A Kensington Palace spokeswoman said: “Sadly there was a delay in the delivery of some of the lights for the tree.
“The lights have now been delivered and the tree will be fully decorated over the coming days.”
Susan Hosford, a member of Dorchester Town Council, said: “The Duchy and town council have both made strong climate change commitments, hence the solar-powered lights.
“The use of sustainable energy is to be encouraged. We’re all going to have to adapt our ideas.
“When you make commitments to tackle climate change you have to walk the walk, otherwise it’s pointless. We’re all going to have to change our ideas about lots of things, such as sustainable lights and environmental wrapping paper.”
Eco lights are not thought to have been used in previous years on the Poundbury Christmas tree, but are in keeping with King Charles’s strong views on environmental issues.
Councillor Richard Biggs said the main issue was that the tree this year had been moved to Crown Square, a principal location in Poundbury.
He said the use of low-energy bulbs was “not really an excuse” for the dim lights, but admitted there has been a move in recent years to “go away from big gaudy ones”.
“Crown Square is a roundabout so we’ve got to be careful about the visibility, it can’t be too big.”
However, he said the issue had “not made a big stir in the community” and the main part of Dorchester was brightly illuminated.