This story is part of the optimistic argument for the future of the planet in our special issue on Earth Day. Read the pessimistic argument and the rest of our stories here.
How to harness wave power
The apparatus above derives energy from the rise and fall of ocean waves and converts it into electricity. The technology, from the Swedish company Eco Wave Power, utilizes a sophisticated system of floats and hydraulic pistons. When a wave passes through the machine, the floats on the device move up and down, compressing and decompressing the pistons. The pressure from the pumping pistons powers a hydraulic motor; its mechanical energy is harnessed by a generator and turned into electricity. Because the apparatus is designed to be attached to coastal structures such as breakwaters, it has a much lower start-up cost than similar devices used offshore. —Annie Roth
Making paint with pollutants
In Appalachian Ohio many streams have been polluted with iron and other minerals in runoff draining from abandoned coal mines. Ridding the waterways of metals is expensive, but two Ohio University professors have found a way to help the process pay for itself. Guy Riefler, an environmental engineer, extracts iron from the polluted water. When the resulting material is fired at different temperatures by art professor John Sabraw, it changes color—and can be used in pigments that Sabraw and other artists employ in their work. —AR
Move over, Edison
Light-emitting diodes, or LEDs, are the bulbs of the future (and the present). They can burn 25 times longer than incandescent lighting yet use up to 80 percent less electricity. By 2035, LEDs are expected to cut U.S. energy consumption from lighting by more than three-fourths. —Daniel Stone
This story appears in the April 2020 issue of National Geographic magazine.