Hot water heater timer
 

This has probably be done before, many times, but.
I put a timer on my 60gal Hot Water heater, it comes on a 11pm and shuts off at 4am. I did this so my heater only comes on when hydro rates are low, 8.7 cents vs 18 cents.
I have never run out of hot water, doesn't matter if I shower in the morning or at night, or twice a day, I have hot water.
My Laundry is always done in cold water so the only other time I need hot water is for dishwashing and washing up.
I did this about 4 months ago and should of done it when I moved in.
I think if I put more insulation around the hot water tank I'd burn even less hydro.

When I set mine, I set the timing it to utilize as much of my PV energy excess as possible, lowering what I send out to the grid as net metered energy. We've got a 50 gallon tank, and rarely noticed any difference in the temps at the tap.

Grey box
 

This timer is marketed for that purpose .

https://www.amazon.com/Intermatic-WH.../dp/B00004W4XI

God bless
Wyr

Insulation around the tank will definitely help keep the heat you paid for in the unit where it belongs. It is a quest of diminishing returns, but the cost is small for a pretty permanent solution. That being said, anything worth insulating is worth superinsulating. Due to the nature of your billing structure, spending "too much" more on superior insulation will only leverage your gains in savings.

Another great idea some other members have had success with is the use of PCM (phase change material) to boost your tank's heat holding capacity. Once unprecedented and obscure, this method has been perfected to the point where you can purchase products to fit your needs. The PCM stores and releases heat using latent energy transfer at a narrow range of temperatures. Using it has the effect of making your tank act larger than it really is.

I have a 240v timer almost exactly like that one for my pool pump. I have been using it for a few years it works well.

I set the timing it to utilize as much of my PV energy excess as possible, lowering what I send out to the grid as net metered energy. We've got a 50 gallon tank, and rarely noticed any difference in the temps at the tap.