Storing energy as hot water (for consumption or a jacuzzi)

Hi Stekker Community! Another idea our family had when thinking about making our vacation home more sustainable and more comfortable.

Are there viable solutions available today to use a solar array to smartly heat a body of water - and then have that water connected to both a hot water source (for showering/cooking, etc) - while use a jacuzzi as a secondary buffer to store additional heat?

Are there already workable solutions available that have fixed many of the issues that arise from building such a setup? Any leads to come up with a decent (multi-year) plan for this would be helpful!

Most HVAC systems connected to radiators or in-floor heating have a zone-based regulation. You can make a zone out of a heat exchanger to heat up water for a Jacuzzi, that normally goes to the building and tap-water heat exchanger.

It would be compatible with the following architecture (at the top you see the heat exchanger):

This is a system that’s currently being provided by ThermoGen BV. Full disclosure: this is a startup that I invested in and am active in.

The system draws its heat from under the PhotoVoltaic panels and stores in in a large body of water. It uses that water or the energy from panels to drive the heat pump at an optimal Coefficient of Performance (CoP). On cold days, the large buffer also acts as a source because the ground is like a large moving average temperature buffer that includes soil and ventilation under the floor. So indirectly it’s a air-water heat pump system but more elaborate and it uses a highly efficient brine-water heat pump.