Originally Posted by noglider

Yes, I think so. A power rating on appliance, such as a light, is a minimum requirement. A 10 watt LED wants 10 watts to operate properly. If the power supply can provide more, the appliance won't use it and will leave the extra power aside, so to speak. A power rating on a power supply is maximum offering, so to speak. An 8 watt dynamo will put out more than 8 watts at times, but not always.

The power supply's maximum rating should be greater than the minimum requirement for the appliance. Consider the appliance rating as a price tag and the power supply's rating as the amount in your wallet. You have to have at least the price in order to buy the goods. Having change leftover is OK. Having less than the price is not OK.