Hyundai are making a big fanfare out of their innovative solar roof, which they highlight as having the following benefits:
- Eco-friendly solar roof system charges vehicle’s battery using solar panels even while driving
- The solar roof system improves fuel efficiency while preventing battery discharge and reducing CO2 emissions
- With the technology, 30 to 60 per cent of a car’s battery can be charged via solar energy
Let’s examine these claims.
- OK, can’t argue that it charges the vehicle’s battery while driving. Fair enough. But that’s the point of the solar panels!
- Improves fuel efficiency and reduces CO2 emissions – by how much, Hyundai?
- 30-60% of the battery can be charged … hmm. Why so little? And how long does that take? And where does the car need to be for that to happen – parked in the hot midday sun?
I’m not convinced by any of this. Solar panels usually need to be large and angled to really produce any sort of power. And as Hyundai are stating that this cannot be used to fully charge the battery, then I wonder just how useful this actually is.
Hyundai go on to say
With 6 hours of daily charging, it is expected to increase drivers’ travel distance by an extra 1,300 km annually.
6 hours of sun a day for the car to charge … to only get us an extra 1,300 km. Let’s assume that the average driver for the Hyundai Sonata 2.0GDi HEV (the car they launched it on) will only be buying a 2.0 engine as they will be travelling larger distances. They didn’t buy this car to do the school runs and drop into the local shop. Therefore the average distance covered each year could easily be in excess of 40,000 km. But let’s play nice for a second, and pretend the average distance each year is less – let’s pick a figure of 30,000 km. That means the new fangled solar roof will give the driver the following fuel saving:
1,300 KM from solar roof in a year
——————————————————- = 0.43 = 4.3% fuel saved
30,000 KM travelled per year
Interestingly, the price for this solar roof is missing from the Hyundai page. If I was only saving 4.3% of my refuelling costs (and remember, I did this calculation on a lower than average distance per year for the sort of driver that Hyundai want to buy this car), then I would rather spend that money on a bigger battery, which would get me more range …
It’s a pity, really. I thought when I first read this that Hyundai had made a huge leap forward with electric cars, and my bugbear that they take forever to charge. Oh well…