Grid Guru September 2026 Newsletter

Neil Avery

13 hours ago

11 min read

Updates on the Solar and Heat Pump Industry in this months Grid Guru September 2026 Newsletter

Electricity is 26.3p from 1 October, VAT on it drops to 0%, and solar has just had a record half-year. Your September briefing.

September 2026 · Monthly Briefing

From Neil Avery at Grid Guru, renewable energy compliance specialists for UK solar PV, heat pump and EV installers.

Five things to know this month. Ofgem's October–December cap puts electricity at 26.32p/kWh, up ~4% on the summer. From the same day VAT on domestic electricity drops to 0%, so every running-cost figure in your quotes changes on 1 October. MCS logged a record 210,000 installs in the first half: solar up 14%, batteries nearly doubled, heat pumps down 17%. The first plug-in solar kits are on sale now. They count toward the G98 limit, see this month's installer question. And it's show month: Solar & Storage Live, NEC, 22–24 September. DNO response times: table below.

THIS MONTH AT GRID GURU

On the desk this month: G99s for winter solar and storage jobs, commercial EV pre-applications ahead of the 76-plate rush, and the first £9,000 BUS heat pump packs. One heads-up: ENA's Connect Direct portal moved to a new API on 24 August and old links are dead. If your software submits notifications direct, check it still does. Or send the jobs to us: same-day G98 and EV notifications, G99 in 3–5 working days.

REGULATION & POLICY

The October Cap and the VAT Cut Land on the Same Day

From 1 October the price cap puts electricity at 26.32p/kWh with a 54.83p/day standing charge, gas at 7.97p/kWh: a typical bill of about £1,725 a year, up ~4% on the summer. The same day, VAT on domestic electricity drops from 5% to 0% until 31 March 2027. Gas stays at 5%.

Gas is the mover: up 8.7% a unit against electricity's 0.8%, and electricity is now taxed less than gas. The published cap already includes the VAT cut. Without it the rise would have been about 6%. For quotes: rework your gas-vs-heat-pump running costs from 1 October, and remember home EV charging goes VAT-free while public charging stays at 20%. Whether the 0% carries on past March is a Budget question. That's 28 October.

Every running-cost figure in your quote tool changes on 1 October: cap rate, VAT line, export assumptions. Update them in one sitting on the day, then leave them alone until January.

£9,000 Oil and LPG Grant: Confirmed to March 2027

Gov.uk now shows the structure plainly: £7,500 for an air-to-water or ground-source heat pump, plus a £1,500 top-up for homes heated by oil or LPG with no mains gas, running to March 2027. Air-to-air stays at £2,500. Only vouchers applied for on or after 21 July get the higher rate. If you're holding an open £7,500 voucher on an oil job, the revoke-and-reapply route can take it to £9,000. Check with Ofgem before you commission.

Demand is moving. Octopus reported its best month yet for heat pump sales in July and BUS applications up 19% on last year, against MCS data showing installs down 17% across the first half. The work is there for whoever chases the off-grid postcodes. The first month's numbers prove it: 8,150 applications in July, up 81% on June and more than double last July.

Requote every oil and LPG job that stalled at £7,500. We do the heat pump design and MCS 021 documentation. See the service.

Check Your Mounting Kit Is Still Certifiable

Two MCS product-standard dates bit this summer. The grace period for solar mounting products under MCS 012 ended on 10 August. Affected listings can no longer be selected when you create a certificate. A handful of lines (some Fastensol, Clenergy and Solar Slate Plate products) got extensions after certification body BBA had its accreditation suspended. Check the MCS Product Directory for grace-period labels before you certificate, not after.

Panels have longer: MCS 005 Issue 4.0 took effect 1 August, and existing module stock can go into certified installs until 1 February 2027. MCS says that one will not be extended. And the scheme deadline stands: everyone must be on the redeveloped installer scheme by 31 March 2027; your certification body contacts you when it's your turn.

GRID & DNO

Gate 2 Phase 2 Starts Now, and Winter Jobs Need Their G99s In This Month

Phase 1 distribution offers keep landing area by area until mid-November. Phase 2 starts this month for transmission and large embedded projects, with Phase 2 distribution offers from mid-October. Same drill as last time: 90 days to respond, and read the queue-management milestones before you sign. Miss one and you lose the place.

Under 1 MW nothing changes except the calendar. A full G99 can take up to 45 working days, so an application that goes in mid-September is a November answer. Anything you want energised before Christmas needs its G99 in now. One process note for commercial work: sites under 5 MW in England and Wales no longer need a Transmission Impact Assessment, which has taken weeks off some jobs.

Send us your September–October job list and we'll file the G99s this week. We prepare G99 applications, SLDs and G100 export-limitation schemes. See how.

Plug-In Solar Is on Sale, and It Counts Toward the Site Limit

The first compliant 800 W plug-in kits went on sale on 27 August, from about £700, with the big retailers to follow. Compliant kit is listed on ENA's device database, and every unit still needs a G98 notification within 28 days of plugging in. Most buyers won't know that. The bit that matters for you: a plug-in device is generation, so it counts toward the site's 16 A per phase limit when you come to add a proper system. Ask on every survey. See the installer question below.

The DNO turnaround table returns below: the full-G99 response times we're seeing from each network, updated monthly. Keep your data coming: reply with your last G99 (network, date in, date approved) and it goes in next month's table.

Got a G99 stuck in a queue? Reply with the reference and we'll take a look. No charge.

Network (DNO) | Typical full G99 response, recent Grid Guru jobs

National Grid Electricity Distribution Midlands, SW England & S Wales: ~31 days

UK Power Networks London, SE & E England: ~23 days

SSEN S England & N Scotland: ~28 days

SP Energy Networks S Scotland, Merseyside & N Wales: ~25 days

Northern Powergrid NE England & Yorkshire: ~26 days

Electricity North West NW England: ~29 days

TECHNOLOGY IN THE INDUSTRY

A Record Half: 210,000 Installs, Solar Up 14%, Batteries Nearly Doubled

MCS certified 210,000 installations in the first half of 2026, up 17% on last year's record start, one install every 74 seconds. Solar PV did almost 150,000 of them, up 14%. Battery storage hit 36,000 in six months, nearly double last year and closing on 2025's full-year record of 40,000. Heat pumps were the odd one out, down 17%. That's the gap the £9,000 grant is meant to close.

Two numbers to use in your own sales calls: one in three installs went onto a home that already had a certified system, and 92% of batteries went in alongside solar. Retrofit is normal now. The battery add-on, the second array, the diverter: your past customers are your best pipeline.

Show Month: What to See at the NEC

Solar & Storage Live, NEC Birmingham, 22–24 September. Free installer tickets, and EVCharge Live runs on the same pass. Everything Electric London is 11–12 September at Twickenham, and the first National Heat Pump Week runs 12–16 October. If you make one trip, make it the NEC.

Kit worth a look while you're there: Enphase's IQ9N GaN microinverters are now shipping in the UK; Sigenergy's SigenStor Neo all-in-one is on its way over; EcoFlow's Stream batteries (from £1,499, aimed at the plug-in market but pro-install) are open for pre-order; Viessmann's Vitocal 200-A ie R290 pump lands this autumn; and zappi now ships with zapsafe supply protection, which should cut nuisance trips. Picks table below.

Category | This month's standout picks

Solar panels: Aiko Neostar 3P (low-light, 30-yr); JA Solar DeepBlue 4.0 Pro (value); REC Alpha Pure-RX (shading)
Inverters: Fox ESS KH/KA Series (all-rounder); Sunsynk ECCO (control); SolarEdge Home Wave (shade); Enphase IQ9N GaN micro (complex roofs, now shipping UK); Sigenergy SigenStor Neo (all-in-one, incoming)
Heat pumps (R290): Vaillant new-gen aroTHERM plus (44 dB, in merchants now); Mitsubishi Ecodan R290 (easier siting); Grant Aerona 290 (value); Viessmann Vitocal 200-A ie (from autumn)
EV chargers: Zappi (solar diversion, zapsafe protection); Ohme Home Pro (smart-tariff auto); Hypervolt Home 3 Pro (all-round); Pod Solo 3S (value, Pod now under EDF)

THIS MONTH'S BEST DEALS

What's worth putting in a quote this month across all three trades.

HEAT PUMPS: £9,000 BUS on oil & LPG homes, to March 2027

Confirmed on gov.uk: £7,500 plus a £1,500 off-gas top-up for oil and LPG properties, air-to-water and ground-source. Stacks with 0% VAT on the install. Applied for on or after 21 July = the higher rate.

SOLAR · VAT: 0% VAT on installs, seven months left

Solar, batteries and heat pumps stay zero-rated to 31 March 2027, then revert to 5%. On a £10,000 job that's £500 back on the table from April. A real deadline to put in autumn quotes.

EV CHARGERS: £500 per socket, plus a VAT edge from October

The chargepoint grant (renters and flat owners, landlords up to 200 sockets, workplaces up to 40) runs to 31 March 2027. Confirm live figures on gov.uk before quoting. From 1 October home charging carries 0% VAT while public charging stays at 20%, in the biggest registration month of the year.

INSTALLER CASH: Baxi £500 per ASHP install to 31 December; Mitsubishi £500 for a first Ecodan

Baxi's £500 cashback (HP40/HP60, MCS installs via Baxi Works, paid in 28–45 days, uncapped) is still live. New: £500 toward Alto Energy's MCS umbrella costs for a first Ecodan install. First 200 installers, to 31 March.

TRADE WATCH: This month's distributor specials

Segen: £895 off JA Solar's BluePlanet C&I storage package, and the Anker SOLIX installer loyalty scheme is live. Details in the portal. Midsummer: heat clearance running (cylinders, Mixergy, Sunamp), and Enphase's IQ Battery 5P FlexPhase has landed: one battery for single or three phase. BimbleSolar: Schletter roof-mount kits ~15% off on clearance while stock lasts. The sharper prices sit behind the trade logins. Check your portal before ordering.

ENERGY TARIFFS THIS MONTH

From 1 October the cap puts electricity at 26.32p/kWh plus 54.83p/day standing charge, gas at 7.97p/kWh, and domestic electricity carries 0% VAT. Rates below verified late August 2026. SEG and smart rates change on ~30 days' notice, and most cap-linked tariffs reprice on 1 October, so check live before advising.

Solar export (SEG): top rates

Octopus Flux: up to 29.32p/kWh peak (Battery + Octopus import)
Good Energy Solar Savings Excl.: 25p/kWh flat, 12-mo fix (Install via Good Energy partner)
So Energy So Bright Export: 20p/kWh, 12-mo (So Energy install + supply)
EDF Export Exclusive (12m, V3): 18p/kWh fixed (Kit bought via EDF; ≤50 kWp)
E.ON Next Export Premium: 17.5p/kWh, 12-mo fix (E.ON install; ≤15 kW)
Outgoing Octopus: 12p/kWh flat (Octopus import)
Standard SEG floor: ~3–4.5p/kWh (Open to anyone)

Unchanged: OVO's install-exclusive up to 20p; British Gas Export Premium 12p (≤15 kW) / Export Extra 8p (BG import customers). Intelligent Octopus Flux is still closed to new sign-ups. One to watch: E.ON's Next Optimise beta (dynamic solar + battery). The first 1,000 get 3p off import 00:00–06:00 and 3p extra on export 16:00–19:00. Import and export don't have to be with the same supplier.

EV charging: off-peak windows

EDF GoElectric Overnight: 6.99p/kWh (23:00–06:00, the longest cheap window going)
Intelligent Octopus Go: 8p/kWh (23:30–05:30 + smart bonus slots)
E.ON Next Drive: 8p (Smart) / 9p fixed (00:00–06:00)
British Gas EV Power: 9p/kWh (00:00–05:00)

ScottishPower EV Saver is 8.5p but the window shifts to 01:00–06:00 during BST on most smart meters. Know that before a customer says their schedule is wrong. OVO Charge Anytime is 14p any-time smart charging, now with monthly-mile plans. Against a ~26p capped day rate, a decent off-peak tariff is still worth more per year than the £500 socket grant.

Heat pumps: dedicated tariffs

Cosy Octopus: ~13p off-peak (regional) (Triple-dip: 04–07, 13–16, 22–00)
British Gas Heat Power: 50% off units (13–16 & 00–07 daily; BG import)
EDF Heat Pump Tracker: standard rate minus 10p (04–07 & 13–16 windows)
Good Energy Heat Pump: 13p/kWh off-peak (05–09 & 13–16; reprices 1 Oct)

ScottishPower Heat Pump Saver holds at 14p (11:00–16:00). E.ON Next Pumped is quote-only by region, super off-peak 22:00–06:00. OVO Heat Pump Plus stays closed to new customers. Every rate here moves with the cap and the VAT change on 1 October. Re-check on the day.

None of it pays without the paperwork: no valid MCS certificate, no SEG registration, and import and export can sit with different suppliers. If the handover pack isn't right, the customer's export earns nothing. See how we handle handover packs.

QUESTION FROM AN INSTALLER

"A customer's just bought one of the new plug-in solar kits. Does it affect the G98 for the proper 3.68 kW system I'm quoting him?"

Yes. G98 covers all generation at the property combined, up to 16 A per phase (3.68 kW single-phase). A plug-in kit is generation with its own G98 notification, so an 800 W device plus your 3.68 kW inverter puts the site at 4.48 kW. Over the line, the whole installation now needs a G99 application, approved before you install, not a notification after.

Three ways to play it. Price the job as a G99 from the start and build in the lead time. Have the customer remove the plug-in kit before you notify. If it's gone, it doesn't count, but it has to actually be gone. Or fit a G100 export-limitation scheme to cap the site at its approved level, often the quickest route through. Either way, ask about plug-in kits on every survey from now on. Finding one after you've submitted is rework you could have priced in.

Not sure which side of the line a job falls? Reply with the spec and we'll tell you, no charge. Questions for next month welcome too. We answer one per issue, named or anonymous.

WHERE WE WATCH

The sources behind this briefing.

Ofgem: ofgem.gov.uk
Price cap announcements, BUS guidance and SEG scheme rules.
Cornwall Insight: cornwall-insight.com
Independent price-cap forecasts ahead of each Ofgem announcement.
NESO: neso.energy
Connections reform timeline, Gate 2 windows and queue data.
GOV.UK (DESNZ & OZEV): gov.uk
BUS grant values, VAT reliefs and chargepoint grant rules.
MCS Certified: mcscertified.com
Installation data, product standards, directory and scheme transition.
Energy Networks Association: energynetworks.org
EREC G98/G99/G100 documentation, Connect Direct and the Type Test Register.
Solar Power Portal: solarpowerportal.co.uk
UK trade coverage of solar PV, storage, policy and market data.
Renewable Energy Installer: renewableenergyinstaller.co.uk
MCS changes, product news and installer business guidance.
Energy Stats UK: energy-stats.uk
Independent smart-tariff pricing across all 14 DNO regions.
MoneySavingExpert: moneysavingexpert.com
Cross-checked import and export tariff comparisons.

HOW GRID GURU CAN HELP

One point of contact for the compliance and design side. Same-day G98 and EV notifications; G99 in 3–5 working days; domestic and commercial.

G98 DNO Notifications — Solar PV and storage G98 notifications — all networks
G99 DNO Applications — Full G99 applications, SLDs and DNO approvals
EV & Heat Pump Notifications — DNO notifications and commercial pre-applications, 1- & 3-phase
Solar PV Design — String sizing, shading analysis and technical specifications
Heat Pump Design — MCS-compliant ASHP design, including MCS 021 documentation
MCS Handover Packs — Compliant domestic & commercial solar PV and heat pump packs
Consultancy — Regulatory guidance, compliance queries and project support

THIS MONTH — FREE AUTUMN PIPELINE CHECK

Booked jobs for October and November ? Reply with your job list one line per job is enough and we'll tell you which need a full G99, which are G98 or notification-only, and the realistic DNO lead time for each. Free, no obligation.

Grid Guru Group Ltd · Co. No. 14645213 · 02920 609009

neil@gridguru.co.uk · www.gridguru.co.uk