Thursday brings a reminder to home energy management startups that they’d better be ready to acknowledge the giants in the field. Honeywell said Thursday that it has shipped more than 350,000 of its UtilityPRO thermostats, which can turn down air conditioners via utility communications or homeowner pre-sets. Some 33 utilities are using them today, and Honeywell expects they’ll be delivering 500 megawatts of peak energy use reduction by next year. At least some of these thermostats come with technology from Cooper Power Systems and subsidiary Cannon Technologies — and Cooper’s Yukon demand response platform is in place at more than 200 utilities. Add in Comverge’s residential demand response portfolio, and you’ve got a good list of the market leaders in residential demand response today. Given the cheapness of the pager-and-thermostat approach, this could remain the dominant platform for smarter home energy technologies to link to for years to come.