Another aspect of #urbanheat is its impact on cooling energy demand. #Coolroofs reduce energy demand the most and #solarpanels reduce it the least.

However, through #energy production, #solarroofs can cover almost half of the total cooling energy demand over the day.

Thus, the electricity generated by #solarroofs more than compensates for their somewhat weaker cooling efficiency (compared to #coolroofs) for the study period and location if we are primarily targeting the energy impacts of #urbanheat (versus outdoor #health impacts).

There are several other considerations and trade-offs (and, of course, uncertainties in representation of these processes in the model), which are discussed more thoroughly in the paper.

For #heatindex or apparent #temperature, #greenroofs end up being much less efficient since they increase near-surface #humidity through #evapotranspiration.

Taking this, the nighttime warming, and cost into consideration, #coolroofs are found to mitigate #heat most efficiently.

#Air #temperature is reduced during daytime in all cases, with the maximum #cooling efficiency seen for city-scale deployment of #coolroofs.

Both #greenroofs and #solarpanels show nighttime #warming due to release of additional #heat stored during daytime.