The study, “Friend or Foe? Teaming Between Artificial Intelligence and Workers with Variation in Experience,” looks at the influence of two major types of human work experience (narrow experience based on the specific task volume and broad experience based on seniority) on the human-AI team dynamics.

“We developed an AI solution for medical chart coding in a publicly traded company and conducted a field study among the knowledge workers,” says Weiguang Wang of the University of Rochester and leading author of the study. “We were surprised by what we found in the study. The different dimensions of work experience have distinct interactions with AI and play unique roles in human-AI teaming.”

“While one might think that less experienced workers should benefit more from the help of AI, we find the opposite — AI benefits workers with greater task-based experience. At the same time, senior workers, despite their greater experience, gain less from AI than their junior colleagues,” says Guodong (Gordon) Gao of Johns Hopkins Carey Business School, and study co-author.

Further investigation reveals that the relatively lower productivity lift from AI is not a result of seniority per se but rather their higher sensitivity to the imperfection of AI, which lowers their trust in AI.

“This finding presents a dilemma: Employees with greater experience are in a better position to leverage AI for productivity, but the senior employees who assume greater responsibilities and care about the organization tend to shy away from AI because they see the risks of relying on AI’s assistance. As a result, they are not effectively leveraging AI,” says Ritu Agarwal of Johns Hopkins Carey Business School, a co-author of the study.

The researchers urge employers to carefully consider different worker experience types and levels when introducing AI into the work. New workers with less task experience are disadvantaged in leveraging AI. Meanwhile, senior workers with more organizational experience may be concerned about the potential risks imposed by AI. Addressing these unique challenges are key to productive human-AI teaming.

“Our results show that even in 2050 going off-grid won’t be the most economic choice, but it could make sense to invest in these kinds of self-sufficient buildings if you are willing to pay more for self-sufficiency,” says lead author Max Kleinebrahm, an energy economics researcher at the Karlsruhe Institute of Technology in Germany.

Grid energy costs are rising while renewable energy technology is becoming more affordable. In pursuit of self-sufficiency, more and more households are showing interest in producing their own renewable energy supplies. Kleinebrahm’s team wanted to know how feasible it would be for individual residential buildings in different parts of Europe to become fully self-sufficient, and whether doing so would come with any financial benefits. Though the potential of converting Europe to 100% renewable energy has been considered at the continental, national, and regional scale, this study is the first analysis at the level of individual buildings.

To identify regions and building types that are more amenable to self-sufficiency, the researchers compiled a database of homes across Europe and identified 4,000 homes that were representative of different regions in terms of architecture, household electricity demand, climate conditions, and the local economic framework. Then, the researchers designed optimal energy systems for each representative home that would fully cover electrical and thermal energy needs while minimizing costs. These systems included measures such as rooftop solar panels, small wind turbines, different types of storage systems, heat pump installation, and retrofitting and insulation measures.

Next, the researchers scaled their results up to estimate the technical and economic feasibility of energy self-sufficiency for Europe’s 41 million freestanding single-family homes. Overall, they estimated that 53% of homes could have technically achieved energy self-sufficiency in 2020, and that this proportion could increase to 75% by 2050 with expected improvements in renewable energy and storage technologies. However, becoming fully self-sufficient was more expensive than remaining fully dependent on the grid, both in 2020 and 2050.

Homes in sunny European countries such as Cyprus, Malta, and Italy have more economic potential for self-sufficiency, while northern European countries such as Finland, Norway, and Sweden (where there is a large mismatch between high winter energy needs and solar radiation) have the lowest potential. Regions with larger rooftops, such as Denmark, Slovenia, the Netherlands, and France, also have greater potential for self-sufficiency. The researchers also noted that there is greater potential for self-sufficient buildings in countries with high on-grid electricity costs, such as Germany, since there is less financial incentive to remain on-grid.

Though becoming fully self-sufficient may not be economically advantageous, the researchers demonstrated that partial self-sufficiency — where a building remains connected to the electricity grid but also invests in a photovoltaic system, heat pump, and insulation — could lower household energy costs. The optimal degree of self-sufficiency varied for different buildings and regions, but for one representative building in Germany, the researchers estimated that it would have been cost-optimal to be 73% self-sufficient in 2020 and 78% self-sufficient in 2050.

The researchers note that high carrier costs make leaving the grid more appealing and say that policymakers and utility companies should encourage even fully self-sufficient households to remain connected to the grid. “At a macroeconomic scale it would be less efficient to have a large number of households abandoning the grid rather than supporting it,” says Kleinebrahm.

Since the costs of supporting the grid are shared amongst users, there is also the potential for grid costs to climb further as households choose to leave the grid. “From the social perspective, you have to consider the possibility that very rich households could go off grid, in which case the rest of the grid operation would have to be paid for by economically weaker households,” says Kleinebrahm.

This study is unable to answer questions about how the expanding number of self-sufficient homes would impact electricity demand and electricity markets, but the researchers plan to address those topics in future.

In recent years, some researchers have been puzzled upon finding that water in their experiments, which was held in a sponge-like material known as a hydrogel, was evaporating at a higher rate than could be explained by the amount of heat, or thermal energy, that the water was receiving. And the excess has been significant — a doubling, or even a tripling or more, of the theoretical maximum rate.

After carrying out a series of new experiments and simulations, and reexamining some of the results from various groups that claimed to have exceeded the thermal limit, a team of researchers at MIT has reached a startling conclusion: Under certain conditions, at the interface where water meets air, light can directly bring about evaporation without the need for heat, and it actually does so even more efficiently than heat. In these experiments, the water was held in a hydrogel material, but the researchers suggest that the phenomenon may occur under other conditions as well.

The findings are published this week in a paper in PNAS, by MIT postdoc Yaodong Tu, professor of mechanical engineering Gang Chen, and four others.

The phenomenon might play a role in the formation and evolution of fog and clouds, and thus would be important to incorporate into climate models to improve their accuracy, the researchers say. And it might play an important part in many industrial processes such as solar-powered desalination of water, perhaps enabling alternatives to the step of converting sunlight to heat first.

The new findings come as a surprise because water itself does not absorb light to any significant degree. That’s why you can see clearly through many feet of clean water to the surface below. So, when the team initially began exploring the process of solar evaporation for desalination, they first put particles of a black, light-absorbing material in a container of water to help convert the sunlight to heat.

Then, the team came across the work of another group that had achieved an evaporation rate double the thermal limit — which is the highest possible amount of evaporation that can take place for a given input of heat, based on basic physical principles such as the conservation of energy. It was in these experiments that the water was bound up in a hydrogel. Although they were initially skeptical, Chen and Tu starting their own experiments with hydrogels, including a piece of the material from the other group. “We tested it under our solar simulator, and it worked,” confirming the unusually high evaporation rate, Chen says. “So, we believed them now.” Chen and Tu then began making and testing their own hydrogels.

They began to suspect that the excess evaporation was being caused by the light itself — that photons of light were actually knocking bundles of water molecules loose from the water’s surface. This effect would only take place right at the boundary layer between water and air, at the surface of the hydrogel material — and perhaps also on the sea surface or the surfaces of droplets in clouds or fog.

In the lab, they monitored the surface of a hydrogel, a JELL-O-like matrix consisting mostly of water bound by a sponge-like lattice of thin membranes. They measured its responses to simulated sunlight with precisely controlled wavelengths.

The researchers subjected the water surface to different colors of light in sequence and measured the evaporation rate. They did this by placing a container of water-laden hydrogel on a scale and directly measuring the amount of mass lost to evaporation, as well as monitoring the temperature above the hydrogel surface. The lights were shielded to prevent them from introducing extra heat. The researchers found that the effect varied with color and peaked at a particular wavelength of green light. Such a color dependence has no relation to heat, and so supports the idea that it is the light itself that is causing at least some of the evaporation.

The researchers tried to duplicate the observed evaporation rate with the same setup but using electricity to heat the material, and no light. Even though the thermal input was the same as in the other test, the amount of water that evaporated never exceeded the thermal limit. However, it did so when the simulated sunlight was on, confirming that light was the cause of the extra evaporation.

Though water itself does not absorb much light, and neither does the hydrogel material itself, when the two combine they become strong absorbers, Chen says. That allows the material to harness the energy of the solar photons efficiently and exceed the thermal limit, without the need for any dark dyes for absorption.

Having discovered this effect, which they have dubbed the photomolecular effect, the researchers are now working on how to apply it to real-world needs. They have a grant from the Abdul Latif Jameel Water and Food Systems Lab to study the use of this phenomenon to improve the efficiency of solar-powered desalination systems, and a Bose Grant to explore the phenomenon’s effects on climate change modeling.

Tu explains that in standard desalination processes, “it normally has two steps: First we evaporate the water into vapor, and then we need to condense the vapor to liquify it into fresh water.” With this discovery, he says, potentially “we can achieve high efficiency on the evaporation side.” The process also could turn out to have applications in processes that require drying a material.

Chen says that in principle, he thinks it may be possible to increase the limit of water produced by solar desalination, which is currently 1.5 kilograms per square meter, by as much as three- or fourfold using this light-based approach. “This could potentially really lead to cheap desalination,” he says.

Tu adds that this phenomenon could potentially also be leveraged in evaporative cooling processes, using the phase change to provide a highly efficient solar cooling system.

Meanwhile, the researchers are also working closely with other groups who are attempting to replicate the findings, hoping to overcome skepticism that has faced the unexpected findings and the hypothesis being advanced to explain them.

The research team also included Jiawei Zhou, Shaoting Lin, Mohammed Alshrah, and Xuanhe Zhao, all in MIT’s Department of Mechanical Engineering.