Battery Storage
Battery Storage
Store excess energy, reduce grid dependency, and protect against power outages with cutting-edge battery solutions.
Why Battery Storage?
Maximise Your
Energy Savings
Battery storage lets you store excess solar energy during the day and use it in the evening when electricity rates are highest. Without a battery, up to 50% of the solar energy you generate could be exported to the grid at a fraction of what you pay to buy it back.
With a home battery, you can increase your self-consumption from around 50% to 80–90% — keeping more of the energy you generate and dramatically reducing your reliance on the grid. As a PAS 2030 certified contractor, our installations meet the highest industry standards for energy efficiency.
Every installation is completed by our dedicated, full-time team. Every member of our team works for Helios Electrical & Solar — so you get consistent quality, direct accountability, and a team that takes genuine pride in every project.
Benefits
Why Add Battery Storage?
Protection Against Rising Energy Bills
Energy prices have risen over 150% in the last 5 years. A home battery lets you store cheap or free energy and use it when rates are highest — locking in your savings regardless of what happens to wholesale prices.
0% VAT on Battery Storage
Battery storage installed alongside solar PV on residential properties is currently VAT-free. That means you save 20% compared to standard-rated goods — hundreds of pounds off your total system cost.
Increase Your Home Value
A solar and battery system makes your home more attractive to buyers. Energy-efficient homes sell faster and for more money — buyers value the prospect of low energy bills and energy independence.
Store & Use Solar Energy at Night
Don't waste the energy your panels generate during the day. Store it and power your home in the evening when you need it most — increasing your self-consumption from ~50% to 80–90%.
Charge from the Grid at Off-Peak Rates
With a time-of-use tariff (like Octopus Go), charge your battery cheaply overnight at 7p/kWh and use it during peak hours when rates hit 30p+/kWh. Even without solar, a battery can save you hundreds per year.
Whole Home Backup During Power Cuts
With the right battery system and backup gateway, your home stays fully powered during grid outages. Lights, heating, fridge, internet, medical equipment — everything keeps running while your neighbours are in the dark.
Reduce Peak Demand Charges
For commercial customers, battery storage can shave peak demand charges — saving thousands per year on half-hourly metered supplies.
Whole Home Backup
Never Lose Power Again
A whole home backup system ensures your entire property stays powered during grid outages. Unlike a standard battery setup, a backup-enabled system automatically detects a power cut and switches to battery power within milliseconds — so you don't even notice the grid went down.
This is especially important for families with medical equipment, home offices, security systems, or anyone who simply doesn't want to be left in the dark. With solar panels recharging your battery during the day, you can ride out extended outages with confidence.
Ask About Whole Home BackupAutomatic Switchover
Battery takes over within milliseconds of a grid outage — no manual intervention needed.
Power Your Entire Home
Lights, heating, fridge, internet, security cameras, medical devices — everything keeps running.
Solar Recharging During Outages
Your solar panels continue to recharge the battery during a power cut, extending your backup duration.
Peace of Mind for Families
Essential for households with vulnerable people, medical equipment, or home-based businesses.
Compatible with Leading Systems
Available with Tesla Powerwall, Fox ESS, and other systems with backup gateway capability.
End-to-End Service
How We Help You Get Battery Storage
Free Consultation
We assess your energy usage, existing solar setup (if any), and recommend the right battery size and brand for your needs. No obligation.
Detailed Quote
You'll receive a transparent quote including battery, inverter (if needed), installation, and all DNO paperwork. Finance options available through Ideal4Finance.
DNO Application
All battery installations require a G99 DNO application — we handle the entire process for you. The DNO has up to 45 working days to approve, so we submit your application as soon as you place your order to minimise the lead time.
Dedicated Installation
Our full-time Helios team installs your battery system — typically in half a day to a full day. We then commission the system, configure your smart energy management, and register everything.
Not sure which battery system is right for you?
Speak to our team for free, honest advice — no pressure, no obligation.
Homeowner's Guide
Battery Storage Guide
Everything you need to know about adding battery storage to your home — whether you already have solar panels or you're starting from scratch.
How Does Battery Storage Work With Solar?
Solar panels generate the most electricity during the middle of the day — but most households use the majority of their energy in the morning and evening. Without a battery, that surplus solar energy is exported to the grid at just 4–15p/kWh, and you then buy it back in the evening at 24–35p/kWh.
A home battery captures that daytime surplus and stores it for use when you actually need it. The result: you use 80–90% of the energy your panels generate, compared to just 40–50% without a battery. This dramatically reduces your electricity bills and your dependence on the National Grid.
Your battery and inverter manage energy flows automatically — there's nothing you need to do day-to-day. Most systems include an app so you can see exactly how much energy you're generating, storing and using in real time.
Battery Chemistry: LiFePO4 vs NMC
LiFePO4 (Lithium Iron Phosphate)
- 6,000+ charge cycles (longest lifespan)
- Most thermally stable — safest chemistry
- Best value over the lifetime of the system
- Used by: Fogstar, BYD, Pylontech
NMC (Nickel Manganese Cobalt)
- Higher energy density (smaller footprint)
- 4,000–6,000 charge cycles
- Established technology, widely used
- Used by: Tesla Powerwall, SolarEdge
Both chemistries are safe and proven for home use. We'll recommend the best option based on your priorities — whether that's maximum lifespan, compact size, or whole-home backup capability.
How to Size Your Battery Correctly
Choosing the right battery size depends on three key factors:
Your Daily Energy Usage
The average UK household uses 8–10kWh per day. If you use most of your energy in the evening (as most families do), a battery sized to cover 5–8kWh of evening usage is a good starting point.
Your Solar Panel Output
A 4kW solar system generates roughly 10–12kWh on a good summer day and 2–4kWh in winter. Your battery should be large enough to capture your typical daily surplus without being oversized for winter.
Your Goals
Want to maximise savings? A 5–10kWh battery covers most homes. Want whole-home backup? You'll need a larger system (10–15kWh+) with a backup gateway. Want to go near off-grid? Consider 15kWh+ with multiple battery modules.
Not sure what size you need? Our Solar Savings Calculator can help estimate, or get in touch for a personalised recommendation based on your actual energy bills.
Controlling Grid Reliance: Path to Energy Independence
One of the biggest motivations for adding a battery is reducing your dependence on the National Grid. Here's how different setups affect your grid reliance:
| Setup | Self-Consumption | Grid Reliance |
|---|---|---|
| Solar Only (no battery) | 40–50% | High — evenings & overnight from grid |
| Solar + 5kWh Battery | 65–75% | Medium — some grid use in winter |
| Solar + 10kWh Battery | 80–90% | Low — minimal grid use year-round |
| Solar + 15kWh+ Battery | 90–95% | Very Low — near energy independence |
| Solar + Battery + Off-Peak Tariff | Up to 95%+ | Minimal — cheapest grid energy only |
With a properly sized solar and battery system, most homeowners can reduce their grid purchases by 80% or more. Combined with the Smart Export Guarantee (earning 4–15p/kWh for surplus energy you export), the financial case for battery storage has never been stronger.
Time-of-Use Tariffs: Save Even More
Even if you don't have solar panels, a battery can save you money by charging overnight on cheap off-peak electricity and discharging during expensive peak hours.
7p
Off-peak charge rate
30p+
Peak grid rate
77%
Saving per kWh
Battery Storage FAQs
Frequently Asked Questions
Ready for Battery Storage?
Free, no-obligation quote. We install Tesla, Fox ESS, Solis, Fogstar and more.