Products — Fox ESS
Fox ESS — compact wall-mounted storage
Stackable battery packs, wall-mounted to keep the footprint small and built to pair with hybrid inverters — a natural fit for new installs and retrofits alike.
Published packages — 2026
Two Fox ESS packages, priced by Athena
Fox ESS
16-panel system
All prices are subject to survey.
Fox ESS
10-panel system
All prices are subject to survey.
What the platform does
Small footprint, big in the evening
Fox ESS keeps storage compact: stackable battery packs, wall-mounted or floor-stacked, sized to what your evenings actually use rather than a one-size-fits-all cabinet.
The packs are built to pair with hybrid inverters, which makes Fox ESS just as happy retrofitted onto an existing solar array as it is in a brand-new installation — and either configuration keeps it garage- or utility-room friendly.
Athena sizes each Fox ESS system around your usage and your roof — MCS-certified installations by a NAPIT-accredited team, with deposit protection and comprehensive warranties.
Design your systemFox ESS on the wall
The wall-mounted option
A wall-mounted install keeps everything off the floor: battery packs and inverter side by side on the wall of a garage or utility room, with the wiring and protection alongside. That is the shape Fox ESS is built for — stackable packs that grow along the wall rather than out into the room.
Where yours goes is settled at the survey: Athena looks at how much electricity you use, when you use it and how much spare generation your panels produce before recommending a capacity — so you are not paying for storage you do not need.
Battery storage installation
Fox ESS or SigenStor?
Which system suits you
This platform
Fox ESS
Best for: tighter spaces, retrofits to existing panels, and value-focused installs.
Get your free quoteThe alternative
SigenStor
Best for: whole-home backup, bigger roofs, and households that plan to add an EV.
Explore SigenStor| Side by side | Fox ESS | SigenStor |
|---|---|---|
| Form factor | Wall-mounted, stackable packs | Floor-standing modular tower |
| Battery capacity | Stackable packs, sized to your evenings | 6 kWh and 9 kWh modules — stack as you grow |
| Inverter | Built to pair with hybrid inverters | Hybrid inverter built into the tower |
| EV charging | Separate EV charger installation available | Optional DC fast-charge module for the stack |
| Best for | Tighter spaces, retrofits, value-focused installs | Whole-home backup, bigger roofs, adding an EV |
| 10-panel package | £7,500 · 3.6 kW inverter · 5 kWh battery | £8,000 · 3.6 kW inverter · 6 kWh battery |
| 16-panel package | £9,500 · 6 kW inverter · 10 kWh battery | £11,000 · 6 kW inverter · 12 kWh battery |
All prices are subject to survey. Package prices are our published 2026 pricing.
Run your own numbers
What would a Fox ESS package do to your bill?
The homepage has a savings calculator — pick Fox ESS, slide in your monthly electricity bill and see an estimate of what solar and storage could save.
Keep exploring
Where the battery fits
Battery storage installation
Store more of the energy you already pay for — systems sized to your property, with monitoring apps and backup power during outages.
Battery storageSigenergy
The SigenStor battery-inverter tower — stackable 6 kWh and 9 kWh modules, with an optional DC EV-charging module.
Explore SigenStorCompare the packages
All four published packages side by side — our prices, subject to survey.
All productsStart your design — tomorrow’s sun is free
Start your Fox ESS design.
Tell us about your roof and your evenings — we’ll design a solar + storage system around them.