Wednesday, September 01, 2021

Research sheds light on how economies may respond to COVID-19 restrictions

by Stephen Johns, Imperial College London

covid economy — Credit: Pixabay/CC0 Public Domain

New research from the Imperial College COVID-19 Response Team sheds light on how economies might respond to different levels of COVID-19 restrictions.

In the latest report, the researchers developed new methods to forecast Purchasing Managers' Indices (PMIs) during and after the COVID-19 pandemic and the potential impact of government virus mitigation strategies.

PMIs, which survey managers at private businesses on their purchasing intentions, are a leading indicator of the direction of economic activity.

The researchers, from the Statistics section of the Department of Mathematics, produced six-month forecasts of the UK composite PMI series under different scenarios of COVID-19 mitigation strategies, ranging from easing, to staying unchanged, to tightening between October 2020 and April 2021.

The new method also incorporates real-time data on the progress of the pandemic.

The researchers created a novel network time series model, which borrows strength from across thirteen world economies over time viewed as a network.

GDP forecasts

Gross domestic product (GDP) economic forecasts were then obtained by modeling the relationship between GDP and PMI using a mixed data sampling (MIDAS) regression model that links monthly PMI indices with quarterly GDP.

The team's results suggested that there would be a 4.5% difference in 2021 Q1 GDP growth and a 4.8% difference in 2021 Q2 GDP growth between the easing and tightening scenarios.

In September 2020, under a tightening scenario, the researchers used the model to estimate a drop in GDP of 1.2% for Q1 2021, with prediction ranges of -5.8 to 2.9. The actual value turned out to be a drop of 1.6%, which was close to the prediction and well within the prediction interval.

The researchers also predicted an increase of 3.2% for Q2 2021, with prediction ranges of -2.0 to 7.1. This prediction was for a linearly easing scenario from November 2020 until April 2021.

The recently announced Office for National Statistics first GDP estimate for Q2 2021 turned out to be a 4.8% increase, which is again well within the prediction range, but the actual underlying conditions were lockdown until 8 March 2021, then a gradual easing.

The research will be presented as a Discussion Paper at a Plenary session of the Royal Statistical Society International Conference this September.

A new way of forecasting the economic impact of COVID-19

Professor Guy Nason, from the Department of Mathematics, said: "This research has revealed a new way to forecast the impact to an economy under different levels of COVID-19 restrictions.

"By integrating economic indicators, people behavioral indices and real-time data from the pandemic we are able to forecast a country's economic performance.

"We are very excited by this methodology and pleased with its performance. It could be a useful tool when trying to understand the economic implications of different virus mitigation strategies."

James Wei, from the Department of Mathematics, said: "It is our hope that this kind of research can bring greater attention to the exciting field of network time series analysis. We see a lot of potential for similar methods to be applied to fields across both the social and natural sciences."

Evaluating the impact of COVID-19 travel bans

More information: Quantifying the Economic Response to COVID-19 Mitigations and Death Rates via Forecasting Purchasing Managers' Indices Using Generalised Network Autoregressive Models with Exogenous Variables. www.imperial.ac.uk/mrc-global- … 45-economic-resonse/

Provided by Imperial College London

The first farmers of Europe found in the Balkans date to the 5th millennium BC

by University of Bern

A research team from the University of Bern has managed to precisely date pile dwellings on the banks of Lake Ohrid in the south-western Balkans for the first time: they came into being in the middle of the 5th millennium BC. The region around the oldest lake in Europe played a key role in the proliferation of agriculture.

Remains of under-water sites are a stroke of luck for pre-historic archeology. The wooden piles from which their foundations were built have been preserved excellently: In the absence of oxygen, they were not corroded by bacteria or fungi. Wood preserved in this way is excellently well suited for dendrochronological examinations, which can be dated using growth rings. The age of the wood, and thus the time at which the settlements were built, can be determined in combination with radiocarbon dating. This method has now been applied outside of the Alpine region for the first time.

Under the leadership of the University of Bern, around 800 piles were dated in the large international EXPLO project (see info box). They come from a site on the east coast of Lake Ohrid. The results were presented recently in the Journal of Archaeological Science. The new findings prove that the settlement in the Bay of Ploča Mičov Grad near the Macedonian town of Ohrid was constructed in different phases. And over thousands of years: From the Neolithic Period (middle of the 5th millennium BC) until the Bronze Age (2nd millennium BC). Until now, it was assumed that it was a settlement from the period around 1,000 BC. This intensive construction activity explains the extraordinary density of wooden piles at the site. The settlements were built virtually over one another.

The cradle of European agriculture

"The precise dates of the different settlement phases of Ploča Mičov Grad represent important temporal reference points for a chronology of prehistory in the south-western Balkans," says Albert Hafner. He is Professor of Prehistoric Archeology at the University of Bern and a member of the Oeschger Center for Climate Change Research. The precise chronological classification, in turn, opened up unimagined possibilities of interpretation for the traces found of the early occupation of Lake Ohrid. A so-called cultural layer is hidden under the present-day lakebed. It consists mainly of organic material and is up to 1.7 meters thick. Among other things, it contains the remains of harvested grain, wild plants and animals, which can provide conclusions on the development of agriculture. In the Balkans, the newly arrived farmers were confronted with comparatively cool and humid climate conditions, which forced them to adapt agricultural practices accordingly. "The interactions between this revolutionary innovation and the environment are largely unknown,"emphasized Hafner. This is precisely the research gap that the EXPLO project aims to fill.

The pile dwellings in the Alpine region and the archeological site in the Balkans are the only remains of settlements from the Neolithic Period with excellent organic conservation. The early findings are particularly interesting as the area played a key role in the proliferation of agriculture: Europe's first farmers lived here. Early cattle breeders and arable farmers from Anatolia first reached the Aegean region, especially northern Greece, and then Central Europe via southern Italy and the Balkans more than 8,000 years ago.

Important cultural heritage in the Balkans

"Our investigations are shining a light on the large potential for future research on the pre-historic settlements in the region," says Hafner. The significance of the settlements on Lake Ohrid is huge: "The pile dwellings around the Alps have been considered a UNESCO World Heritage Site since 2011, and the wetland settlements in the south-western Balkans are no less significant," said Albert Hafner. The region offers a situation comparable to the area around the Alps: Relics of prehistoric settlements have been preserved in numerous lakes in modern Albania, northern Greece and North Macedonia. However, with few exceptions, the sites in the Balkan region have hardly been studied so far.

Bern researchers are also pursuing other goals over the long term. "We want to help ensure that the value of these wetland settlements is recognized locally and that these cultural assets are better protected," explained Hafner. Sites are not only located on the north Macedonian shore of Lake Ohrid, where the EXPLO team conducted fieldwork campaigns in 2018 and 2019, but also on the Albanian western shore of the lake, where the researchers were active this summer at the Lin 3 site. In the long term, it is planned to expand collaboration with local partners, support the education and training of researchers from the region and promote local initiatives.

More information: Albert Hafner et al, First absolute chronologies of neolithic and bronze age settlements at Lake Ohrid based on dendrochronology and radiocarbon dating, Journal of Archaeological Science: Reports (2021). DOI: 10.1016/j.jasrep.2021.103107

Journal information: Journal of Archaeological Science

Provided by University of Bern

JULY 1, 2021

'Gone to hell': The battle to save Europe's oldest lake

by Darko Duridanski and Joseph Boyle

Lake Ohrid formed more than 1.3 million years ago and is home to dozens of unique species.

Dimitar Pendoski marches to the end of a rickety walkway, skips around sunbathing youngsters and sweeps back a tarpaulin protecting his empty lakeside restaurant, recently closed by officials under pressure from UNESCO.

North Macedonia's government is scrambling to enforce environmental protection rules and shut down places like Pendoski's self-built restaurant, to save Lake Ohrid from being placed on the UN culture agency's list of endangered world heritage sites.

"This way, everybody loses—the employees, the local economy, and of course the tourists because they have no place to go on the beach," Pendoski tells AFP, a point hotly contested by environmentalists.

Thanks to its unique animal and plant life, prehistoric ruins and Byzantine churches, Lake Ohrid and its surroundings have enjoyed four decades as a UNESCO world heritage site.

Only a few dozen places around the world have won the status for both their nature and their culture, a source of prestige for Lake Ohrid—and a major bonus in marketing the area to tourists.

But the UN body has said the Ohrid region will be put on the "in danger" list during a high-level meeting later in July because of concerns over uncontrolled urbanisation and pollution.

Unless North Macedonia can perform diplomatic miracles, the lake will be cited along with such marvels as Australia's Great Barrier Reef.

Ohrid city mayor Konstantin Georgieski is at the centre of a tangle of local and national government bodies tasked with addressing the problems.

His mission is complicated by the international dimension—part of the lake is in Albania, and their officials are also taking part in discussions with UNESCO.

But Georgieski is not panicking.

A major tourism industry has sprung up around the lake, feeding the local economy—but also leading to environmental damage — A major tourism industry has sprung up around the lake, feeding the local economy—but

"It is not going to mean the end of the world," he says of the UNESCO's decision, pointing out that the heritage status does not bring any funding.

"After 30 years of negligence, it's normal that they (UNESCO) are losing patience."

'Cancer of the lake'

UNESCO first added the Macedonian side of the lake to its world heritage list in 1979, expanding the entry to include the Albanian side only in 2019.

During the time of Yugoslavia, Ohrid was a sleepy settlement known mostly for its hospitals and as a training post for sports teams.

After Macedonia's secession and Yugoslavia's chaotic disintegration in the 1990s, however, tourist developments began expanding along the lakeshore.

Esplanades, five-storey hotels, restaurants and bars have sprung up—and with them came apartment blocks amounting to a satellite of the old town.

Entrepreneurs exploited legal loopholes to build on protected land, often without even connecting to the sewerage system.

UNESCO estimates one third of buildings in the wider Ohrid region pump waste directly into the lake.

"Everything has gone to hell," says Nikola Paskali, an archaeologist who has spent two decades diving on the lake.

Dimitar Pendoski claims his restaurant was closed down despite having received all the necessary permits — Dimitar Pendoski claims his restaurant was closed down despite having received all the

Sometimes he searches for Bronze Age relics but sometimes he hunts out junk—TVs, toilets and even a full-size bathtub are among the items he has pulled from the deep.

"Litter is the cancer of the lake," he says, accusing the government of doing little to protect biodiversity in a lake that formed more than 1.3 million years ago and is home to dozens of unique species.

UNESCO has highlighted problems from illegal buildings, logging and fish farms, to river diversions and haphazard road construction.

Much of this is underpinned by the region's desire to become a centre for tourism.

"If we started now, it would take years and years to repair the damage we have done," says Katarina Vasileska from grassroots environmental group Ohrid SOS.

'This is not Ibiza'

But cleaning up the lake comes with risks.

Mayor Georgieski recently ordered the destruction of several structures built over the lake that served as makeshift nightclubs and restaurants.

"It's difficult to destroy someone's property in a small town like ours," he says. "I'm a personal enemy of these people now."

But he reflects that business owners need to change their mindset, adding: "This is not Ibiza."

Ohrid's mayor Konstantin Georgieski has ordered the destruction of several lakeside nightclubs and restaurants, but it has won h — Ohrid's mayor Konstantin Georgieski has ordered the destruction of several lakeside

Georgieski envisages a town that welcomes sustainable levels of tourists attracted by culture and nature rather than partying.

But UNESCO said in its most recent report that restoration work had damaged the "authenticity" of some churches, and that the unique wood-beamed buildings of the old town were at risk from uncontrolled development.

Restaurateur Pendoski does not disagree with UNESCO or the mayor, but he claims he was closed down despite having received all the necessary permits.

"We all share the goal of having more guests while protecting the lake and nature, but there has to be some local economic development," he says.

Environmentalists argue, however, that pitting economic development against ecological concerns is a false debate.

"We have to keep the lake clean because otherwise we will lose everything, we will lose tourism," says diver Paskali.

Activist Vasileska also points out that receiving permits is not a green light for pollution.

"You may employ 30 people," she says, "but you pollute the lake for 50,000."

Macedonians send out SOS from Europe's oldest lake

Increasing trends of warm and wet extremes slowed in China during recent global warming hiatus

by Li Yuan, Chinese Academy of Sciences

Increasing trends of warm and wet extremes found to slow in China during recent global warming hiatus — Heavy rain caused lake level to rapidly rise. Credit: QIN Peihua

Although annual concentrations of atmospheric greenhouse gases have increased continuously in past years, the global surface air temperature did not increase as much as expected during a period starting from 1997/1998 with a strong El Nino and ending around 2017

This unexpected warming hiatus has received much attention, and researchers want to figure out what contributed to it and how climate extremes changed during the warming hiatus.

Recently, Dr. QIN Peihua from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences and his collaborators investigated trends of precipitation and temperature extremes in China during the global warming hiatus relative to the reference period (1982–1997) and the whole historical period (1982–2017).

During the global warming hiatus, annual warmest days and the number of summer days over China and most of its four subregions were found to decrease relative to both periods. Annual coldest nights over China and its four subregions were found to decrease moderately relative to both periods, whereas the number of frost days increased consistently.

"We found precipitation extremes showed more temporal and spatial variability than temperature extremes. Trends of annual wet extremes during the hiatus decreased relative to the whole historical period and the reference period, whereas the dry extreme index during the hiatus was found to increase generally over China and in most subregions," said QIN.

The study suggests that lighter winds and lower relative humidity over most areas of China might have contributed to less pronounced trends of wet extremes during the hiatus period.

This work was published in the International Journal of Climatology on August 20.

Global warming intensifies precipitation extremes in China

Simple economic method to measure soil health in dryland farming

by United States Department of Agriculture

USDA, Agricultural Research Service's (ARS) Northern Plains Agricultural Research Laboratory, in collaboration with the Soil Health Institute in N.C., evaluated the measurement of carbon dioxide flush—a rapid, reliable, and inexpensive method producers can use to measure soil health on dryland cropping systems—and refined it to be closely associated with most soil properties and long-term crop production.

Farmers, producers, and managers increasingly want to use soil health assessments to measure the level of desired properties in their soil, like soil aggregation, microbial activity, nutrient cycling, salinity, acidity, and organic matter. Generally, producers have to use several methods and indicators to measure many soil properties, and testing can become expensive.

Given that this knowledge can contribute to the decision-making of soil management practices for crop production, there is a need for an inexpensive and reliable test that can provide suitable data for measuring soil health, especially for nitrogen mineralization. Nitrogen mineralization is the amount of nitrogen that naturally becomes available from soil during a growing season, and knowing it can help farmers use less nitrogen fertilizer, still maintain crop yields, and reduce environmental degradation. Scientists are concentrating their efforts on identifying indicators and parameters for what makes a soil healthy, which can help producers to know if more practices could help them increase crop production while maintaining sustainable, healthy soil for generations to come.

One soil health indicator that scientists had focused on is the measurement of the carbon dioxide gas released (flushed) after rewetting of dry soils. The method involves adding water to a sample of dry soil and incubating for one day in a jar. The carbon dioxide released inside the jar during incubation indicates microbial activity in the soil. The higher the amount of carbon dioxide flush, the healthier the soil is.

Although the test has been known for a long time and the carbon dioxide flush has been related to crop yields, it has not been related to a large number of soil properties or tied to long-term crop yields.

In the study, published in the Soil Science Society of America Journal, ARS research soil scientist Upendra M. Sainju and collaborators used this method on soil samples collected from two long-term experimental sites for dryland farming (14- 36-year-old sites in Eastern Montana), with the goal to identify a promising soil health indicator that relates to most soil properties and crop yields and is economical and easy to use by farmers. Samples were tested for carbon dioxide flush after 1-day incubation period using water and 4-day incubation period using an alkali solution and related to 54 different soil properties and the average crop production across years in dry regions.

"Measuring soil health could be difficult for producers," said Sainju. "Our team was able to refine the 1-day incubation method to relate to most soil physical, chemical, biological, and biochemical properties when farming in semiarid conditions. After comparison, the 1-day incubation method was not only faster, but also accurate because it is connected to more soil properties and had a better relationship with crop production than the 4-day method. The shorter time required for incubation and mixing soil with water without the use of chemicals also make it more practical and cheaper for producers."

The team of scientists wants to continue validating this simple process for short-term experiments with different soils in both dryland and irrigated cropping systems and share the results with producers. "Knowledge is critical to maintaining healthy soils, which has a direct impact in yearly crop harvest, and requires a simple, easier, reliable, and inexpensive test to measure," said Sainju.

Soil carbon and nitrogen mineralization after the initial flush of CO2

More information: Upendra M. Sainju et al, Carbon dioxide flush as a soil health indicator related to soil properties and crop yields, Soil Science Society of America Journal (2021). DOI: 10.1002/saj2.20288

Journal information: Soil Science Society of America Journal

Provided by United States Department of Agriculture

When walked on, these wooden floors harvest enough energy to turn on a lightbulb

by Cell Press

Researchers from Switzerland are tapping into an unexpected energy source right under our feet: wooden floorings. Their nanogenerator, presented September 1 in the journal Matter, enables wood to generate energy from our footfalls. They also improved the wood used in the their nanogenerator with a combination of a silicone coating and embedded nanocrystals, resulting in a device that was 80 times more efficient—enough to power LED lightbulbs and small electronics.

The team began by transforming wood into a nanogenerator by sandwiching two pieces of functionalized wood between electrodes. Like a shirt-clinging sock fresh out of the dryer, the wood pieces become electrically charged through periodic contacts and separations when stepped on, a phenomenon called the triboelectric effect. The electrons can transfer from one object to another, generating electricity. However, there's one problem with making a nanogenerator out of wood.

"Wood is basically triboneutral," says senior author Guido Panzarasa, group leader in the professorship of Wood Materials Science located at Eidgenössische Technische Hochschule (ETH) Zürich and Swiss Federal Laboratories for Materials Science and Technology (Empa) Dübendorf. "It means that wood has no real tendency to acquire or to lose electrons." This limits the material's ability to generate electricity, "so the challenge is making wood that is able to attract and lose electrons," Panzarasa explains.

To boost wood's triboelectric properties, the scientists coated one piece of the wood with polydimethylsiloxane (PDMS), a silicone that gains electrons upon contact, while functionalizing the other piece of wood with in-situ-grown nanocrystals called zeolitic imidazolate framework-8 (ZIF-8). ZIF-8, a hybrid network of metal ions and organic molecules, has a higher tendency to lose electrons. They also tested different types of wood to determine whether certain species or the direction in which wood is cut could influence its triboelectric properties by serving as a better scaffold for the coating.

A prototype of how energy could be captured from footsteps on a functionalized wood nanogenerator to light a bulb. Credit: Sun et al./Matter

The researchers found that a triboelectric nanogenerator made with radially cut spruce, a common wood for construction in Europe, performed the best. Together, the treatments boosted the triboelectric nanogenerator's performance: it generated 80 times more electricity than natural wood. The device's electricity output was also stable under steady forces for up to 1,500 cycles.

"Our focus was to demonstrate the possibility of modifying wood with relatively environmentally friendly procedures to make it triboelectric," says Panzarasa. "Spruce is cheap and available and has favorable mechanical properties. The functionalization approach is quite simple, and it can be scalable on an industrial level. It's only a matter of engineering."The researchers found that a wood floor prototype with a surface area slightly smaller than a piece of paper can produce enough energy to drive household LED lamps and small electronic devices such as calculators. They successfully lit up a lightbulb with the prototype when a human adult walked upon it, turning footsteps into electricity.

Besides being efficient, sustainable, and scalable, the newly developed nanogenerator also preserves the features that make the wood useful for interior design, including its mechanical robustness and warm colors. The researchers say that these features might help promote the use of wood nanogenerators as green energy sources in smart buildings. They also say that wood construction could help mitigate climate change by sequestering CO2 from the environment throughout the material's lifespan.

The next step for Panzarasa and his team is to further optimize the nanogenerator with chemical coatings that are more eco-friendly and easier to implement. "Even though we initially focused on basic research, eventually, the research that we do should lead to applications in the real world," says Panzarasa. "The ultimate goal is to understand the potentialities of wood beyond those already known and to enable wood with new properties for future sustainable smart buildings."

Using softened wood to create electricity in homes

More information: Matter, Sun et al.: "Functionalized wood with tunable tribo-polarity for efficient triboelectric nanogenerators" www.cell.com/matter/fulltext/S2590-2385(21)00393-3 , DOI: 10.1016/j.matt.2021.07.022

Journal information: Matter Provided by Cell Press

Making the case for hydrogen in a zero-carbon economy

by Leda Zimmerman, Massachusetts Institute of Technology

As the United States races to achieve its goal of zero-carbon electricity generation by 2035, energy providers are swiftly ramping up renewable resources such as solar and wind. But because these technologies churn out electrons only when the sun shines and the wind blows, they need backup from other energy sources, especially during seasons of high electric demand. Currently, plants burning fossil fuels, primarily natural gas, fill in the gaps.

"As we move to more and more renewable penetration, this intermittency will make a greater impact on the electric power system," says Emre Gençer, a research scientist at the MIT Energy Initiative (MITEI). That's because grid operators will increasingly resort to fossil-fuel-based "peaker" plants that compensate for the intermittency of the variable renewable energy (VRE) sources of sun and wind. "If we're to achieve zero-carbon electricity, we must replace all greenhouse gas-emitting sources," Gençer says.

Low- and zero-carbon alternatives to greenhouse-gas emitting peaker plants are in development, such as arrays of lithium-ion batteries and hydrogen power generation. But each of these evolving technologies comes with its own set of advantages and constraints, and it has proven difficult to frame the debate about these options in a way that's useful for policymakers, investors, and utilities engaged in the clean energy transition.

Now, Gençer and Drake D. Hernandez SM '21 have come up with a model that makes it possible to pin down the pros and cons of these peaker-plant alternatives with greater precision. Their hybrid technological and economic analysis, based on a detailed inventory of California's power system, was published online last month in Applied Energy. While their work focuses on the most cost-effective solutions for replacing peaker power plants, it also contains insights intended to contribute to the larger conversation about transforming energy systems.

"Our study's essential takeaway is that hydrogen-fired power generation can be the more economical option when compared to lithium-ion batteries—even today, when the costs of hydrogen production, transmission, and storage are very high," says Hernandez, who worked on the study while a graduate research assistant for MITEI. Adds Gençer, "If there is a place for hydrogen in the cases we analyzed, that suggests there is a promising role for hydrogen to play in the energy transition."

Adding up the costs

California serves as a stellar paradigm for a swiftly shifting power system. The state draws more than 20 percent of its electricity from solar and approximately 7 percent from wind, with more VRE coming online rapidly. This means its peaker plants already play a pivotal role, coming online each evening when the sun goes down or when events such as heat waves drive up electricity use for days at a time.

"We looked at all the peaker plants in California," recounts Gençer. "We wanted to know the cost of electricity if we replaced them with hydrogen-fired turbines or with lithium-ion batteries." The researchers used a core metric called the levelized cost of electricity (LCOE) as a way of comparing the costs of different technologies to each other. LCOE measures the average total cost of building and operating a particular energy-generating asset per unit of total electricity generated over the hypothetical lifetime of that asset.

Selecting 2019 as their base study year, the team looked at the costs of running natural gas-fired peaker plants, which they defined as plants operating 15 percent of the year in response to gaps in intermittent renewable electricity. In addition, they determined the amount of carbon dioxide released by these plants and the expense of abating these emissions. Much of this information was publicly available.

Coming up with prices for replacing peaker plants with massive arrays of lithium-ion batteries was also relatively straightforward: "There are no technical limitations to lithium-ion, so you can build as many as you want; but they are super expensive in terms of their footprint for energy storage and the mining required to manufacture them," says Gençer.

But then came the hard part: nailing down the costs of hydrogen-fired electricity generation. "The most difficult thing is finding cost assumptions for new technologies," says Hernandez. "You can't do this through a literature review, so we had many conversations with equipment manufacturers and plant operators."

The team considered two different forms of hydrogen fuel to replace natural gas, one produced through electrolyzer facilities that convert water and electricity into hydrogen, and another that reforms natural gas, yielding hydrogen and carbon waste that can be captured to reduce emissions. They also ran the numbers on retrofitting natural gas plants to burn hydrogen as opposed to building entirely new facilities. Their model includes identification of likely locations throughout the state and expenses involved in constructing these facilities.

The researchers spent months compiling a giant dataset before setting out on the task of analysis. The results from their modeling were clear: "Hydrogen can be a more cost-effective alternative to lithium-ion batteries for peaking operations on a power grid," says Hernandez. In addition, notes Gençer, "While certain technologies worked better in particular locations, we found that on average, reforming hydrogen rather than electrolytic hydrogen turned out to be the cheapest option for replacing peaker plants."

A tool for energy investors

When he began this project, Gençer admits he "wasn't hopeful" about hydrogen replacing natural gas in peaker plants. "It was kind of shocking to see in our different scenarios that there was a place for hydrogen." That's because the overall price tag for converting a fossil-fuel based plant to one based on hydrogen is very high, and such conversions likely won't take place until more sectors of the economy embrace hydrogen, whether as a fuel for transportation or for varied manufacturing and industrial purposes.

A nascent hydrogen production infrastructure does exist, mainly in the production of ammonia for fertilizer. But enormous investments will be necessary to expand this framework to meet grid-scale needs, driven by purposeful incentives. "With any of the climate solutions proposed today, we will need a carbon tax or carbon pricing; otherwise nobody will switch to new technologies," says Gençer.

The researchers believe studies like theirs could help key energy stakeholders make better-informed decisions. To that end, they have integrated their analysis into SESAME, a life cycle and techno-economic assessment tool for a range of energy systems that was developed by MIT researchers. Users can leverage this sophisticated modeling environment to compare costs of energy storage and emissions from different technologies, for instance, or to determine whether it is cost-efficient to replace a natural gas-powered plant with one powered by hydrogen.

"As utilities, industry, and investors look to decarbonize and achieve zero-emissions targets, they have to weigh the costs of investing in low-carbon technologies today against the potential impacts of climate change moving forward," says Hernandez, who is currently a senior associate in the energy practice at Charles River Associates. Hydrogen, he believes, will become increasingly cost-competitive as its production costs decline and markets expand.

A study group member of MITEI's soon-to-be published Future of Storage study, Gençer knows that hydrogen alone will not usher in a zero-carbon future. But, he says, "Our research shows we need to seriously consider hydrogen in the energy transition, start thinking about key areas where hydrogen should be used, and start making the massive investments necessary."

Green hydrogen production from curtailed wind and solar power

More information: Drake D. Hernandez et al, Techno-economic analysis of balancing California's power system on a seasonal basis: Hydrogen vs. lithium-ion batteries, Applied Energy (2021). DOI: 10.1016/j.apenergy.2021.117314

Provided by Massachusetts Institute of Technology

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

A carbon-neutral response to rising electricity demand

by Michèle Marti, ETH Zurich

Many everyday activities rely on electricity. As we look to 2050, this dependence is set to increase, with demand for electricity in Switzerland likely to rise to 50 percent. The increased demand can only be met by transforming the energy system.

Switzerland has set itself the goal of ending its greenhouse gas emissions by 2050. With this net zero target, the country hopes to play its part in limiting global warming to less than 1.5°C. The implications of this target for future electricity requirements—and the potential contributions of geothermal energy and hydropower in particular—have been the subject of ETH-led research at 25 Swiss scientific institutions, industrial companies and federal authorities as part of the Swiss Competence Center for Energy Research—Supply of Electricity (SCCER-SoE). Although this project initially focused on renewables as a substitute for nuclear energy, it ultimately took on a much broader scope. After all, the energy system of the future will not only need to deliver more power, but do so with negative emissions wherever possible. This requires much more comprehensive and, above all, more integrated solutions.

The electricity mix of the future

Led by the SCCER-SoE, a total of eight competence centers used scenarios to model the future composition of electricity supply and demand. The increased demand for electricity by 2050 will be largely driven by electrification in two areas: transport and heating.

To meet this rising demand and, above all, to compensate for the elimination of nuclear power plants, the supply of renewable energies will need to almost double by 2050. The greatest potential lies in photovoltaics. "However, this potential can only be utilized in full if we also take measures to offset the deficienciescompensate the fluctuations of this form of energy," says Peter Burgherr from the Paul Scherrer Institute. Photovoltaics are poorly suited to delivering sufficient power in the winter months, and they produce a surplus of energy in the middle of the day in the summer months, which can tax the power grid.

To better cope with the irregular supply of electricity, it is imperative that we also make better use of the potential offered by other renewables such as wind, hydropower, biomass and geothermal energy. Surplus energy from photovoltaic systems could be stored in batteries temporarily, used for pumped storage plants, or converted into heat or hydrogen.

This is where hydropower comes into play. As the most important domestic energy source in Switzerland, both now and in the future, it not only contributes directly to the electricity supply but is also taking on an important role as a form of energy storage. But Robert Boes, head of the Laboratory of Hydraulics, Hydrology and Glaciology and a professor at ETH Zurich, qualifies this potential: "A significant expansion of hydropower in the next few decades is unrealistic given the stringent environmental protection requirements, profitability which is low or non-existent, and poor public acceptance of such projects." Even under optimistic assumptions, that means additional electricity imports and domestic gas-fired power stations will still be required to meet demand.

In Switzerland, geothermal energy has the potential to contribute to future power generation and to provide a large proportion of the heat needed for heating purposes, hot water and certain industrial processes. And it is not only that water can be heated underground and then extracted—the subsurface can also be used to store water heated on the surface using surplus energy from photovoltaics or waste incineration plants, for example.

Not without negative emissions

As well as expanding its use of renewable energies, increasing the efficiency of existing technologies and implementing measures to minimize energy consumption, Switzerland will need to achieve negative emissions if it is to meet the net zero target. For example, these negative emissions could be achieved by capturing carbon dioxide directly from ambient air (direct air capture) or by burning biomass, capturing the resulting CO2, and placing it in long-term storage underground. Current findings suggest that the options for underground storage in Switzerland are not as extensive as originally hoped, and so there is a need for further exploration—along with research into storage options abroad.

The results from the SCCER-SoE's seven years of research indicate that the net zero target is technically achievable by 2050. "However, this will require extensive and coordinated adjustments in many different areas that affect the whole of society. We can't afford to waste any more time if we want to meet the stipulated climate goals by 2050," says Domenico Giardini, professor at ETH Zurich and Head of the SCCER-SoE.

Switzerland's energy transition

Provided by ETH Zurich

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