Researchers at the University of New South Wales are developing a "reverse solar panel" that generates small amounts of electricity at night by harvesting infrared heat radiated from Earth. "In the past, scientists have demonstrated that a 'thermoradiative diode' can convert infrared radiation directly into electricity; when used to convert heat from Earth, they exploit the temperature difference between Earth and the night sky, generating a current directly from heat," notes ExtremeTech. "This approach completely eliminates the need for heat to generate steam, though the resulting capacity is fairly low." From the report: The researchers estimate they could generate only about a watt per square meter, which isn't much. One reason for the low output is that the Earth's atmosphere lessens the heat differential that drives the generative process; in space, though, that's not an issue. Now, researchers believe that the ability to generate power in the moments between direct sunlight could help power satellites. That could be especially true in deep space, where periods without sunlight can be longer, and sunlight is often weaker; in these situations, losing electricity to heat loss is unacceptable. Many satellites already use heat to generate electricity, though with a much more rarified "thermoelectric generator" that uses rare, expensive materials like plutonium to create heat. With thermoradiative diodes, the heat source can be the Sun-warmed body of the satellite itself.

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California-based Karman Industries "says it has developed a cooling system that uses SpaceX rocket engine technology to rein in the environmental impact of data centers," reports the Los Angeles Times, "chilling them with less space, less power and no water." Karman has developed a cooling system similar to the heat pumps in the average home, except its pumps use liquid carbon dioxide as refrigerant, which is circulated using rocket engine technology rather than fans. The company's efficient pumps can reduce the space required for data center cooling equipment by 80%. Over the years, data centers have used fans and air conditioning to blow cold air on the chips. Bigger facilities pass cold liquid through tubes near the chips to absorb the heat. This hot liquid is sent outside to a cooling yard, where sprawling networks of pipes use as much water as a city of 50,000 people to remove the heat. A 50 megawatt data center also uses enough electricity to power a mid-sized city... Cooling systems account for up to 40% of a data center's power consumption and an average midsized data center consumes more than 35,000 gallons of water per day... U.S. data centers will consume about 8% of all electricity in the country by 2030, according to the International Energy Agency... The cooling systems are projected to use up to 33 billion gallons of water by 2028 per year... To serve this seemingly insatiable market, Karman has developed a rotating compressor that spins at 30,000 revolutions per minute — nearly 10 times faster than traditional compressors — to move heat... About a third of Karman's 23-person team came from SpaceX or Rocket Lab, and they co-opted technologies from aerospace engineering and electric vehicles to design the mechanics for the high-speed motors. The system uses a special type of carbon dioxide under high pressure to transfer heat from the data center to the outside air. Depending on the conditions, it can do the same amount of cooling using less than half the energy. Karman's heat pump can either reject heat to air, or route it into extra cooling, or even power generation. The company "recently raised $20 million," according to the article, "and expects to start building its first compressors in Long Beach later this year...."

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