AC doesn't really create heat though, aside from minor amounts from the compressor/fan motors, it merely moves it from inside to outside, or into the metro stations as you mention.
The AC cools the house at the cost of many more KW.
The house gets cooler but this is all heat from the electrical usage.
The AC cools the house using about 3-4kW, total.
The roof on the house (assuming 29N because the article is about Houston, so between 10AM and 2PM, that's a Solar irradiance of 1kW/m^2) is receiving 157.9kW of sunlight, and then absorbing about 85% of that.