What is the Cost of Charging an EV at Home in the UK?

As electric vehicles (EVs) gain popularity, understanding the cost of charging an EV at home becomes crucial for current and prospective EV owners. This article provides a comprehensive analysis of home charging costs in the UK, considering various factors such as electricity rates, charging efficiency, and real-world usage scenarios.

01 Understanding the Basics

Electricity Rates
The cost of electricity in the UK varies depending on the provider and the tariff plan. As of 2024, the average cost of electricity is approximately 34 pence per kilowatt-hour (kWh). However, many households have access to cheaper rates during off-peak hours through time-of-use tariffs, such as Economy 7 or Economy 10, where electricity can cost as low as 10-15 pence per kWh during night-time hours.

EV Charging Efficiency
Electric vehicles have varying efficiencies, typically measured in miles per kWh. Most modern EVs average between 3 to 4 miles per kWh. This efficiency plays a crucial role in determining the overall cost of charging.

02 Calculating the Cost of Charging

To calculate the cost of charging an EV at home, you need to know:

1. The battery capacity of the EV (in kWh).
2. The electricity rate (in pence per kWh).
3. The efficiency of the EV (miles per kWh).

Example Calculation
Let's consider a typical EV with a 60 kWh battery and an average efficiency of 3.5 miles per kWh.

• Full Charge Cost:
  If the electricity rate is 34 pence per kWh, the cost to fully charge a 60 kWh battery is:

  $$60\text{kWh}\times 34\text{pence/kWh}=2040\text{pence}=\mathrm{\pounds }20.40$$

• Cost Per Mile:
  Given an efficiency of 3.5 miles per kWh, the cost per mile is:

  $$\frac{34\text{pence}}{3.5\text{miles/kWh}}\approx 9.7\text{pence/mile}$$

Off-Peak Charging
If using off-peak rates at 15 pence per kWh, the cost calculations change:

• Full Charge Cost:

  $$60\text{kWh}\times 15\text{pence/kWh}=900\text{pence}=\mathrm{\pounds }9.00$$

• Cost Per Mile:

  $$\frac{15\text{pence}}{3.5\text{miles/kWh}}\approx 4.3\text{pence/mile}$$

03 Impact of Different Tariffs and Charging Habits

Standard Tariff vs. Time-of-Use Tariff
Households on a standard tariff pay a flat rate for electricity regardless of the time of day. In contrast, time-of-use tariffs offer lower rates during specified off-peak periods, typically at night.

Case Study: Dual-Rate Tariff Savings
A household with a dual-rate tariff, charging their EV mostly during off-peak hours, can save significantly:

• Daily Commute Scenario:
  If an EV owner drives 30 miles daily, they would use approximately 8.57 kWh (30 miles / 3.5 miles per kWh).

  • Standard Tariff Cost:

    $$8.57\text{kWh}\times 34\text{pence/kWh}=291.38\text{pence}=\mathrm{\pounds }2.91$$

  • Off-Peak Tariff Cost:

    $$8.57\text{kWh}\times 15\text{pence/kWh}=128.55\text{pence}=\mathrm{\pounds }1.29$$

  Annually, this equates to savings of:

  $$(\mathrm{\pounds }2.91-\mathrm{\pounds }1.29)\times 365=\mathrm{\pounds }1.62\times 365=\mathrm{\pounds }591.30$$

04 Additional Considerations

Installation Costs
Installing a home charging station can range from £500 to £1,000, though grants like the Electric Vehicle Homecharge Scheme (EVHS) can offset these costs.

Maintenance and Efficiency Losses
Over time, charging efficiency can decrease due to battery degradation and other factors. Regular maintenance and monitoring can help maintain optimal performance.

Renewable Energy Integration
Households with solar panels can further reduce charging costs by utilizing solar energy. Integrating home storage solutions can also maximize the use of renewable energy for EV charging.

05 Real-World Example

Example: Family in London
A family in London with a 40 kWh Nissan Leaf and an Economy 7 tariff charges their EV primarily overnight.

• Night-time Charging Rate: 12 pence per kWh
• Daytime Charging Rate: 35 pence per kWh

Assuming they drive 50 miles per day (using approximately 14.3 kWh):

• Night-time Charging Cost:

  $$14.3\text{kWh}\times 12\text{pence/kWh}=171.6\text{pence}=\mathrm{\pounds }1.72$$

• Daytime Charging Cost:

  $$14.3\text{kWh}\times 35\text{pence/kWh}=500.5\text{pence}=\mathrm{\pounds }5.01$$

By primarily charging at night, they save £3.29 per day, translating to an annual saving of approximately £1,201.85.