Kind of odd, though - if the panels will so clearly pay for themselves, why did they have to be mandated?  Just to be clear, it isn&#x27;t a purely rhetorical question - I suppose there&#x27;s a chance that the people who have to pay the upfront costs don&#x27;t get to realize the savings (buyers don&#x27;t always factor in the savings, so construction companies may be reluctant to pay for them).  Alternatively, people will sometimes just stick with a very inefficient system for a long time, never really getting around to it until they&#x27;re prompted (by a mandate or tax incentive).  Sometimes this is because people are just unable or reluctant to eat large upfront costs, other times it&#x27;s something they&#x27;ve intended to get around to for a long time but haven&#x27;t taken the first step.<p>That said, I do think that if the cost of carbon emissions were genuinely reflected in the price, all these specific technology mandates wouldn&#x27;t be necessary.  I do understand that a single municipality is in no position to make that happen, though.