dont be fooled by noise about limitations. The basic fact is that all mater in the universe can and does carry a charge, and we are a very very long way from exhausting possible battery and PV candidates, as all mater in the universe is also photo reactive, and very subtle changes in how crystline structures are aranged has a huge impact on how matter and energy interact, and again we are only begining to be able to study and control how there characteristics can be utilised. Current battery and PV technology is proving to be acceptable forgrid scale implimentation, but recent work points towards significant improvements in efficiency, with other advancements in manufacturing showing very quick time frames for comercialisation, where new types are designed to be produced on existing equipment.