Be Wise › Solar Wise guides › Solar FAQs › G98 and G99: connecting solar to the grid
When G98 notification is enough, what a G98 Form B involves, when G99 approval is needed and how a battery can change the route.
Reviewed · fast-moving answers are re-checked against the official pages listed every week
Rules are changing quickly. Every answer lists its official sources and when it was last reviewed. General information, not legal, electrical or financial advice. See how we check and what has changed recently.
G98 covers type-tested generators up to 16 amps per phase, about 3.68 kW on a single-phase supply. On a three-phase supply you can use G98 with up to 3.68 kW on each phase, or up to 11.04 kW as a single three-phase system. You connect first, and your installer notifies the network operator afterwards.
Sources: Electricity North West: G98 and G99 application guide (2021 slides, PDF) · MCS: notifying distribution network operators (G98 and G99)
Your installer completes a G98 Form B and sends it to the network operator within 28 days of commissioning. It needs the manufacturer's reference from the ENA Type Test Register for the equipment. You do not wait for approval before switching on, but ask your installer for a copy of the notification.
Sources: Electricity North West: G98 and G99 application guide (2021 slides, PDF) · MCS: notifying distribution network operators (G98 and G99) · Energy Networks Association: Connect Direct device register (plug-in solar)
G99 applies to installations above 16 amps per phase (3.68 kW), or that do not meet the G98 requirements, and it covers generation and energy storage together. You must apply to your network operator and get its agreement before installing. Smaller G99 installations have a simplified process, and network operators may have their own forms.
Sources: National Grid Electricity Distribution: G99 connection procedures · MCS: notifying distribution network operators (G98 and G99)
It can. Storage counts towards the total: where the combined capacity of generation and storage is no greater than 16 amps per phase the G98 procedure applies, and above that G99 does. Adding a battery to an existing installation can therefore tip it into G99, so ask your installer to check the total before you order.
Sources: National Grid Electricity Distribution: G99 Form A1-2 for integrated micro-generation and storage (PDF) · MCS: notifying distribution network operators (G98 and G99)
The Be Solar Wise app lets you choose your country and ask its assistant follow-up questions.
Open Be Solar WiseAll FAQsReviewed 2026-09-21. General information, not legal, electrical or financial advice. Confirm current rules before you buy or connect anything.
