Harvesting power from naturally evaporating water could become a brand new form of renewable energy, according to new study.
The researchers reckon harnessing the “evaporation energy” of small lakes in the US could theoretically provide the same amount of power as almost 70 per cent of what the country generated in 2015.
While ways to actually to harness evaporation energy are in their early stages, the researchers say it could provide a more stable form of power generation than wind or solar.
They say natural water evaporation could provide power densities three times that of wind power.
Nearly half of the solar energy absorbed at the Earth’s surface drives evaporation – which affects ecosystems, water resources, weather, and climate. Recent studies show the ability to convert evaporation energy into work, yet there is little understanding on the availability, reliability and potential of this resource.
Ozgur Sahin developed a model to describe how an evaporation-driven engine affects the evaporation rate, and provide predictions on how these energy harvesters could optimally perform in the natural environment.
The team estimates up to 325 gigawatts of power is potentially available from evaporation from existing lakes and reservoirs larger than 0.1 km2 (excluding the Great Lakes) in the United States, which is over 69 per cent of the US electrical energy generation rate in 2015.
The findings indicate the power available from this natural resource is comparable to wind and solar power, but it doesn’t suffer as much from varying weather conditions.
Finally, the technology can cut the evaporative water losses by nearly half, which might favour the implementation of these energy harvesting systems in regions suffer from periods of water stress and scarcity.
These findings might just motivate the improvement of materials and devices to convert energy from evaporation, and provide a way to address the intermittency problem of renewable energy.
[Nature]