Royalty arrived in Millhouse by helicopter as the Queen's youngest son took time out to tour an umbrella factory and speak to workers.
Prince Edward was welcomed by staff at Booth Brothers based at Bullhouse Mill. The site includes The Old Corn Mill, which is one of only about 15 'carbon negative' commercial properties in England and Wales, meaning it produces more energy than it consumes.
Business owner Charles Booth, 48, felt the visit was a big success.
He said: "We were all apprehensive - what do you say to a prince? But you felt like you could go up and talk to him.
"He’s a lovely fella and put everyone at their ease. He had the common touch really and was very knowledgeable about renewable energy."
The Earl of Wessex asked employees about their roles and also showed a sense of humour as he unveiled a plaque to mark the visit.
"If anyone’s told you this is boring, don’t believe them,” he quipped, before moving to sign a visitors’ book and adding: “If you thought that was exciting, wait for this bit."
Booth Brothers employee Simon Bakewell, 42, said: "Meeting him is a once-in-a-lifetime experience. He put everybody at ease.”
Colleague Katie Lovelady, 25, said: "He makes you feel very comfortable, you don’t feel you’re in the presence of royalty when you’re talking to him."