Solar Kiln Concept
I posted a tiny shed studio design on Tiny House Design and Facebook the other day and a reader, Gretchen, posted a comment questioning the environmental impact of gas and electric kilns. I agree that this is a big problem.
To fire pottery to high temperatures (cone 10 is 2340° Fahrenheit) takes a lot of energy. The resulting benefit is that you get vitrified pottery that can last many lifetimes or until someone drops it 
But this is not much of an offset so the kind of energy requirement is still an issue.
Years ago, inspired by a story I heard told about Paul Soldner and an experiment he did with mirrors and a bunch of people, this kiln design popped into my head. Using solar trackers and mirrors couldn’t a simple small focused solar energy kiln be rigged?
The circular drum would be built from hard brick to help transfer and store the heat as it builds up. The roof and floor would be made of soft brick in a similar fashion to an electric kiln, which would provide access and help keep the heat inside the kiln. The entire drum would rotate slowly (via electric motor) inside an insulating layer. One small opening would face the mirrors to continually heat the surface of the hard brick wall as it spins slowly.
I like this idea, but I think it will take a much larger reflective area to heat it. This idea could be made into a reduction kiln easily.