#LosAngeles is becoming too hot to bear. Can it design its way cooler?
The city is forecast to double the number of days it reaches 95F by 2050, but innovative materials may help fight off the heat https://www.theguardian.com/us-news/2023/jan/03/los-angeles-is-becoming-too-hot-to-bear-can-it-design-its-way-cooler #heatisland #climate #coolroofs

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.

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.

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.