A Watt has no time constant. A watt is an amount of energy consumed at
a moment (ie, a 60 watt light bulb), not an amount of energy over time
(like a watt-hour; for instance, a 60 watt light bulb uses 60
watt-hours of power every hour, or 1.44 kwatt-hrs per day).
There is a direct correlation between watts and btu's, and that is:
watts * 3.413 = btu
You're confusing Watts and joules. One Watt is one joule of energy per