Because we love these reader back-and-forths:
The reader in the March 11 post claims that a small solar cell can supply enough electricity to separate hydrogen from water, and then the resulting hydrogen can be used to power everything in your home. The reader clearly does not understand thermodynamics or chemistry. The laws of thermodynamics in very basic lay-person language are thus:
1. You cannot win.
2. You cannot break even.
3. You must play the game and lose badly every time.
So, whatever energy is spent getting the hydrogen and oxygen apart cannot exceed the amount of energy gained by putting them back together. All hydrogen fuel cells work by putting hydrogen and oxygen back together. So, the solar cell would need to provide (much) more energy than the energy ultimately supplied by the hydrogen cell. Thus, there is simply no possible way that a small solar cell that cannot power your home will suddenly and magically make enough energy to produce enough hydrogen to power your home. This is basic, simple stuff that seems to elude otherwise smart people time after time, particularly while wishing for the eternal sunshine, lollipops, and flying unicorn dreams of greenies. As with everything else in this world, there is no free lunch, and you have to work for the lunch you get.
However, the hydrogen thing does solve the problem of storing excess electricity produced by solar cells for later use, albeit less efficiently. Currently, there is no need for such an arrangement since almost all power companies allow customers to use the grid as a type of battery by pushing excess energy into the grid from solar and wind homes for a credit (usually 1 to1) for later use (also called spinning the meter backwards). Even with this arrangement, solar power is simply not economical without subsidies and requires a huge initial capital investment.