The idea to grow grass to cool South Australia's airport was the brain-child of Greg Ingleton from South Australia Water, who not only planted a series of grasses at the airport before settling on lucerne, he also tested the theory at his own home.
The temperature issue for airports is the planes simply can't take off if it gets too hot - or at the very least, they need to use more fuel and runway to get the lift needed to take off. As temperatures increase, and Adelaide is already well known for its hot, dry summers and advanced water conservation strategies. With 12 days in the first three months of 2019 where daytime temperatures exceeded 37C, including a maximum temperature of 46.6C on January 24, you get the picture.
The Adelaide study has been running for 3 years and is now being presented to Airport Authorities around the world as it has successfully dropped the Adelaide airport ambient temperature by 3 degrees.
Several types of grasses were tried before setting on lucerne, which now covers 4 hectares of land, about 600 metres from the airport. Watering the lucerne uses between 12 and 15 millimetres of recycled suburban stormwater up to three evenings a week.
Greg Ingleton tested the theory in his own home by watering the lawn around his house for no more than the equivalent time of a shower most nights. His home temperature dropped a whopping 10 degrees and he says that while his water bill went up slightly, his energy bill dropped by around $200.
The temperature drop is something I can personally vouch for, having undertaken a version of this plan as well. In my house, the air conditioning has been on only 3 times this very hot spring / summer.
If neighbourhoods adopt a green grass policy, not only do homes stay cooler, but a kind of local climate microcosm develops, making entire suburbs cooler.
The SA government is also looking at the issue of keeping municipal parks and public gardens green rather than letting them go brown and die off. Not only are they a cool respite for citizens, but they are now proven to be a simple and legitimate method of cooling the air around them.
As a side point, Adelaide Airport now has a side hustle, baling it's lucerne as hay.