Heat storage vessels for use with heat pumps and solar panels

A solar heat storage system comprising in combination:

• an externally-insulated heat storage vessel containing and substantially filled by a liquid heat storage medium,
• a first heat exchanger deeply immersed in said storage vessel,
• solar panel means, having an upper end and a lower end, operatively connected by a pair of delivery and return conduits to said first heat exchanger for delivery of solar-heated liquid from the upper end of said solar panel means to said deeply immersed first heat exchanger, and return of the liquid to the lower end of said panel means,
• a second heat exchanger shallowly immersed in said vessel,
• and a heat pump operatively connected by a pair of conduits to said second shallowly immersed heat exchanger for pumped circulating delivery of heat storage liquid to said heat pump for use in both heating and cooling operation,
• the heat storage vessel being surrounded externally by a heat-insulating layer, and formed by a plurality of discarded imperforate and liquid-impervious vehicle tires of substantially the same size adjacently arrayed parallel to each other with their adjacent beads firmly anchored together, and with the outermost tire at each end of the arrayed plurality of tires having its exposed bead substantially sealed by a metal plate clamped thereto, whereby the heat storage vessel is formed as an externally-insulated, substantially sealed, leak-proof container for the liquid heat storage medium.