BIPV stands for Building-Integrated Photovoltaics, which are products like Sunslates, pictured left: it's a shingle! it's a PV panel! it's both a shingle AND a PV panel!
It sure looks nifty. But is it a good idea?
On the upside: combining building components saves money -- at least in principle. Why pay for two when you can get one thing that does the job of both? And researchers have suggested that in some cultures, traditional PV panels may stand out too much from a house and therefore be considered unattractive.
On the downside: What happens if the roof leaks? If the contractor doesn't install the panels just right? If the roof isn't oriented in the right way for solar generation? And who installs these things? Roofers? Electricians? It can be difficult to coordinate the schedules of tradespeople, let alone get them to work together well.