"If there is no power available locally, are they sure there are homes nearby which will benefit from a mobile signal?"
Rule of thumb, it's £100 a metre to lay cable into an open site. If there are tree roots, walls, other obstacles expect to double or triple it. If the best site for signal propagation is 500 metres away from the nearest point to hook up to, your site just got very expensive. You'd end up subisidising households to the tune of £10K just to provide the power to the site.
Telcos are pretty savvy - if they've not chosen to provide coverage to an area, there'll be a reason for it.
Biting the hand that feeds IT
