There are many sites about pressure cookers that explain the basics of how they work and why they conserve energy. For solar cooker users, the latter reason isn’t really critical, but it does help to have a pressure cooker that is dark colored to better absorb the sun’s energy. Most solar cookers also have limited space, so I looked for pressure cookers in the 3-4 qt. range.
There were not many that fit my requirements and I chose the Hawkins Futura line (3 litre version) primarily because Hawkins has many years of experience in building pressure cookers. I emailed them to confirm that the anodized aluminum Futura cooked at 15 psi and quickly received an affirmative reply. I had been advised that some pressure cookers (especially aluminum ones) only reached 10-12 psi. Spec sheets across the board rarely listed the psi rating.
A similarly priced option was the 2.8 L Halulite made by GSI Outdoors, the company famous for its lightweight camping gear.
This is probably also a safe option, but it might be a bit harder to find a replacement gasket in the future. Since GSI usually focuses on light weight gear, it’s no surprise that their pressure cooker at 2.75 lbs. weighs less than half of the similarly sized Futura at 6.2 lbs. I did not verify the psi spec, so you’ll want to do that if you’re interested in this one.
The additional thermal mass of the Futura would actually be a benefit with a parabolic solar cooker because it would more evenly distribute the intense energy usually generated. In fact, a standard 4 qt. stainless steel pressure cooker would probably work just fine on a 4-5 ft. parabolic cooker. However, if you intend to use the pressure cooker in a Parvati solar oven (a parabolic funnel), the thinner walled Halulite would probably be the better choice.
Hawkins has a unique design that requires a modified version of closing & opening the lid. You should read these instructions carefully. Browse their excellent website for more info on pressure cookers.