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For decades, slabs of crystalline silicon have dominated the solar industry. Other materials that can be layered in thin films, such as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe), have captured less than 5% of the market, because it’s hard to make them as efficient or cheap as conventional solar panels. Perovskites could be a different story. They should be cheaper to make and seem impressively efficient at converting sunlight into electricity — in the laboratory, at least.


Companies say they are close to commercializing cheap perovskite films that could disrupt solar power — but are they too optimistic?

Los Angeles Power and Water officials have struck a deal on the largest and cheapest solar + battery-storage project in the world, at prices that leave fossil fuels in the dust and may relegate nuclear power to the dustbin.

Later this month the LA Board of Water and Power Commissioners is expected to approve a 25-year contract that will serve 7 percent of the city’s electricity demand at 1.997¢/kwh for solar energy and 1.3¢ for power from batteries.

“This is the lowest solar-photovoltaic price in the United States,” said James Barner, the agency’s manager for strategic initiatives, “and it is the largest and lowest-cost solar and high-capacity battery-storage project in the U.S. and we believe in the world today. So this is, I believe, truly revolutionary in the industry.”

They used to call it RoboBee—a flying machine half the size of a paperclip that could flap its pair of wings 120 times a second. It was always tethered to a power source, limiting its freedom. Now, though, RoboBee becomes RoboBee X-Wing, as Harvard researchers have added solar cells and an extra pair of wings, freeing the robot to blast off to a galaxy far, far away. Or at least partway across the room, as it can sustain flight for only half a second, and only indoors.

But hey, baby steps. The teeniest of quadrotors measure a few inches across and weigh a third of an ounce. RoboBee X-Wing is about the same size as those untethered fliers, but weighs a hundredth of an ounce, which earns it the distinction of being the lightest aerial vehicle to manage sustained untethered flight. One day that could make it ideal for navigating tight, sensitive spaces in a galaxy very, very near.

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Physicists have discovered a novel kind of nanotube that generates current in the presence of light. Devices such as optical sensors and infrared imaging chips are likely applications, which could be useful in fields such as automated transport and astronomy. In future, if the effect can be magnified and the technology scaled up, it could lead to high-efficiency solar power devices.

If SpaceX gets a fully reusable Super Heavy Starship flying to orbit in 2020 and then has 100 fully reusable flights by 2023 then the cost of space will drop by 100 times. This will start fulfilling the plans for lunar bases, lunar mining, and space-based solar power.

If each Super Heavy Starship costs $300 million and has $1 million in operating and maintenance cost per flight then the per flight cost is $4 million. Super Heavy Starship is supposed to launch about 100 tons to orbit.

Assuming that 800 Starlink satellites are launched by April 2020, then SpaceX will start doubling its revenue from $2–3 billion to $5–6 billion in 2020 and ten billion in 2021. This will mean that SpaceX will be able to afford to build dozens of Super Heavy Starships.

Popeye would be proud.


Popeye uses spinach to power his muscles. Now, scientists are looking to spinach as a power source for making electricity.

A solar cell converts sunlight into electricity. Most of these, today, are made of a material called silicon. The new device instead uses proteins from spinach and from a bacterium called Rhodobacter sphaeroides.

To make the solar cell, a team of biologists and chemists at the Massachusetts Institute of Technology in Cambridge extracted certain light-sensitive proteins from the spinach and the bacteria. They placed about 2 billion of these proteins on a piece of glass. They made the proteins stick by embedding them in a special framework that looks and acts like a cell membrane.