Dear Sara

I guess by solar Energy, you are refering to use of Solar PV... "Even Wind where possiable". The Solar PV will need the Batteries as a form of backup/ storage, Or you will need to use other means like using Solar PV to generate Hydrogen then later or directly use fuel cell to produce electricity.Currently the problem of solar hydrogen fuel cells system is reduction in overall efficiency, Hydrogen storage technology not yet perfected and hydrogen gas leaks due its atomic size characteristics.

In overall, Renewable Energy is affected by wheather conditions therefore, alone is not reliable to be used without batteries, especially for Biomedical applications systems (human support systems) which need realiable power supply.

However, depending on the energy reguirement situation, for example power requirement amount/ size, hours to power, when to recharge or charge and avaliability of solar energy. Renewable energies can be used to provide energy for any application including Biomedical systems as long as the design is good, together with Energy/power management plan.