In the summer of 2015, Hawaii faced a record-breaking heatwave. When schools started in August, classroom temperatures were above 90º F, and students and teachers were showing signs of heat exhaustion. The conditions weren’t entirely new — as students and teachers had first protested hot classrooms in 2013 but by 2015, the public was demanding action.
The problem the Hawaii Department of Education (HIDOE) faced was the $1.7 billion price tag for 100% air conditioning conversion for all schools — including the installation of the air conditioning units as well as essential associated upgrades to school infrastructure. In addition, older schools couldn’t handle the additional load of new A/C — with some classrooms already struggling to support the loads of computer use with only four outlets per classroom. Once installed, operating costs were further predicted to spike utility bills, as previous experience saw full a/c retrofits double a school’s electricity costs.
With a limited budget and energy use constraints to contend with, IDeAs engineers while working at a former employer collaborated with WRNS Studio, the Hawaii Department of Education and several other architect/engineering teams to develop a game-changing solution, using microgrids with rooftop PV and distributed battery energy storage to power new split system air conditioning units to cool individual classrooms. The capital cost of implementing these microgrid systems was substantially lower than the cost to retrofit traditional central air systems, avoiding costly building upgrades. Plus, having on-site energy storage and flexibility in programming the power electronics allowed schools to keep their current energy costs and energy access stable while maintaining grid-connection for backup power.
