This makes me happy. I have a house with electric heat and eight thermostats pushing Nest costs into unreasonable territory. I'd love to be able to remotely set all my thermostats to 55 degrees or get certain zones to react based on events fired from my phone, (e.g. coming, leaving, charging with screen off aka sleeping, pending alarm)
Unfortunately, with my electric heat the thermostats sit inline with the heater's power source so I need devices that can safely handle 120v.
Nest thermostats seem to be around $250. If you want thermostats that you can control with Applescript, Perl, mobile apps, etc., check out these Insteon-based ones for $150:
http://www.smarthome.com/2441TH/INSTEON-Thermostat/p.aspx
One problem with the Nest is that if your thermostat is in a poor location (more of a problem with central heating), the motion sensor won't see you. With the ones I suggested above, you can programmatically link those to ~$40 motion sensors installed in the correct locations that will actually work.
I have one of those; it works pretty well. Before the Insteon was released I had a X10 thermostat which was somewhat cheaper. I worked around the "X10 is only 95% reliable" problem by having misterhouse set the temp every 5 minutes or whatever it was.
The financial payback time is unfortunately infinite but it was interesting.
One advantage of programming an insteon thermostat is its just plain old off the shelf technology to all end users including repair guys, although how its temp is set is magic and done by computer.
Most of the software work is already done by the misterhouse system, its not like you have to write your own insteon drivers or write your own sensor drivers or whatever. Misterhouse's support for Insteon has varied a bit over the decades. Last time I had to mess with anything it was a little fuzzy. I would imagine things have advanced considerably in the last half decade or so. I do not currently have misterhouse controlling the insteon thermostat mostly out of lazyness, I'll eventually re-enable it.
Not large at all. One thermostat per room. With electric heat you have to put a thermostat in line between the circuit breakers and the heating element (radiant panels in my case). Centralizing the house on a single thermostat, like you would with forced air, would actually be incredibly difficult. It would also lose the benefit of fine control; one of the few positives of electric heat.
Worth pointing out (and you touch on this above) that this is not a function of electric heat but a function specifically of the type of electric heat (radiant in this case). I have electric heat by way of a ducted electric heat pump which is not zoned and thus centralized. Zoned ducted and non-ducted electric heat pumps both offer localized control over heating.
I think it's pretty funny how much gnashing of teeth there is over a $250 item that's installed in a house, given how expensive so many other things in a house are.
Replacing an existing item in your house with something for 10x the cost is not something you want to be doing too often as a homeowner. The benefits have to be quite significant. I've got a simple programmable digital thermostat that works fine. If I come home earlier than normal, I just bump up the heat manually. Calling ahead with my phone wouldn't add all that much value for me. If it was $50, I'd think about it. $250? No chance.
I mean, I just don't get why people are so angry that someone would possibly want to spend some extra money to have a cool thermostat. If it was a cool video card for $249 that just lets them play games, no one would blink an eye. But because it's for a house, but for a part of the house that is supposed to be utilitarian, it's a sin.
Electric heat means they have electric baseboards in each room, making individual control logical and obvious, so eight rooms really isn't outside of the ordinary. Compare that to central HVAC where there's one furnace and at most you have electric dampers restricting flow to an area of the house (though few houses have even that).
Not only that, but basic, programmable load bearing thermostats are relatively expensive compared to the typical control line alternatives. However, even with basic programmable thermostats (>=$75 a piece), I saw my electrical bill drop considerably vs. a 30 year old mechanical thermostat in an apartment I lived in the past 4 years.
We've moved since then and took the thermostats with us. I still have two if you want to buy some slightly used aube programmables (nothing with wifi, but better than nothing).
I have the exact same situation but I have spoken to Nest Customer Service and other "smart" thermostat CS and all have told me that they will not work with the wiring for electric heaters commonly controlled by a single dedicated mechanical thermostat. I was out of luck so if you find an working "smart" thermostat I would love to get one.
Unfortunately, with my electric heat the thermostats sit inline with the heater's power source so I need devices that can safely handle 120v.