Types of solar panel - Which is best?
Evacuated tubes or Flat plate solar thermal collector?
So, You've decided you are ready to install a solar thermal hot water system. Which type of solar thermal collector do you go for? Basically, for domestic solar installations, there are two types of solar thermal collector, and both are widely available, but different site conditions will warrant a different choice of collector. Both have advantages and disadvantages:
Evacuated tube collectors are widely seen as 'more efficient'(we'll come onto efficiency in a moment) In some ways they are, but they are also less versatile
When to consider Evacuated Tube Collectors
- Where efficiency is more important than cost of the system
- Where there is no possibility of tube breakage
- Where roof integration is not being considered
Flat Plate Collectors
The big selling point for the flat plate collector is that most can be integrated into the roof to minimise protrusion, as well as being mounted on top of the roof.
In-roof integration, up until recently (when brackets for on-roof fixing became better engineered and panels have become thinner), was the only way to ensure an installation fell within 'permitted developments' for the building regulations.
Nowadays, most collector manufacturers, whether fitted in-roof or on-roof will satisfy this requirement (for most applications, a maximum of 150mm protrusion from the roof line)
When to consider Flat Plate collectors
- If you would like to integrate your solar panels into the roof
- If you are considering re-roofing your home in the near future (the cost of roof tiles/slate can be offset by the space taken up by your solar panels)
- Where there is a risk of tubes being broken/smashed (flat panels are much tougher)
See the table below for the pros and cons of each