Solar concentrator, solar receiver and thermal storage

A solar concentrator comprising:

• a base;
• a framework, the framework being hingedly joined to the base such that the framework can be rotated relative to the base;
• and
• a plurality of mirrors arranged relative to a first axis of the framework, each mirror being fixed to the framework and each mirror being arranged to reflect light travelling parallel to the first axis towards a common focus which lies on the first axis,
• the mirrors being arranged such that the first axis can be directed substantially towards the horizon of a ground plane by rotating the framework relative to the base while the base is rested on that ground plane, wherein the framework is hingedly joined to the base such that the framework can be rotated around a second axis other than the first axis, the second axis being coincident with the common focus, wherein the base is rotatable about a third axis and the third axis passes through the common focus,
• wherein the plurality of mirrors form a plurality of concentric semi-circular arcs centered on the first axis, wherein each arc comprises proximate and distal edges, the proximate edge being closer to the common focus than the distal edge,
• wherein the plurality of concentric arcs comprises a first semi-circular arc and a second semi-circular arc located inside the first semi-circular arc, wherein the distance between the proximate edge and the distal edge is greater in the second semi-circular arc than in the first semi-circular arc.