks is overhauling the parameters of its G99/NI Fast Track application process. For anyone planning solar PV, battery energy storage (BESS), or a combined system in Northern Ireland, it's a genuinely significant shift.
The short version: the Total Installed Capacity limit for a Fast Track application is rising from 16A to 60A per phase — a near-quadrupling. That translates to systems of up to 13.8kW on single phase or 41.4kW on three phase. The maximum export capacity, the application fee, and the underlying inverter requirements all stay the same.
If you've been put off by the old 16A ceiling — or been told a combined solar-and-battery project couldn't be processed under the Fast Track route — the numbers just got a lot more workable.
What is G99/NI Fast Track?
G99/NI Fast Track (officially the Integrated Micro Generation and Storage Procedure) is a streamlined application route with NIE Networks for connecting generation and storage equipment — typically solar PV with battery storage — to the electricity network. It sits between the simpler G98/NI microgeneration notification process and a full G99/NI application.
It's designed to be quicker than a standard G99 application while still ensuring your installation connects safely to the distribution network. Crucially, it is not a "fit and inform" process — approval must be granted before installation begins.
Under the current rules, a Fast Track project has to keep generation and storage each under 16A per phase, broadly matching the G98/NI threshold. That's the ceiling that's lifting on 1 May 2026.
What's changing on 1 May 2026
Total Installed Capacity (TIC) up to 60A per phase
The headline change. From 1 May 2026, the total installed capacity under a Fast Track application rises to:
Up to 13.8kW on single-phase supply (previously 3.68kW)
Up to 41.4kW on three-phase supply (previously 11.04kW)
This is what makes the Fast Track route genuinely useful for small and medium commercial projects, not just domestic installs.
Improved diversity of connected equipment
The new rules allow a greater mix of generation and storage equipment to sit under one Fast Track application, rather than forcing projects into a full G99 route. In practice, that means solar PV, battery storage, and other qualifying assets can be stacked under a single streamlined application — provided the totals fall within the new limits.
What's staying the same
Three important parameters are not changing, which is largely good news.
Maximum Export Capacity (MEC) unchanged at 16A per phase
Export back to the grid remains capped at 3.68kW single phase / 11.04kW three phase, managed through a G100-compliant export limitation scheme. You can install a bigger system, but what leaves the site stays within existing network limits.
This is actually the key to why the change works. NIE Networks isn't increasing the load on the grid — it's recognising that a well-designed solar-plus-battery system keeps most of its generation on site for self-consumption.
Application fee unchanged
A bigger system, the same Fast Track process, the same application fee as today.
Inverter requirements unchanged
Inverters must still be type-tested to G98/NI or G99/NI Type A and listed on the ENA Type Test Register. Before specifying kit for a new project, verify via Connect Direct that the inverter is approved for use in Northern Ireland.
Why NIE Networks is making this change
NIE Networks has cited three reasons for the update:
Alignment with industry. The new 60A limit brings Northern Ireland broadly in line with the Small Generation Installation (SGI) framework used by Distribution Network Operators across Great Britain.
Recognising change in the market. System sizes have grown meaningfully in recent years, particularly with the rise of home battery storage and growing commercial demand for resilience.
Greater understanding of the network. Years of operational data have given NIE the confidence that larger installed capacity, combined with robust export limiting, can connect safely under a streamlined route.
What this means for different project types
Homeowners
If you've looked at a solar-plus-battery install in recent years and found the 16A ceiling either forced a compromise on system size or pushed you into a full G99 process, the new limits give genuine breathing room. A typical home can now cover a much larger roof array and pair it with a meaningfully sized battery — still under the Fast Track route, and still at the same application fee.
Small and medium businesses
This is arguably where the biggest unlock sits. At 41.4kW on three phase, serious commercial rooftop solar paired with battery storage now becomes viable under Fast Track. For SMEs, that means faster turnaround on applications and a much stronger business case for on-site generation. NIE Networks itself expects a significant uptick in renewable and BESS connections from this segment.
Larger commercial and industrial sites
Projects that exceed 60A per phase will still need to follow the full G99/NI process. But for many mid-sized installations that previously sat in an awkward middle ground — too big for the old Fast Track, too small to justify a full G99 — Fast Track is now a real option.
Practical implications for new applications
Assessment may be more detailed. NIE has acknowledged that the review process for Fast Track applications becomes more complex under the new rules. Build this into project timelines, particularly for three-phase commercial projects.
Export limiting becomes essential on most projects. Almost any system with installed capacity above the export cap will need a G100-compliant export limitation scheme specified from the design stage, complying with NIE Networks Policy 21/007 and EREC G5/4-1.
Documentation matters. Single-line diagrams, datasheets, inverter certification, and site layout plans should all be prepared in advance to avoid application delays.
Timing existing applications. If you have a Fast Track application in progress under the old rules, speak to your installer about whether it makes sense to wait and reapply under the new framework, or proceed as-is.
Frequently asked questions
When exactly do the new rules take effect?
1 May 2026. Applications submitted from that date will be assessed under the new parameters.
Does the export limit really stay at 16A per phase?
Yes. Maximum Export Capacity remains 3.68kW (single phase) and 11.04kW (three phase). The change only affects how much generation and storage can be installed on site.
Does this replace G98/NI?
No. G98/NI still covers installations up to 16A per phase. G99/NI Fast Track sits above that, and a full G99/NI application applies beyond 60A per phase.
Do I still need a G100 export limitation scheme?
Yes, wherever installed capacity exceeds the export cap — which will apply to virtually all Fast Track projects under the new rules. The scheme must comply with NIE Networks Policy 21/007 and EREC G5/4-1.
Can I use my existing inverter?
Only if it is type-tested to G98/NI or G99/NI Type A and listed on the ENA Type Test Register. Check via Connect Direct before confirming any specification.
Will my application be approved more quickly?
For smaller G99 applications being shunted into the Fast Track route, yes — timelines are expected to reduce. For more complex Fast Track applications, the assessment itself may take a little longer than today's simpler process.
The bottom line
The 1 May 2026 changes to G99/NI Fast Track aren't just a technical tweak. They meaningfully expand what's possible for on-site generation and storage in Northern Ireland, particularly for homes and businesses that want to size a system around their actual energy use rather than an artificial grid cap.
At Wilson Power & Energy, we specialise in solar PV, BESS, EV charging, and microgrid design across Northern Ireland, the Republic of Ireland, and Great Britain. We're already helping customers rethink projects that previously sat in the too-hard pile under the old Fast Track rules.
If you're considering a solar, battery, or combined project and want to understand what the new Fast Track limits mean for your site, get in touch. We'll walk through the numbers, the timing, and the right application route for your project.
Source: NIE Networks — G99/NI Fast Track Installations. This article is for general information and does not constitute technical design advice for a specific installation.