As Hawaii’s cooling tradewinds have faltered and ocean temperatures rise, Hawaii’s leadership moved earlier this year to invest a significant chunk of its resources, more than $100M, to cooling its schools. Last year, temperatures sweltered above 100 degrees, and health concerns forced the Hawaii Department of Education (HIDOE) to consider suspending school for “heat days.” In Hawaii, the heat crisis in schools is shining a stark light on in-building heat as an obstacle to the State’s prosperity and economic survival. Only 6% of the state’s classrooms have air-conditioning, and Hawaii’s Department of Education (HIDOE) estimates that installing air conditioning in all classrooms would cost $1.7B and saddle schools with an even heavier burden of maintenance expenses.
Air conditioning: Antidote to the “Curse of the Tropics”
Air conditioning has been one of the unheralded tools behind the success of other tropical economies, such as Singapore, and desert economies such as Israel, in the latter 20th Century. Economist Jeffrey Sachs quantified the impact that air conditioning has had in tropical economies on productivity by simulating temperate environments that enabled northern countries in Europe and North America to attain leadership during the 19th and 20th centuries.
But as air conditioning helps Hawaii overcome one of the “curses of the tropics,” it carries a financial burden and makes their energy burden heavier. An analysis of schools with campus-wide AC compared with schools of similar size and relative location that do not have campus-wide AC indicates that the cost of electricity may increase by more than 80% in an air conditioned school. The HIDOE spends more than $62 million a year on electricity, gas, water, and sewage fees — a 50 percent increase over the past ten years. HIDOE estimates it will pay an electricity bill of $47.6 million this year.Worldwide power consumption for air conditioning alone is forecast to surge 33-fold by 2100 as developing world incomes rise and urbanization advances.
Ka Hei: Hawaii makes cooling part of the curriculum
With limited budgets, the state of Hawaii has designed a program that taps into community resources along with innovation and renewable energy sources. It’s ambitious Ka Hei program combines the facility upgrades for cooling with science and engineering education. The program is attempting design the heat abatement program to empower our students and teachers to adapt new ideas about sustainability for the benefit of our greater community. In Hawaiin, Ka Hei is the snare made of ropes that the Hawaii god Maui used to capture the sun. Ka Hei also means “to absorb as knowledge or skill.”
Through a combination of energy efficiency measures, clean energy generation (including the HIDOE’s ongoing photovoltaic project, small-scale wind turbines, and other viable systems) and a comprehensive sustainability program, HIDOE is designing Ka Hei to improve the learning environment so students and teachers can perform at their best. Current options include passive cooling, which prevents heat from entering a building, and night thermal flushing to get rid of stored heat in a classroom overnight. Even when supplemental mechanical cooling is necessary, these concepts make conventional air conditioning (AC) systems more efficient. HIDOE has also been piloting new technologies that could reduce cost and be more sustainable. One of the most promising is photovoltaic (PV) air conditioning. A portable classroom at Waianae High is into its second year of running a pilot system using three PV panels for each AC unit.
