"Thousands of buildings across the United States are staying cool with the help of cutting-edge batteries made from one of the world's simplest materials," reports the Washington Post — ice. When electricity is cheap, the batteries freeze water. When energy costs go up, building managers turn off their pricey chillers and use the ice to keep things cool. A typical building uses about a fifth of its electricity for cooling, according to the International Energy Agency. By shifting their energy use to cheaper times of day, the biggest buildings can save hundreds of thousands of dollars a year on their power bills. They can also avoid using electricity from the dirtiest fossil fuel plants. In places where the weather is hot and energy prices swing widely throughout the day — for instance, Texas, Southern California and most of the American Southwest — buildings could cut their power bills and carbon emissions by as much as a third, experts say...

When every building is blasting its air conditioner at the same moment on a hot day, power companies often fire up backup generators, known as peaker plants, which are generally extra pricey and polluting. If utilities avoid using peaker plants, they'll pollute less and save money. Last year, the Energy Department struck a tentative $306 million loan deal with the ice-battery-maker Nostromo Energy to install its systems in 193 California buildings to make energy cheaper and cleaner while lowering the state's blackout risk.
"The batteries themselves are huge..." the article acknowledges, citing one in New York City that uses 100 parking spot-sized tanks "which collectively make 3 million margaritas' worth of ice each night... But that's starting to change." (And they believe new smaller designs "could bring the batteries into smaller buildings and even houses.") Wherever they can squeeze into the market, ice batteries could be a cheaper and longer-lasting option than the lithium-ion batteries that power phones, cars and some buildings because their main ingredient is water, experts say. The pricey chemicals in a lithium-ion cell might degrade after 10 years, but water never wears out.
And according to the article, one company has already installed ice batteries in over 4,000 buildings...

Japan Today reports: As reported by Japan's Nihon Keizai Shimbun, in a meeting on Nov 2, the Energy Conservation Subcommittee of the Ministry of Economy, Trade and Industry resolved to begin working group discussions with the aim of gaining the ability to remotely turn down privately owned air conditioner/heater units. The goal would be to decrease energy usage during expected power shortages, which the committee feels are a growing concern as Japan attempts to shift towards renewable energy sources such as solar power, where the amount generated can be affected by day-to-day climate, making it difficult to stabilize the amount of total power available. The ministry says that AC unit usage accounts for roughly 30 percent of household electricity consumption in Japan.

From a technical standpoint, the plan wouldn't be particularly difficult to implement. Japanese air conditioner units have long had remote controls, so external inputs aren't a problem, and many models now allow the owner to turn the system on and off or adjust temperature settings through the internet. By asking manufacturers to extend such access to government regulatory organizations, and granting those organizations override functions over other inputs, the plan could easily be put into practice for internet-connected AC units, and water heaters are another home appliance the committee is looking to gain the ability to throttle back. [...] According to Nihon Keizai Shimbun, the committee is currently working under the concept that the government would only be able to turn down AC units if their individual owners have agreed, in advance, to grant that authority.

The New York Times reports: As global warming fuels deadly heat waves across the country, more Americans in places like the Pacific Northwest are rushing out to buy air-conditioners for the first time. One common concern is that a surge in air-conditioning could make the planet even hotter, by increasing the need for electricity from power plants running on coal or gas, which produce emissions that drive global warming.

But some energy experts, as well as cities like Denver and Berkeley, California, have recently started exploring a counterintuitive strategy: Soaring demand for air-conditioning might actually be a prime opportunity to reduce fossil fuel emissions and fight climate change. The idea is simple: If Americans are going to buy air-conditioners anyway, either for the first time or to replace older units, why not convince them to buy electric heat pumps instead? Although the name can be confusing, an electric heat pump is essentially an air-conditioner that is slightly modified so that it can run in two directions, cooling the home in the summer and providing heat in the winter. That extra heating function is the key to helping tackle climate change. During the cooler months, heat pumps could warm homes far more efficiently than the furnaces that run on fossil fuels or electric resistance heaters that most households currently use, which would cut down on carbon dioxide emissions. Existing furnaces would only need to be used as backup on the coldest days of the year, since many heat pumps work less efficiently in subzero temperatures.

Most manufacturers already offer heat pump versions of the air-conditioners they sell, but they're typically about $200 to $500 more expensive to make. So, the idea goes, policymakers would have to step in with subsidies or regulations to make adoption universal. But if done right, proponents say, households would see utility bills either drop or stay largely unchanged, and they would even enjoy a more comfortable heating experience.
The Times spoke to Nate Adams, a home performance consultant who proposed the idea in a recent paper written with experts at Harvard University CLASP, a nonprofit formerly known as the Collaborative Labeling and Appliance Standards Program advising governments on energy efficiency. "Working with energy modelers, Mr. Adams and his co-authors estimated that, if two-way heat pumps become the standard option when people installed new central air-conditioning, they would be in 44% of American homes by 2032, up from just 11% today. On average, those homes could cut their fossil fuel use during the colder months by at least one-third. And, as states move to clean up their electricity grids by adding more wind and solar power, the climate benefits from those electric heat pumps would increase..."

"Homes and offices account for 13 percent of the nation's annual greenhouse gas emissions, with much of that from oil or natural gas burned in furnaces, hot water heaters, ovens, stoves and dryers. While the United States has made major strides in reducing pollution from power plants, building emissions have barely budged since 2005."

sciencehabit shares a report from Science Magazine: It sounds crazy: a refrigerator made from a rubber band. But if you stretch one and hold it against your lips, it will be noticeably warmer. Release it, and it cools. This simple "elastocaloric" effect can transfer heat in much the same way as compressing and expanding a fluid refrigerant in a fridge or air conditioner. Now, scientists have created a version that not only stretches the rubber band, but also twists it. It may one day lead to greener cooling technology. As a demonstration, the researchers built a tiny fridge about the size of a ballpoint pen cartridge powered by twisted nickel titanium wires. Using this "twistocaloric" method, they cooled a small volume of water by 8C in a few seconds. Next, the team plans to run the device on a repeating cycle, alternately heating the water (and moving that heat to the outside world) and cooling it (so that it can absorb heat from the interior volume). Coated with temperature-sensitive dyes, the fibers could also serve as strain gauges or mood rings. The study has been published in the journal Science.

Germans have always looked down on America's fondness for artificially chilled air as wasteful, unnatural and wimpy. Rather than install climate control in buildings and subways, schools and offices will simply close if it gets too hot. Now, the increasing frequency of triple-digit highs have forced a national reckoning. From a report: Germany's Trade Association for Air Conditioning said that last summer, the second-warmest on record since 1881, yielded a 15% jump in sales to 200,000 units. That figure is expected to climb this summer, as more Germans rebel against the nation')s obsession with energy conservation. High temperatures are known to make people act out of character. Police in the German state of Brandenburg stopped a man riding naked on a motorcycle. He said it was too hot for clothes.

German authorities have even imposed speed limits on stretches of the Autobahn, fearing it could buckle like heated wax. Old-fashioned oscillating fans have always been the preferred way for Germans to keep homes and offices cool. Property leases for apartments implore tenants to open their windows several times a day to help regulate temperature. A video from the German news magazine Focus, keeping to tradition, suggested a cooling method using "a fan, a towel, and a bowl of water." Retailers fear a fan and air conditioner shortage this summer. Annabell Feith, a spokeswoman for the retail group that owns two of Germany's largest electronics stores, MediaMarkt and Saturn, said the chains were bolstering their orders. Last year, some stores sold out by August. "We are advising customers, if they want to buy a fan, to be very quick, because we expect more heat," she said, "and we are almost sold out, especially in Berlin."

necro81 writes "The US National Renewable Energy Laboratory has announced that it has developed a new method for air conditioning that reduces energy use by 50-90%. The DEVap system (Desiccant-Enhanced eVaporative air conditioner) cools air using evaporative cooling, which is not new, but combines the process with a liquid dessicant for pulling the water vapor out of the cooled air stream. The liquid dessicant, a very strong aqueous solution of lithium chloride or sodium chloride, is separated from the air stream by a permeable hydrophobic membrane. Heat is later used to evaporate water vapor back out — heat that can come from a variety of sources such as solar or natural gas. The dessicants are, compared to typical refrigerants like HCFCs, relatively benign on the environment."

guzugi writes "This is a project I have been working for several months and been hypothesizing for much longer. The basic idea is to shortcut the need for an air conditioner when cooling multiple computers. Swimming pool water is pumped into the house and through several waterblocks to effectively cool these hot machines. This greatly reduces noise cooling requirements."

inkey string writes "Summer has arrived, and I've been busy slowly overheating in my student house without central air. I decided to put my thermodynamics classes to work however, and produced this ~24$ homebrew air conditioner. It'll cool a room to a comfortable level in 15-20 mins, and will run for a few hours on a garbage pail full of water. It's cheap, environmentally friendly (just fire the waste water off to your garden), and makes a good one hour project for a quiet evening."