Sunday, June 15, 2008

Sun Oven Smackdown

Global Sun Oven (GSO - pictured, left) or Tulsi Hybrid Sun Oven (THSO - pictured, right)? Today, we compare.

I got my GSO at LATOC for about $200, and the THSO off of Amazon for about $250.

Ease of setup and storage:
They both set up in a minute or so (not counting travel time). They are both a bit awkward for a 110 lb woman to carry through a doorway. The THSO is more secure in a suitcase-style setup, but is heavier and has 2 awkward side-reflector panels that I don't know how to store yet. They are both easy to position aimed at the sun, but work differently. The THSO uses an adjustable lid to aim at the sun. With the GSO, you actually raise and lower the whole box, while a self-leveling device keeps your food stable inside.

The THSO is wider and can accomodate a full size lasagna, full pizza or cookie sheet. However, it is not deep and cannot fit a 2-qt pot. The THSO does come with it's own stainless steel 4 cooking pans, which look cheap because they have been painted black, but seem to work well. The GSO is deeper, and you can fit taller items like stockpots, but you can only make half-size lasagnas.

They both need dark colored pots/pans with lids to cook the best, or dark colored sheets/pans for baking. The GSO warms up much faster and seems to reach higher temperatures (325+ degrees). This is great for items that take more cooking like beans and potatoes, will cook banana bread in between 1-2 hours. I have only seen the THSO get up to 250 degrees. The THSO is fine for fish, warming up canned veggies, cooking cut-up beets, and pita pizzas. Since the GSO seems to warm up faster, I prefer it even on cloudy days, but the THSO does have a backup electrical capacity, which I have not yet used.

The THSO has a base that sits upon the ground, while the GSO is positioned by ratcheting up a inch-round leg. The THSO is much more stable, although I have noticed the add-on side reflectors have flown off in high wind. Also the THSO thermometer is not attached to the box so it is always falling over. The GSO must be stablized with several bricks during our regular Oklahoma wind-fests.

Hilarity of Users Manual
The THSO wins hands down on this one. Sun BD is an Indian company.... The document begins
"Congratulations, on becoming the owner of this technological solar cooking marvel, which will open a whole new world of safer and healthier life support for your family and the world. " It goes on to explain the importance of solar cooking for your manly vigor and glorious skin complexion. Apparently, there are 23 key benefits of the THSO. #21 is: Food with lesser oil can be cooked, solves obesity problem. #23 is: Enhances charm and beauty of family members, specially women folk.

Overall, the THSO is handier for cooking more types of food, but the GSO seems to work a little better.


Verde said...


I think I'd like to combine the two ovens from your description. Any chance of your designing an oven that matches the best of both worlds?

anajz said...

Frau-Are the insides of these ovens black? And have you used a parobolic cooker?
Great review!

Lewru said...

Very interesting! My own solar project is on hold until I can get to the glass store!

Lewru said...

...and I just ordered my piece of double-strength glass from a local shop. Woo-hoo!

Hausfrau said...

The insides of both are black, yes. I have not used a parabolic cooker. My Dad, who's pretty handy, wants to make a Sun Oven soon - I will be giving him lots of input. And, although I have purchased my 2 Sun Ovens, I would like to learn how to make one as well - a very handy skill post-peak 1. to help prevent deforestation. 2. as source of income for people who want to reduce energy costs or not rely on the grid for cooking.

MeadowLark said...

Would you, could you, PLEASE keep us up-to-date on your father's project? I want my husband to build one... projects are about the only way to get him to buy in to my peak-oil crackpotness. He would just think he was building something ;)

Melissa said...

what are the actual dimensions? I only have a balcony space and am wondering if it would fit...also, how many hours of sunlight does it need to receive to be effective?

Hausfrau said...

Hi Melissa,

The GSO box is 19 x 19; depth of 11 inches. With the reflectors extended add about 12 inches on each side.

The THSO box is 21.25 x 21.25; depth of 7 inches. With the reflectors extended add about 8 inches on each side (but not the front).

To be effective, you need sun anytime between 10 am and 5 pm. "Preheat" for about 15 minutes, then you can cook many fish, egg, pita pizza dishes in 1 hour, banana bread, enchiladas, lasagna, in 2 hours, things like beans or baked potatoes take 4?? or so.

rferrell1 said...

I was gifted 2 large round aluminum outdoor lamp shades. they are highly polished inside, very reflective and i'm certain would make terrific solar oven.

Anyone interested in a DIY solar oven workshop? We could hold it at my shop in OKC.

Frau--when your Dad figures his out, perhaps he can guide us.

thanks for the info.


Anonymous said...

did you have any issues with the smell from tulsi hybrid oven when it was brand new?

Peak Oil Hausfrau said...

Anon - It was annoying but seemed to dissipate fairly quickly. I don't really remember much about it now.

Kathi in NJ said...

Amy Daczyzyn has instructions for making a solar cooker on the cheap in one of her "Tightwad Gazette" books!