And on a cloudy day, it won't boil at all. Rubbish!

@Jon A.
And on a rainy day my socks will get wet!

I think that is really cool and green. I think it would be very useful for times when the power is out. I think it would be also very good for camping or trips.

Given the high weight, tiny capacity, and long heating time it is not even remotely practical.

it takes an electric kettle 2 minutes to boil that much water with 2000 watts, so if you had a bike powered electric generator it would take 20 minutes on slow pedal speed, or 10 going like a crazy guy. so in 2 hours 120 minutes, it's about... 30 watts...
a 30 watts thin film solar panel is about 30 pounds, and it's alot more versatile, and same as a couple of a2 sheets of paper. and it's also lighter.
interesting.

Designed by a British engineer, it should generally have a good chance of working in sunnier climes! I wonder though, if filled right up for use on a very sunny day, is there any risk of steam pressure expelling contents when opened? Or is there an 'over-pressure' valve incorporated? I agree it seems a bit heavy for hikers though, they are usually worrying about every little gram.

Great design concept. But, 500 ml in 2 hours is too little and too long. And this is solar powered so you will have to be stationary for 2 hours. Self defeating.

I am planning a climb up an 8000 meter mountain this summer. I was thinking that this might be a good solution to the drudgery of having to spend half the day melting ice for drinking.
NOT
Obviously, this guy got an engineering degree without having learned anything about engineering. If this device covered a MUCH larger area with something light like mylar, it might actually have some potential. As it is, it is an embarrassing failure.

I think it's a great idea. I'd love to see how efficient it is and if it could be integrated into solar hot water for the home. Humans are very wasteful with energy, I'd love to see more environmentally friendly solutions like this. Obviously this wouldn't suit all climates, and latitudes but there are many in which this would work extremely well.

Interesting title but dissapointing product. I mean, my respect for the designer but two hours for boiling point it is too much time for an emergency. Well, probably in my my country with a 34 celsius average temperature work faster, or in africa.