What battery storage systems do you install?

We install leading brands including Tesla Powerwall and GivEnergy. We advise on the right capacity for your home based on consumption and generation profile.

Can I add battery storage to my existing solar panels?

Yes. We retrofit battery systems to most existing solar installations. We assess your inverter compatibility and DNO requirements before recommending a solution.

How much can I save with a home battery?

Savings depend on your tariff, generation and consumption. Most customers significantly reduce grid imports by storing daytime solar generation for evening use.

Battery Solar Grid Integration Surrey and SW London | G99 DNO Approval | Export Limiting | Smart Arbitrage

Your Estate as a Virtual Power Plant - Buying Cheap, Self-Consuming, and Selling High

Standard solar and battery installations are designed to reduce your energy bill. A fully integrated Battery, Solar, and Grid system is designed to generate yield. By connecting a high-capacity Tier-1 solar array and intelligent battery storage into the national grid through a precisely engineered three-layer architecture, your Surrey or SW London estate becomes a profitable node in the wider energy network. The system's brain buys cheap electricity from the grid overnight on Octopus Agile or Flux off-peak rates - currently 7 to 9p/kWh. It self-consumes free solar generation during daylight hours at full grid replacement value. And it exports stored energy back to the grid during peak evening demand windows at the highest available export rates - currently up to 15p/kWh on Octopus Flux. Each cycle is executed automatically by the hybrid inverter platform, 365 days a year, without any manual intervention. For large Surrey estates with arrays of 12kWp or more and battery capacity of 27 to 40kWh, the combined annual return from self-consumption, arbitrage cycles, and SEG export income routinely exceeds 3,000 to 5,500 GBP per year. This is not energy saving. This is automated energy trading from a private estate microgrid.

Three Pillars of Elite Grid-Integrated Energy Architecture

Home energy app showing solar import and export — battery discharge savings London MCS electricalworks

Octopus Flux Arbitrage - Automated Buy Low, Export High

Octopus Flux is the first UK residential tariff designed explicitly for battery owners with solar. It offers a structured import rate of 7 to 9p/kWh overnight and a simultaneous export rate of up to 15p/kWh during the 4pm to 7pm peak demand window. Your hybrid inverter connects to the Octopus API, receives half-hourly pricing data 24 hours in advance, and executes the optimal charge and discharge cycle autonomously every day. For a Surrey estate with 27kWh of battery capacity cycling on the full Flux spread, the annual pure arbitrage yield - before self-consumption savings are applied - is 1,200 to 1,800 GBP per year. Combined with maximum solar self-consumption and SEG export income, the integrated system generates a total annual return that routinely exceeds the equivalent of a modest investment portfolio at current interest rates.

Wall-mounted lithium home battery with isolators — backup power for London homes G98 compliant MCS

G99 DNO Applications for Large Estates and 3-Phase Systems

Standard residential solar installations below 3.68kW per phase qualify for automatic G98 notification to the Distribution Network Operator. A luxury Surrey or SW London estate with a 12 to 20kWp solar array and 27 to 40kWh of battery storage will exceed this threshold on every phase - triggering the mandatory G99 application and DNO engineering approval process. This is a formal submission to UK Power Networks or SSEN requiring electrical load flow calculations, protection relay coordination data, and inverter technical compliance documentation. We manage the full G99 application on your behalf - from initial DNO feasibility enquiry through to grid connection approval. Our G99 track record with both UK Power Networks and SSEN ensures no delays in the approval timeline that would hold back your installation programme.

Retrofit AC-coupled battery beside existing solar — increased self-consumption London electricalworks

Export Limiting for Constrained Rural and Suburban Grids

Many affluent Surrey and SW London postcodes are served by overhead low-voltage distribution networks that were not designed for significant residential generation export. When the local grid has insufficient headroom to accept your full array export capacity, the DNO issues an export limitation condition as part of the G98 or G99 approval - restricting your permitted export to 0kW or a low fixed value per phase. Export limiting resolves this constraint without reducing your array size or your self-consumption potential. A smart current transformer installed on the grid connection point feeds real-time import and export data to your hybrid inverter, which modulates the battery charge and discharge rate to mathematically guarantee that export never exceeds the DNO-permitted value at any instant. Your estate installs the full-scale array it requires for maximum self-consumption and arbitrage return, while the grid sees only the approved export figure at all times.

Battery Partners

Installation Gallery

Tesla Powerwall 2

Richmond, TW10

Myenergi Libbi modular battery system — expandable storage with solar diversion London MCS

MyEnergi AIO

Clapham, SW4

Solis hybrid inverter with battery port — DC-coupled storage option for London PV upgrades

Solis Home

Hampstead, NW3

Loft-mounted battery inverter system — space-saving install with fire detection London BS 7671

Loft Install

Ealing, W5

From Grid Constraint Assessment to Live Trading System

Grid Feasibility and DNO Assessment

We assess your property's existing DNO connection, phase configuration, and local grid export headroom before any system is specified. For systems above 3.68kW per phase, we initiate the G99 DNO feasibility enquiry with UK Power Networks or SSEN to establish the approved export limit and identify any export limiting requirements from the outset.

Three-Layer System Architecture

We design the solar array, battery capacity, and grid connection architecture as a single integrated programme. String layout, phase balancing, inverter platform selection, CT sensor placement, and export limiting configuration are co-designed from day one to ensure DNO compliance and maximum system yield simultaneously.

G99 Submission and Compliant Installation

We manage the full G99 application, compile all required technical documentation, and co-ordinate DNO approval before installation commences. Our NAPIT master electricians execute the full installation programme - solar array, hybrid inverter, battery, CT sensors, export limiting hardware, and consumer unit integration - to MCS and BS 7671 standards throughout.

Octopus Flux Commissioning and Live Trading

We configure Octopus Flux or Agile tariff scheduling, verify export limiting is operating correctly within DNO-approved parameters, complete SEG registration, and issue all G99 compliance and MCS documentation before engineers leave site. Your estate begins automated energy trading from commissioning day.

The Engineering Detail of Grid-Integrated Energy Architecture

Smart Grid Arbitrage - The Octopus Flux Financial Mechanics

The Octopus Flux tariff is structurally designed for battery owners with solar - with a defined low-rate import window overnight and a high-rate export window in the evening peak.

The import rate of 7 to 9p/kWh applies from 2am to 5am. The export rate of up to 15p/kWh applies from 4pm to 7pm. Your hybrid inverter connects to the Octopus API, receives the half-hourly price schedule 24 hours ahead, and executes the optimal charge and discharge cycle automatically. In summer, the battery fills on solar during the day and exports during the 4pm to 7pm peak. In winter, the overnight cheap import cycle fills the battery for daytime self-consumption and evening peak export.

Flux import rate: 7 to 9p/kWh overnight versus standard daytime rates of 25 to 35p
Flux export rate: up to 15p/kWh during 4pm to 7pm peak window
Annual arbitrage yield: 1,200 to 1,800 GBP per year on a 27kWh battery cycling the full Flux spread
Zero manual management: all scheduling executed automatically via the Octopus API integration

AC-coupled battery inverter schematic - retrofit battery on existing solar London MCS

DC-coupled battery with hybrid inverter - higher round-trip efficiency new solar London electricalworks

G99 DNO Applications - Engineering Large Estates Beyond the Standard Grid Limit

Any system exceeding 3.68kW per phase triggers a mandatory G99 application to the Distribution Network Operator - a formal engineering submission requiring load flow calculations and inverter compliance documentation.

A luxury Surrey estate with a 12 to 20kWp solar array exceeds the G98 automatic notification threshold on every phase of a 3-phase supply. We manage the complete G99 application process: initial DNO feasibility enquiry, electrical load flow modelling, protection relay coordination data, inverter G99 compliance certificates, and all correspondence with UK Power Networks or SSEN from first submission to grid connection approval.

G99 threshold: any single or 3-phase system above 3.68kW per phase requires formal DNO engineering approval
Full application management: feasibility, load flow calculations, compliance documentation, and DNO correspondence
UK Power Networks and SSEN: established track record with both DNOs covering Surrey and SW London
3-phase system design: phase balancing and string layout optimised for maximum generation within DNO-approved limits

Modular battery stack expansion - scalable kWh for growing EV and heat pump loads London

Export Limiting - Maximum Array Size on a Constrained Grid

A DNO export limitation condition does not mean a smaller array - it means smarter engineering. Export limiting allows a full-scale installation while guaranteeing the grid never receives more than the approved export value at any instant.

Surrey and SW London suburban and rural overhead distribution networks frequently carry export limitation conditions of 0kW to 3.68kW per phase. A smart CT sensor on the grid connection point feeds real-time import and export data to the hybrid inverter, which adjusts battery charge and discharge rates in milliseconds to ensure export never exceeds the approved limit - even during peak solar generation periods with low household consumption.

CT sensor grid monitoring: real-time import and export measured at the grid connection point continuously
Millisecond inverter response: battery charge rate modulated to prevent export breach at all times
Full array size preserved: 12 to 20kWp arrays installed for maximum self-consumption regardless of export limit
DNO compliance guaranteed: mathematical export control verified and documented for DNO submission

Battery installed in ventilated utility room - clearance and fire regulation compliance London

Heat and smoke detection near battery store - insurance and DNO best practice London install

0% VAT, Server-Grade Aesthetics, and Flawless Compliance

The complete integrated hardware stack - solar, battery, inverter, and grid connection infrastructure - qualifies for 0% VAT when installed as a single concurrent programme.

On a Surrey grid-integrated system investment of 25,000 to 45,000 GBP, the zero-rated VAT position delivers a capital saving of 5,000 to 9,000 GBP applied at invoice. Every installation is executed by our directly-employed NAPIT master electricians - with all DC and AC cabling concealed through building fabric, powder-coated steel trunking where surface routing is unavoidable, and plant room equipment positioned and mounted to data-centre layout standards.

0% VAT at invoice: full hardware stack and all labour zero-rated as a qualifying energy-saving installation
Capital saving: 5,000 to 9,000 GBP on a typical Surrey grid-integrated system
NAPIT and MCS certified: every installation certificated for G99 compliance, SEG registration, and buildings insurance documentation
Concealed cable topology: no surface conduit on visible walls - same standard as every other premium system on the estate

Agile import export grid trading screen - battery arbitrage with Octopus-class tariffs London

SMETS2 smart meter with CT clamps - accurate import export for battery control London MCS

Client Success Stories

James O.

Weybridge, Surrey

★★★★★

"We have a 3-phase supply and a 16kWp array that required a G99 application. The team managed the full DNO submission to UK Power Networks and kept us informed throughout the approval timeline. The Octopus Flux configuration was set up on commissioning day. In the first monitored quarter, the combined self-consumption saving, Flux export income, and overnight arbitrage return came to just over 1,100 GBP - ahead of the pre-commitment model projection."

Elena M.

Richmond, TW10

★★★★★

"Our property is in an area with a strict 0kW export limitation on the local network. We were told by another installer that this meant we could only install a small system. The electricalworks team engineered a full 12kWp array with 27kWh of storage and an export limiting solution. The grid sees zero export at all times. Our self-consumption is running at 91 percent. The installation aesthetics in the plant room are exceptional - every cable concealed and every component mounted exactly as the pre-installation render showed."

What Every Large-Array Owner Should Understand Before Grid Integration

Battery cycle life versus depth of discharge chart — warranty expectations London MCS customers

G98 vs G99 - Which Applies to Your Estate

G98 is the automatic self-notification route for single-phase systems up to 3.68kW and 3-phase systems up to 11.04kW total. Above these thresholds, a formal G99 application to your Distribution Network Operator is mandatory before any installation can proceed. Most luxury Surrey estates with arrays above 8kWp on a single-phase supply, or 12kWp on a 3-phase supply, will require G99 approval. We identify the correct route during the initial feasibility assessment and manage the entire DNO process on your behalf at no additional engineering charge.

Hybrid inverter commissioning menu — battery charge limits and grid charge settings London

Why Octopus Flux Outperforms Agile for Large Battery Owners

Octopus Agile offers variable half-hourly import rates that can drop to 1p/kWh or below during overnight low-demand periods - useful for maximising overnight charging on highly variable pricing. Octopus Flux offers a structured and predictable import rate of 7 to 9p/kWh overnight combined with a guaranteed export rate of up to 15p/kWh during the 4pm to 7pm peak window. For estate owners with large battery capacity who need to model a reliable annual export income, Flux's predictable two-rate structure delivers a more consistent financial model. We configure and review the optimal tariff for your specific battery capacity and consumption profile annually.

Winter solar yield versus battery reserve — seasonal performance expectation London electricalworks

Export Limiting Does Not Mean a Smaller System

A common and costly misconception: a DNO export limitation condition of 0kW or 3.68kW per phase does not restrict your array size. It restricts what you can send back to the grid. With export limiting hardware and a correctly sized battery, a 16kWp array can be installed on a 0kW export-limited connection - capturing the full generation for self-consumption and battery storage, with the CT-sensor-controlled inverter mathematically guaranteeing zero export at every instant. Homeowners who accept a scaled-down array in response to a DNO export limitation have not been given the correct engineering advice.

Frequently Asked Questions

When does my system require a G99 DNO application rather than a G98 notification?

A G99 application is required when the total installed generation capacity exceeds 3.68kW per phase on a single-phase supply, or when the combined system capacity on any phase of a 3-phase supply exceeds 3.68kW. For a typical luxury Surrey estate with a 10 to 20kWp solar array, a G99 application to your Distribution Network Operator - either UK Power Networks or SSEN depending on your postcode - is almost certain to be required. G99 approval must be received before installation commences. We initiate the feasibility enquiry as the first step of every large system project and manage the full application on your behalf.

What is an export limitation condition and how does it affect my system?

An export limitation condition is a restriction issued by the DNO as part of your G98 or G99 approval, specifying the maximum amount of power you are permitted to export to the grid. Common limits are 0kW, 3.68kW per phase, or a fixed value per phase. Export limiting does not restrict how much solar you can generate or store for self-consumption - it only restricts what you send back to the grid. A CT sensor on the grid connection point monitors real-time export, and the hybrid inverter modulates battery charge and discharge to guarantee the DNO limit is never exceeded. We engineer export limiting solutions as a standard capability for all Surrey and SW London estate installations.

How much can a Surrey estate earn annually from Octopus Flux grid trading?

For a Surrey estate with a 12 to 16kWp solar array and 27kWh of battery storage on Octopus Flux, the total annual financial return combines three streams: solar self-consumption savings of approximately 1,400 to 2,200 GBP (replacing 25 to 35p grid imports with free solar generation), peak export income of approximately 600 to 900 GBP from battery discharge at up to 15p/kWh during the 4pm to 7pm window, and overnight import arbitrage of approximately 400 to 600 GBP from charging at 7 to 9p/kWh overnight. Total combined return: 2,400 to 3,700 GBP per year from a single 3-phase grid-integrated system. We model your specific property with your actual consumption data and provide this forecast before any commitment is made.

Does the complete grid-integrated system qualify for 0% VAT?

Yes. When solar panels, battery storage, and all associated grid integration hardware are installed as a single concurrent programme, HMRC classifies the entire project as a qualifying energy-saving installation at 0% VAT. This applies to the full hardware stack: solar modules, hybrid inverter, battery modules, mounting system, CT sensors, export limiting hardware, consumer unit amendments, and all installation labour. On a Surrey grid-integrated system investment of 25,000 to 45,000 GBP, the 0% rate saves 5,000 to 9,000 GBP at invoice. We confirm the correct VAT treatment in writing at quotation stage before any commitment is made.

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Battery + Solar + Grid Integration: Transform Your Estate into an Automated Energy Trading Node