wrote:

But you're still losing 76 watts of energy.

That's power, not energy.

In cold weather, if you could recover 100% thay would be 76 watts less
(or equivalent) energy used for other purposes.

That's power, not energy.

Phil Sherrod wrote:

If you are going to try to increase the efficiency of a hot water heater,
it is better to use an insulating jacket than a timer. But regardless of
what you do, you won't save more than $4/month unless you either (1) reduce
your hot water usage or (2) change to a cheaper source of energy (gas,
heat pump, solar, etc.).

Or

3) use cheaper off-peak electrical energy, or

4) use a greywater heat exchanger.

Nick