Energy Savings Calculator

Estimate your annual and lifetime savings with balcony solar.

System Configuration

400W 200W to 1000W
Current UK rate: approximately 24p/kWh
5 hours South UK: ~5-5.5h, North UK: ~4-4.5h

Battery Storage (Optional)

Battery helps store excess generation for evening use

Your Potential Savings

Annual Generation

730 kWh

energy produced yearly

Annual Savings (Solar)

£175

from solar generation

Total Annual Savings

£175

all sources combined

Battery Savings (Annual)

£0

from battery arbitrage

Off-Peak Arbitrage

£0

grid charging savings

Payback Period

5.1

years (assuming £900 system cost)

10-Year Projection

£1,750

total savings over decade

CO2 Avoided

0.18

tonnes per year

Understanding Your Results

Annual Generation

The total electricity your system produces yearly, calculated from system size × sunlight hours × 365 days. More sun and larger systems = more generation.

Annual Savings

The monetary value of electricity generated by your solar system, based on your local electricity rate. This is the free energy your system produces that would otherwise be purchased from the grid.

Battery Savings

Additional savings from storing excess solar energy in a battery for evening use, avoiding peak-rate electricity purchases. Only available if you add battery storage.

Off-Peak Arbitrage

Savings from charging your battery during cheap off-peak hours and using that stored energy during peak times. This only applies if you enable grid charging and have off-peak rates.

Payback Period

How many years until your total savings equal your initial system investment. Based on an assumed system cost of £900; adjust this estimate based on your actual quote.

CO2 Avoided

Tonnes of carbon dioxide not released into the atmosphere because your system generates clean, renewable energy instead of grid electricity. Average UK grid: ~0.233 kg CO2 per kWh.

Tips for Accurate Estimates

  • Sunlight Hours: Southern England typically gets 5-5.5 hours of usable daily sunlight; Scotland and northern regions average 4-4.5 hours. Use online UK solar resource maps for precision.
  • Electricity Rate: Check your latest energy bill for your actual rate. Rates vary significantly by supplier and region.
  • System Size: Most balcony systems are 400W or less. Larger systems generate more but may face approval hurdles.
  • Battery Addition: Batteries add £1500-£3000 to system cost. They're worthwhile if you can use stored energy during peak-rate hours.
  • Realistic Payback: Calculations assume consistent 2025 electricity rates. If rates increase (likely), payback accelerates and long-term savings grow.
  • Performance Variance: Real-world generation varies ±15% due to weather, seasonal changes, and shading. Our estimates are conservative.