Because all the roofing strategies offer cooling effects, they reduce AC consumption. Cool roofs reduced AC energy consumption the most, followed by green roofs and solar panel roofs. Energy demand was shown to be reduced by 16.6%, 14.0%, and 7.6%, when cool roofs, green roofs and solar panel roofs are deployed, respectively.
“The difference in cost between the roofs is approximately a factor of three,” said Kotamarthi, who is also the CROCUS science director. “Which option is the most cost effective to get the most benefit? If a community is deciding on a strategy, we can look at the model and give them an actual answer.”
“We have very few measurements for green roofs,” said Kotamarthi. “We need to measure how much energy goes in, how much goes out, and how much water it needs and how fast it retains it. We need these measurements to give us a complete understanding of the process so we can refine calculations and models.”