Solar Battery Storage Installation in West Sussex & the South East
Store solar energy during the day. Charge from the grid when rates are low. Use your stored energy when your home or business needs it most. Omni3 designs and installs smart battery storage systems from EcoFlow, Sigenergy and SolaX — helping you reduce reliance on the grid, make better use of your solar panels and take advantage of time-of-use tariffs.
Spread the cost of your battery storage installation with finance options available through Ideal4Finance — many customers find this fits comfortably alongside the energy savings they generate.
OMNI3 LIMITED is an Introducer Appointed Representative of Ideal Sales Solutions Ltd, t/a Ideal4Finance. Ideal Sales Solutions Ltd is a credit broker and not a lender (FRN 703401). Finance available subject to status. The rate offered is always provisional and will depend upon your personal circumstances, the loan amount and the term.
How battery storage works
A battery stores energy from your solar panels or the grid when electricity is cheap, then releases it when you need it most.
With solar panels
- → Panels generate free electricity during daylight
- → Surplus energy charges your battery instead of being exported
- → Battery powers your home in the evening at zero cost
- → Self-consumption jumps from 50–70% to 70–90%
Without solar (grid-only)
- → Battery charges overnight at the cheapest tariff rates
- → Stored energy powers your home during expensive peak hours (4–7pm)
- → Ideal for time-of-use tariffs like Octopus Agile or Go
- → Typical savings of 30–50% on peak electricity costs
Best results: solar + battery + smart tariff
Combining all three gives you maximum control over your energy costs. We design systems optimised for half-hourly tariffs, load shifting and energy arbitrage.
Learn about solar panel installation →Not ready to get a quote yet?
Download our free Home Battery Storage Buyer's Guide — sizing, brands, costs, smart tariffs and questions to ask.
How battery storage works with smart tariffs
Modern electricity tariffs vary the price you pay by time of day. A battery lets you exploit that — charging when electricity is cheapest, then using stored energy when it is most expensive. This is called energy arbitrage, and it significantly improves the financial return of your battery investment, even without solar panels.
A typical day on a time-of-use tariff
Off-Peak
Midnight–7am
~7–12p/kWhSolar Hours
7am–4pm
Free generationPeak
4pm–7pm
28–45p/kWh grid priceEvening
7pm–midnight
Standard rateIllustrative only. Exact rates vary by tariff. Agile prices fluctuate half-hourly.
Octopus Agile
Agile prices change every 30 minutes — falling very low (sometimes negative) in the early hours. A battery with smart scheduling charges automatically during the cheapest slots and discharges at peak. Typical savings vs standard tariff: 30–50% on electricity costs.
Octopus Go & Intelligent Go
Go provides a fixed cheap rate overnight (typically 7–9p/kWh vs 28–35p peak). Intelligent Go goes further, scheduling your battery and EV charger automatically. Simple, predictable and very effective for households with an EV.
What is energy arbitrage?
Arbitrage means buying low and using high. Your battery buys energy at 7p overnight and displaces energy that would otherwise cost 35p at peak. On a 10 kWh battery cycled daily, that difference alone can be worth £700–£1,000 per year.
Why this improves ROI
Solar pays back through self-consumption. Tariff optimisation adds a second return stream — grid arbitrage — that works every day regardless of weather. Combined, the two mechanisms typically deliver payback in 6–9 years on a full system, with 20+ years of useful life.
We configure tariff schedules as part of every installation
Your battery is set up for your specific tariff before we leave site — not left to you to figure out afterwards.
You do not need solar panels to benefit from battery storage
Many customers assume battery storage only makes sense alongside solar panels. That is not the case. A battery charged from the grid on a smart tariff can still deliver meaningful savings — particularly for households on Octopus Agile, Go or Intelligent.
Installing a battery now also makes financial sense if you are planning solar panels in the future. Your battery is already in place and configured — adding solar later becomes simpler and cheaper because the inverter infrastructure is already there.
Ask About Battery-Only InstallationGrid arbitrage from day one
Charge at 7–12p overnight. Avoid paying 35p+ during peak hours. No roof, no panels, no waiting.
Future-proof your property
Install now, add solar later. The inverter and battery are already in place — solar panels simply connect to the existing system.
Backup power without solar
On EPS-capable systems, battery storage provides backup power during grid outages even without solar generation.
Qualify for 0% VAT
Standalone battery installations at residential properties qualify for 0% VAT — regardless of whether solar is installed.
Whole home backup — what it is and what to expect
When the grid goes down, most homes go dark. A battery system with backup capability changes that — but it is important to understand what "backup" actually means in practice before you invest based on that expectation.
What happens in a power cut
On EPS-capable systems (most modern hybrid inverters including SolaX, EcoFlow and Sigenergy), the inverter detects the grid failure and switches to island mode within milliseconds. Your home continues to run from the battery. If solar panels are generating, they contribute too.
Critical circuits vs whole home
Some configurations protect selected circuits only — fridges, lighting, key sockets. Whole-home backup protects your entire electrical distribution board. The right approach depends on your battery capacity, inverter specification and how long you need backup to last.
Being realistic about capacity
A 10 kWh battery powering an average home will last 8–14 hours without solar. High-draw appliances (electric showers, immersion heaters, large ovens) can deplete it quickly. We help you understand what your battery can realistically cover before purchase.
How the systems differ
Important: backup is not guaranteed without the right specification
Not all battery systems support backup mode by default. Not all existing inverters can be upgraded to support it. We confirm backup capability, configuration requirements and realistic duration expectations as part of your free survey — before you commit to anything.
Discuss Backup Power RequirementsSpecialist battery brands we install
We do not believe in one-size-fits-all battery storage. The right system depends on your property, your usage, your tariff, your solar setup and whether you want EV charging or backup power. That is why Omni3 focuses on three strong battery storage platforms: EcoFlow, Sigenergy and SolaX.
EcoFlow
EcoFlow battery storage is a strong choice for homes that want flexibility, clean design and intelligent energy control. The PowerOcean system is expandable, uses LFP battery chemistry, supports app and web monitoring, and supports dynamic tariff optimisation. It allows you to store surplus solar energy, charge from the grid at cheaper times and manage your energy through a clear app-based platform.
Best for: Smart modular home battery storage
Sigenergy
Sigenergy's SigenStor system is designed for customers who want more than a standard battery. It brings energy storage, solar control, EV charging capability and intelligent energy management into one integrated platform — a premium all-in-one 5-in-1 system combining solar inverter, EV DC charger, battery PCS, battery pack and energy management. For homes and businesses looking for a high-end, future-ready energy system, Sigenergy is one of the most advanced options we install.
Best for: Premium all-in-one energy system
SolaX
SolaX battery storage is a practical, reliable option for homes that want to get more from their solar panels. The X1-Hybrid G4 range includes 3.0kW to 7.5kW single-phase hybrid inverters, can form the X-ESS G4 system with battery and Matebox, and supports smart EV charger and heat pump integration. With hybrid inverter technology, smart energy management and compatibility with wider home energy systems, SolaX is a strong choice for households looking to reduce grid reliance and improve solar self-consumption.
Best for: Reliable hybrid solar & battery storage
Which battery system is right for you?
| Brand | Best for | Typical customer |
|---|---|---|
| EcoFlow | Smart modular home battery storage | Homeowners wanting flexibility, app control and expandability |
| Sigenergy | Premium all-in-one solar, battery and EV energy system | Customers wanting the most integrated, future-ready setup |
| SolaX | Reliable hybrid solar and battery storage | Homeowners wanting a practical, proven solar battery system |
During your survey, we look at your roof, electrical supply, energy bills, usage pattern, tariff and future plans. We then recommend the most suitable battery system rather than pushing one brand for every property.
Which battery system is right for you?
The right battery depends on your property, your existing setup, whether you have or plan to have an EV, and what you need from backup power. This comparison is intended to help you understand the key differences — we will give you a specific recommendation after a free site survey.
Smart modular home battery storage
EcoFlow
Best for
Flexible households, tariff-savvy buyers, app-first users
Property type
Residential homes, flats with suitable space
Expandable
Yes — add modules without replacing inverter
Backup power
Yes — automatic island mode on grid outage
Smart features
Dynamic tariff integration, app + web monitoring, HEMS
Ideal customer
Homeowners on Octopus Agile/Go who want flexible, expandable storage with strong app control
Premium all-in-one energy system
Sigenergy
Best for
Whole-system upgrades, EV integration, future-ready buyers
Property type
Residential and commercial; new builds and full upgrades
Expandable
Yes — battery capacity scalable
Backup power
Yes — whole-home capable
Smart features
5-in-1 HEMS, integrated DC EV charger, V2G-ready platform
Ideal customer
Buyers installing solar + battery + EV charger together who want the most integrated, future-proof solution
Proven hybrid solar and battery
SolaX
Best for
Solar retrofits, reliable hybrid storage, practical buyers
Property type
Residential homes; excellent for retrofit to existing solar
Expandable
Yes — via stacked battery modules
Backup power
Yes — EPS mode via Matebox
Smart features
Octopus integration, EV charger coordination, smart scheduling
Ideal customer
Homeowners adding battery to existing solar, or those wanting a well-supported, proven hybrid system
Not sure which system is right for you?
During your free survey we assess your property, energy bills, usage pattern, roof (if applicable), tariff and future plans. We recommend the most suitable system — not the most expensive.
What affects battery storage cost?
Battery capacity (kWh)
A typical home battery is 5–13 kWh. Larger homes or those with EVs may need more. Commercial systems can be 50 kWh+.
Hybrid vs AC-coupled
Hybrid inverters (combined solar + battery) are more cost-effective for new installations. AC-coupled batteries can be retrofitted to existing solar systems.
Number of battery units
Most brands allow stacking multiple units. More capacity means more stored energy but higher upfront cost. We size to your actual usage.
Integration with solar
Adding a battery to a new solar installation is cheaper than retrofitting. We design combined systems from the start for maximum efficiency.
Smart tariff compatibility
Systems optimised for Octopus Agile, Go or similar tariffs need specific inverter settings and scheduling. We configure this as part of commissioning.
Installation complexity
Wall-mounted batteries are standard. Floor-standing units need adequate space. Outdoor installations may need weatherproof enclosures.
Battery storage typically adds £3,000 – £8,000 to a solar installation
Standalone battery-only systems start from around £4,000. We provide exact pricing after your free survey.
NICEIC Approved • 0% VAT • Free Survey
Want to know what battery storage would cost for your home?
We assess your property and give you a fixed-price proposal — no obligation.
Common battery storage mistakes
Buying too small a battery
A 5 kWh battery sounds affordable but may only cover 2–3 hours of evening usage. We size batteries based on your actual consumption patterns, not just budget.
Ignoring tariff optimisation
A battery without smart tariff scheduling is leaving money on the table. We configure charge/discharge schedules to buy cheap and use smart — especially on Octopus Agile or Go.
Not pairing with solar
A battery-only setup works, but combining with solar panels dramatically improves ROI. Free daytime generation plus cheap overnight charging gives you the best of both worlds.
Expecting zero grid usage
Even with solar and battery, you will still use some grid electricity — especially in winter. We set realistic expectations so you are never disappointed.
Reduce your reliance on the grid — and the decisions made for you
Every unit of electricity you generate, store and use yourself is one you did not buy from an energy supplier. As wholesale prices rise, that buffer becomes increasingly valuable — not just financially, but in terms of control.
Battery storage gives you the ability to make decisions about your energy in advance — charging when prices are low, discharging when they are high, and insulating yourself from the price spikes that affect households entirely dependent on the grid.
Combined with solar panels and a smart tariff, a well-sized battery system can reduce grid dependency by 60–90% in summer months. Even in winter, the arbitrage benefits of smart tariff charging remain in play.
Better control over electricity costs
You decide when to charge, from where, and when to discharge. That flexibility — guided by smart scheduling — turns a fixed monthly bill into something you can actively manage.
Greater resilience
A battery-backed home is less exposed to grid outages and price volatility. EPS-capable systems provide automatic backup. Tariff arbitrage protects against peak rate increases.
Long-term flexibility
The energy landscape is changing — new tariffs, EVs, heat pumps, V2G technology. A battery system installed today positions you to benefit from those changes as they arrive, rather than being locked into a reactive position.
Financial predictability
Reducing grid reliance means a greater proportion of your energy costs become fixed and predictable — solar and battery investment amortised over 20+ years, rather than subject to annual supplier price reviews.
Battery Storage & 0% VAT
Battery storage systems installed at residential properties currently qualify for 0% VAT — whether installed alongside solar panels or as a standalone unit. This follows a rule change in February 2024 that extended the 0% rate to standalone batteries.
On a typical battery installation costing £3,000–£5,000, the VAT saving is £600–£1,000. For a full solar and battery system, the total saving can reach £2,000 or more. All Omni3 proposals reflect the correct 0% rate.
Battery Storage VAT Guide — Full Eligibility RulesWhy choose Omni3 to install your battery storage?
Battery storage is a significant investment. Getting the specification, installation and commissioning right determines how well it performs over the next 15–20 years.
NICEIC Approved Contractor
All electrical installation work is carried out to BS 7671 and certified by NICEIC — the UK's leading electrical contractor accreditation body.
RECC Member
We operate to Renewable Energy Consumer Code standards, including transparent pricing, clear contracts and consumer protection on all renewable energy installations.
ISO 9001, 14001 & 45001 Certified
ISO-aligned management systems covering quality, environmental management and occupational health & safety — applied to every project we deliver.
City & Guilds Qualified
Our engineers hold City & Guilds qualifications in Solar PV, Battery Storage and EV Charging — the industry benchmark for renewable energy installations.
MCS-Compliant Installations
All battery and solar installations comply with MCS standards, ensuring your system is eligible for SEG (Smart Export Guarantee) payments.
Direct Access to Engineers
When you contact us, you speak to the people who design and install the systems — not a call centre. Direct communication throughout.
Manufacturer-Trained Installers
We are trained installers for EcoFlow, Sigenergy and SolaX, with direct access to manufacturer technical support for commissioning and warranty queries.
Long-Term Support
We remain available after installation for monitoring queries, firmware updates, tariff optimisation advice and warranty claims. We treat every installation as a long-term relationship.
Battery storage FAQ
Battery Storage Projects We Have Completed
Solar & Battery Installation — Peacehaven, East Sussex
8 Aiko panels with SolaX hybrid inverter and 10.2 kWh battery. Estimated 70–90% self-consumption and £800–£1,200 annual savings.
Solar & Battery Installation — Pulborough, West Sussex
4.8 kWp solar with GivEnergy 9.5 kWh battery. Self-consumption increased to 75–85% with annual savings of £900–£1,100.
Solar Panel Removal & Reinstallation — Hannington, Hampshire
Existing solar PV system removed for roof works and fully reinstalled, tested and recommissioned.
SolarEdge Optimiser Replacement — Basingstoke
Fault finding and replacement of failed SolarEdge optimisers — restoring full generation without replacing the inverter.
Recent battery storage installations
A selection of recent battery storage installations completed by Omni3 across West Sussex and the South East.
Installation photo
Peacehaven, East Sussex
SolaXSolaX hybrid inverter installed alongside 8 Aiko solar panels. Battery sized for evening coverage and Octopus Agile optimisation.
Outcome
Estimated 70–90% solar self-consumption. Projected annual savings £800–£1,200.
Installation photo
Pulborough, West Sussex
GivEnergyBattery storage retrofitted to an existing solar installation. Inverter upgrade included to enable hybrid operation.
Outcome
Self-consumption increased from ~55% to 75–85%. Annual savings £900–£1,100.
Photo coming soon
We add new completed projects here regularly. Check back for recent installations.
More completed projects are added regularly. For detailed case studies see our full case study archive.
The Omni3 Smart Energy Bulletin
Each month we publish a short, practical email covering energy price movements, smart tariff changes, government incentives, battery technology updates and seasonal energy-saving advice. No sales content — just useful information.
Your Battery Is Part of a Bigger Picture
Battery storage works best as part of a complete energy system. Pair it with solar, EV charging and smart monitoring — then protect the whole investment with Energy Shield.
Omni3 Smart Energy System™
Bring solar, battery storage, EV charging and smart monitoring together into one seamlessly managed energy solution — designed and installed by a single accredited team.
Omni3 Energy Shield™
Long-term protection and ongoing support for your installation — insurance-backed guarantees, full documentation, priority support and annual health checks.
Related services and products
Solar Panel Installation
Add panels to maximise battery self-consumption
EV Charging Installation
Combine battery and EV charging for maximum savings
EcoFlow Battery Systems
Modular LFP storage with intelligent tariff control
Sigenergy SigenStor
All-in-one solar, battery and EV charging platform
SolaX Battery Storage
Proven hybrid solar and battery storage for UK homes
Solar & Battery Costs
Understand what affects your total installation cost
Battery Storage VAT Guide
0% VAT rules explained — who qualifies and what applies
Solar Configurator
Design your system and get an instant estimate online
For Businesses & Organisations
Commercial Solar & Energy Insights Hub
Guides on ESG credentials, VAT relief, EBITDA impact and business energy strategy.
Battery storage guides and resources
Everything you need to understand battery storage, smart tariffs, backup power and energy independence — written by our engineers, not a marketing team.
Home Battery Storage Guide
Everything you need to know before buying a home battery — sizing, brands, costs, tariffs and what to expect.
Battery Storage VAT Guide
0% VAT on residential battery storage — who qualifies, how it applies and what it means for your quote.
EcoFlow PowerOcean Guide
Modular LFP battery storage, dynamic tariff integration and whole-home energy management.
Sigenergy SigenStor Guide
The 5-in-1 all-in-one system — solar, battery, EV charging and energy management in one platform.
SolaX Battery Storage Guide
X1-Hybrid G4 and X-ESS G4 — a proven hybrid solar and battery solution for UK homes.
Smart Tariffs & Battery Storage
How Octopus Agile, Go and Intelligent tariffs work with home batteries — and how to maximise savings.
Whole Home Backup Guide
What happens during a power cut, which systems support backup, and what backup actually protects.
Energy Independence Guide
Reducing grid reliance, controlling your electricity costs and building long-term energy resilience.
Request a free battery storage survey
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