I'm renovating my kitchen and adding engineered hardwood floors to my dining room and living room at the same time. I'm interested in putting an electric radiant heat floor beneath the kitchen, living room, and dining room, and I've gotten quotes from Warmly Yours, Warmup, and step Warmfloor. My concern is less with the cost of materials and insulation and more with the cost of running the system. Both Warmup and Warmly Yours will cost about .41/kWh to run and therefore suggest running for limited periods of time during my heating season (2 hours in the morning and 2 hours in the evening--except of course I work from home but $300/month is more than my current heating bill which tops out at around 200 in the worst month). Step Warmfloor requires a tranformer (because it's a DC system) but cost estimates to run are about 65 to 86 per month during the heating season (and it may help save on my heating bill). Is there an electric radiant heat system that is green friendly in terms of both its materials and its energy usage that I've overlooked? Has anyone had experience with Step Warmfloor that can help inform my decision?

At 41 cents kwh there is no electric resistance radiant system that makes financial sense. That's 3x the US national average for electricity, and significantly higher than the 25 year lifecycle levelized cost of solar power financed at 5% interest even in not-so-sunny places. Is this a diesel fired island electric utility or something?

For a HUGE upfront installed expense there are hydronic output air source or ground source heat pumps that would have a much lower operating cost. But that would be way more to get into than is appropriate for a kitchen & dining room renovation project.

What is your current heat fuel source?

My current fuel source is natural gas which runs between .81 and 1.01 per Therm.

I'd consider hydronic radiant. Or box in the area underneath the floor and pump in additional heat with the existing system (won't work with slab on grade).

Consider adding some PV solar and reducing, not increasing your electricity usage.

There really is no question. There are many sub-floor hydronic systems available along with some sandwich systems with reasonably low profiles.

If you have a boiler hook it up.

If you don't use your water heater to drive the radiant floors. You may need to upgrade but the 2/3rds fuel saving will go a long way...

No kidding!

In the land cheap gas and ridiculously expensive electricity, hands-down it'll be worth the upcharge for a hydronic solution rather than a cheap electric-resistance solution that bleeds your pocketbook forever.

If your space heating is via a hot air furnace, a gas-fired hot water heater (isolated with a plate-type heat exchanger) for running the small radiant floor zone(s) has plenty of capacity, as BadgerBoilerMN rightly suggests.