I don't want to come off as a pedant, but "watts an hour" doesn't make sense in this context.
Watts are a unit of power, energy per time. Joules are a unit of energy.
One watt is precisely one joule per second.
"Watts [per] hour" would be a change in power per time which is equivalent to an acceleration of energy and not an amount of energy.
To get an amount of energy, you multiply the power (watts) by an amount of time. If you want the energy in units of joules, you multiple the watts by the number of seconds in which the power was consumed. That's why kilowatt-hour a is a unit of energy; it's equivalent to one watt applied for one hour. One hour is 3600 seconds, so one kilowatt-hour is equal to 3600 kilojoules.
I believe you meant that the screens consume 200+ watts.
Watts are a unit of power, energy per time. Joules are a unit of energy. One watt is precisely one joule per second.
"Watts [per] hour" would be a change in power per time which is equivalent to an acceleration of energy and not an amount of energy.
To get an amount of energy, you multiply the power (watts) by an amount of time. If you want the energy in units of joules, you multiple the watts by the number of seconds in which the power was consumed. That's why kilowatt-hour a is a unit of energy; it's equivalent to one watt applied for one hour. One hour is 3600 seconds, so one kilowatt-hour is equal to 3600 kilojoules.
I believe you meant that the screens consume 200+ watts.