Solar Cooker Cookoff


Pinto Beans

Almost everything I read online tells me that the Global Sun Oven (GSO) is a better oven than the SOS SPORT.  There are several reasons for this, but it is mainly because it  is supposed to get hotter than the SPORT.  So I decided to put them to the test – side by side – and see what each could do.   In order to give each oven an equal and fair test, I wanted to be sure that the amount in each oven was exactly the same.  I chose pinto beans because the ingredients could be measured and controlled.  Plus I decided to go one step further and see how well the COOKIT could compete against the big boys.  And  I also pulled out the crock-pot  for comparison purposes.

The night before, I put 1 cup, cleaned and washed, pinto beans into three granite ware pots and the crock-pot.  Then added 2 cups of water to each pot and let soak overnight.  The next morning I found that the beans needed a little more water to cover them, so I added another 1/2 cup of water to each.

Four pots of pinto beans

Here is the cooking chart:

Pre-heat Ovens 9:15 a.m. 41° No pre-heat No pre-heat
Beans into ovens 10:00 a.m. 48° 160° 250° No pre-heat No pre-heat
Temp Check 11:30 a.m. 55° 250° 300° 200°
Reposition Ovens 12:30 p.m. 68° 300°
+1/2 cup water
beans soft, but still need cook time
+ 1/2 cup water
beans very soft, almost done


beans hard, just beginning to cook

+1/2 cup water
beans hard, just beginning to cook
Gone Midday
Beans done 3:30 p.m. 72° 250° 275° 200°
beans soft and fully cooked beans soft and fully cooked beans medium stage, needs to cook longer beans soft and fully cooked

In this test, ovens were beginning to cool off in the afternoon even though the temperature outside was still warm.  The SPORT heated up quickest, held the temperature longer, and cooked the beans faster.  The GSO took longer to heat up and lost the temperature faster as well.  The COOKIT, of course, does not have the insulation and the capabilities of the ovens, but even so, managed a fair job on the beans, coming out almost as well as the crock-pot.  In the summer, with longer and hotter days, the COOKIT might be able to cook the beans.  The crock-pot got off to a slow start, but also fully cooked the beans in the same amount of time.

GSO, CooKit, and Sport



Here is a site that also conducted a side by side test of solar cooking.

Which Solar Cooker Cooks the Best? Testing 3 Solar Cookers Side-By-Side



8 thoughts on “Solar Cooker Cookoff

  1. Hello. I own both a GSO and an SOS.

    I enjoy using both solar ovens. However, if forced to choose one over the other, I would take the SOS without hesitation.

    Why would I go with the SOS over the GSO?

    1.The SOS does not get as hot as the GSO – and that is a good thing. It means it is easier to slow cook food without worrying about things being over cooked. Meats are more tender when cooked at about 200f. Hotter is not better.

    2. I can take the reflectors on or off the SOS, depending on how fast I want to cook a dish.

    3. The SOS can cook two pots at once, or a larger tray, thus offering superior versatility.

    4. The SOS is BY FAR the more rugged solar oven, and is much easier to repair if damaged – which is a very important factor in an emergency (and/or in areas where replacing the unit is not an option). The older GSO ovens were better made than the current models. This is clearly observable in Africa where I have personally seen the SOS ovens literally outlive the GSOs under years of daily use. Further, most African tribal people will immediately choose the SOS over the GSO simply because it is larger and FAR MORE steady in winds (wind is a big issue in many otherwise solar rich areas. The GSO ovens require more tending simply due to having to keep them secured against the wind, which is exacerbated due to having to always deploy the big reflector panels which are mostly superfluous in areas close to the Equator. Reflector panels are only actually of any use in Northern climates, especially during the winter months).

    5. The SOS is much more affordable, as compared to the GSO which is very overpriced. If I had to purchase another one new the SOS delivers a lot more bang for the buck.

    I should be forthcoming by saying that I own two SOS ovens and two GSO ovens. I picked up a used GSO and a used SOS off Craig’s list years after I already had one of each. I have 2 SOS ovens, 2 GSO ovens, 2 parabolic solar cookers, and a few homemade CookIt style reflector ovens – I am obviously a solar cooking enthusiast/fanatic.

    6. If you have a family then the SOS is the ONLY choice. The GSO will only cook enough food to feed a small family of Munchkins. If you have more than one hungry mouth to feed go with the SOS.

    Again, I am glad I have both ovens and I like using them both, but the SOS is a demonstrably superior unit in every important regard. If I am just making a single dish and am pressed for time then the GSO is what I will use. That is its only advantage – and I say this after years of experience using both ovens (and I have probably used both more than 200 times each over the years – to cook everything from roasts, pizzas, stews, dehydrating, cakes, breads, meats of all kinds, beans, clams, seafood, burgers, soups, side dishes, the list goes on and on).

    If you want the best possible combination get the SOS oven and a CookUp200 ultralight parabolic solar cooker. I have a CookUp200 which I got at an inventory liquidation sale off Ebay for a steal-deal price. I also have a larger (1.3 meter) parabolic solar cooker which I also purchased, used, of Ebay for next to nothing. I cook with solar as often as I can, which is quite a lot.

    Anyone who tells you the GSO is the better choice over the Solar Oven Society Sport solar oven has no idea what they are talking about. The SOS is the better unit, hands down.

    I hope this helps.

    • Thanks for the testimonial. The SOS is my favorite as well, for all of the reasons that you mention. Plus, I just find it extremely difficult to reach inside the GSO, and getting past the reflectors. Getting a hot pot out is almost impossible for me. For my husband, being taller and with longer arms, it is no problem. Furthermore, the GSO has a problem with the steam steaming up the inside of the glass window, which has to be monitored and cleared, but that is not a problem with the SOS. I like the fact that the SOS holds two pots. The GSO claims to hold two stacked pots, but those pots really do not stack well. The only thing that I really use the GSO for is for my tall stockpot and for turkey. Thanks for stopping by.

  2. Thanks for conducting this side-by-side test. I also own a GSO, and like it a great deal, but have wondered about the SOS Sport cooker. As I’ve talked to other solar cooking enthusiasts, who own a SOS and GSO, they back up your findings. In fact, using the SOS with reflectors will guarantee the higher temperature goes to the SOS. I’ve always been a bit disappointed with my GSO when altitude angles are below 45 degrees, and added more reflectors. I don’t believe the GSO was made to get to high temperatures, as the reflectors are at a fixed angle, undersized (IMHO), and I don’t think they are at the optimal angle. I’m currently experimenting with two identical panel cookers that I built, similar to the All Seasons Solar Cooker, to see what the optimal angles are. I’ve read that 15 degrees above the altitude angle is a good rule of thumb, but my test rig will determine that conclusively. You may have done a bit better, judging from the picture, tilting the GSO forward a bit more.

    • Thanks for the input and confirmation from other owners with both types of cookers. The common consensus seems to be that the GSO is the better oven. But I love the Sport. I love the design and I love how it holds two pots. I find it difficult to reach into the GSO. An interesting difference between the two ovens is that the GSO collects high condensation on the inside of the glass lid, necessitating that the oven be opened and the glass wiped down (& decreasing the oven temp), because it blocks the light; but the condensation in the Sport does not collect in the lid. It collects between the walls of the cooker. Although the cooker must be tipped when finished cooking to drain out the water, the condensation does not block the sunlight coming into the box. My complaint about the Sport is that the lid is so poorly constructed. The hard plastic lid does not hold up well. I had to replace the first lid after about 6 months, and this lid may need to be replaced soon as well. I will be interested to hear how your panel cookers turn out. I would like to build my own, and have been exploring some options. Happy Cooking!

      • The problem of the glass condensation on the GSO was addressed by the Solar Chef on her previous blog (she now blogs for GSO at

        What she did was place a tea cloth between her pot lid and vessel. Very clever. I usually just open the lid a bit and let it evaporate off, which loses some heat, but I’ve learned to live with it.

        I performed the sun angle test today, and it came out that my top panel angle was always 30-35 degrees higher than the altitude angle of the sun. For those cooks that want to quickly find their daily angle, just go here:
        Choose solar time, check altitude, enter your latitude (mine is 36.04 Las Vegas), pick your day, choose every 15 minutes for resolution, and enter.You should get a nice simple date, time and altitude angle for that day. Used that site quite a bit when I was helping my neighbor’s kid with a science project.

        My bottom panel in previous tests, helped add around 25-35 degrees of temperature to the cooking vessel (filled with water), but that panel’s angle could be 15-30 degrees and not make much more of a difference.

      • Recently, I attended a demonstration hosted by Paul Munsen, president of Sun Ovens, Inc. I asked him about the condensation problem, since the demo ovens also had condensation. He said that the best thing he recommended to do was to put a small stick (like a matchstick) on the upper corner between the glass and the rubber gasket to create a small vent hole. The glass will still fasten down tightly. I have tried this, and it does help some – depending on the size of the vent and what’s cooking. I will give the tea towel idea a try too.
        Thanks for all the useful information on the angles. I’ll be checking out that website for information on the sun altitude for my area

  3. Great cook-off. I’m a little surprised at the results and wonder what would happen with breads! I’m in the middle of a first-degree murder trial and just thought I’d give you something to do while I’m busy! What do you think the Sport performed so well? Is it the new reflectors? Just curious.

    • I too was surprised at the results. I really don’t know why the Sport outdid the GSO. I was expecting the opposite. I do admit that I really like the design of the Sport, but am disappointed in the inferior quality of construction. If the Sport was made better, it would really give the GSO some serious competition. I intend to do this experiment again in the summer. It would also be interesting to see how they handle a tougher assignment than beans. I’ll think about that. Good luck with the trial.

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