Abstract: A hemispherically shaped solar heater and storage unit comprises an insulated base, a hemispherically shaped inner dome having a surface capable of absorbing solar energy, and attached to the base to form a reservoir capable of withstanding a preselected pressure, a substantially transparent hemispherically shaped outer dome having a diameter larger than the inner dome and positioned over the inner dome, means for introducing a fluid under pressure into the bottom area of the reservoir, a diffuser for introducing the fluid into the reservoir without substantially disturbing the fluid at the top of the reservoir, and means for removing heated fluid from the top of the reservoir.