Running a small business in the UK in 2025 is a bit like baking bread in a gale - you can do everything right, but the conditions still have a say in the outcome.
Energy prices are still volatile, net zero deadlines are creeping closer, and customers increasingly expect you to be walking the sustainability walk, not just talking it.
That’s where battery storage comes in. Once seen as high-tech overkill, it’s now a practical, cost-cutting, downtime-dodging bit of kit that more and more SMEs are installing.
Whether you’re a high street bakery, a light manufacturer, or a farm shop, battery storage can help you control costs, keep running during power cuts, and polish your green credentials in one move.
🔑 Key Takeaways:
Payback can be quick – Most small businesses see ROI in 4–8 years, faster if paired with solar or time-of-use tariffs.
Best fit for SMEs – 50–200 kWh systems cover peak shaving, load shifting, and short-term backup without taking over your premises.
Tax perks matter – The 2025 enhanced capital allowance “super-deduction” allows up to 130% of qualifying costs to be claimed against taxable profits.
It’s not just about savings – Think energy independence, outage protection, and stronger ESG credentials to help win contracts.
What Is Commercial Battery Storage?
Think of commercial battery storage as your business's personal power bank, but scaled up for serious energy needs.
These systems capture electricity from the grid or renewables, holding it ready for when you need it most.
Lithium-ion batteries dominate the market, offering high efficiency (90-95%) but at a premium price.
Flow batteries shine for long-duration storage (8+ hours) with virtually no degradation, though they're bulkier and costlier upfront. Lead-acid options provide budget entry points but fall short on lifespan and performance.
Grid-connected setups integrate seamlessly with your existing supply, while off-grid systems deliver total independence for remote operations.
Each type suits different business scales: lithium-ion for most urban sites, flow for energy-intensive factories needing extended backup.
Why Battery Storage Is Having a Moment
A decade ago, batteries in business meant a hefty six-figure invoice and a long wait for payback.
Now, small manufacturers, retailers, and service-based SMEs are quietly adding battery systems because they:
Dodge peak pricing by running on stored electricity when the grid is most expensive.
Stay open during outages, avoiding lost sales and wasted stock.
Earn money through National Grid schemes like Firm Frequency Response.
“Battery storage isn’t just about keeping the lights on - it’s about control. The moment you can decide when and how you use electricity, you’re no longer at the mercy of the market. For small businesses, that’s massive.” - Ben Price, Heatable Co-founder.
How It Works Without the Tech Headache
Think of a battery storage system as your own energy vault. It charges from cheap grid power or on-site renewables, then discharges during expensive or high-demand periods.
For most SMEs, 50–200 kWh hits the sweet spot - big enough to make a dent in costs, compact enough to fit without major disruption.
Battery types to know:
Lithium-ion – The SME favourite: efficient, compact, and lasts 10–15 years.
Flow batteries – Long-duration discharge with minimal degradation, but bulkier and pricier.
Lead-acid – Low upfront cost, but shorter lifespan and lower efficiency.
The Big Names in SME Battery Storage
The Tesla Powerwall 3 is stealing the limelight this year.
Each unit stores 13.5 kWh, comes with an integrated inverter, and stacks neatly to build systems up to SME scale.
Tesla’s energy management software is one of the slickest around, making it easy to optimise when and how you charge or discharge.
Other strong options include:
Sonnen Eco – Premium lithium-iron-phosphate with German engineering and long cycle life.
Alpha ESS Smile G3 – Modular, scalable, hybrid-ready.
BYD Battery-Box – Flexible sizing and robust build.
Pylontech Force L2 – Budget-friendly lithium option for smaller premises.
Brand & Model | Tech Type | Capacity per Unit | Efficiency | Scalable | Warranty | Notable Features |
Lithium-ion NMC | 13.5 kWh | 90–95% | Yes | 10 years | Integrated inverter, smart software | |
Sonnen Eco | Lithium-iron-phosphate (LFP) | 10–20 kWh | 94–96% | Yes | 10 years | High cycle life, German engineering |
Lithium-iron-phosphate (LFP) | 10.1–60 kWh | 93–95% | Yes | 10 years | Modular, hybrid inverter | |
BYD Battery-Box | Lithium-iron-phosphate (LFP) | 3.84–12.8 kWh | 93–95% | Yes | 10 years | Flexible sizing |
Pylontech Force L2 | Lithium-iron-phosphate (LFP) | 3.55–4.8 kWh | 90–95% | Yes | 10 years | Cost-effective |
Battery Costs & ROI in 2025
Expect to pay £400-800 per kWh for SME systems (50-500 kWh), dropping to £300-600 for larger setups thanks to economies of scale.
Maintenance runs 1-2% of system cost annually, with lithium-ion batteries lasting 10-15 years before needing replacement.
ROI typically lands at 4-8 years, influenced by your tariff structure and usage patterns – businesses on time-of-use rates see quicker returns through arbitrage.
Factor in National Grid ESO schemes like Firm Frequency Response, where batteries earn £50,000-100,000 per MW annually.
What Your Business Could Save with Battery Storage in 2025:
System Size | Installed Cost | Annual Savings | ROI Period |
100 kWh | £40,000-80,000 | £8,000-15,000 | 5-8 years |
500 kWh | £150,000-300,000 | £30,000-60,000 | 4-7 years |
1 MWh+ | £300,000+ | £60,000+ | 3-6 years |
Payback usually falls in the 4–8 year range. Pairing with solar or using time-of-use tariffs can bring that down sharply.
Worked Example: A Bakery Installs Tesla Powerwall 3
Imagine a Midlands bakery with ovens firing from dawn, fridges running 24/7, and a till ringing during the morning rush. They’ve had two short power cuts in a year, losing stock both times.
The system - Three Tesla Powerwall 3 units (40.5 kWh total), installed for ~£30,000. They’ve already got a 10 kW solar array and a time-of-use tariff (14p off-peak, 41p peak).
How it works:
Overnight charging at cheap rates.
Batteries discharge during the morning rush to dodge peak tariffs.
Solar runs the bakery and tops up batteries at midday.
If the grid drops, fridges and ovens keep going until it’s back.
Metric | Value |
Energy shifted from peak to off-peak | ~12,000 kWh/year |
Price difference | £0.27/kWh |
Annual savings (peak shaving) | ~£3,240 |
Extra solar self-consumed | ~4,500 kWh/year |
Value of extra solar | ~£1,845 |
Downtime avoided | ~£2,000/year |
Total annual benefit | ~£7,085 |
Payback: 4.2 years - with tax relief bringing it closer to 4. After that, it’s pure savings and peace of mind.
Installation Considerations for Businesses
Space needs vary - a 100 kWh system fits in a 20-foot container, but you’ll need 1–2 metres clearance around it for ventilation and maintenance.
Regulations are non-negotiable - UK rules require MCS-accredited installers and compliance with DNO connection processes.
Larger systems will almost certainly need G99 approval before they can be switched on.
Safety first - Most sites will need fire suppression systems and a minimum 5-metre setback from occupied buildings.
If you’re pairing with solar, integration adds complexity but can significantly improve ROI - hybrid inverters make the job smoother and cheaper.
Common Mistakes to Avoid:
Undersizing – A too-small system misses peak shaving opportunities.
Oversizing – Waste of capital that delays payback.
Ignoring scalability – Choose modular designs that grow with your needs.
Forgetting degradation – Lithium-ion batteries lose 2–3% capacity a year; plan for it in your ROI.
Overlooking warranty detail – Some cover full replacement, others just repairs. Read the fine print.
Grants, Incentives, and Finance
While there’s no national battery-only grant, SMEs can offset costs through:
The enhanced capital allowance (super-deduction) - claim up to 130% of qualifying spend against taxable profits.
Green loans from banks or local funds.
Leasing or Power Purchase Agreements (PPAs) with zero upfront costs.
Next Steps For Your Battery Journey:
When planning to install battery storage for your home, there are several important factors to consider. Make sure to refer to the following guides to help you make informed decisions:
To dive deeper into these topics, head over to our advice section, check out our YouTube channel for informative videos, or read a customer case study to see how others have benefited from their battery installation.
Get a Quote for a Battery Today
Without boasting, you should get your battery storage installed with us, here's why:
Thousands of Happy Customers: We boast an average score of 4.9 on Trustpilot, outperforming the market leader.
Which? Trusted Trader: Heatable is proudly recognised as a Which? Trusted Trader.
Tesla Certified Installer: Heatable is proudly certified and approved by Tesla to install the Powerwall.
MCS Accredited: Our accreditation by the Microgeneration Certification Scheme (MCS) ensures high-quality standards.
Consumer Protection: As members of the HIES consumer code, we provide 2-year deposit protection.
Flexible Payment Options: Choose from multiple payment methods, including finance options.
Fixed Price Guarantee: Enjoy transparency with no hidden costs.
Save Your Quote: You can save your quote and decide later.
Bespoke Battery Quote Tool: Find out which battery is ideal for your home, here.
