A previous writer suggested that electrical energy could be conserved by using swamp coolers. That is correct at face value. However, this summer has been more humid and swamp coolers don’t work very well with high humidity. Just check your psychrometric charts.
Another article along with a number of previous articles suggested replacing grass lawns with Astro turf and/or volcanic rocks. In hot weather these two surfaces are 10 to 15 degrees above ambient temperature. Please think about what you are suggesting. These surfaces would create a hot zone around your home and cause your air conditioner to work harder.