EV Depreciation vs Solar Savings
If you buy a new electric car and charge it mostly from your own solar and battery setup, the running costs can look brilliant. The catch is depreciation can still bulldoze those savings if you overpay for the car or finance it badly.
That is the whole argument in one line. Solar-charged EV driving can be genuinely cheap. New-car depreciation can still be brutal. You need both numbers on the same page.
These help you keep tabs on usage, cable mess and the small stuff around home charging. SmartKoala may earn from qualifying purchases.
| Question | What matters more than people think |
|---|---|
| Can solar make EV charging cheap? | Yes, especially if you already have spare daytime solar |
| Can battery charging help? | Sometimes, but the battery economics still need to stack up |
| Can depreciation wipe out the savings? | Absolutely, especially on expensive new EVs |
The part EV fans undersell
If you already have solar, and especially if you are exporting cheap power back to the grid during the day, charging an EV at home can be a strong use of that energy. That part is real.
If you also have a battery, you may be able to shift some charging away from expensive evening power. But batteries are not free money either. You still need to look at the cost of the battery system and how hard you are cycling it.
The part car ads underplay
A new car loses value fast. EVs are not magically exempt. If you buy new, take the biggest depreciation hit, and then congratulate yourself for saving a bit on fuel, you may be telling yourself a very flattering story.
This is where most people get caught. They compare EV charging costs to petrol and stop there. The bigger number can be depreciation, finance interest, or both.
When the maths can still work
- You already have solar: the economics are cleaner if the system is already there.
- You drive a lot: higher kilometres make charging savings more meaningful.
- You keep the car longer: that spreads depreciation over more years.
- You buy sensibly: not every new EV is a good deal just because it plugs in.
What to compare properly
Before buying, compare the full stack: purchase price, expected resale hit, charging cost, finance cost, registration, insurance, and maintenance. If you skip half the list, you are not doing a comparison. You are doing wishful thinking.
Check your numbers with the EV Charging Cost Calculator, EV Solar Calculator, Car Finance Calculator, Loan Repayment Calculator, and state solar pages like Solar VIC, Solar QLD, or Solar NSW.
Bottom line
Buying a new EV and charging it with solar can make good sense. But only if the depreciation hit and finance cost do not quietly eat the savings. Compare the whole cost, not just the charging bill, and the answer gets a lot less romantic.