Abstract: This invention relates to a solar cooker assembly comprising a circular and convex Fresnel lens having its convex side facing either upward or downward, a protective frame unit rigidly fitted to the periphery of said Fresnel lens, a support unit for swingably supporting said Fresnel lens so that the elevation and the aximuth of the lens can be freely chosen without restriction and a cooking unit located at the focal point of said Fresnel lens.

Abstract: In a solar heat powered plant according to the present invention, hot water is normally circulated through a hot-water tank, a low-temperature-side heat load unit, a return tank, a low-temperature-side heat exchanger, and again through the hot-water tank, in the order named, under the condition in which first and second valves are opened and closed, respectively. On the other hand, in warming up the hot-water tank, the first and second valves are closed and opened, respectively, so that the hot water is circulated between the hot-after tank and the low-temperature-side heat exchanger, through a by-pass pipe. Thus, the warming up of the hot-water tank can be achieved in a short time.

Abstract: A solar heat plant comprises a first system including a high temperature heat collector for changing solar energy to high temperature heat energy under usual sunshine and to low temperature heat energy under poor sunshine to supply the heat energy to a high temperature heat medium, a high temperature heat load which works under usual sunshine using the heat energy supplied to the high temperature heat medium, a second system including a low temperature heat collector for changing solar energy to low temperature heat energy under usual or poor sunshine to supply the heat energy to a low temperature heat medium, and a low temperature heat load which works under usual sunshine using the heat energy supplied to the low temperature heat medium and also works under poor sunshine using the heat energies supplied to the high and low temperature heat media.