In theory, yes - on a clear day we get around 1000W per square metre in the UK so a large enough array of solar panels for both electricity and heat, plus a massive storage battery system, could run a house.
In practise, the cost would be astronomical as you have to guarantee sufficient storage capacity to run the house for days at a time during bad weather, and have enough generation capacity to recharge the system quickly as well as running everything.
Most energy efficient buildings use mains electricity and use the grid as the 'storage' system; you are paid for power you produce when there is excess, which offsets the cost of electricity when your (small) storage system is depleted.
Re. the underfloor heating: The best system is an integrated air conditioning/heating system using a reversible heat pump setup with an underground 'heatsink'. You dump excess heat several metres underground from the air conditioning, then pull it back for heating.
You get roughly 3KW of heat transfer for 1KW of power to the heat pump.