Rapid increasing shareof the electricity supply of renewable energy sources (RES) occurs a temporalsurplus of electrical energy due to high volatile nature of wind and solarenergy. Power-to-Gas (PtG) technology converts wasted powerinto a gas (hydrogen or methane) so that it can contribute to solving thischallenge. Water electrolysis is a promising method for hydrogen production from renewable energy sources. An alkaline water electrolyzer (AWE) has been available for a long time on a MW-scaleon a commercial basis. However, AWEs exhibit poor performance in terms of a slow rampingrate, low partial load range, and low operating pressure compared to protonexchange membrane (PEM) electrolyzers. Here, we introduced the recent progressof diaphragm membrane that overcomes the drawbacks stated above which enables theAWEs can operate more efficiently.