£8 Per Month Energy Bills With Solar Panels

The Setup

This 4-bed detached home received a premium solar and battery installation:

• 4.2kW solar array with 14 premium panels
• 10.5kWh battery storage system
• SolarEdge SE4000H inverter with module-level monitoring
• Annual generation capacity: 4,000 kWh

The Remarkable Results

From April 2025 to January 2026 (8 months), the household situation is:

• Total amount paid: £64
• Account credit balance: £180 remaining
• Monthly average cost: £8 (mostly standing charges)
• System is simultaneously generating and storing energy while paying for itself

Financial Breakdown

Here's exactly how the numbers work over the 8-month period:

Energy consumed:

• Grid electricity: £486.29
• Gas: £306.45
• Total consumed: £792.74

Energy exported:

• Solar exports: 3,196 kWh at 15p per kWh = £479.34
• This nearly offsets the grid electricity consumed

Fixed costs:

• Standing charges: £280 for 8 months (£35/month typical)

Why Battery Storage Is Critical

The 10.5kWh battery system is crucial to these results. It allows the household to:

• Store excess generation from midday hours
• Use stored energy in the evening peak demand period
• Minimize grid imports when they're most expensive
• Maximize the value of every kWh generated by the panels

Without battery storage, much of the midday generation would be exported at 15p per kWh rather than kept for evening use.

25-Year Projection

With such low ongoing costs and export earnings exceeding grid consumption:

• Total 25-year savings: £35,000+
• Payback period: approximately 5.5 years
• Free generation years: 19.5+ years