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:

Intelligent software for district renewable energy management
CSEM has developed Maestro, an intelligent software application that can manage and schedule the production and use of renewable energies for an entire neighborhood.
Renewable energy transition makes dollars and sense
New UNSW research has disproved the claim that the transition to renewable electricity systems will harm the global economy.
Renewable energy advance
In order to identify materials that can improve storage technologies for fuel cells and batteries, you need to be able to visualize the actual three-dimensional structure of a particular material up close and in context.
Illuminating the future of renewable energy
A new chemical compound created by researchers at West Virginia University is lighting the way for renewable energy.
Using fiber optics to advance safe and renewable energy
Fiber optic cables, it turns out, can be incredibly useful scientific sensors.
Renewable energy developments threaten biodiverse areas
More than 2000 renewable energy facilities are built in areas of environmental significance and threaten the natural habitats of plant and animal species across the globe.
Could water solve the renewable energy storage challenge?
Seasonally pumped hydropower storage could provide an affordable way to store renewable energy over the long-term, filling a much needed gap to support the transition to renewable energy, according to a new study from IIASA scientists.
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.
More Renewable Energy News and Renewable Energy Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at Radiolab.org/donate.