Firstly, a common tactic some installation companies use, where the company just adds their logo to imported panels, then claim to manufacture them.
Familiar branded panels, like Panasonic, LG, Sanyo are generally sold at a premium price, but generally higher output. Ask what wattage, and whether they are Monocrystalline or Polycrystalline cells.
I would prefer Polycrystalline, but would look to pay a couple of grand less. Without knowing more about the specification’s.
We have lots of trusted installers on the site. Getting three quotes will certainly give you comparison quotes.
If you are going to get solar panels fitted you need the following information confirming before they start, and remember you have fourteen days to cancel your contract from the date you signed the contract. An installer who produces the correct shading foil as required by the MCS.
Has the workmanship, insurance policy in place for you.
The installer will notify building control for the solar PV installation and the extra electrical circuit installed.
Hasn’t over sold the in house self consumption, use of the solar panels usually 30% to 35%.
Uses quality materials.
Doesn’t install solar panels using a ladder, but a proper scaffolding or tower scaffold.
Get recommendations from past customers.
Not all solar panel installers are equal. Some are a lot better than others.