I am building a 900 sq.ft., 3-level home this spring using ICF (Nudura)...the house will be partially powered by a wind turbine, so an electric boiler(s) is the way to go for my water heating. (I love geo-thermal, but this house doesn't warrant the costs) This being said I plan to heat my slab as well as the floors above using LW concrete w/superplastisizer over 3/4 plywood an 16" floor trusses. The floors will remain exposed concrete throughout, for now anyways....

Does anyone have any insight on to how my proposed system will perform, as I haven't crunched any numbers, these are just my ideals... The floorplates have each have generous openings in them (stairs/loft/etc..), so I am hoping to run less PEX in the 2nd and 3rd floors and bank on the basement slab picking up the difference...am I out to lunch?  Thanks in advance for any info you may be able to provide.

We sell a lot of electric boilers in this type of application. If you are off the grid you will need a pile of battery's to support the demand of an electric boiler, If you are grid tied this is a good choice as you can pull the amp load of the grid when you need it and trickle it back as you make watts.
Small electric boiler, 1 pump, 3 motor zone valves, air eliminator, expansion tank, zone valve control, a few more parts and you are there.
Pipe is not expensive, place it well in all three floors.
Dan

Doing a similar electric boiler set up for a passive solar home in Boulder Colorado.  We are doing electric boiler because we will have 6kW PV system, passive solar and active solar heating. So electric boiler will be backup to active hydronic solar which is backup to passive solar.  The heat loss / demand will be too low to justify paying $15/month just for gas meter.  
Agree that for small, low demand well insulated homes geothermal rarely makes sense.

Instead of a gypcrete floor we will be using a warmboard type radiant floor (ceiling in the carpeted bedrooms) because I believe it can more readily respond to a passive home without overheating.

It would be very helpful when asking for an option on whether a system will work, if you stated WHERE the project is located.
Your project could be in Florida or Alaska, and you will get different answers in those two extremes.
The single most important piece of information when discussing a HVAC system, a solar system or an insulation system is location, location, location.

Thanks for the replies...I have tried to attach some floor plans, etc. but the files are always too large. I am located in Regina Beach, SK., so the weather is comparable to that of Colorado's', but closer to Minnesota's I guess. Anyways, I am set on a L.W. concrete floor, and hope that the wind turbine(either a Skystream, or sim. sized turbine) can supplement the electrical needs and get us closer to being off the grid. For now it will be grid-tied w/solar domestic hot water. If anyone else has recommendations for certain boiler systems, I would love to hear them. Gas/LP are not options, strictly electrical only.

Geo-thermal

You have not mentioned your buildings heat loss values. I highly recommend passive solar integration and super insulation values. Look at your NRCan R-2000 building program:
http://oee.nrcan.gc.ca/residential/personal/new-homes/r-2000/standard/current/purpose.cfm?attr=4
You will find that you really are not like Colorado and building guidelines that are outlined in this program will better suite your latitude and climate. I am in Southwestern Montana and have been using NRCans' Hot2000 heat load analysis software for over 25 years. It is very accurate, in northern climates. I have the reports and the power bills to prove it.
If you look at my project album- Alternative Homestead in Helena Montana, you can see an example of electric boiler - radiant slab heat in a super insulated residence. You can email me from there, if you have any questions. South facing glass, insulation and thermal mass!!!!

I'm building a 2K f^2 home close to the same lattitude as you in WA state. It will be a slab-on-grade, passive solar home with poured walls and high density polyurethane on the outside. Slab will be thermally isolated. I am curious how you like your radiant floor heating and what you pay per kw hour for your electricity. I plan to have a very tight home with an ERV system.

My thoughts are if it is worth it for hydronic radiant heating with this high of insulation, passive solar, and HTM (conrete poured walls). You thoughts and experience would be appreciated.

Slab on grade is an easy hydronic install not to be passed up, a cold slab is not the best. pipe is easy to staple to 2 inch rigid foam required in Washington, you can heat with a wide variety of fuels from solar, electric, oil propane and more. We will be happy to help with the system design and lay out and are local to Washington.
Dan

The tighter the house the less it matters. Solar gain not withstanding your heat source need only keep up with heat loss. With proper controls virtually any in-slab radiant floor can be controlled quite easily. Roth willnegate some of the solar gain and coupled with outdoor reset and a good boiler will serve with distinction.

I would be curious about electric radiant in floor heat vs hydronic in your situation. As I understand it, every time energy changes form there is loss. So turning electricity into heat in the boiler and then circulating the hot water, vs heating the floor directly with electricity should be more efficient, plus you don't need to run any pumps. You also would not need the boiler. I have not crunched any numbers, either.

The down side is not being able to change your mind. Say, when electricity doubles in price.

I guess that could happen, but doesn't the govt regulate that to some extent? I guess with a hydronic system and an electric boiler he could switch to a gas boiler. Or oil.

I live in New York City. I have a 1 BR apt and my electric bill is higher than my friend's bill is for their whole house, which is in upstate NY. So I guess electric rates vary quite a bit.