Question from Bernie Kirk, via e-mail:
I have recently completed two solar panel installations using Worcester Bosch equipment. One was in-roof panels and the second on roof panels. The additional cost of the in-roof installation, several hundred pounds for all round flashing and the extra work involved, makes me wonder why use the in-roof system. It is far less expensive to tile/slate the area involved and far less time consuming. The on-roof system has a slightly higher profile but is less likely to leak.
So my question is why complicate the fixture and fittings issue with an in-roof kit that is more expensive, takes much longer to fit and aesthetically is less pleasing on the eye?
Answer from Martin Bridges, director of marketing & technical support at Worcester:
The in-roof system was developed for customers who didn’t like the protrusion of the on-roof solar panels above the existing roof tiles – this is generally a height of around 150mm above the existing tiles. In-roof allowed a relatively level roof line to be maintained and sometimes blended in better, particularly when other in-roof products were installed such as loft windows etc. Some Local Authorities also had this as a requirement of their local planning requirements, particularly with listed buildings, however the permitted development regulations have since relaxed a lot of this.
Ultimately, the choice is down to the customer and the installer. I agree that the installation of in-roof panels is a little trickier than on-roof, but some customers may say that it is worth the extra effort, while others are quite happy with the on-roof installation. Either way the systems will perform exactly the same and provide up to 60% of a household’s domestic hot water requirements throughout the year.