[jeff5may]

Ok, so unicorns exist. You're moving your solar heat back and forth between heat exchangers and States of matter for free. Your sustained energy savings is attainable at low cost. A third of a ton of heat capacity is going to make a world of difference. Have at it big bang scientist. Don't forget to send lots of pics and test figures.

Not trying to pick a fight here. You just repeated part of what I said. The rig you propose will do something. How much of something depends on materials and execution. Time and temperature, combined multiple hx chain effectiveness, and outdoor thermal storage and insulation come to mind. I would definitely not run any extra pumps or blowers that consume electric power unless they are also solar.

Considering between the lines here. You hint at a tubular collector. Is it an evacuated tube collector? If so, the advantage of this type is high grade output. This means hot water that can burn you with indirect sunlight. Concentrated energy should be kept that way and only spent at the other end of the chain. If the solar panels can boost the heat pump indoors, either or however, it would certainly be more efficient.