Three companies, three different jobs
People often assume the company that sends their electricity bill is the one that decides about solar. It is not. Three parties are involved in connecting panels to the grid in Chester, and it helps to know which is which before you read a quote.
| Who | What they are | What they do for your solar |
|---|---|---|
| SP Energy Networks | The network operator for the SP Manweb licence area, which covers Merseyside, North Wales and parts of Cheshire, Chester among them | Receives the G98 notification, or decides the G99 application and any export limit |
| Your electricity supplier | The company you buy electricity from and pay bills to | Can pay you for exported power under the Smart Export Guarantee |
| Your MCS installer | The firm that designs and fits the system | Designs to a route, notifies or applies to the network operator, and issues the MCS certificate |
| You | The householder | Choose the installer and the export tariff, and keep the paperwork |
SP Energy Networks sets out its rules on its connecting to the grid page, and Cheshire West and Chester Council’s support schemes page also names it as the local electricity network operator. You do not choose your network operator; it comes with the address. You do choose your supplier, and you can change it.
G98: connect first, then notify
G98 is an Engineering Recommendation, one of the technical standards the electricity industry uses for connecting small generators to the local network. It covers generation of up to 16 amps per phase. On a single-phase supply, the kind most homes have, that works out at 3.68 kW: 16 amps at the standard 230 volts.
“Single-phase” and “three-phase” describe how electricity reaches the building. A single-phase supply has one live conductor coming in to the meter, and it is what most houses and flats have. A three-phase supply has three, and is found in some larger homes and in buildings with heavy loads. The installer checks which one you have, and the answer feeds straight into which route applies.
Under G98 the installer connects the system and then notifies SP Energy Networks within 28 days. Nothing has to be approved in advance, so if a design fits under the limit there is no wait for the network operator at all.
What counts towards the limit is output, measured at the inverter. The inverter is the unit that converts direct current from the panels, or from a battery, into the alternating current the house uses. When you compare quotes, ask what each inverter is rated at and whether the design is meant to stay within G98.
G99: apply before anything is fitted
Anything above the G98 limit goes through G99. That includes larger arrays, homes on a three-phase supply, and solar plus a battery whose combined inverter output is over the limit. The installer applies to SP Energy Networks before installation. Approval can take weeks, and the network operator may set an export limit as a condition.
An export limit is a cap on how much power the system may send to the grid at any one time. It restricts what can flow out, not what the panels make for use in the house. If one is set, the design has to keep to it, so ask the installer how theirs would.
Treat a G99 decision as a step in the timetable, in the same way as planning consent on a listed building. Equipment that needs approval should not be fitted before the approval is in writing.
| Situation | Route |
|---|---|
| Inverter output up to 3.68 kW on a single-phase supply | G98: connect, then notify within 28 days |
| Inverter output above 3.68 kW on a single-phase supply | G99: apply and wait for approval before installation |
| Solar plus a battery with combined inverter output above 3.68 kW | G99: apply and wait for approval before installation |
| A battery or more panels added to an existing system | The combined output decides; ask before ordering |
| A three-phase supply | Ask the installer which route the design takes |
What the installer should do, in order
A competent MCS installer handles the network side as part of the job. You do not need to contact SP Energy Networks yourself, but you should know the sequence so you can tell whether it has been followed.
- Check the supply. Whether it is single-phase or three-phase, and whether there is any existing generation, such as older panels, that counts towards the total.
- Design to a route. State the inverter rating and the combined output with any battery, and say in the quote whether that means G98 or G99.
- For G99, apply first. Submit the application to SP Energy Networks and wait for approval, including any export limit, before fitting.
- Install and commission the system, which means setting it up and testing it before handover.
- For G98, notify SP Energy Networks within 28 days of connection.
- Hand over the paperwork. The MCS certificate, the commissioning record, and a copy of the G98 notification or the G99 approval. Keep them with the house documents, because a buyer may ask for them when you sell.
The wider checks on an installer, from the MCS directory to the consumer code, are in our guide to choosing a solar installer in Chester.
Planning a timetable around G99
A G99 wait only matters if there is a date you care about, and at the moment there is one: VAT on installed home solar and batteries is 0% until the end of March 2027, then 5% from 1 April 2027 (HMRC VAT Notice 708/6). If a design needs G99, ask the installer when the application will go in and plan from there.
Grid connection and planning are separate processes, and neither stands in for the other. A listed home needs planning permission and Listed Building Consent before work starts, as our listed buildings guide explains, and that is in addition to any G99 approval. A shared array on a block of flats may need G99 as well as the freeholder’s consent; see our flats guide.
Being paid for what you export
Connection and payment are separate too. SP Energy Networks connects the system; it does not pay for exported power. Payment comes from an electricity supplier under the Smart Export Guarantee, which Ofgem administers. Licensed suppliers must offer an export tariff above zero for systems up to 50 kW. To qualify, the installation must be MCS certified and you need a smart meter that can record exports. Tariffs vary from supplier to supplier and there is no single SEG rate, so compare them before you sign up.
Most exporting happens between spring and early autumn, when the panels make more than the house uses. To see what a Chester roof is likely to produce through the year, use our roof output estimator.
Chester situations that come up
- Larger detached houses. Handbridge Park has the highest share of detached homes of Chester’s seven wards, 37.5% of households according to Census 2021. Bigger roofs make bigger arrays possible, and a bigger array is more likely to go past the G98 limit, so ask early which route a design takes.
- Adding a battery later. The new equipment counts alongside the old, so a battery added to panels already on the roof can turn a G98 system into a G99 one. Our battery guide covers this.
- Buying through the council’s group-buy. The same G98 and G99 rules apply to a Switch Together Solar installation as to any other; the network does not treat it differently. See our Switch Together guide.
- A listed home in the centre. The planning consents come first, and the grid step still applies to whatever is approved.
Questions to put to an installer about the connection
- What is the inverter rating, and what is the combined output with any battery?
- Does this design go through G98 or G99, and who makes the notification or application?
- If it is G99, when will the application go in, and will you wait for approval before fitting anything?
- If an export limit is set, how will the system keep to it?
- Will I get copies of the MCS certificate, the commissioning record and the network paperwork?