congestion

Giant batteries and the grid

May 31, 2024 By EarthWise Leave a Comment

All across the country, electric utility companies are starting to use giant batteries to counteract the biggest weakness of renewable energy; namely, that the sun doesn’t always shine, and the wind doesn’t always blow. Solar panels and wind turbines can keep generating energy when people don’t need it and batteries can store up that energy for when they do.

Over the past three years, battery storage capacity on US grids has grown by a factor of ten adding up to 16 gigawatts. This year, it is expected to double again, led by massive growth in Texas, California, and Arizona.

California generates more electricity from solar power than any other state. But it has a timing problem: solar power is plentiful during the day, but it disappears in the evening when people get home from work and start using lots of electricity. The previous solution was to burn lots of fossil fuel to produce it.

This has been changing thanks to battery storage. Since 2020, California has installed more giant batteries than anywhere else in the world other than China. Batteries are gradually replacing fossil fuels for California’s evening power needs. On the evening of April 30th, for example, batteries supplied more than 20% of California’s electricity. This is equivalent to the output of seven large nuclear reactors.

Batteries have multiple uses in the grid. They handle big swings in generation from renewable sources, they reduce congestion on transmission lines, and they help to prevent blackouts during heat waves. Batteries are starting to eat into the market for fossil fuels and will play an ever-growing role in the electricity grid. As the role of renewables grows, so will the role of batteries.

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Giant Batteries Are Transforming the Way the U.S. Uses Electricity

Photo, posted December 5, 2022, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Benefits Of Zero-Carbon Cities

November 8, 2019 By EarthWise Leave a Comment

A new report issued by a coalition of 50 leading international institutions shows that low carbon initiatives in cities could reduce urban emissions by nearly 90% and support 87 million jobs worldwide by 2030. The report finds that implementing low carbon measures in cities would be worth almost $24 trillion by 2050.

Cities are home to more than half the world’s population but produce 80% of gross domestic product and 75% of carbon emissions. The research highlights the significant benefits carbon reduction can bring to cities in areas such as public health, job creation, and poverty alleviation.

The report shows that it is possible to cut 90% of emissions from cities using currently available technologies and practices including carbon savings from buildings, transportation, materials efficiency, and waste reduction. Doing so would require an investment of nearly $2 trillion per year but would generate annual returns of nearly $3 trillion in 2030 and $7 trillion in 2050 based on cost savings alone. Many low carbon measures would pay for themselves in less than five years, including more efficient lighting, electric vehicles, improved freight logistics, and solid waste management.

In addition to economic benefits, compact, connected and clean cities could provide a higher standard of living and greater opportunity for all. These measures would also reduce air pollution, cut chronic traffic congestion, and improve worker productivity.

The report offers case studies from around the world where national and local governments have worked together to rapidly and profoundly transform their cities for the better within 20 or 30 years.

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The benefits of investing in zero-carbon cities

Photo, posted September 8, 2018, courtesy of Steffen Flor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Weather-Responsive Traffic Signals

April 17, 2019 By EarthWise Leave a Comment

We all spend time sitting at red lights – sometimes it seems like a whole lot of time. There is a fair amount of science applied in the design of traffic signals that at least has the aim of easing congestion and improving traffic safety.

Signals in modern cities are timed using optimization models that analyze multiple factors including traffic volume and speed with the goal of safely getting as many vehicles as possible through intersections. It sure doesn’t seem that way in many places, but that is the intent in any case.

But a real problem with these models is that they assume normal conditions including weather conditions. In places that experience real winter conditions, the assumptions of traffic models fail. If the road surface is covered with snow and ice and visibility is poor, variables like speed and stopping distances become very different.

Researchers at the University of Waterloo in Canada collected data from real-world intersections and ran computer simulations to determine the effects of adjusting traffic signal behavior in bad weather (as well as in the presence of other conditions such as accidents or construction.) They found that such adjustments could reduce traffic delays by as much as 20%.

Cities with computerized signal systems are already equipped to remotely and inexpensively adjust the timing of traffic lights. To gain the benefits of smarter signals, there would need to be video cameras and a certain amount of artificial intelligence software that would be able to automatically tweak the timing of lights in response to traffic changes caused by weather, accidents or construction.

It sounds like a great idea.

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