G98 vs G99: how solar and batteries get connected in Edinburgh and the Lothians
Before any solar panel system or battery connects to the electricity network, the local network operator needs to know about it. In Edinburgh and the Lothians, that's SP Energy Networks, the distribution network operator (DNO) for central and southern Scotland. Which process you go through, G98 or G99, makes a real difference to your timescale.
Who is SP Energy Networks?
Your energy supplier (the company that bills you) is not the same as your DNO. The DNO owns and runs the cables, substations and poles that bring power to your property. In Edinburgh and the Lothians that's SP Energy Networks, whichever supplier you use.
G98: connect, then notify
Engineering Recommendation G98 covers small, fully type-tested systems. The limit is 16 amps per phase, which is about:
3.68kW on a normal single-phase home supply
11.04kW on a three-phase supply
If your system is within the limit and uses type-tested equipment, the installer can usually fit it and then notify the DNO within 28 days. There's no waiting for approval first.
Many smaller home solar systems fall under G98.
G99: apply, then connect
Engineering Recommendation G99 covers anything bigger than G98, or systems that don't qualify for it. Under G99, the installer applies to SP Energy Networks before connecting, and the DNO checks whether the local network can take it. They might:
Approve it as it is
Approve it with an export limit, so the system can generate more than it exports
Ask for network work, sometimes at a cost, before a larger system can connect
The time it takes varies by the size of the system and the network. For homes and small businesses, plan for weeks, not days. For larger commercial systems, it can be longer.
Why batteries complicate things
A battery counts as generation for connection purposes, because it can export power. So a 3.68kW solar system plus a 5kW battery inverter may tip you over the G98 limit, even though neither is very big on its own.
SP Energy Networks has a G99 fast-track route for some combined home systems. It applies where the solar and the battery are each no more than 3.68kW per phase, the total generation including storage is no more than 7.36kW, export is limited to 3.68kW per phase, and the system doesn't operate during a power cut. The installer can tell you whether your design fits.
Export limitation
If the DNO caps your export, or you want to stay within G98, the installer can fit an export limitation device. It stops the system exporting more than the agreed amount, while still letting you generate and use more yourself. With a battery, that surplus can go into storage rather than being wasted.
What this means for you
Small home system, no battery: often G98, the quickest route.
Larger home system, or solar plus battery: often G99 or G99 fast-track. Allow time.
Commercial or farm system: almost always G99. Rural lines can have less capacity, so the answer may shape the design.
Adding a battery to existing solar: the combined system is what counts. A retrofit may need a new notification or application.
Timing and the VAT deadline
If you're aiming to finish before the 0% VAT rate on home solar and batteries ends on 31 March 2027, build in time for the DNO process. See our VAT guide.
How Pentland Renewables handles it
We check your supply on the survey, design around the G98 or G99 route that fits, and handle the paperwork with SP Energy Networks.
FAQs
What is the G98 limit for solar panels?
16 amps per phase, which is about 3.68kW on a single-phase supply or 11.04kW on three-phase, using type-tested equipment.
Do I need DNO approval for solar panels in Edinburgh?
Small systems under G98 usually just need notifying after installation. Larger systems, or solar with a battery over the limit, need a G99 application and approval before connecting.
Does a battery count towards the G98 limit?
Yes. Batteries can export, so they count as generation for connection purposes.
How long does a G99 application take?
It depends on system size and the local network. For homes and small businesses, plan for weeks. Larger systems can take longer.
What is export limitation?
A device that stops your system exporting more than an agreed amount, so a bigger system can connect where the network has limited capacity.
Ask us to check your connection
Send us your postcode and what you're thinking of fitting. We'll tell you which route is likely and how long to allow.
Send the form with your postcode and what you want priced. We survey your home, then send the written quote. You decide after you have read it.