Solar Cooking Archive Discussion Forums

Stewart · Joined: 10 Jul 2007 Posts: 10 Location: London

Great to find this forum. I'm an architect with a long term interest in energy conservation.

I've been trying to perfect a decent UK box solar cooker for a few years now, here in north east London. However the temperate maritime weather is usually the problem.

My first attempts were laughable, porous boxes with plastic covers.......these usually got soaked and trashed, but could get to about 60-70C but not keep the temp. in the cloudy times. I thought I had it sussed with double cardboard design insulated with warmcel newspaper insulation, and a double glazed unit. Got it to 80 once and baked a potato, but when left to slow cook it invariably rains at some point, the achilles heel of cardboard box cookers in this climate...........i'll post some pics of the remains sometime!.

I've now got two boxes on the go, London is good to harvest good free materials from. One i'm concentrating on at the mo. is a plastic box, with silver backed insulation batts forming the inner oven bit, and a aluminium thermally broken frame and double glazed unit.

Unfortunately since I've got this one cooking (get's to 60C even in overcast times) the weather has been the pits.

I'll keep you updated as time go's by.

Sorry about the longwinded first post
all the best

Stewart

coconino · Joined: 21 Nov 2006 Posts: 77 Location: Sunny Brixton

Yes, London weather is completely rubbish this summer! It's incredibly frustrating to try and do anything with solar. I was at the Lambeth fair on Saturday in Brockwell Park, trying to demonstrate solar cooking, but it was obviously hopeless given the overcast and rain we had. Sunday was better weather but I was booked elsewhere.

On 7th July I did a demonstration at a school fair in Streatham and that was reasonably successful, actually managing to cook rice and bean stew. I even got a half page in the local newspaper.

Have a look at my posts around this forum, and the solar pics on my flickr page.

You might find, as I did, that a different design of cooker works better here.

Stewart · Joined: 10 Jul 2007 Posts: 10 Location: London

Thanks for the swift reply.

I've got a heavens flame collector ready to put on the high efficiency box..................but going on hol's next week, so its on hold till late august.

Its been my evolving conclusion so far that reflective foil and a sealed void between boxes is only good for near constant sunshine. This design doesnt have the mass to keep temps. up for long when the sun goes in.

Since the sun 'goes in' a lot around here, i've been superinsulating the boxes.

I've found that it can stay at above 60C 2 hours after no sun on a nice afternoon.

any body else used thermal insulation?

Stew
ps
Cant wait to try the heavens flame collector.

SharonID · Joined: 24 Jun 2007 Posts: 74 Location: northern Idaho