Knowledge
Ensuring the project is delivered
Solar PV installations and battery storage systems require multiple trades to be able to install them correctly.
Knight & Day Solar Installations have put together a team of trusted professionals and trades to ensure that each job is delivered in good order and ontime.
The transition to a decarbonised residential home through electrifying heat is a challenging prospect but the use of Solar panels to generate electricity a much more viable option.
Although their are barriers such as planning and construction workforce avaialbility these challenges can be overcome with good project management and communication.
How do you save energy with solar panels
1. Key Factors Affecting Payback
- a) System Costs
- Solar PV System: £4,000–£8,000 for a 3–5 kW system.
- Battery Storage: £4,000–£7,000 for a 5–10 kWh battery.
- Total Cost: Combined system costs typically range between £8,000–£15,000.
- b) Energy Savings
- Solar panels reduce electricity bills by generating power during the day.
- Battery storage further increases savings by storing excess solar energy for use during peak times, reducing reliance on grid electricity.
- c) Energy Prices
- The average UK electricity price is around 30p per kWh (as of 2024), and higher energy prices shorten the payback period.
- d) Export Earnings
- The Smart Export Guarantee (SEG) pays you for exporting excess electricity back to the grid.
- Rates range from 2p to 15p per kWh depending on the energy supplier.
- The SEG contributes to the payback calculation if you export significant excess energy.
- e) System Efficiency and Usage
- Homes with higher daytime energy usage benefit more from solar PV alone.
- Battery storage adds value by covering evening and nighttime usage, especially for homes with low daytime consumption.
2. Typical Payback Periods
- Solar PV Only
- Small System (3 kW): £4,000–£6,000
- Annual savings: £300–£600
- Payback period: 6–12 years
- Medium System (5 kW): £5,000–£8,000
- Annual savings: £500–£1,000
- Payback period: 6–10 years
- Solar PV with Battery Storage
- System Cost: £8,000–£15,000
- Annual savings: £500–£1,200 (from solar + battery use).
- Payback period: 10–15+ years, depending on:
- Battery cost.
- Savings from stored energy used during peak times.
- Export income via SEG.
3. Enhancing Payback
- Maximise Self-Consumption:
- Use more solar-generated energy by running appliances during the day.
- Choose the Right SEG Tariff:
- Select an energy supplier offering high export rates.
- Energy Price Increases:
- Rising electricity prices reduce reliance on the grid, accelerating payback.
- Battery Lifespan:
- Modern batteries last 10–15 years, aligning with the payback period.
4. Lifetime Financial Benefits
- Solar PV systems last 25–30 years, so after the payback period, you'll enjoy free electricity for many years.
- Battery storage may need replacement once during this time, depending on usage and battery technology.
5. Example Calculation
- System Details:
- 4 kW solar PV system: £6,000
- 5 kWh battery: £4,500
- Total cost: £10,500
- Annual energy savings: £800
- SEG income: £200/year
- Total annual benefit: £1,000
- Payback Period:
- Payback Period = System Cost Annual Savings + SEG Income = 10, 500+ 1,000 = 10.5 years
- Payback Period= Annual Savings + SEG Income System Cost = 1,000 + 10,500 = 10.5 years
6. Conclusion
- Solar PV only: Payback in 6–12 years.
Solar PV + battery storage: Payback in 10–15 years. While the payback period for battery systems is longer, they provide additional benefits like energy independence, backup power, and resilience against rising energy costs.