That the East Hampton School District might radically overhaul its entire energy and heating approach is intriguing news. If the school board signs on, Johnson Controls, a leading national firm, would install 634-kilowatts of solar panels atop the district’s three schools. It would also improve the way oil is burned for heating, decrease heat loss and gain in classroom windows, and seek to make doors more airtight. The heating systems in the three buildings would have better insulation and power-wasting light fixtures would be replaced.