The add-ons on a UK solar quote fall into three groups. Bird mesh costs about £25 a panel and ArcBox connector enclosures about £25 each, and both are cheapest fitted during the main install, because adding them later usually means paying £600 to £800 for scaffolding again. Hot water diverters and optimisers only pay off in specific homes, and a mains voltage optimiser sold to solar owners is one to refuse.
