Any chance you'd consider a hot water dispenser instead?
We love ours.

You are also talking safety issues, depending on the temp. of the water. If you put what luann talks about. you could either label it, or safety value if children or elderly are around, if they make such a valve.

We have a circulator pump on our hot water line. I get hot water within two seconds at every tap in the house. If you want *boiling* hot water you need the dispenser luann_in_pa is talking about.

Millions of people have electric water heaters, so I'm having a hard time spotting the nuances in this statement: ".... go electric and ... the local REA would treat this as a commercial install due to poor efficiency of same..."

Millions of people have electric water heaters, so I'm having a hard time spotting the nuances in the ensuing query: ".... Does anyone have a suggestion to deliver hot water promptly to the kitchen sink (electric hot water heaters) ..."

What am I missing?

Electric tankless models use 100-150 amps when they fire. A typical home electric panel is 200 amps. To be able to have an electric tankless, most people will need a larger electrical service to their home. Perhaps that is what is being referred to as a "commercial" installation, but it's very far from that! A 400 amp panel will usually do it, but if you have to retrofit it instead of planning it from the beginning, the timeline for the payback for the additional costs associated with the change is very lengthy. You may not recuperate the costs within your life time. Standard electric tank heaters are very very efficient and electric tankless heaters don't really improve on that energy efficiency to any large degree. The only savings you achieve is reduction of standby loss, and in a modern well insulated tank heater, that standby loss isn't that great. Gas tankless provide much more savings over their tanked counterparts, but aren't without larger startup costs themselves.

How fast hot water gets to a certain faucet has zero to do with how it is produced. It has to do with it's location relative to the faucet in question as well as the plumbing runs involved. Tankless only produces "instant" heat at the heater itself. It still takes the same amount of time for the water to travel to the distant location through the pipes as it would if produced by a traditional tanked model. Thus, locating the heater at a central location in the home design will help to eliminate the lengthy wait at any one faucet.

Another method to have faster hot water is to install a "holding tank" downline from the tankless with a recirculating pump. Recirculating pumps work just fine with standard tanked models as well. However, pumps can eat up quite a bit of energy savings (both water and electric) if you keep them active all the time. Having them activate to a light switch or door opening can mitigate some of the energy loss.

You can also install a very small tanked heater underneath the kitchen sink(5-10 gallon) so that hot water production is right there where needed with little wait time. Those also use energy in favor of convenience, so it will depend on your priorities. The best method remains good plumbing design, which is usually a distant after thought in home design. Plumber are usually brought in long after the design phase and have to put things in less optimal spots because builders and architects don't priortize well designed infrastructure.

A whole house tankless uses 150-200A but a kitchen is a small demand rate and all you need is a small 10gal point of use or a small tankless heater.

Look into a small point of use hot water tank unit that runs off 110V. The unit i have holds 4 gallons and uses about 900 watts. The water is plenty hot. If you do a search on amazon, there are a number of them that pop up for less than 200 dollars.

There are two issue with these tank units. The first is that they take up a good amount of space under the sink. The other is getting power to them. I had the electricians put a dedicated circuit with an outlet below my sink to run my water tank. Be leary of plugging this type of water heater into the garbage disposal outlet (if you have one) since the two units combined might exceed the capacity of the circuit.

I looked into smaller tankless point of use systems but the power requirements were high (220V, 30 amps for the one I looked at). They are a little smaller in size and cost a little more.

In our last three homes, we had the plumber put in a return line that feeds back to the hot water heater, and the water recirculates constantly via convection. No pump, no electricity. DH had to explain to the plumber what we wanted, and it took him a bit to understand the concept. It's been great. Instant hot water at the faucets. And we also have a hot water dispenser for tea, etc.