SigEnergy Cost 2026: SigenStor Prices Explained
What a SigEnergy SigenStor costs installed in 2026, what drives the price, 0% VAT, and how it compares to EcoFlow and Tesla — from Scotland's SigEnergy specialist installer.
Quick answer
A SigEnergy SigenStor costs roughly £8,000-£14,000 fully installed for a typical single-phase home configuration of about 8-16kWh in 2026, rising to £18,000-£35,000 for a larger or three-phase tower with more battery modules and the integrated EV-charger option. Because the SigenStor is a modular, stackable platform rather than a fixed box, the only accurate number is a surveyed fixed-price quote — the figure is driven by inverter rating, how many battery modules you stack, whether you add EV charging, and your electrical works. Qualifying residential installs also carry 0% VAT until 31 March 2027, which reduces the price. Below we break down exactly what you pay for, the five things that move the cost, how it compares to EcoFlow and Tesla, and how to size a SigenStor so it pays its way. For the full platform detail see our SigEnergy installer Scotland hub.
What does a SigEnergy SigenStor cost? (2026 price ranges)
The SigenStor is sold as a configurable tower, so "the price" is really a range that depends on the modules you specify. Treat the table below as indicative installed pricing — every figure is confirmed against a survey before we quote, and your exact number depends on the points in the next section.
| SigenStor configuration | Indicative capacity | Indicative installed price (2026) |
|---|---|---|
| Entry single-phase | ~8kWh, single-phase inverter | £8,000-£10,500 |
| Popular single-phase home | ~13-16kWh, single-phase inverter | £10,500-£14,000 |
| Single-phase + integrated EV charger | ~16kWh + bi-directional DC EV module | £13,500-£18,000 |
| Three-phase / larger home | ~20-30kWh, three-phase inverter | £16,000-£26,000 |
| Three-phase, fully loaded | up to ~48kWh + EV charger | £24,000-£35,000 |
These ranges assume a residential install with reasonable access and an existing solar array or a battery-only retrofit. Adding a new solar PV array is a separate line and changes the total. All capacity and specification figures reflect SigEnergy's published specifications; your installer confirms the precise modules and price for your property.
The 5 things that drive SigenStor price
If you understand these five levers, you understand the quote.
1. Inverter rating — single-phase vs three-phase. A single-phase SigenStor (3.6-12kW) is the cheaper, most common choice and suits the majority of Central Belt homes. A three-phase tower (5-~25kW) costs more but is the right call for larger detached homes, rural properties and small commercial units with a three-phase incomer.
2. Number of battery modules. Capacity is built from stacked LFP modules of roughly 5.2kWh or 8.0kWh, up to about 48kWh per tower. Each module you add is a real cost — which is why sizing to your actual evening demand, not the biggest tower available, keeps the price sensible.
3. The optional EV-charger module. The SigenStor can take a bi-directional EV DC charger that stacks into the same tower. It adds cost up front, but it is cheaper and tidier than a separate charger, a second consumer-unit feed and another install visit later.
4. Electrical and supply works. Older single-phase boards or a three-phase supply can need a consumer-unit upgrade; a three-phase incomer changes the install entirely. We quote any board or supply work explicitly — it is never hidden.
5. Paired with new solar or retrofitted. A SigenStor specified alongside a new solar array shares scaffolding and an install visit; a battery-only retrofit onto existing solar is usually a shorter job. Both are common, and both affect the total.
0% VAT and what it means for the price
There is a genuine discount built into UK battery pricing right now. Qualifying residential battery-storage installations currently benefit from 0% VAT until 31 March 2027 under the government's energy-saving materials relief — and that applies to standalone battery retrofits as well as battery-with-solar packages. On a £12,000 install that relief is worth around £2,000 against the old 20% rate, so it is a material saving rather than a rounding error. The relief is time-limited, so the net cost of a SigenStor is lower today than it is likely to be once the relief window closes. Your installer confirms the VAT treatment in the written fixed-price quote, and you can check the underlying scheme detail with the Energy Saving Trust.
SigenStor cost vs EcoFlow and Tesla
A fair cost comparison has to be like-for-like, because these systems are not all trying to do the same job.
| System | Typical capacity | Relative installed cost | What you are paying for |
|---|---|---|---|
| EcoFlow PowerOcean | 5-30kWh modular | Lowest on a battery-only basis | Value single-phase home storage, IP-rated, app-controlled |
| Tesla Powerwall 3 | 13.5kWh fixed | Mid | Integrated 11.5kW inverter, EPS backup, strong brand and app |
| SigEnergy SigenStor | ~5-48kWh modular | Higher, scales with modules | Three-phase option, integrated EV charging, AI EMS, expandable tower |
On a straight battery-only basis the EcoFlow PowerOcean usually comes in lower than a comparable SigenStor — that is not a quality judgement, it is a function of architecture. The Tesla Powerwall 3 sits broadly between the two at a fixed 13.5kWh. The SigenStor earns its higher price where you need three-phase power, integrated EV charging in the same tower, or a modular system you can grow to ~48kWh — capability the cheaper single-phase boxes simply do not offer. If your needs are simpler, we will tell you so and quote the cheaper option; our EcoFlow vs SigEnergy comparison walks through that decision in full, and the SigenStor battery guide covers the platform itself.
Does a SigenStor pay for itself? Worked Scottish example
Cost only means something next to the return. A battery pays its way when it is charged cheaply and discharged (or exported) when power is expensive — which is exactly what the SigenStor's AI EMS is built to do on a time-of-use tariff such as Octopus Flux:
- Import cheaply overnight (around 15p/kWh in the off-peak window)
- Run the house from stored energy through the expensive evening peak (avoiding ~30p/kWh import)
- Export genuine surplus when the export price is highest (up to ~24p/kWh on Flux peak export)
A well-sized home battery cycled through this window typically returns a few hundred pounds a year — putting simple payback in the region of 8-12 years on the storage alone, and faster once you add the avoided peak import and SEG-style export income on top. The bigger, fully loaded towers cost more but also displace more expensive grid power, so the payback maths does not simply get worse with size — it depends on how hard the battery is cycled. We model the real numbers for your roof, tariff and usage before quoting. Our Octopus Flux + battery maths shows a worked example, and the battery storage overview explains how storage fits the wider system.
How to keep the cost sensible (without buying too little)
The most common mistake is buying capacity by the roof rather than by the evening. To get the price right:
- Size to your real evening and overnight demand, not the biggest tower available — oversized storage rarely pays back.
- Decide on EV charging up front. If an EV is genuinely on the horizon, specifying the integrated module now is cheaper than retrofitting a separate charger later; if it is not, leave it off and save the cost.
- Check your supply early. Knowing whether you are single- or three-phase, and the state of your consumer unit, avoids surprise electrical works.
- Use the 0% VAT window. The relief runs to 31 March 2027 — installing within it lowers the net price.
- Get a fixed-price, surveyed quote, not a phone estimate. A modular platform like the SigenStor needs a survey to be priced honestly.
Why buy a SigenStor through Ecoaim
Ecoaim is Scotland's SigEnergy specialist installer and among the first in Scotland to specify the SigenStor, with stock supplied direct by SigEnergy's UK Platinum Distributor. As a Sigenergy-certified, MCS-registered installer working from our Livingston EH54 base, we design and price the platform around your property — not a one-size box — and quote a fixed price with the real numbers, including the 0% VAT relief where it applies. We are also arranging a mobile show-stand sales tour with the Platinum Distributor so customers across the Central Belt can see the platform in person before they commit — get in touch to be notified of dates. If you already run an EcoFlow system and your needs have grown, our SigEnergy installer Scotland hub explains your options and the upgrade path.
Bottom line
A SigEnergy SigenStor costs roughly £8,000-£14,000 installed for a typical single-phase home and £18,000-£35,000 for a larger or three-phase, EV-charging-equipped tower — but because it is a modular platform, your real figure is set by inverter rating, battery modules, the EV option and your electrical works, and only a surveyed fixed-price quote is accurate. The 0% VAT relief to 31 March 2027 lowers the net cost today. On a battery-only basis a SigenStor sits above an EcoFlow PowerOcean and around a Tesla Powerwall 3, and it earns that premium when you need three-phase power, integrated EV charging or a tower you can expand to ~48kWh. As a Sigenergy-certified, MCS-registered SigEnergy installer Scotland team, Ecoaim sizes and prices the SigenStor honestly around your home. Book a free survey and we will tell you exactly what it costs — and whether it pays its way for you.
Sources and further reading
- SigEnergy — SigenStor product specifications and pricing inputs — sigenergy.com
- Microgeneration Certification Scheme (MCS) — mcs.co.uk
- Energy Saving Trust (DESNZ delivery partner) — battery storage and 0% VAT guidance — energysavingtrust.org.uk
Related Ecoaim guides:
Frequently asked questions
How much does a SigEnergy SigenStor cost in 2026? +
As a guide, a single-phase SigenStor lands in the region of £8,000-£14,000 fully installed for a typical home configuration of roughly 8-16kWh, and a larger or three-phase tower with more battery modules and an integrated EV charger can reach £18,000-£35,000. The price depends on inverter rating, how many battery modules you stack, whether you add the EV-charger module, and your electrical works — so the only accurate figure is a surveyed fixed-price quote.
What drives the price of a SigenStor up or down? +
Five things move the number: inverter size (single-phase vs three-phase), the number of stacked battery modules (each ~5.2kWh or ~8kWh adds cost), whether you specify the optional bi-directional EV-charger module, your consumer-unit and supply works (a three-phase or older single-phase board can need upgrading), and whether the SigenStor is paired with a new solar array or retrofitted to an existing one. Sizing capacity to your real evening demand — not your roof — is the single biggest way to keep the cost sensible.
Is there VAT to pay on a SigEnergy battery? +
Qualifying residential battery-storage installations in the UK currently benefit from 0% VAT until 31 March 2027 under the government's energy-saving materials relief. That applies whether the battery is fitted with new solar or retrofitted to an existing system, and it materially reduces the installed cost. Your installer confirms the VAT treatment in your written fixed-price quote.
Is the SigenStor more expensive than an EcoFlow PowerOcean or Tesla Powerwall? +
On a like-for-like, battery-only basis the EcoFlow PowerOcean usually comes in at a lower installed cost than a comparable SigenStor, and a Tesla Powerwall 3 sits broadly between them at a fixed 13.5kWh. The SigenStor justifies its price where you need three-phase power, integrated EV charging in the same tower, or a modular system you can expand to ~48kWh — capability the cheaper single-phase boxes do not offer.
How long does it take a SigenStor to pay for itself? +
Payback depends on your tariff and how hard the battery is cycled. Paired with a time-of-use tariff such as Octopus Flux — cheap overnight import, expensive evening peak run from stored energy, surplus exported at the best price — a well-sized home battery typically returns a few hundred pounds a year, putting simple payback in the region of 8-12 years on the storage alone, faster if you also avoid peak import and earn export income. We model the real numbers for your property before quoting.
Who installs the SigEnergy SigenStor in Scotland, and what is the show-stand tour? +
Ecoaim is a Sigenergy-certified, MCS-registered installer and among the first in Scotland to specify the SigenStor, with stock supplied direct by SigEnergy's UK Platinum Distributor from our Livingston EH54 base across Edinburgh, Glasgow, Falkirk, Stirling and the wider Central Belt. We are arranging a mobile show-stand sales tour with the Platinum Distributor so customers can see the platform in person before committing — get in touch to be notified of dates.
Duncan leads Ecoaim's technical design and survey team from our Livingston EH54 base, with 10+ years specifying MCS-certified solar PV and battery storage across the Scottish Central Belt. Ecoaim is a Sigenergy-certified installer and among the first in Scotland to specify the SigenStor, supplied direct by SigEnergy's UK Platinum Distributor.
Call 03330 384 380 or get a quote online — survey + quote within 24 hours.