This then needs to be compared against system cost. The system we chose to install was a relatively expensive, roof-integrated solution. We chose this partly for aesthetic reasons, and partly because we wanted to demonstrate what can be achieved with the latest solar solution design.
A standard system with the same rated output (4.16kWp), however, would achieve the same performance and therefore deliver the same value.
Such systems are available today for around $12,500. Adding that to a 25-year mortgage along with the rest of the housebuild cost would result in additional mortgage payments of $962 a year.
With the first year value and cost being basically equal, this shows a PV system this size on a house with this energy profile can pay for itself from the first year of operation. Then, in subsequent years, as energy prices increase (and assuming feed-in tariffs remain) the annual cost of the system stays the same but the value it delivers (by avoiding increasingly expensive imported electricity) will increase - the system then starts to return a profit.