Are free solar panel offers any good?

There's nothing exciting to report about the bungalow plans; our planning application has been given a reference number by the district council but not yet allocated a case officer.  If we get any real news I'll report it here...

So here's a relevant if slightly tangential blog about the merits or otherwise of the increasing number of free solar panel offers - companies offering to install photovoltaic solar panels for free on your roof, in theory giving you the benefit of free electricity.  I keep coming across these and a few people have asked me about them.  Sparked by the latest request for comment (specifically about these people: A Shade Greener) I found myself giving a rambling answer and thought I'd try and edit it into more coherent form to post here.

The free solar companies finance the panels they fit by using the Feed-in-Tariff/FIT (for more about the FIT and planned changes to it please see here: Solar Rush; or for more general FIT info this site is useful - http://www.fitariffs.co.uk/FITs/).  The FIT is in two parts: payment for all electricity produced by your solar panels - even that which you use yourself, and a bonus payment for electricity you don't use that gets exported to the grid.

On top of that there should be a saving on your electricity bill when you use electricity from the panels rather than importing it from the grid.

My understanding is that the free panel companies install and own the panels and receive both parts of the FIT. You get any saving from using power generated on your roof.  This can be worthwhile but it depends on how you manage your electricity use.

Solar Rush

Our plans for planning application are virtually complete and now only lack details of solar photovoltaic/electric (PV) panels, and solar thermal (hot-water) panels on the south-southwest facing rear roof.  We will definitely install solar thermal panels to provide around 60% of our annual hot-water needs.  This is easier to plan as the panels are a fairly standard size.  We hope to also install PV panels, but this depends on the amount that can fit on the roof and the potential output of the system balanced against the cost.  As the sizing of PV panels is much less standard and the calculation of output and which panels to use in what configuration around roof-windows is much more complex, we need this information from solar installers.  Two local firms have agreed to provide a quote including all the relevant information, enabling us to reach a decision and - if we decide to go ahead - to include accurate details of solar installation on our plans for planning permission.