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One way to reduce evaporation of water is to cover it up. But putting
a lid on a large reservoir would be very expensive.
Alamaro came up with a different design. His plan involves placing
a very thin layer of vegetable oil on the surface of the water. This layer
is called a monolayer because it is one oil particle thick. The monolayer
is made of olive, palm, or coconut oil, so it is safe for animals. If the
monolayer stays in place, it can reduce evaporation rates by about 75
percent. That’s a lot of water saved!
The idea of reducing evaporation with oil is not new, but the idea
hasn’t worked because of wind. The wind pushes the monolayer to
one end of the reservoir. Alamaro is working to solve this problem.
His idea is to place skimmers around the perimeter of the reservoir.
These skimmers would collect the oil that piles up, and then pump
it upwind through pipes. He’s working in California, Texas, and
Massachusetts to try this on a large scale. If it works, droughts might
be just a little less scary.
Could you set up an experiment to see if oil reduces evaporation?
Give it a try!
U
P
W
I
N
D
D
O
W
N
W
I
N
D
W i n d d i r e c t i o n
Pipeline
Pump
Skimmer
The wind
pushes the
monolayer
to the end
of the
reservoir.
Current weather
information can
control many
reservoirs by
remote control.
Skimmers along the
edge of the reservoir
collect the oil that piles
up from the wind.
The monolayer is a thin
layer of vegetable oil on the
water’s surface in a reservoir.
The monolayer can reduce
evaporation by 75 percent.
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