Wednesday 22 November 2023

Xerion': another battery breakthrough going into commercial production

https://www.forbes.com/sites/erikkobayashisolomon/2023/11/17/xerion-out-of-stealth-mode-with-a-major-battery-breakthrough/

Sunday 12 November 2023

Solar air heater and attic heat store for 100%solar heating

Solar air heater and attic heat store for 100% solar heating David Delaney ddelaney@sympatico.ca Ottawa, November 2004 keywords: solar air heater, thermosyphon, natural convection, flow organiser, flow organizer, attic heat store, thermal crawl space, thermal closet, heat store, passive solar, solar fraction, solar thermal energy, bed of stones, bin of stones, rock bed, damper A house in Ottawa, Ontario (45.3N, 75.6W, continental climate) can get 100% of its winter space heat from the sun in the thermal scheme described here. A solar air heater operates by natural convection to charge an attic heat store. The house uses common materials, simple components, simple control, and simple building techniques. The attic heat store holds enough heat for seven days without sun. The house has no dampers in the air loops that charge the heat store and regulate the temperature of the living space. The house has no control system or fan for charging the heat store. The air against the glazing of the solar air heater is cool (living space temperature). The temperature of the living space is controlled accurately by extremely simple means. The only moving part in the system is a conventional ceiling fan. On the other hand, the house needs a stronger structure than an ordinary house to support the weight of the overhead thermal mass. The heavily insulated attic heat store lies above the living space and extends above a thermosyphon solar air heater that forms the south facade of the house. When the sun shines, heating the air heater, air moves by natural convection from the air heater to the attic heat store and back. When the sun stops shining, air stops moving between the air heater and the attic heat store, because the air in the heater is then colder and denser than the air in the attic heat store above it. The flow organizer (flow organiser) allows the sheet of hot air rising from the air heater to cross through the sheet of cool air moving south along the floor of the heat store attic. The sheet of cool air eventually falls through an east-west slit in the floor of the heat store attic, then falls through the air heater against the glazing, keeping the rising hot air away from the cold glazing. A massive but relatively thin layer of small smooth river stones provides heat storage. The stones are from 1-1/2" to 2-1/2" (35 mm to 65 mm) in diameter. The stone layer is suspended one or two feet above the floor of the heat store attic on a wire mesh. There is a one foot air space above the stone layer so that hot air from air heater can spread out above the stones. The stone layer extends above the whole of the habitable space below. The stones present an enormous surface area for heat transfer between stone and air. There is very little resistance to convective vertical flow through the stone bed because of its very large horizontal cross sectional area. To match the volume flow rate of air coming up from the air heater, air will move down through the stones at a volume rate equal to the volume rate of the air rising from the flow organiser. The rate of descent through the stones will be the volume rate divided by the effective duct area of the stones. The effective duct area of the stones will be approximately the product of the void fraction and the area of the top of the stone bed. Given that the stone bed extends over the whole of the living area, the velocity of air descending through the stones will not exceed about a twentieth of the velocity of the air rising by natural convection through the flow organiser. As a result, resistance to the flow through the stone bed is small enough that convective forces within the stone bed are sufficient to drive the necessary volume of air throught it. (See a more detailed description of the convective air flow here, with a calculation of convective forces and resistance to flow through the stone bed.) 100 lb of stone per square foot of ceiling area (490 kg/m2) is about right to produce the desired thermal capacity. 100 lb/ft2 corresponds to a 1 ft (0.3 m) depth of stone with a 40% void fraction. The heat store attic extends 3 to 4 ft (0.9 to 1.2 m) from its floor to its ceiling. A ducted ceiling fan moves hot air from above the stone layer down into the living space. A conventional 4 ft (1.2 m) diameter ceiling fan is located in the lower end of a 4.5 (1.4 m ) diameter circular duct that runs from the ceiling of the living space up through the lower part of heat store attic, then up through the stone layer to the top of the stone layer. The ceiling fan operates at reduced speed, and consumes 50 watts or less when running. It might be powered by a small area of solar photovoltaic panel. Control of the temperature of the living space can be very simple: a thermostat that turns on the fan when the living space is colder than desired. A large solar air heater, super insulation, and thermally efficient windows that are not too large, are required to get all needed space heat from the sun in Ottawa Ontario. Ottawa has a difficult December, with 1483 F heating degree days below 64.4F, (824 C heating degree days below 18 C) (according to NASA). The average December temperature is 14F (-10C). In December, a total of 2.16 kWh per day of solar radiation falls on each square meter of a south facing vertical surface (NASA). Design calculations are currently based on the assumption that the air heater can transfer 50% of the December incident solar energy into the attic heat store as heat. Dimensions and suitable R values for a small bungalow in Ottawa, Ontario: Living space: 40 ft (12.2m) east-west, 30 ft (9.1 m) north-south, 1200 square feet (112 m2). Insulation: ceiling of heat store attic : R 100 (RSI 17.6); walls of heawt store attic: R 57 (RSI 10); walls of living space R 50 (RSI 8.8); underslab: R20 (RSI 3.5). Windows: window R-value: R 4 (RSI 0.7 ); window area: 120 square feet (11.1 m2). Fresh air: 45 ft3/min (21 l/s) The air heater must have an area of 430 ft2 (40 m2), which could be achieved with an east-west glazing 40 ft (12.2 m) long and 11 ft (3.4 m) high. These air heater dimensions are based on the assumption that the air heater can transfer 50 per cent of the energy of the solar radiation that falls on the exterior of its glazing into the attic heat store. The calculations to justify these specifications, and to create the graphs below, may be seen in 100% Solar heated house with attic heat store for Ottawa, Ontario. (PDF) AT 430 ft2 (40 m2) the air heater is sufficient for December space heat, but 30% larger than is needed for either November or January, the next most demanding months. The surplus heat available in the less demanding winter months might be used to heat domestic hot water. The air-water heat exchanger might be placed in the top of the attic heat store directly above the air heater, where it would be accessible for maintenance and repair. A stone layer area of 1100 ft2 (102 m2) at 100 lb (45.5 kg) of stone per square foot provides a thermal capacity of 22,000 Btu/F (11.6 kWh/C). Assume a non solar heat gain of 600 W, of which 200 W is due to two human bodies. If the temperature of the stones is 100 F (38 C) and the outdoor temperature is 14 F (-10 C) when the sun ceases to shine for several days, and the fan is controlled to maintain a desired temperature of 70 F (21 C), the temperature of the habitable space will not fall below that desired temperature until after 120 hours of darkness, and will fall to 59.8F after 168 hours of darkness, and to 39.1 F (4 C) after 20 days of darkness. This calculation is quite conservative. In Ottawa, a prolonged period of no-sun days is almost always accompanied by relatively warm weather, say around 32 F (0 C). When the temperature descends to 14F ( -10 C) , as in this calculation, or lower, there is almost always some clear sky each day. The 430 ft2 (40 m2) air heater specified above can maintain the average temperature of the heat store (the attic heat store) at 110 F (43 C) and the habitable space at 70 F (21 C) during an Ottawa December of infinite duration but typical temperatures and sun. (with 600 W non-solar heat gain). If the utility electricity fails in a typical December, but there is PV power to run the fan, the temperature of the habitable space will not fall below the desired temperature unless there is a long string of no-sun days. (Assuming a 200 W non-solar heat gain, just the two human bodies). As the graph to the right shows, the heat store (the attic heat store) even in the absence of dark days, the temperature falls to equal (a comfortable) habitable space temperature, making it impossible to maintain this temperature during multiple dark days. Backup heat might be desired to anticipate multiple dark days during a prolonged December electrical utility failure. Backup heat would not be needed for prolonged electrical failures in other months. A wood or propane cooking stove would provide sufficient backup heat. If there is a failure of the fan or of the electricity supply that drives the fan, a door, a window, or a special opening in the south wall of the house may be opened during the day, producing the flow pattern through the house and air heater shown to the right. The air heater will be less efficient in this configuration, and much of the benefit of the attic thermal mass will be lost, but substantial solar heat gain will still occur. The thermal mass will still keep the attic heat store hot, providing some heat at night by radiation to the living space below and eliminating heat loss from the living space through its ceiling. References 1] Flow organizer: Organizing the air flow between a thermosyphon solar air heater and a thermal mass located above it. 2) Calculation of solar gain and heat loss for the example house: 100% Solar heated house with attic heat store for Ottawa, Ontario. 3) A detailed description of the convective air flow through the heat store, with a calculation of convective forces and resistance to flow through the stone bed. 4) Calculation of the diffusion of moisture from attic heat store to cold air heater Home

Sunday 29 October 2023

Aluminum to the rescue! for safer batteries!

https://scitechdaily.com/cheaper-safer-and-more-powerful-batteries-aluminum-materials-show-promising-performance/

Thursday 19 October 2023

iron and saltwater redox flow battery from ESS, video from just have a think

iron and saltwater redox flow battery from ESS, video from Just have a think, https://youtu.be/XZ4GlcVCU6E?si=CmW2EswWlhD1Ggv9

Thursday 24 August 2023

Five myths of H2 via rmi

ne of the factors constraining global decarbonization is the scarcity and value of renewable electricity, which is used to produce “green” hydrogen. Already the world needs vastly more clean electricity infrastructure, as power consumption in 2050 is expected to double from population and economic growth alone — and only 10 percent of electricity today comes from solar and wind. Add in the electricity required to make green hydrogen to decarbonize heavy industry and transport, and power consumption could triple. Given this backdrop, at a macro level, it is important to prioritize reducing electricity consumption and using renewable electricity most efficiently. As such, many of today’s micro-level business cases of hydrogen for heating buildings, generating power, or fueling light-duty vehicles are better suited for investments in energy efficiency or direct electrification (see Exhibit 1 below). https://rmi.org/five-hydrogen-myths-busted/

Sunday 20 August 2023

passive cooling strategies needed

A forthcoming change to B.C.’s Building Code that will require all new homes to have at least one temperature-controlled room presents an important opportunity to build creatively for the future, says an expert in environmental design and sustainable architecture. The government is proposing that all new homes have a minimum of one living space that is designed not to exceed a temperature of 26 C, through either passive cooling measures, such as shading, or a cooling appliance. Two years ago, a deadly heat wave killed 619 British Columbians. A coroner’s death review panel found that the majority of victims were older adults with compromised health, who lived alone in homes without adequate cooling systems. “Mandatory requirements for new buildings will help address the effects of extreme heat events on building occupants to improve public safety and better prevent future fatalities,” said a statement from the Ministry of Housing, provided by communications manager Tasha Schollen. The updated building code is expected to be implemented in December. Vivian Loftness, a professor of architecture at Carnegie Mellon University in Pittsburgh, with 30 years of focus on environmental design and sustainability, said there are proven design strategies to help cool the home. These include “cool roofs” designed to reflect more sunlight than conventional roofs, strategic window placement and retractable awnings and other window coverings. Rainscreen facades – a cladding layer separated from the exterior wall by a small gap – offer additional protection against rain, heat and cold. Extreme, deadly heat in Canada is going to come back, worse than ever. Will we be ready? New condo towers can be built with quiet, high-efficiency heat pumps and dynamic shading devices over balcony windows. Transom windows with exhaust fans can pull cool nighttime breezes through the condo unit. “The design professions, and the building professions, are perfectly capable of delivering a house that does not overheat as long as the outside air is 30 degrees Celsius or less,” Ms. Loftness said. “It gets tough to do it when it’s 40 outside, but I think the important thing for the design profession is to not let them get sloppy, not let them just say, ‘Oh, well, we’ll just put in an air conditioner.’ They really have to be held to account for keeping that cooling load just to the hours and the days when the outside is really too hot.” In Switzerland, strict environmental laws set at the canton level make it difficult to purchase an air conditioner; in Geneva, for example, a homeowner must prove that they have a legitimate need for one. Other cantons require that air conditioners meet certain energy-efficiency standards. Ms. Loftness said it would be wise for B.C.’s updated Building Code to include some conditions so that builders don’t simply default to air conditioning, which relies heavily on electricity generated by burning fossil fuels and contributes to the emission of greenhouse gases. Mark Bernhardt, vice-president of the Canadian Home Builders’ Association of B.C. (CHBA BC) and a licensed builder and developer based in Victoria, said recent updates to the Building Code regarding energy-efficiency requirements have already spurred changes in how homes are built and designed. These have included extra insulation, strategic window placement and slightly bigger overhangs on the south side of a single-family home to shade windows. How does the human body respond to rising temperatures? This one-of-a-kind lab in Ottawa is trying to find out Exterior roller blinds on east- and west-facing windows is another cost-effective solution that requires little to no maintenance, and basements would likely stay relatively cool, he said. Mr. Bernhardt said condos will be more difficult, citing as an example smaller units with one bedroom, one living room and not many options to reconfigure. In parts of B.C.’s Southern Interior, where temperatures regularly exceed 30 degrees in the summer, most homes are already being built with cooling devices or the required hookups if the devices are not installed at the time of construction. “More energy use is not desirable, of course; there’s emissions associated with the electricity use,” Mr. Bernhardt said. “Shifting that demand from the winter, where it’s currently peaking, to the summer, is a really sort of different way of thinking about our grid.” BC Hydro set a new record for highest August peak hourly demand on Monday when 14 daily temperature records were set and consumption reached more than 8,400 megawatts. That is about 1,000 megawatts more than usual, and the equivalent of turning on about one million portable air-conditioning units, according to the energy supplier. Mr. Bernhardt said where he foresees challenges is with the existing housing stock. “You can’t force people to spend money on their homes, as much as we’d like to, in the name of saving people’s lives,” he said. “The hope is that over time, these buildings will go through an upgrade process and solve that problem. But in the meantime, I think we’re going to see a lot of portable air conditioners and things like that.”

Thursday 17 August 2023

Hydrogen storage without high pressure tanks, but in a liquid with baking soda!

Here’s how it works: Solutions of formate ions (hydrogen and carbon dioxide) in water carry hydrogen based on non-corrosive alkali metal formate. The ions react with water in the presence of a catalyst. That reaction makes hydrogen and bicarbonates the “baking soda” Autrey admires for its absence of environmental impacts. With the right mild tweaks in pressure, the bicarbonate-formate cycle can be reversed. That provides an on-off switch for an aqueous solution that can alternately store or release hydrogen. Before baking soda, the PNNL hydrogen storage team looked at ethanol as a liquid organic hydrogen carrier, the industry’s blanket term for storage and transport media. In tandem, they developed a catalyst that releases the hydrogen. Catalysts are designer additives that speed the processes used to make and break chemical bonds in an energy-efficient way. In May 2023, for a project related to the PNNL effort, EERE granted OCOchem of Richland, Washington, $2.5 million in funding over two years to develop an electrochemical process that makes formate and formic acid from carbon dioxide. The process would bind carbon dioxide with the hydrogen located in water’s iconic chemical bond, H2O. In a partnership just starting, PNNL will develop ways to release hydrogen from the OCOchem products. Hydrogen storage that ‘looks like water’ In the world of hydrogen storage research, the bicarbonate-formate cycle has created a buzz for quite some time. After all, it is based on materials that are abundant, non-flammable, and non-toxic. The cycle is built on an aqueous storage solution so mild it “looks like water,” said Autrey. “You can put out a fire with it.” But for formate-bicarbonate salts to become a viable means of storing hydrogen energy, researchers must still develop economically feasible scenarios. So far, the technology stores hydrogen at only 20 kilograms per cubic meter, compared to liquid hydrogen’s industry standard of 70. More fundamentally, said Autrey, researchers need a systems-level understanding of the required electrochemistry and catalysis. In engineering terms, to date, the idea of a workable bicarbonate-formate cycle has a low technical readiness level. “If we solve the catalysis problems,” he added, “we could get some real interest.” ‘An amazing shiny thing’ On the plus side, the salt solutions under consideration at PNNL release hydrogen upon reaction with water. They also operate at moderate temperatures and low pressures. In theory, at least, as Autrey and Gutiérrez describe in their 2023 paper, the bicarbonate-formate cycle represents “a feasible green alternative for storing and transporting energy” from hydrogen. The baking soda idea is also at the nexus of what the 2023 paper calls “several urgent scientific challenges.” Among them are how to make a hydrogen storage media from captured excess carbon dioxide. And even to use the same media to store electrons, which offers the promise of direct formate fuel cells. In addition, the PNNL work could provide insights for catalysis in the aqueous (water) phase. For now, the PNNL team is using palladium as their candidate catalyst. Their efforts include finding ways to make the rare metal more stable, reusable, and longer-lived. All in all, the baking soda idea “is this amazing shiny thing” for hydrogen storage, said Autrey. “What’s exciting are the possibilities.” *** https://oilprice.com/Energy/Energy-General/Simple-Kitchen-Ingredient-Might-Revolutionize-Hydrogen-Storage.html

Tuesday 8 August 2023

Cooling without compressors, blowers, or noise was perfected in Iran, now used in Seville

The structure is a part of CartujaQanat, an architectural experiment in cooling solutions that doesn’t rely on burning more planet-warming fossil fuels. The site, about the size of two soccer fields, includes two auditoriums, green spaces, a promenade and a shaded area with benches. But its star performer remains hidden — the qanat, a network of underground pipes and tubes inspired by Persian-era canals. The CartujaQanat project in Seville is sitting in limbo as administrative and technical hurdles have delayed its opening Photographer: Àngel García/Bloomberg The grid of aqueducts can lower surrounding temperatures by as much as 10C using just air, water and solar power, according to Emasesa, the Seville public water company that helped to build it. The system is modeled on ancient tunnels dug to bring water to agricultural fields that were first documented in what is today Iran. The Persians realized 1,000 years ago that the running water also cooled the air in the canals, so they fashioned vertical shafts to bring that air to the surface. “This is not an air-conditioning system like the one you may have in your home,” says Juan Luis López, the project’s supervisor and an engineer at Emasesa. “We use natural techniques and materials to reduce temperatures.” The CartujaQanat was designed by researchers at Universidad de Sevilla, who added some modern twists to the Persian engineering marvel that served as its inspiration. At night, water runs through an aqueduct outside, which takes it over solar panels on the roof and into giant tanks underground. Contact with the lower temperatures cools the water, while the closed circuit minimizes waste. When the day starts to get hot, solar-powered pumps push the same water through small pipes that run in front of fans to generate cold air. Small openings in the floor and steps allow the refreshing current to seep into the square. The square itself has features that make sure temperatures inside are lower even when the qanat system isn’t operating. It sits two (6.5 feet) underground, is covered by a white heat-reflecting roof and surrounded by columns and vegetation that help cool it down. read the rest here: https://www.bloomberg.com/features/2023-seville-spain-extreme-heat/?cmpid=BBD080823_GREENDAILY

Saturday 1 July 2023

Geothermal energy from lower heat sources makes it much more cost effective with Sage Geosystems.com

No longer do we need to pump water deep in the ground, this system is closed loop and does not consume any water! Sage deploys an enhanced geothermal system using a combination of off-the-shelf oilfield equipment and proprietary technology to capture geothermal power from any underground formation where the required heat level exists. The beauty of this approach is that the oil and gas industry has been drilling into many suitable formations for decades now, and that project execution requires the same basic fields of expertise used in the oil and gas business since its inception. The next challenge, she says, comes in determining “how do you cost effectively then harvest that heat out of the earth and then bring it to the surface, and then cost effectively convert that heat to electricity? That's the challenge that the geothermal industry has faced for about 40 years.” Once the well is drilled into the target formation (the process can even sometimes tap into pre-existing wellbores, thus cutting costs), Sage then deploys what Taff calls a “cycle of injection and production” similar to “huff and puff” pumping systems used by the oil and gas industry for many years. here is the link: https://www.forbes.com/sites/davidblackmon/2023/06/29/is-geothermal-the-magic-bullet-for-renewable-baseload/ the company is called Sage Geosystems, here is an interview with the CEO, : https://www.sagegeosystems.com/geothermal-talks-empowering-the-future-with-david-blackmons-podcast/

Saturday 4 February 2023

Forget all those expensive, exotic technologies, we already have the tools to live sustainably!

“Combustion is the problem – when you’re continuing to burn something, that’s not solving the problem,” says Prof Mark Jacobson. The Stanford University academic has a compelling pitch: the world can rapidly get 100% of its energy from renewable sources with, as the title of his new book says, “no miracles needed”. Wind, water and solar can provide plentiful and cheap power, he argues, ending the carbon emissions driving the climate crisis, slashing deadly air pollution and ensuring energy security. Carbon capture and storage, biofuels, new nuclear and other technologies are expensive wastes of time, he argues. “Bill Gates said we have to put a lot of money into miracle technologies,” Jacobson says. “But we don’t – we have the technologies that we need. We have wind, solar, geothermal, hydro, electric cars. We have batteries, heat pumps, energy efficiency. We have 95% of the technologies right now that we need to solve the problem.” The missing 5% is for long-distance aircraft and ships, he says, for which hydrogen-powered fuel cells can be developed. Jacobson’s claim is a big one. He is not just talking about a shift to 100% renewable electricity, but all energy – and fossil fuels still provide about 80% of that today. Jacobson has scores of academic papers to his name and his work has been influential in policies passed by cities, states and countries around the world targeting 100% green power. He is also controversial, not least for pursuing a $10m lawsuit against researchers who claimed his work was flawed, which he later dropped. https://www.theguardian.com/environment/2023/jan/23/no-miracles-needed-prof-mark-jacobson-on-how-wind-sun-and-water-can-power-the-world?CMP=share_btn_tw

Thursday 2 February 2023

GM parts with LG, stops using pouch cells, switches to 4680, like BMW!

https://cleantechnica.com/2023/01/28/gm-switching-to-cylindrical-battery-cells/ A report by South Korea’s TheElec claims that General Motors is planning to stop using pouch cells in its future electric cars and switch to cylindrical cells. The move has caused some stress in the relationship between GM and its primary battery supplier, LG Energy Solution. The two companies are have already agreed to jointly construct and operate three battery factories in the US. One is already in operation in Ohio and two others are under construction — one in Michigan and the other in Tennessee. A fourth factory was planned for Indiana, but this latest decision seems to have put that plan on hold. The talks between GM and LGES about that plant have ended, sources tell TheElec, and GM is reportedly reaching out to at least one other battery manufacturer, as yet unnamed. There are precious few details available but the information TheElec got from its sources in South Korea is that General Motors will use the 4680 format cylindrical cells first used by Tesla. Cylindrical cells may be somewhat easier to manufacture than pouch cells, since the production techniques have been in use since the Carter administration, which could make them a lower cost option at a time when battery materials prices are rising.

Saturday 7 January 2023

Net Zero hotel reno, of a classic brutalist building designed by Marcel Breuer

Kone elevators use the gravity of cars descending to generate power like automotive regen, also energy storage with weights csan be utilised during peak power periods. All lighting for a 200 room hotel only draws 5000W, since they use low voltage DC power direct from the solar panels or battery, sent to each room on cat 6 power over ethernet! no power wasted with a transformer in each bulb! nice power roll down blinds controlled from bedside. very nicely done dining area, all cooking is done on induction cooking ranges.