Nav: Home

Are we underestimating the benefits of investing in renewable energy?

October 16, 2019

As policymakers seek to reduce carbon dioxide and other pollutants through increases in renewable energy, improving energy efficiency or electrifying transportation, a key question arises: Which interventions provide the largest benefits to avoid the negative health effects of air pollution?

To address this question, it is important to understand how much pollution is released at different times by power plants on the electricity system. The amount of pollution that is produced per unit of energy on the electric grid is measured by what is known as emissions intensity. Traditionally, policymakers and energy modelers have used annual average emissions intensities - averaged across all power plants over an entire year - to estimate the emissions avoided by a power system intervention. However, doing so misses the fact that many interventions affect only a certain set of power plants, and that these effects may vary by time of day or year.

By using marginal emissions that are collected on an hourly basis and account for location, policymakers may be able to glean important information that would otherwise be missed, according to new research. This approach may help decision-makers more clearly understand the impacts of different policy and investment options.

Average vs. marginal emissions - an important difference

Scientists tested the difference between average and marginal emissions by analyzing electricity from PJM, the largest wholesale electricity market in the United States. PJM produces about 800 terawatt hours of electricity per year - enough to power a fifth of the U.S. - and contributes roughly 20 percent of U.S. power sector emissions. Their findings, published in Environmental Science & Technology, show that ignoring the difference between marginal and average emissions can lead to large errors when estimating the emissions avoided by interventions - as well as the associated health, environmental and climate change damages.

The researchers show that for certain interventions, using PJM average emissions intensities can underestimate the damages avoided by almost 50 percent compared to marginal intensities that account for which power plants are actually affected. In other words, using average values may cause a policymaker to think an intervention is only half as effective as it really is, potentially compromising its implementation despite its large benefits.

While officials have historically used average emissions intensities to calculate pollution in the electricity sector, in certain cases, this has led to incorrectly estimating impacts compared with a marginal emissions approach, said study co-author Inês Azevedo, an associate professor in the Department of Energy Resources Engineering at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth).

The researchers also highlight the importance of using up-to-date emissions intensity estimates. In their paper, they show that using estimates only one year out of date can overestimate the damages avoided by 25 to 35 percent.

"The electric grid is changing rapidly, but emissions intensity data is often released with a large lag," said Priya Donti, a PhD student at Carnegie Mellon University and study co-author. "Our study demonstrates the importance of frequently updating this data."

Improving policies

"Boston University used some of our prior work on marginal emissions to decide where to procure renewable energy, by modeling the extent to which different procurements would reduce emissions," said Azevedo, referring to the institution's Climate Action Plan. "It's interesting to think about whether other decision-makers could start using the same sorts of tools to inform climate action plans at the city and state levels."

These kinds of tools can help decision-makers understand the impacts of different policy and investment options, Donti said. "We want to help them design interventions that provide the biggest benefits when it comes to tackling climate change and improving human health."

Azevedo is also a senior fellow at the Stanford Woods Institute for the Environment. J. Zico Kolter of Carnegie Mellon University is a co-author on the study. The research was supported by the Center for Climate and Energy Decision Making (CEDM) in an agreement between Carnegie Mellon University and the National Science Foundation. The study was also funded by the National Science Foundation Graduate Research Fellowship Program and the Department of Energy Computational Science Graduate Fellowship.
-end-


Stanford's School of Earth, Energy & Environmental Sciences

Related Renewable Energy Articles:

Scientists take strides towards entirely renewable energy
Researchers have made a major discovery that will make it immeasurably easier for people (or super-computers) to search for an elusive 'green bullet' catalyst that could ultimately provide entirely renewable energy.
Where to install renewable energy in US to achieve greatest benefits
A new Harvard study shows that to achieve the biggest improvements in public health and the greatest benefits from renewable energy, wind turbines should be installed in the Upper Midwest and solar power should be installed in the Great Lakes and Mid-Atlantic regions.
Croissant making inspires renewable energy solution
The art of croissant making has inspired researchers from Queen Mary University of London to find a solution to a sustainable energy problem.
Are we underestimating the benefits of investing in renewable energy?
Scientists have estimated the emissions intensity of carbon dioxide and other air pollutants from a major electricity distributor and highlighted key consequences - essential information for policymakers shaping decisions to reduce electricity system emissions.
Lighting the path to renewable energy
Professor Mahesh Bandi of Okinawa Institute of Science and Technology Graduate University (OIST) has co-developed a novel, standardized way of quantifying and comparing these variations in solar power.
How much energy storage costs must fall to reach renewable energy's full potential
The cost of energy storage will be critical in determining how much renewable energy can contribute to the decarbonization of electricity.
Renewable and nonrenewable energy in Myanmar's economic growth
An international group of scientists including a researcher from Ural Federal University developed a mathematical model that describes the influence of regenerative and non-regenerative energy sources on the economic growth of Myanmar.
Shifts to renewable energy can drive up energy poverty, PSU study finds
Efforts to shift away from fossil fuels and replace oil and coal with renewable energy sources can help reduce carbon emissions but do so at the expense of increased inequality, according to a new Portland State University study
Microgrids can help maximize efficiency of renewable energy consumption
A group of Italian researchers has developed a method that enables more efficient use of energy by smart homes that are connected to a microgrid -- a web of individualized units that are connected to one another and one common energy source.
Renewable energy generation with kites and drones
A group of researchers at Universidad Carlos III de Madrid has recently developed a new software aimed at the analysis of energy generation systems based on kites and drones.
More Renewable Energy News and Renewable Energy Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.