using solar energy directly for household needs, limits the use of this energy in the forms of heat and light. moreover, it limits the options for energy storage in batteries, and actually limits energy storage at all, and therefore alowwing direct use of the energy only in daytime.
direct energy usage is limited to day times only. the number of applications that can be activated with heat or light energy alone is limited. If energy storage is possible, its limited to less common ways such as thermal storage which is short-termed (or hydrogen storage in the future).
therefore - ways to use appliances directly by heat/hot air/steam or light should be found to lower the electricity demand of the household. additionaly, it is desired to find ways to store heat efficiently (that could be used for at least more then a night) and compatible with as many household appliances as possible.
moreover, there must be a consideration in the scale of the wanted energy harvesting/using system and storing system as well as integrating the systems to household needs in several scales (a single home, a building, a neighborhood, a city, or a whole country). thats because different systems are more efficient/simple/cost effective in different scales.
the project is completed when a direct alternative for the usage of solar energy for households is proposed.
Solution might incorporate one or more of those 3 functions regarding solar energy:
There isnt a single, simple, perfect solution - because the problem is complicated, and dependent on scale, use, space and technological development.
the most ideal solution should include the option to be incorporated with electricity - thus making it less specific and therefore more flexible and more common.
all of the above offering a way to be less dependent on the electricity grid and lowering the load on it, helps avoid curtailment of electricity from renewables, usage of waste energy and eventually using the energy more efficiently and reducing costs.
A good example of how to use 40 Inventive Principles for ideas generation.