Michel
In addition to nearly all of the energy savings applications previously listed, the ISY allows me to take significant advantage of my electric supplier's optional "time of use" variable electric rate schedule. Peak rate hours, which are 4am-9am and 6pm-9pm weekdays from my supplier, are billed at about $0.126/kwh. All other time periods are $0.046/KWH. My ranch is nearly 'all electric', so carefully programming irrigation pump times, and following sunset and sunrise changes for lighting need makes a big difference. Additionally, we heat the entire contents of the 200 gallon electric hot water heater 90 minutes before peak rate time and then, in the unlikely event we consume all of the stored hot water during peak hours, the ISY allows for just a touch up of the top 40 gallons during peak rate time. The walk-in refrigerator, shop air compressor, laundry facilities, and hot tub are all 'time controlled' (with override capability) as well. These are easy applications when the ISY controls the heavy 'definite purpose contactors' which power up these items.
The ISY also assists in switching between 'primary' electric heat and 'backup' propane heat at the appropriate times of day during the heating months. Since implementing this program, the typical ranch monthly electric bill has decreased from $300-380 to $150-190.
The ability to program seasonal variables into the ISY would significantly enhance and simplify our use of these energy savings programs. Simple Insteon motion sensor equipment, which appears to be on the way, should also allow additional energy savings applications.