MIT has developed a hybrid photovoltaic/electrolysis system that may make it possible to generate electricity around the clock.
A liquid catalyst was added to water before electrolysis to achieve what the researchers claim is almost 100-percent efficiency. When combined with photovoltaic cells to store energy chemically, the resulting solar energy systems could generate electricity around the clock, the MIT team said.
Currently, MIT is working with photovoltaic cell manufacturers to incorporate electrolysis using their catalyst into solar energy systems. By combining the two, excess capacity during the day could be stored as hydrogen and oxygen, then used in fuel cells at night when needed.
One of the biggest problems with photovoltaic systems has been a means of efficiently storing excess power generated during the day. While batteries have been the primary means of doing so, they aren't nearly efficient enough and need to be replaced on a regular basis in order to maintain system efficiency. But if the excess power can be used to electrolyze water, splitting it into hydrogen and oxygen, and the hydrogen stored in a low pressure system, the hydrogen can then be used to generate electricity in a fuel cell when the sun goes down.
MIT's system greatly reduces the cost of the electrolysis equipment while at the same time increasing the electrolysis efficiency to almost 100%.
This is but one more step towards affordable and efficient solar energy systems.