Related Clues:

• Joule piece
• Light bulb measure
• Rowing machine unit
• See 17 Across
• Solar panel unit
• 0.1 microjoule
• Bulb measure
• A light amount?
• Nutrition-label unit
• One joule/second
• A bit of a joule
• Tiny fraction of a British thermal unit
• A little bit of work
• Inventor
• Eponymous Scottish inventor