Caltech scientists are beaming solar energy from a satellite to earth using microwaves. Also, hydro panels can use the power of the sun to draw drinking water out of the air.

Microwaving solar power from orbit to the Earth’s surface

Experimental microwave-powered invisible energy beams transmitted from space to strike American soil has been a plot point of science fiction movies since the 1950s. But now it’s really happening, and it’s not space aliens aiming rays at the earth. It’s scientists at the California Institute of Technology.

Researchers at Caltech’s Space Solar Power Project (SSPD) have been working through the theory and practice of transmitting energy from orbit since 2011. After putting the Solar Space Power Demonstator-1 satellite into orbit in January, the team was able to send their first microwave energy beam powered to a Caltech laboratory rooftop. (1)

Unlike the alien energy beam in the movie Independence Day that blew up the White House, this beam lit a pair of small LEDs attached to an energy receiver. But that small amount of energy could amount to big things someday.

Using microwaves to transmit energy is nothing new. Most of us do it every day in our kitchens when we shoot them at bags of popcorn kernels or our cold leftovers. In those cases, the microwaves strike water particles which absorb the energy and get hot. But this is the first time the technology has been used to send solar energy from orbit down to the earth’s surface.

The amount of solar energy available in space is practically limitless. NASA has been relying on it for decades, and even recently upgraded the International Space Station’s solar panels to ensure that it continued to have the energy it needs. (2) Combining that virtually limitless energy with an efficient way to get it, where it can do some good, presents interesting opportunities.

Just like the alien weapon, a microwave energy transmission can be aimed nearly anywhere in a reasonable range. A space-based solar energy system could send power to remote areas that do not have access to other electricity infrastructure or into emergency situations where other sources have been knocked out of commission.

Researchers at SSPD envision a string of solar arrays circling the earth, sending tight beams of energy anywhere they’re needed on the planet’s surface. Solar panels on earth require glass and other structures to protect them from the elements, but outside the earth’s atmosphere, they need less structure. The proposed satellites would start as tightly packed one-square-meter packages that would unfurl into 50-meter-by-50 meter solar arrays once they reached orbit.

But just like the microwave in your kitchen, the technology is not without its dangers. Microwaves can be deadly and some scientists worry that a misplaced beam could be highly destructive.

Let’s hope these scientists use their powers for good and not evil.

Solar energy can bring water to the most remote places

Running water is the most fundamental service for most homes in America today. We turn on a spigot and we get clean, fresh water. Eating, drinking, cleaning and personal hygiene all depend on it. We take it for granted. But there are vast swaths of the American landscape where there is no easy water supply.

In these places, the infrastructure to pipe water in is too far away and sinking a well is not practical. The water table is too deep and the groundwater is too saturated with dissolved minerals. For many, trucking water in to fill a storage tank is the only option. Those water tanks can carry parasites and harmful bacteria, so residents still have to buy bottled water to drink or brush their teeth.

People make their homes in these areas regardless, however. Near the Mexican border in Texas, small communities without water or other services are known as “colonias”. One such colonia is Hueco Tanks, in El Paso county where most of the residents are low-income Latino or Hispanic U.S citizens.

Image of Hueco Tanks in El Paso, TX

Fortunately, some of the people who live in Hueco Tanks have been given a solution thanks to solar energy. Working with Arizona-based SOURCE Global, Project Bravo, a local non-profit, produces safe, clean water, on-site, using nothing but the sun and the air. (1)

The effort is driven by SOURCE Global’s hydro panels. The self-contained devices use solar energy to power intake fans that pull in water vapor from the air. Warm air inside the panels turns the vapor into water, which is treated with minerals for taste and health and then stored in hygienic tanks. The amount of water each panel produces is dependent on the amount of sun and the humidity levels in the air, but in Hueco Tanks, two SOURCE Global panels supply enough drinking water for a family of three and their dogs.

Although the lack of water in Texas’s colonias is mainly a financial issue, clean water is a challenge for many around the world. SOURCE Global’s technology can be part of the solution for people facing water-scarcity.

The Weekly Sunsong

In 1979, Orchestral Manoeuvres In the Dark recorded Electricity with the lyric,

Our one source of energy
All we need to live today
A gift for man to throw away
The chance to change has nearly gone
The alternative is only one
The final source of energy
Solar electricity

Forty-four years later, we couldn’t agree more