It's also important to realise that, in any given situation 'cost effective' doesn't necessarily mean 'affordable' (or affordable-enough to lead to the people i

It's also important to realise that, in any given situation 'cost effective' doesn't necessarily mean 'affordable' (or affordable-enough to lead to the people installing them). The people need to have the available funds, etc. It may save momey but that's not an immediate payoff. Any increase in efficiency vs costs will help with that equation.