Why Solar + EV Is the Ultimate Combination
Solar panels generate free electricity during the day. Electric vehicles need electricity to run. When you combine the two, you can charge your EV with solar power — effectively fuelling your car for free. This combination can save Irish households €2,000-€3,000 per year compared to paying for both grid electricity and petrol/diesel.
The Energy Numbers
The average Irish driver covers approximately 16,000 km per year. An electric vehicle uses approximately 18-22 kWh per 100km, so annual consumption is around 3,000-3,500 kWh.
A 6kW solar system generates approximately 5,400-5,800 kWh per year in Ireland. That's more than enough to cover the EV's annual charging needs and still provide significant savings on household electricity.
Charging Your EV with Solar
To charge your EV with solar, you ideally have a smart charger that responds to solar generation. These systems detect when your panels are producing excess electricity and automatically divert it to charge the car rather than export it to the grid.
Without solar diversion: You export solar at 21 cent/kWh and charge your EV at 35-40 cent/kWh from the grid — losing the price difference each time.
With solar diversion: You use your own solar electricity at zero marginal cost for charging — saving 35-40 cent for every kWh that would otherwise have been exported.
The Combined Annual Saving
Household electricity savings: A 6kW system saves approximately €1,100-€1,400 on household bills per year.
EV fuel savings: Replacing 16,000 km of petrol/diesel (at €60-€80/tank, roughly €2,000/year) with solar-charged electricity (essentially free) saves approximately €1,800-€2,000.
Export income: With solar diversion, export is reduced but there is still some — approximately €150-€250/year.
Total combined annual saving: €3,050-€3,650
The Investment
A 6kW solar system from Billmanage costs approximately €7,200 fully installed. After the maximum SEAI grant of €2,100, the net cost is €5,100. Adding an SEAI-supported EV charger (€300 grant available) adds approximately €700-€1,200 net cost.
Total investment: approximately €6,300
Annual saving: approximately €3,350
Combined payback period: under 2 years — one of the strongest ROI profiles of any home investment available.
Thinking About an EV?
If you're considering switching to an EV, installing solar at the same time maximises the financial benefit and simplifies the decision. You're building an integrated home energy system rather than making two separate investments.
Use Billmanage's Solar ROI Calculator to model the combined return for your home, driving habits, and current energy usage.