UC Davis Developing Tech Using Current Air Conditioning Systems to Combat Climate Change Effects

DAVIS, Calif. (KGO) — The Western Cooling Efficiency Center at UC Davis is trying to develop new air technology that addresses problems with the grid and the challenges of climate change using our current AC systems.

This research would address the problem of energy consumption in peak periods on hot days.

“The grid is stressed late afternoon and what occurs is that there’s too much demand for electricity. One way to address that is to use a battery. This new technology instead of using a battery uses a liquid that absorbs moisture and by using this liquid that absorbs moisture it acts like a battery but is much less expensive that a battery for doing the same thing,” said Mark Modera, the former Director of the Cooling Efficiency Center.

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Heat pumps: Coming to a home near you?

Karl Johnson was just looking for a way to keep his Corbin Park home, built in the early 20th century, comfortable.

The gas-fed furnace was on its way out, and his central air conditioner had already failed. To cool the home, Johnson had several portable units running throughout the day in the summer, belching hot air back into the rooms and driving up his energy bill each month.

“At some point, it’s just insanity to keep up with trying to address the issue,” Johnson said.

So he started researching central air systems online and settled on a heat pump for his home – a combination heating and cooling, electrified system that policymakers and the White House have been pushing as a method to reduce greenhouse gas emissions.

Democrats’ Inflation Reduction Act, which passed the Senate by a razor-thin 51-50 vote on Sunday, includes a major boost for climate-friendly energy systems, including heat pumps. 

The bill includes rebates and incentives for the purchase of heat pumps for both air and water conditioning in residential structures. The legislation would provide rebates of up to $8,000 to install heat pumps in homes for the next decade, according to Bloomberg. Those who wouldn’t qualify for the rebate could still get tax credits of up to $2,000.

The inflation act also piggybacks on a decision made by President Joe Biden in June to use the Defense Production Act to spur domestic production of appliances that help curb carbon emissions, including heat pumps, by providing $500 million in that effort, according to The Hill.

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Do DIY air filters work against California wildfire smoke? What to know about cost and safety

Do-it-yourself air filters are safe, effective and can be used to protect your lungs from California wildfire smoke.

Wildfire smoke is harmful and can stretch hundreds of miles. The smoke from the 2021 Dixie Fire in California was felt as far as Denver, The New York Times reported. Here are two safe options, according to the University of California, Davis, the U.S. Environmental Protection Agency and the California Air Resources Board.

WHEN SHOULD I USE AN AIR FILTER?
Good air filters can remove dangerous smoke particles from your home. According to the California Air Resources Board, indoor air cleaners help filter out small particulate matter that can cause health concerns.

Wildfire smoke produces harmful air pollutants that can aggravate existing health problems and increase the risk of heart attack or stroke.

The resource board recommends using a certified air cleaner whenever the air quality index is at an unhealthy level, which you can check at AirNow.gov. The agency also says if a board-certified commercial system is not an option for your home, a DIY is an OK alternative.

“These temporary air cleaners should be used with extreme caution, and only if other air cleaning options are unavailable,” the board writes on its website. It says never leave the device unattended and only use box fans manufactured in the last 10 years (after 2012), as those fans “will have a fused plug, which will prevent electrical fires if the device is knocked over.”

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close up of an EV being charged

Ask a Scientist: In Search of a ‘Green’ Electric Car Battery

Lithium-ion batteries are the most popular battery in use today. First commercialized in 1991, their cost has declined by a remarkable 97 percent over the last three decades, enabling the rapid growth of mobile phones, laptops and more recently, electric cars. Global demand for the batteries is projected to increase dramatically by the end of this decade, largely due to the growing adoption of electric vehicles (EVs) around the world.

More EVs is good news for the climate. After all, as a 2020 Union of Concerned Scientists (UCS) analysis shows—and an updated, soon-to-be-released analysis will confirm—EVs’ lifecycle global warming emissions are dramatically lower than that of gas- and diesel-powered vehicles. But mining the materials used in EV batteries, including cobalt, lithium and nickel, comes with its own set of public-health, environmental and human-rights challenges. Despite EVs’ considerable environmental benefits, it will be imperative to “green” the material sourcing process to ensure a more sustainable and ethical supply chain as the world transitions to an electrified transportation system.

Fortunately, scientists are on the case. They are altering battery chemistries to reduce reliance on certain metals, such as cobalt, for example, and coming up with ways to recycle and repurpose batteries to minimize the need for new raw materials altogether.

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Modeling Impacts of Ventilation and Filtration Methods on Energy Use and Airborne Disease Transmission in Classrooms

Lowering the potential of airborne disease transmission in school buildings is especially important in the wake of the COVID-19 pandemic. The benefits of increased ventilation and filtration for reducing disease transmission compared to drawbacks of reduced thermal comfort and increased energy consumption and electricity demand are not well described. A comprehensive simulation of outdoor air ventilation rates and filtration methods was performed with a modified Wells-Riley equation and EnergyPlus building simulation to understand the trade-offs between infection probability and energy consumption for a simulated classroom in 13 cities across the US. A packaged heating, ventilation, and air conditioning unit was configured, sized, and simulated for each city to understand the impact of five ventilation flow rates and three filtration systems. Higher ventilation rates increased energy consumption and resulted in a high number of unmet heating and cooling hours in most cities (excluding Los Angeles and San Francisco). On average, across the 13 cities simulated, annual energy consumed by an improved filtration system was 31% lower than the energy consumed by 100% outdoor air ventilation. In addition, the infection probability was 29% lower with improved filtration.

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Research Team Selected for $4.6 M Department of Energy Award to Advance Concentrating Solar-Thermal Power

Concentrating solar-thermal power technologies can help eliminate carbon dioxide emissions from the energy sector. UC Davis and eight partnering institutions were selected to receive $4.6 M from the Department of Energy to advance high temperature receiver development for industrial process heat and solar thermal power generation. The team, led by Vinod Narayanan and Erfan Rasouli at UC Davis, will design, develop, and de-risk a 150-kilowatt solar-thermal receiver able to heat supercritcal carbon dioxide or air to temperatures from 600-900°C.

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Activists fear a new threat to biodiversity—renewable energy

A small Nevada wildflower named Tiehm’s buckwheat might still be living in obscurity if it had not happened to grow in soil full of lithium. As it is, that could prove its downfall.

Lithium is needed to make the high-powered batteries that are helping the world transition to electric vehicles. Demand is soaring, and mining companies are eager to take it out of the ground at several new sites in Nevada, already home to the only existing lithium mine in the U.S.

But Tiehm’s buckwheat is rarer than lithium. It grows only on approximately 10 acres of land at Rhyolite Ridge in southwestern Nevada—right where one of the new lithium mines is planned.

“One guy on a bulldozer could drive it extinct in one afternoon,” says Patrick Donnelly, the Great Basin Director for the Center for Biological Diversity and one of the flower’s biggest advocates. 

He and some other conservationists see the flower and the mine as emblematic of a broad and disturbing trend: There is a growing conflict, they say, between efforts to address two environmental crises—a rapidly warming climate on the one hand, and a staggering rise in extinction on the other. 

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A District Energy System Design Could Cut More Emissions for Proposed Davis Innovation Sustainability Campus

Homes and businesses use over 25 percent of California’s energy. With a number of different space heating and cooling technologies available to developers, it is important to understand and quantify potential greenhouse gas (GHG) impacts.

A study, completed by the UC Davis Western Cooling Efficiency Center (WCEC), analyzed the GHG emissions for two different heating and cooling options for a proposed development in Davis – the Davis Innovation Sustainability Campus (DiSC). Researchers analyzed GHG emissions for: 1) the proposed all-electric, high-efficiency design, which would use packaged heat pump equipment for heating and cooling the buildings and 2) a potential upgrade to an all-electric, very high efficiency design, which would use a district energy system. A district energy system uses a central plant heat pump and chiller to heat and cool water that is piped to buildings for heating and cooling. 

“Based on predicted energy consumption data provided by Trane, we found that a district energy system could further improve energy efficiency by 26%, reduce total energy consumption by 14%, and reduce GHG emissions by 16% over the already highly efficient proposed design,” said lead researcher David Vernon, Co-Director of Engineering for the UC Davis Western Cooling Efficiency Center.

DiSC energy system options

DiSC is a proposed development that would build new residential, office, laboratory, and manufacturing buildings on the eastern edge of Davis. The developer team is required by the Davis City Council to build an all-electric design with an energy efficiency level 30% more efficient than required by Title 24 building codes.

“The developer funded us to look at a district energy system design with large thermal energy storage because it has the potential to greatly reduce GHG emissions,” Vernon said. “It can help stabilize the grid by using energy when renewable generation is high and reducing energy consumption when renewable generation is low.”

To meet California’s climate goals requires large increases in renewable energy generation, energy storage, and load shifting technologies. District energy systems with large thermal energy storage have the potential to be an effective energy storage and load shifting strategy. The WCEC mission is to advance design, monitoring, and objective reporting of the performance of these types of technologies to inform policy and economic decisionmakers.

Energy modeling and analysis

The heating, ventilation, and air conditioning (HVAC) manufacturer Trane completed energy models of the proposed baseline and district energy system designs and provided the hourly energy consumption results. The WCEC researchers then used these hourly energy consumption results to calculate Time Dependent Valuation—a metric that incorporates the social and environmental impacts of energy used to evaluate energy efficiency, total energy consumption, and GHG emissions of the designs.   

“Our analysis shows that district energy systems offer significant opportunities to reduce energy consumption and GHG emissions compared to more common HVAC designs,” said Vernon. “It is important to note that our results are on the conservative side, and implementation of this design could result in even larger GHG savings.”

This study was funded by Ramco Enterprises, Inc. and the Buzz Oates Group of Companies.

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Energy Bites Seminar May 19, 2022

Thursday, May 19, 2022  |  12pm – 1:00pm PST

Bite 1: “So What Happens to the Batteries?” Electric Vehicle Battery End-of-Life Management and Policy Recommendations for California
Meg Slattery, Energy Graduate Group

Bite 2: UC System Central Plants and the Transition to Carbon Neutral Operation
Leslie Nelson, UCOP Carbon Neutrality Fellowship

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Energy Bites Seminar May 12, 2022

Thursday, May 12, 2022  |  12pm – 1:00pm PST

Bite 1: High-Temperature High-Pressure Heat Transfer – STEEL Lab Research Update
Erfan Rasouli, Western Cooling Efficiency Center

Bite 2: District Energy Update & Electrification Strategies
Josh Morejohn, Facilities Energy & Engineering

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