🔋Home Battery Storage
Home Battery Storage Sizing & Savings Calculator
Storage capacity, cycles & self-consumption
📍Location-calibrated simulation by town or outward postcode:
⌘K
Storage Sizing
Battery Capacity London
Determine optimal storage capacity balancing overnight load against local solar generation (986 kWh/kWp).
Recommended Size
7.5 – 11.0Rooftop Solar Array
5 kWp
1 kWp (Small / Garage)20 kWp (Full Roof)
Overnight Load
kWh
Autonomy Buffer
x
Electricity Unit Rate Auto-Sync
p/kWh
LFP Lithium TechnologyDoD: 90% usable | RTE: 90%
Currently calculating with: 25.4 p/kWh
📍London (986 kWh/kWp)
Cycle Utilization
Wirtschaftlich träge (<135 Zyklen)Expected Full Cycles
~92cycles/yr
Shifted Solar Energy
770kWh / yr
Annual Power Bill Savings
+ £104/ yr
Net margin: ~13.5 p per cycled kWhEst. Hardware Cost~£5,617
Payback Period~> 50 yrs
❓Frequently Asked Questions: Home Battery Storage
Key UK engineering benchmarks, Ofgem standards, and clean energy incentives at a glance:
What battery capacity is recommended for a typical UK home?▼
Most UK households install 5 to 10 kWh of usable battery capacity for an average 4 kWp solar array, or 10 to 14 kWh if operating alongside an EV or heat pump on off-peak dynamic tariffs.
Are home batteries exempt from VAT in the UK?▼
Yes. Since February 2024, the UK Government extended 0% VAT relief to standalone domestic battery storage, as well as batteries retrofitted to existing solar arrays.
Does a home battery automatically supply power during a power cut?▼
Standard grid-tied batteries switch off during outages for lineman safety. To support power cuts, an optional Emergency Power Supply (EPS) circuit or automatic transfer switch must be wired into essential consumer circuits.
How do smart off-peak tariffs (e.g. Octopus Agile or Go) maximize battery ROI?▼
Smart tariffs offer cheap overnight electricity (often 7p to 9p per kWh). A home battery charges during these cheap overnight hours in winter and discharges during expensive peak periods (24p–30p/kWh), generating year-round savings.
How long do Lithium Iron Phosphate (LiFePO4) home batteries last?▼
Modern LFP battery cells provide 6,000 to 8,000 full charge cycles. At typical UK residential cycling frequencies, this equates to 15 to 20 years of operational service with 80% remaining capacity.
What is the round-trip efficiency of domestic storage systems?▼
Premium residential battery storage systems achieve 88% to 92% round-trip efficiency, meaning approximately 8% to 12% of stored energy is lost as heat during AC/DC conversion cycles.
💡
Suggestion or Feature Request?
Are you missing a specific calculation, UK regional metric, or export tariff? We welcome any feedback from homeowners and energy professionals.
🐞
Report an Issue
Did you spot an inaccurate calculation, incorrect town data, or broken link? Let us know directly so we can patch it immediately.
