If you have bought an EcoFlow STREAM battery, or you are about to, you will have come across G98. It is the part of the job most owners have never heard of, and the part forums argue about most. This guide sets out what G98 is, who submits it, and what changes if you already have solar panels. We wire in STREAM batteries for homes across Mid Somerset and Bath, and the notification is part of every install we do.
What G98 is
G98 is the standard route for telling your District Network Operator (DNO) that equipment able to feed power into the grid is connected at your property. A home battery that connects to your wiring counts, because it can push power back through the meter.
EcoFlow's own UK guidance puts the G98 route at a total of up to 16A per phase, which is about 3.68kW on a normal single-phase house supply (EcoFlow: G98 vs G99). Above that, or with equipment that is not type-tested, the route is G99 instead.
Who submits it, and when
For a standard single-house G98 install, EcoFlow's UK guidance says the installer notifies the DNO within 28 days of commissioning, and the 28 days include the day the system is switched on (EcoFlow: G98 notification). The same guidance says the owner is responsible for making sure the DNO has actually received it, and that there is normally no separate DNO fee for a standard G98 notification.
In practice that means the electrician who wires the battery in does the paperwork. On our installs we submit it and give you a copy for your records, so the notification and the electrical certificate sit together.
When it becomes G99
G99 applies when the total generation and storage at the property is above the G98 limit, or the equipment is not type-tested. The difference that matters to you: under G98 the DNO is told after the system goes in; under G99 the DNO assesses the application before anything is connected (EcoFlow: G98 vs G99). That adds time, so it needs planning before you book.
EcoFlow's G98 article gives the STREAM AC 5000 up to 3,000W of grid-connected AC output (EcoFlow: G98 vs G99); its product page puts a single unit lower. Either way, on its own it sits inside the G98 limit. Added to an existing solar system, the combined figure can go over it, which is when a G99 application comes in.
Already have solar panels?
This is the one people get caught on. EcoFlow's guidance says that before a battery is added to existing solar panels, the installer should check the original DNO records and the existing inverter, and that the earlier G98 or G99 should not be assumed to apply to the new battery (EcoFlow: G98 vs G99).
So when you enquire, tell us what is already on the roof: the inverter make and size, and any paperwork from the original install. We check the existing notification first and tell you whether the battery is a G98 notification or a G99 application before you commit.
G98, MCS and Part P are three different things
- G98 tells the network operator that the equipment is connected.
- Part P covers the electrical work itself. A new circuit is notifiable, and an electrician registered with a competent person scheme (we are NAPIT registered) self-certifies it and issues the certificate.
- MCS is a separate certification scheme. EcoFlow notes that an MCS certificate does not replace G98 (EcoFlow: MCS).
Common questions
Is the EcoFlow STREAM G98 compliant?
EcoFlow's UK material describes STREAM installs going through the G98 route, with the installer handling the notification (EcoFlow: STREAM Ultra). Whether your install is G98 or G99 depends on the total at your property, including any existing solar, so we check that before the job.
Can I submit the G98 myself?
EcoFlow's guidance has the installer submitting it. If we wire the battery in, we submit it as part of the job and give you a copy.
Does a power cut mean the battery keeps my house running?
Not automatically. EcoFlow's G98 guidance says a battery only gives backup if the battery and the installation are designed for it, and that G98 is about the grid connection, not backup (EcoFlow: G98 notification). If backup matters to you, say so when you enquire.
Do you install EcoFlow STREAM in my area?
Yes, across Mid Somerset and Bath: Wells, Shepton Mallet, Glastonbury, Street, Frome, Radstock, Midsomer Norton, Bruton, Castle Cary, Wedmore and Bath. See EcoFlow STREAM installation.
Sources checked 26 October 2026. EcoFlow and STREAM are trademarks of EcoFlow. DS Electrical Installations (SW) Ltd is an independent electrical contractor and is not affiliated with EcoFlow.