Tesla Powerwall installer covering Teesside and County Durham

ALPS Electrical is based at Kirklevington, just outside Yarm. We are MCS Certified, NAPIT Registered and a Tesla Certified Installer — one of around 50 in the UK by our own count, though Tesla does not publish that number. We hold 500+ five-star reviews across Checkatrade and Google and won Checkatrade's Sustainability Champion award in 2024 (see accreditations). Andy Pemberton surveys and specifies every system himself.

Tesla's guidance says installation should only be performed by a Tesla Certified Installer, and in the UK you are connected to one, who then contacts you about pricing. Tesla publishes no UK price. Our own guide price is from £8,500 installed for a single Powerwall 3; the survey sets the final figure.

One Powerwall 3 stores 13.5 kWh of usable energy with the solar inverter built in — three MPPT inputs, up to 20 kW of solar at STC. In the UK it is single-phase 230 V, and the installer sets its continuous output at commissioning between 3.68 kW and 11.04 kW (16 A to 48 A). That number drives everything below, because it decides how Northern Powergrid treats your battery storage connection.

Every home in this patch sits on Northern Powergrid's network — the distribution operator for the North East, Yorkshire and northern Lincolnshire, 3.9 million homes and businesses through more than 66,000 substations. Its connections office is on our doorstep at Alix House, Falcon Court, Preston Farm, Stockton-on-Tees TS18 3TU, the address printed on its generation application forms.

G98: fit it, then notify

G98 covers fully type-tested micro-generation up to and including 16 A per phase — 3.68 kW single-phase — and explicitly counts electricity storage devices, so a home battery is in scope. If the aggregate capacity at your property stays inside that limit we fit the system, then notify Northern Powergrid within 28 days of commissioning. That is a legal requirement, not a courtesy.

G99: the route most Powerwall jobs take

Above 16 A per phase it is G99, and the application must go in before any generation equipment is installed so the operator can assess the impact and issue a Connection Offer; the acceptance window is typically 30 to 90 days. The industry's connection guide is blunt about batteries: one installed alongside PV usually takes total generation past 16 A per phase, so G99 applies.

There is a fast track that cuts the operator's confirmation from 45 days to 10 days or less. Northern Powergrid's rules require combined generation-plus-storage under 32 A per phase, each device under 16 A per phase, export limited to 16 A per phase by a G100-compliant limiter, and no island mode.

That last condition is the one that catches Powerwall buyers. Island mode is exactly what backup power is, so if you want the house to stay lit through an outage the fast track does not apply. A whole-home backup Powerwall in Middlesbrough, Darlington or Durham is a full G99 application: plan around the statutory maximum of 45 working days for a low-voltage generation quotation.

One closing point on kit: from 1 March 2026 new storage devices must switch from import to export mode if grid frequency falls below a defined threshold, and anything commissioned after September 2022 has to be fully G98 or G99 compliant. Powerwall 3's UK datasheet lists certification to G98, G99 and G100.

Half of this job is electrical and half is deciding where a 1,105 x 609 x 193 mm, 130 kg unit lives for the next decade. The housing here changes that answer street by street.

Semis dominate. Redcar and Cleveland is 45.3% semi-detached, Stockton-on-Tees 42.4% and Middlesbrough 42.3%, against 31.5% for England — and about 51% of Redcar and Cleveland's 66,390 dwellings, 45% of Stockton's 90,280 and 43% of Middlesbrough's 66,160 date from 1945 to 1982. In houses of that era there is nearly always a garage, utility or side wall that takes the unit cleanly, close to the board.

Terraces are the harder brief. Hartlepool is 32.9% terraced, the highest in the Tees Valley, and County Durham 35.4% against England's 23.0% — much of it old, with about 22% of the county's 254,180 dwellings pre-dating 1919. No garage, no side passage, a shared yard. Powerwall 3 is indoor and outdoor rated at IP55, runs from -20°C to 50°C and is flood resistant to 0.6 m, so a yard or gable wall is usually the answer. On noise, Tesla quotes under 50 dB(A) typical at one metre: keep it off a bedroom party wall and nobody notices it.

The newer estates are different again. Stockton has the highest share of 1983-2008 housing of the six local authorities — about 22% of its stock, roughly 19,900 homes, the Ingleby Barwick and Eaglescliffe era. Integral garages and short runs back to the board, but often a narrow side passage. Up to three Expansion units stack behind a floor-mounted Powerwall, each adding 13.5 kWh and weighing 110 kg, so the access route matters as much as the wall.

One constraint decides more surveys than anything else: the bottom clearance of a Powerwall can be no more than 1,140 mm, which rules out most high-level positions. And be realistic about what a battery fixes — the median EPC score for pre-1929 homes across these six council areas is 58 to 62, band D, against 83 to 84 for homes built from 2012. A battery does nothing for fabric.

Look at the postcodes and a mileage rule makes no sense here. TS15, which covers Yarm and the villages around our base, spans both North Yorkshire and Stockton-on-Tees. TS9 at Stokesley spans North Yorkshire and Redcar and Cleveland. TS21 around Sedgefield straddles County Durham, Darlington and Stockton-on-Tees. DL2 spans four authorities at once, and DL1 and DL5 straddle Darlington and County Durham.

Elsewhere it is tidier: TS1 is Middlesbrough, TS16 and TS18 Stockton-on-Tees, TS24 Hartlepool, TS10, TS12 and TS14 Redcar and Cleveland, DL3 Darlington, DH1 Durham city. We work across all of it from Yarm and cover North Yorkshire on the other side of the same postcode areas. If you are near an edge, ask.

These are the towns we work in most often, with the dedicated Tesla Powerwall page where we have one.

Tees Valley

• Middlesbrough — 60,262 households, 42.3% semi-detached (also Tesla Powerwall in Middlesbrough)
• Stockton-on-Tees — 83,756 households, the highest detached share of the six authorities at 26.5% (also Tesla Powerwall in Stockton)
• Thornaby, Eaglescliffe, Ingleby Barwick and Yarm — the Stockton estates on our doorstep
• Billingham and Hartlepool — 40,932 Hartlepool households, a third terraced
• Redcar, Saltburn and Guisborough — 61,637 households
• Stokesley — TS9, on the North Yorkshire line

Darlington and County Durham

• Darlington — 48,920 households, 28.5% terraced (also Tesla Powerwall in Darlington)
• Durham — County Durham, 234,761 households, 4.1% purpose-built flats against 17.1% for England
• Sedgefield — TS21, spread across three council areas

For the wider picture, start with solar panels across Teesside. Local government is pushing the same way: carbon neutral targets of 2039 in Middlesbrough, 2030 in Redcar and Cleveland, 2050 in Stockton-on-Tees and a net zero county by 2045 in Durham. Homes are why — County Durham's 2022 footprint was 2,006.6 ktCO2e, of which domestic emissions are 38%.

Survey. Andy looks at the board, the roof if solar is part of it, and where the unit can go. Two things get settled that day: G98 or G99, and whole-home or partial backup — with partial backup the circuits are chosen at design stage and the system excludes everything else. If a heavy motor load has to ride through the changeover, Powerwall 3 starts loads up to 185 A LRA.

Gateway. In the UK, Powerwall 3 is installed with Backup Gateway 2 — the supported islanding device on the UK datasheet and in Tesla's EMEA owner's manual. It is an 11.4 kg wall-mounted unit, IP55 rated, 100 A nominal single-phase, with a ten-year warranty of its own. There is also a non-backup configuration using a Tesla Remote Meter: cheaper, but no backup power, Storm Watch or Backup Reserve, though a Gateway can be added later.

Paperwork and VAT. We handle the Northern Powergrid application or notification either way. Home battery storage currently carries 0% VAT: HMRC's zero rate for energy-saving materials runs to 31 March 2027 and reverts to 5% on 1 April 2027, and since 1 February 2024 it has covered retrofitted and standalone batteries too.

Install day. Tesla's guidance is a full day on site with the power off for roughly four to six hours, or longer where extra electrical work is needed; that matches what we see. It needs a reliable internet connection — Wi-Fi, Ethernet or cellular as a fallback — which Tesla expects the customer to provide.

Handover. We set the app up before we leave: your tariff under Utility Rate Plan, so Savings mode charges when energy is cheap; a Backup Reserve, which the app flags as low under 20% and which, below 5% when an outage hits, means the house goes dark until solar recharges it; and Storm Watch, which charges to full on a Met Office Amber or Red alert mentioning a risk of power cuts — worth having on the coast at Redcar and Hartlepool. Note for EV owners: Intelligent Octopus Go is not used by Powerwall for cost optimisation, though Intelligent Octopus Flux enrols it in Octopus's virtual power plant.

Warranty. Ten years from installation, warranted at 13.5 kWh on day one and 80% retention at ten years for UK installs, unlimited cycles for self-consumption, time-based control and backup — provided it stays online, because Tesla may limit the warranty to four years if the unit cannot reach the internet and it cannot contact you. Finished work is on our projects page.

We would rather talk you out of the wrong system than fit it. Start with the physics: the UK datasheet gives 89% for the solar-to-battery-to-home path against 97.5% solar-to-home, so routing energy through the battery costs about a tenth.

You already have a Powerwall 2 and want more storage. Powerwall 3 will not do it — Tesla is explicit that it cannot be added to a Powerwall 2, and Expansion units are Powerwall 3 only.

Price per stored kWh is the only thing that matters. Then say so at the survey. We also install Fox ESS battery and hybrid-inverter systems (including the Fox Cube battery) and have two complete installs documented on our YouTube channel. We are also an early adopter of the Sigenergy SigenStor in the North East — we install and commission SigenStor systems and have two complete installs documented on our YouTube channel. Sometimes one of those is the better buy, and we will say so.

You are buying a battery to cut your heating bill. It will not. This is one of the most gas-connected corners of England: 2.1% of Hartlepool's properties are off the gas grid, 3.2% in Stockton-on-Tees, 3.5% in Middlesbrough, 5.9% in Darlington and 6.5% in County Durham, against 15.5% across England. A battery here earns on electricity — self-consumption instead of export, time-of-use tariffs, EV charging and backup. It can go in without solar and charge from the grid, alongside new solar, or onto an existing array (Tesla says it is compatible with all major inverter brands). Send us your postcode and a photo of the board.