MCS & NAPIT Certified — SigEnergy Installer
SigenStor Battery Storage Milton Keynes
Depth of Light is a certified SigEnergy installer in Milton Keynes. We supply and install the SigenStor range of intelligent battery systems — V2H ready, modular from 9kWh to 54kWh, with the same one-app ecosystem managing your solar, battery and EV charger. MCS & NAPIT certified.
What is the SigenStor?
SigenStor is SigEnergy’s flagship home energy platform, built around a “5-in-1” architecture that consolidates what used to be separate boxes into a single integrated unit.
Those five functions are:
- Solar hybrid inverter — converts DC from your panels to AC for home use
- Battery storage — LiFePO4 modules starting at 9kWh, stackable to 54kWh
- Energy management system (EMS) — AI-powered logic that decides when to charge, store, or export based on tariff, weather, and usage data
- Backup power controller (BPC) — switches to battery automatically in a grid outage
- Optional DC EV charger — direct DC charging from battery and panels, bypassing the AC conversion for higher efficiency
The result is a clean installation with fewer components, fewer points of failure, and a single app for everything.
The 5-in-1 platform at a glance
- Solar hybrid inverter
- LiFePO4 battery (9kWh modules)
- AI energy management (EMS)
- Backup power controller (BPC)
- Optional DC EV charger
SigenStor Key Specifications
| Specification | Value |
|---|---|
| Usable capacity per module | 9 kWh |
| Battery chemistry | LiFePO4 (lithium iron phosphate) |
| Cycle life | 10,000 cycles (one cycle/day = 27+ years) |
| Warranty | 10 years (battery + inverter) |
| Maximum stackable capacity | 54 kWh (6 × 9kWh modules) |
| Continuous output per module | 5 kW |
| Compatible with | New and existing solar installations |
| EV charging option | Optional integrated DC EV charger |
How Much Does SigenStor Cost Installed?
Prices below are for supply and full installation in Milton Keynes and Buckinghamshire, including all cabling, commissioning, and registration. 0% VAT applies to residential battery storage installations under current HMRC rules.
| System size | Configuration | Installed price (inc. 0% VAT) |
|---|---|---|
| 9 kWh | 1 × SigenStor module | From £4,500 |
| 18 kWh | 2 × SigenStor modules | £6,000–£7,500 |
| 27 kWh | 3 × SigenStor modules | From £9,500 |
| 36–54 kWh | 4–6 × modules (commercial/large home) | Price on survey |
The 18kWh system is the most common residential choice. It covers a typical household’s evening and overnight electricity needs, with capacity left over if you are also running an EV or have higher usage. Larger configurations suit homes with high electricity consumption or where the solar and battery package includes 5kWp+ of panels.
All prices are fixed — we do not charge extra for difficult cable routes within the standard scope. If your property needs significant groundwork or a consumer unit upgrade, we will tell you at survey stage before any money changes hands.
0% VAT on residential battery storage
Battery storage systems installed in residential properties qualify for 0% VAT under current HMRC rules. That is a 20% saving on the installed cost compared to the standard rate. The 0% rate is guaranteed until at least March 2027.
SigenStor vs Tesla Powerwall — An Honest Comparison
We install both. Here is a straight comparison without the marketing gloss.
| SigenStor | Tesla Powerwall 3 | |
|---|---|---|
| Usable capacity | 9kWh per module | 13.5kWh per unit |
| Maximum capacity | 54kWh (6 modules) | 40.5kWh (3 units) |
| Chemistry | LiFePO4 | LiFePO4 |
| Warranty | 10 years | 10 years |
| Cycle life | 10,000 cycles | Rated to 70% at 10yr |
| EV charging integration | Optional integrated DC charger | Via Powerwall app (AC) |
| Typical 18kWh install cost | £6,000–£7,500 | £8,000–£10,000+ |
| App & brand maturity | Strong — growing rapidly in UK | Very strong — established globally |
| Minimum entry size | 9kWh | 13.5kWh |
Our honest take: The technical performance of both systems is excellent and comparable. SigenStor costs less per kWh of storage and offers finer-grained sizing flexibility — you can start at 9kWh and add a module later, whereas Powerwall 3 starts at 13.5kWh. Powerwall has stronger brand recognition and a more polished app. For most UK residential installs, the difference in day-to-day performance is minimal.
If budget is the main driver and flexibility matters, SigenStor is usually the better choice. If brand confidence or a specific Powerwall ecosystem integration is a priority, we install Tesla Powerwall too. We will give you a straight recommendation at survey based on your actual situation.
Why Depth of Light Installs SigEnergy
We started installing SigenStor because the product kept coming up when we were doing our own research on what was arriving in the UK market. Since then, we have put systems into homes across Milton Keynes and Buckinghamshire and have seen how they perform in the real world — not just in datasheets.
A few things stand out:
- The build quality is solid. The enclosure, cabling, and internal components are well-finished. It does not feel like it has been rushed to market.
- The energy management logic works. The AI scheduling — which adjusts charging and discharging based on tariff data, weather forecasts, and usage history — is genuinely useful, not just a marketing headline. We have seen it make sensible decisions on homes running Octopus Agile and similar time-of-use tariffs.
- UK support is there. SigEnergy has established UK support infrastructure. We have been able to get answers when we needed them. For a brand that has only been in the UK market a short time, that matters.
- The stacking architecture makes sense. For customers who want to start with 9kWh and expand later, the modular design works as advertised. We have done staged installations where a second module was added six months after the first.
We do not install every battery system on the market. We install the ones we have confidence in based on performance and support. SigenStor makes that list.
MCS & NAPIT certified installation
All SigenStor installations by Depth of Light are carried out by MCS and NAPIT certified engineers. You receive full documentation, MCS certificate, and warranty registration as standard. This is the certification required to access any future battery grant schemes and to ensure your home insurance remains valid.
SigEnergy V2H — your EV as a home battery
SigEnergy is the only V2H system we currently install — and that's a deliberate choice. It's the most mature bidirectional charging platform available in the UK in 2026, and the SigenStor cabinet you put in for battery storage is the same hardware that will run V2H when you add a compatible EV.
What V2H means in practice:
- Your EV battery (typically 40–100 kWh) becomes a much larger backup than any wall-mounted home battery
- The car powers your home during peak tariff hours and during grid outages
- One app — the SigEnergy app — manages solar generation, battery state, EV charging and V2H discharge automatically
- Future-proof: when V2G (export to grid) arrives in the UK, the same hardware upgrades via firmware
Read more about V2H
How it works, which cars are compatible, what it costs and whether it's right for you.
Annual SigenStor health check
SigEnergy recommends an annual system health check to maintain warranty validity. We offer this as part of our wider solar maintenance service — combined with an annual panel clean if you have solar, it's a single visit, single price, no hassle.
The annual check covers:
- Battery module performance vs spec — capacity, voltage, balance
- Inverter and gateway firmware updates
- Communication and cloud connection
- EMS scheduling profile review (does it still match your tariff and usage?)
- BPC backup test (we test the auto-changeover, so you know it works when you need it)
- Written health report and warranty-valid documentation
From £90 per visit, or bundled with a solar maintenance plan from £180/year covering both panels and battery.
SigenStor FAQ
What is the SigenStor and what makes it a 5-in-1 system?
SigenStor is SigEnergy’s all-in-one home energy platform. The 5-in-1 refers to five functions in a single unit: solar inverter, battery storage, energy management system (EMS), backup power controller (BPC), and an optional DC EV charger. Instead of separate boxes for each function, SigenStor integrates everything into one system managed through a single interface.
How much does SigenStor cost installed in Milton Keynes?
A single 9kWh module starts from around £4,500 fully installed. A typical 18kWh system (two modules) costs £6,000–£7,500 installed, including cabling, mounting, and commissioning. 0% VAT applies on residential installs. Contact us for a fixed-price quote based on your property.
Can SigenStor be added to an existing solar system?
Yes. SigenStor works with existing solar panel installations. We assess your current inverter and array at survey to confirm the connection method. Some existing inverters can be retained; others require replacement with the SigenStor hybrid inverter. We will be upfront about this before any work starts.
How does SigenStor compare to the Tesla Powerwall?
Both use LiFePO4 chemistry and carry 10-year warranties. SigenStor is generally cheaper per kWh and offers more flexible sizing — starting at 9kWh vs Powerwall’s 13.5kWh minimum. Tesla has stronger brand recognition and a more mature app. For most UK residential installs, the day-to-day performance difference is small. See our full comparison above for the numbers side by side.
What warranty does SigenStor carry?
10 years on both the battery modules and the hybrid inverter. The battery is rated for 10,000 charge-discharge cycles. At one cycle per day, that is over 27 years of cycling before the warranty threshold is reached. In practice most households do not do one full cycle every day, so the real-world lifespan is longer.
Get a Free SigenStor Quote
Free site survey across Milton Keynes and Buckinghamshire. Fixed price. MCS & NAPIT certified installation. No obligation.
Or email info@depthoflight.co.uk | Send a message
Also see: Battery storage overview | Tesla Powerwall | Solar & battery packages