I’ve seen a few questions floating around lately about ditching gas and going fully electric in campervans. Induction cooking usually comes up pretty quickly in that conversation.
It sounds great in theory. No gas bottles, no refills, no open flame and often the major consideration no compliance! Just a clean electric setup.
But the question I kept coming back to was pretty simple:
how much solar do you actually need to make that work?
Not in ideal conditions.
Not parked in the sun in the middle of summer.
More like… middle of winter, van parked up, doing normal daily life.
Starting point
Solar is one of those things where location matters a lot. You see people online talking about setups that work for them, but they might be in completely different conditions.
So I based this on home — New Zealand — and more specifically a winter scenario where you’re only getting about:
~2 hours of usable solar per day
That’s not worst-case survival mode, but it’s realistic enough if you’re actually using the van year-round.
What I wanted to figure out
I wasn’t trying to design a full system.
Just answer one question:
If I use induction for cooking, how much solar do I need to replace just that energy each day?
The numbers I ended up with
| Induction Cooking | Daily Energy (Wh) | Solar Needed (W) |
|---|---|---|
| Light (20 mins) | 600 | 400 |
| Moderate (30 mins) | 1000 | 650 |
| High (1 hour) | 2000 | 1300 |
How I got there
Nothing fancy here. Just breaking it down.
First step was estimating how much energy the induction hob uses.
I based it on a 2000W unit, which is about the upper end of what you’d realistically run off a 12V system with a 2000W inverter.
Then I guessed usage:
- Light use
boiling water, quick meals
~20 minutes per day at full power - Moderate use
boiling + simple cooking (pasta, etc)
~30 minutes per day - High use
proper cooking, multiple meals
up to 1 hour per day
From that, you get daily energy use:
- 2000W × time = Wh per day
That part’s straightforward.
The part people often miss
The solar side of it is where things get a bit more interesting.
Instead of just guessing panel size, I used solar irradiance (solar hours).
I pulled that from my own calculator here:
https://ianganderton.com/solar-calculator/
That tool is set up to estimate full system output, but in this case I just wanted the solar hours figure that’s also there so I could work backwards.
Once you’ve got:
- daily energy use (Wh)
- solar hours (kWh/m²/day or “sun hours”)
You can estimate panel size pretty easily.
I chucked it into a spreadsheet and worked out how many watts of solar you’d need to replace what you used that day.
Reality check
This is where it starts to get interesting.
That 1300W of solar for heavier use?
That’s a lot on a van roof.
Even 400–650W is starting to push into “this needs to be thought through properly” territory, especially once you factor in other loads (fridge, lights, charging gear)
And that’s before you even get into battery size.
What this doesn’t show (but matters)
A couple of things this simple calculation doesn’t capture:
- Inverter losses (you’ll lose ~10–15%)
- Battery charge/discharge inefficiency
- Behaviour changes (you might cook differently once you see the power impact)
But even allowing for those, the overall picture doesn’t change much.
The takeaway (at least how I see it)
You can run induction cooking off solar.
But in winter, in NZ conditions:
- it’s not a small system
- it’s not a cheap system
- and it’s definitely not “set and forget”
What usually ends up happening is people land somewhere in the middle:
- induction for occasional use
- gas as a backup
- or adjusting cooking habits
Here are some other numbers:
| Device | Voltage Type (12V/AC) | Peak Watts | Duty Cycle (%) | Hours Used per Day | Daily Energy (Wh) | Solar Irradiance (kWh/m²/day) | System Efficiency (%) | Solar Watts Needed |
|---|---|---|---|---|---|---|---|---|
| 12V Fridge (Small) | 12V | 45 | 40 | 24 | 432 | 2 | 75 | 288 |
| 12V Fridge (Large) | 12V | 70 | 50 | 24 | 840 | 2 | 75 | 560 |
| Phone Charging | 12V | 10 | 100 | 2 | 20 | 2 | 75 | 13 |
| Laptop | AC | 45 | 100 | 2 | 90 | 2 | 75 | 60 |
| Maxxair Fan (Low) | 12V | 10 | 100 | 8 | 80 | 2 | 75 | 53 |
| Maxxair Fan (High) | 12V | 40 | 100 | 4 | 160 | 2 | 75 | 107 |
| Induction cooking (light) | AC | 2000 | 100 | 0.3 | 600 | 2 | 76 | 395 |
| Induction cooking (moderate) | AC | 2000 | 100 | 0.5 | 1000 | 2 | 77 | 649 |
| Induction cooking (high) | AC | 2000 | 100 | 1 | 2000 | 2 | 78 | 1282 |
| Air Fryer | AC | 1700 | 60 | 0.5 | 510 | 2 | 78 | 327 |
If you want to run your own numbers
Here is a DROPBOX LINK to the spreadsheet I used so you can plug in your own setup and see what happens.
That’s probably the most useful way to approach it — everyone’s usage is slightly different, and small changes add up quickly.
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