Climate Break

Perovskite Solar Cells
Conventional solar panels are usually heavy and expensive to install. Perovskites are a class of materials that have the potential to create lighter weight and cheaper solar cells that still convert the sun to electricity at a high efficiency. Perovskite solar cells could potentially make solar energy more affordable, accessible, and environmentally friendly.
What Are Perovskite Solar Cells?
Perovskites are a group of materials in which hydrogens and carbons bind to a metal, such as lead, and a halogen, such as chlorine, and form a three dimensional crystal lattice. Thousands of different chemical compositions are possible, which allows perovskite solar cells to absorb many different colors of the solar spectrum, depending on which composition is used. This ability makes it possible for the perovskite solar cells to be used in tandem with or on top of other kinds of solar cells, such as traditional silicon solar cells, because each type of cell absorbs different parts of the solar spectrum. Together with the silicon cells, the total power conversion efficiency, or the efficiency of converting solar energy into electricity, increases to over 33 percent.
To make a perovskite solar cell, a thin layer of perovskite ink solution is deposited onto a base and then heated to set it into a film. The thin perovskite layer absorbs light, exciting a type of charged particle called electrons. These electrons are then extracted to generate electricity. Additional layers of material help direct the flow of electrons and laser scribed channels separate the film into individual cells. Separating the film into individual cells helps lower the current and raise the voltage, making a higher voltage solar device.
The Benefits
When compared to traditional silicon solar panels, perovskites solar cells are cheaper and create fewer emissions. Silicon is rarely found in its pure form, which is the form it is needed in for conventional solar panels. Silicon is mostly found in beach sand as silicon dioxide. To get rid of the excess oxygen, the silicon dioxide is heated in a furnace to a very high temperature of about 1500 to 2000 degrees celsius. The energy required to run these furnaces not only increases the production cost of the silicon solar panels, but also creates additional greenhouse gas emissions. By comparison, perovskite solutions are made and set at lower temperatures, therefore resulting in fewer emissions and potentially costing less to produce.
Conventional solar panels are rigid, flat, and heavy, so they are mostly installed on top of roofs or as solar farms. Perovskite solution can be deposited on bases of many different shapes, and it weighs very little. This gives perovskite solar cells more flexibility in the ways they can be used. Perovskite also appears to be more resilient to imperfections in its crystal lattice structure than other materials typically used in solar panels, which improves its performance. These features of the perovskite solar cells, as well as their high power conversion efficiency, that matches that of traditional solar panels at over 26 percent, gives perovskites solar cells the potential to improve accessibility of solar panels.
The Challenges
According to the Integrated Energy Systems Office of the US Department of Energy, there are four primary challenges to the commercialization of perovskite technology: durability, power conversion efficiency at scale, manufacturing, and technology validation and bankability.
The durability of perovskite cells is limited when compared to other solar cells. Perovskites can decompose when exposed to stressors like moisture, oxygen, light for extended periods of time, heat, and applied voltage. Early perovskite devices degraded within a matter of minutes or hours, but now they can last for several months. Still, devices that cannot operate for more than 20 years, or ideally 30, are not likely to be commercially successful.
Perovskites have shown high power conversion efficiency as small devices, but maintaining these high efficiencies in larger devices still needs to be achieved. Methods used in labs for producing perovskite devices are not easily scalable, making uniform and high-performing perovskite material difficult to produce in a large-scale manufacturing facility. This can lead to significant differences between the efficiency of small devices and larger devices.
The US Department of Energy has created several funding programs for perovskite cells, but getting investment from other financial institutions is still a challenge. The testing protocols for perovskite devices are not standardized and there is a lack of field data on their long-term operational behavior. To increase investment in their production, confidence in the technology needs to be increased through standardized testing protocols that can accurately demonstrate how perovskite technologies fare in real-world circumstances.
Marina Leite’s Take
Marina Leite believes that perovskite solar cells have great potential. Perovskite solar cells could reduce the cost of solar panels by at least 30 percent while being better for the environment to produce. Perovskite solar cells can also be placed on top of existing solar panels, increasing overall efficiency.
Leite’s lab is working on discovering the best perovskite materials to use in the solar cells by utilizing machine learning models that help predict the efficiency and durability of each material. The materials are tested under different conditions of light, temperature, oxygen, and humidity to see how they degrade, then machine learning models help extrapolate those results to other environmental conditions and predict the behavior of the material under such conditions days and weeks into the future.
About Our Guest
Marina Leite began her work with solar cells as a post-doctoral scholar at the California Institute of Technology between 2008 and 2011. Currently, Leite is an associate professor at the University of California, Davis, in the Department of Materials Science and Engineering, conducting scientific research that helps our society mitigate climate change. Leite is also a UC Davis Chancellor’s Fellow.
Resources
US Department of Energy, Perovskite Solar Cells
National Laboratory of the Rockies, Photovoltaic Research
Journal of Manufacturing Science and Engineering, Laser Scribing of Solar Cells
US Department of Energy, Perovskite Research Challenges
World Economic Forum, Solar power has big limitations, but Perovskites could change that
UC Davis Material Science and Engineering, Faculty Spotlight: Marine Leite
Leite Lab, Materials for Energy Harvesting
For a transcript of this episode, visit https://climatebreak.org/developing-perovskite-solar-cells-with-dr-marina-leite/

Cellular Agriculture
Livestock farming is a major driver of global greenhouse gas emissions, deforestation, and water consumption, yet global demand for meat continues to rise. Cellular agriculture offers an alternative by cultivating meat from animal cells in a bioreactor. This could significantly reduce the climate and environmental impacts of meat production while delivering the same quality of meat consumers love.

Cells to Meat - How and Why
Current food production systems, particularly for meat, can be among the most harmful human activities for the environment. They often require vast amounts of fresh water and land, are a major source of water pollution, and contribute to about one third of the world’s greenhouse gas emissions. Yet, the demand for meat continues to rise, with the Food and Agriculture Organization of the United Nations projecting the demand to reach 445 M metric tons by 2050, which is a 76 percent increase from 2005. Cultured, or cell-based, meat has the potential to remedy these issues. Meat cultured in a bioreactor can avoid harming animal welfare, producing methane, or spreading food-borne diseases, and promotes a more humane, sustainable, and safe way to consume meat without substantial change to consumption habits.
Cultured meat is created by taking cells from an animal and growing them in bioreactors. Through controlling temperature, exposure to nutrients, and other aspects, the cells can be tricked into believing that they are still inside of an animal. Under these carefully monitored conditions, the cells divide and proliferate, or grow exponentially, and mature into muscle and fat tissue through a process called differentiation.

The Potential and the Challenges
Advocates for cultured beef project that it will use less land and water, and produce less greenhouse gas emission compared to farmed beef. Cultured meat additionally has the potential to benefit public health by reducing the spread of food-borne illness, infectious disease, and antimicrobial resistance. Farmed meat can carry countless pathogens, including zoonotic diseases, or diseases that can be passed from animal to human, such as influenza A. During the pandemic, meat-packing plants experienced multitudes of COVID-19 outbreaks. Cell-based meat production is conducted under more sterile conditions, so it has a lower chance of spreading such pathogens.
Despite the promising potential of cultured meat, it faces many challenges when it comes to commercialization. The primary concern of lab-grown meat is the cost. Media, or the food the cells use, is extremely expensive, and bioreactors, which were originally designed to cultivate small quantities of cells at a time, still need to be scaled. Cells are also finicky, so when conditions are unfavorable, they stop growing. With large vessels it is difficult to ensure that the conditions are always optimal for growth. Due to these high production costs, some estimates of the potential cost of cultured meat are approximately $37 per kilogram, which is 10 times more expensive than the cost of regular meat.
In addition, many studies have shown that attitudes towards lab-grown meat are mixed, with some customers having concerns about the ‘unnaturalness’ and about the safety of the product. One study showed that although 65 percent of respondents were willing to try cell-based meat, only approximately 33 percent were willing to eat it regularly or as a replacement for farmed meat. To gain consumer acceptance, the lab-grown alternative must be at a minimum equivalent, if not superior in quality to that of regular meat, which can be especially challenging for meats that require structure, like steak.

Natalie Rubio’s Perspective
Natalie Rubio believes that despite the challenges cell-based meats face, there is tremendous potential and that areas in which current technology is lacking are simply opportunities for new technologies to develop.
Rubio co-founded Deco Labs to take on some of the challenges posed to cultured meat and develop solutions to them. Currently, Deco Labs are experimenting with genetic engineering to make the cells more productive and with creating cheaper media to feed the cells and lower the cost of production. Natalie Rubio believes that despite the current cost of cultured meat, cheaper inputs can lead cell-based meats to becoming cheaper than conventional meat.

About our Guest
Natalie Rubio was one of the first interns at New Harvest and later became a New Harvest Research Fellow. As a fellow, Rubio completed her Ph.D. at Kaplan Lab at Tufts University, being among the first in the world to complete a Ph.D. in cellular agriculture. Currently, Natalie Rubio is a co-founder and CEO of Deco Labs.

Resources
TEDx Talks, Natalie Rubio on the Journey of Cellular Agriculture
Fraser et al, The Foundations of Cellular Agriculture
Rubio et al, Plant-based and cell-based approaches to meat production
Economics Research Service USDA, The Economics of Cellular Agriculture
New Harvest, Natalie Rubio among world’s first cellular agriculture Ph.D
A transcript of this episode can be found at https://climatebreak.org/growing-meat-from-cells-with-dr-natalie-rubio/

What is the Valley Clean Infrastructure Plan?
Golden State Clean Energy aims to turn a large swath of struggling farmland in western Fresno County into a large solar panel installation. The Valley Clean Infrastructure Plan (VCIP) would repurpose up to 136,000 acres of salty, waterlogged agricultural land into more than 20,000 megawatts of solar energy, capable of producing enough electricity to meet up to 15% of California’s needs. The project would also help push California toward its Senate Bill 100 mandate, which requires the state to reach 100% clean electricity by 2045. A single project the size of VCIP could make a meaningful dent in that goal.

Benefits
Chief Operating Officer of Golden State Clean Energy Patrick Mealoy says VCIP alone could cover 10-15% of California's electricity needs– enough to power roughly nine million homes. The project would also cut electricity-related carbon dioxide emissions by 15%. The project’s new transmission line would carry clean power throughout Northern California, reducing the region’s reliance on natural gas, and would ease one of the grid’s worst congestion points between Northern and Southern California. Because the existing farmland is degraded by salt buildup and drainage problems, VCIP frames itself as putting failing land to better use, including optimizing scarce water supplies and cutting dust pollution. The project will also create roughly 6,000 construction jobs and 1,2000 permanent operations jobs. And for family farms sitting on the impaired ground, VCIP offers long-term lease income while keeping the land in the family’s name.

Drawbacks and Critiques
The scale of VCIP makes it a hard sell. Projects this size can spend years in development waiting for energy grid interconnection studies and environmental permitting. Fallow fields can serve as habitat for species that have adapted to the Central Valley, so large solar buildouts still face scrutiny over their ecological impact. And converting farmland to energy infrastructure at this scale raises questions about who holds the water rights tied to that land once it’s no longer farmed, and what happens to the site itself decades from now when the panels are eventually decommissioned.

Patrick Mealoy’s Take
Mealoy sees VCIP as making the best of land that has few other viable uses. This ground is already failing as productive farmland, in a district that’s already fighting drainage and salinity problems. In his view, the choice is between using this land to generate clean power or leaving it fallow, generating no return for the farmers who own it.

About our Guest
Patrick Mealoy is the Chief Operating Officer of Golden State Clean Energy, the developer behind the Valley Clean Infrastructure Plan.
Resources
Golden State Clean Energy, The Valley Clean Infrastructure Plan
Canary Media, A Huge Solar Project Grows in California
A transcript of this episode can be found at https://climatebreak.org/building-large-scale-solar-infrastructure-with-patrick-mealoy/

Disabilities During Disasters
Extreme weather events are increasingly frequent and severe, yet emergency response systems often fail to protect disabled people. The Partnership for Inclusive Disaster Strategies (PIDS) is a non-profit working to reform emergency management in the United States by centering disability rights, equity, and accessibility before, during, and after climate-induced disasters.

The Work of The Partnership
Disability inclusion in disasters is multi-faceted; PIDS, or The Partnership, envisions, “disability inclusive engagement throughout disaster preparedness, mitigation, response and recovery to build back better, optimize community resilience, and improve disaster outcomes for all.” The effort to increase inclusivity is critical to improving lifesaving efforts, with 16% of the world’s population and 27% of the US’s population living with a disability. People with disabilities are significantly more likely - up to four times - to be killed or injured during natural disasters. That’s largely because emergency preparedness and response have not been developed to include the disabled community.
One link that has become clearer in recent years is the overlap in the needs of those who have disabilities and those who are aging - both in everyday independent living and in the wake of disasters. Recognizing this, PIDS participates in the Disability and Aging Network, a group of organizations supporting disabled and aging individuals after disasters. PIDS especially supports disability-led organizations in their efforts to meet the needs of their communities.
Before, during, and after a disaster, PIDS can coordinate with emergency response efforts by organizations like FEMA and the Red Cross to advocate for the needs of disabled and aging individuals and to fill other gaps in the traditional humanitarian response. PIDS provides direct services to members of the disabled community and their family and friends during disasters - for instance, they operate a Disability & Disaster hotline, which anyone can call to get help. The hotline provides information and resources, and assistance finding accommodations like temporary housing and transportation.

Broader Applications
PIDS not only does crucial work in times of disaster - they also work behind the scenes to influence advocacy, policy, and systems change. The work PIDS is doing for the disabled community may have applications for others. For instance, the UN reports that, when climate-driven extreme weather events occur, women and children are 14 times more likely to die than men. The strength and frequency of extreme weather is a global issue - though all people are susceptible to the effects of climate change, a community may be more vulnerable due to factors like its geographic situation, economic strength, and demographic makeup. Improving advance planning and emergency response policy, like PIDS advocates for, is important to other vulnerable communities that have been historically underserved during disasters.

Germán’s Take
Germán underscores the population-wide benefits of disability-inclusive strategies. One advantage of a resource like the Disability & Disaster hotline is that it lightens the load on first responders who already have a lot going on. Also, adaptations made to include people with disabilities often have unintended benefits for everyone else. Germán points to curb cuts, which are the ramps between the sidewalk and the street. Though they were initially designed to accommodate wheelchairs and other mobility aids, they also benefit strollers, carts, and children on bicycles and scooters, making the transition from the sidewalk to the street smoother for all.
One way that the disabled community is disproportionately affected by heat waves, storms, and other disasters is power outages. Many people with disabilities or medical conditions rely on energy-intensive devices that support their independence and, in some cases, their survival. Restoring power to individuals can be difficult, especially when they live far from hospitals or other critical services that utilities focus power delivery to in a disaster. Germán sees utility-run battery programs as a step forward in relieving energy anxiety, like PG&E’s Portable Battery Program.

About our guest
Germán Parodi is Co-Executive Director at the Partnership for Inclusive Disaster Strategies, a disability-led organization that addresses the needs of people with disabilities in disaster situations. He serves as the Focal Point for Persons with Disabilities in the Americas for the United Nations Disaster Risk Reduction office.

Resources
PIDS, Introduction
NASA, Worsening Extreme Weather
UN Women, Climate Action to Support Women, Youth, and Girls
Enterprise Community, Effects of Extreme Weather on Vulnerable Communities
For a transcript of this episode, visit https://climatebreak.org/building-disability-inclusive-disaster-strategies-with-german-parodi/

What is Solar Grazing?

The deployment of utility scale solar has often required clearing vegetation and then using fossil-fuel-powered mowers or toxic herbicides to prevent overgrowth. To reduce these harms, solar grazing is a dual land use approach where livestock is taken to solar farms to manage the vegetation that can grow and interfere with the panels. Solar grazing reduces maintenance emissions, provides a revenue stream for local ranchers, and promotes soil health.

Why it Works: Sheep

Solar grazing is a type of targeted grazing, which is, “the controlled application of specific livestock at a designated season, duration, and intensity to achieve specific landscape and vegetation management goals”. Those goals often include weed control, fire risk reduction, and wildlife habitat enhancement. Solar grazing specifically refers to livestock grazing on solar farms, or, under and around solar arrays. According to the American Solar Grazing Association (ASGA), other terms associated with solar grazing include agrivoltaics (the co-location of agriculture and solar), agrisolar, agri-pv, or rangevoltaics. One grazier compares solar grazing to silvopasture - or, grazing under trees - “Just with metal trees”.

Sheep have been found to be an excellent match for the needs of solar grazing. Sheep are nimble and can work around solar installments, eliminating work that, without re-designing or raising solar panels, can be difficult for humans. The benefits of solar grazing extend beyond vegetation management: sheep have been measured to have lower body temperatures, both in their wool and skin, when they’re shaded by solar panels. Additionally, forage quality and moisture content are higher in the shade where water in the soil evaporates more slowly. Sheep have been shown to drink less water during solar grazing, which reduces water needs for graziers. Solar grazing also eliminates competition for land use between solar developers and graziers.

What’s Left to Learn

Solar grazing has been expanding across the country for the last decade; however, long-term studies on the effects of grazing on biotic and abiotic factors - as well as changes in cost over time - have not been widely conducted. One of the highest costs in solar grazing is transportation and logistics, so in places like the US’s Northeast where most solar farms are around 11 acres, moving sheep makes grazing less affordable. In regions with large or interconnected farms, that cost is reduced; Stacie reports that many sheep are born and live out their lives on one farm. Solar grazing is often viewed as just “mowing with sheep” - not as an active agricultural practice. The American Farmland Trust emphasizes that, on the contrary, “It’s a way to grow food, build soil, create habitat, and generate renewable energy at once.”

Stacie’s Points

Stacie emphasizes that grazing - even in areas where animals have to be rotated between sites - contributes less fossil fuel emissions than mowers that run on diesel. Mowers and weed-whackers have other side effects: blades have a tendency to “throw” rocks, or pick up and eject rocks, which can damage panels and add costs to operation. Also, using any machine powered by combustion increases fire risk.

There’s a demographic shift supported by solar grazing. Often, the greatest financial hurdle to a grazing operation is buying or leasing pasture; for young people who won’t inherit pastureland, solar grazing lowers the barrier to entering the industry. Stacie says that polling done by ASGA shows a lower average age of participants compared to the national average, which sits around 65. Also, a greater proportion of women are involved. Another upside: solar graziers are contracted by solar farms - meaning, instead of paying to lease or buy land, they’re being paid for their service - which adds economic opportunity. On the climate side, Stacie underscores improvement in overall soil health, but especially carbon sequestration. The use of agrivoltaics tends to improve public acceptance of large-scale solar, a key strategy for reducing the country’s dependence on fossil fuels.

About our Guest

Stacie Peterson is the Executive Director of the American Solar Grazing Association. She was a developer of the AgriSolar Clearinghouse for the Department of Energy and the Director of Energy Programs at the National Center for Appropriate Technology. Her environmental research includes the development of a protocol for domestic dogs to serve as bioindicators of metal contamination and cleanup efficacy.

Resources

Society for Rangeland Management, Targeted Grazing

Fonseca et al, Solar Shade on Sheep

American Farmland Trust, Grazing Between the Panels

Andrew et al, Sheep grazing as sustainable vegetation management for solar energy

For a transcript of this episode, visit https://climatebreak.org/grazing-livestock-on-solar-farms-with-stacie-peterson/