I don't think your landlord was right. From memory, splitting water into Hydrogen and oxygen via electrolysis, only to be converted back to electricity is very

I don't think your landlord was right. From memory, splitting water into Hydrogen and oxygen via electrolysis, only to be converted back to electricity is very lossy. I believe that most hydrogen generated at industrial scale is derived from fossil fuels. Storage is also very difficult. Hydrogen is so small it can squeeze through a lot of gaps, making it hard to contain. You probably have to store it at high pressure and at cryogenic temperatures.