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Cleaning the grid can create messes

January 9, 2024 By EarthWise Leave a Comment

The electric grid is increasingly embracing renewable energy sources like solar and wind power as well as the energy storage systems that support them. These generation sources differ from traditional sources in that they produce direct current electricity rather than alternating current electricity. Our power grid runs on alternating current. Traditional generators produce alternating current that synchronizes with the grid. Wind and solar power connect to the grid using electronic power converters called inverters that produce the required alternating current.

All of this technical detail is something we don’t pay much attention to, except that the current state of inverter technology can lead to some problems that don’t exist with a fully synchronous power system.

The electric grid frequently experiences disruptive events like trees falling on powerlines, squirrels shorting out substation equipment, and so on. These things normally don’t cause widespread trouble, although there have been notable exceptions such as the massive Northeast blackout of 2003 triggered by an overloaded transmission line drooping onto foliage.

The issue with inverters is that they can shut down in the presence of certain disturbances to the grid. This has happened on a number of occasions and has exposed vulnerabilities that need to be addressed by the industry. Inverter-based resources currently constitute only a relatively small fraction of the grid, but that fraction is growing steadily and can have an increasingly widespread impact. The grid was built predominantly for synchronous generation, and it must be adapted and improved to assure the reliability that is required and expected. It is an issue that can’t be ignored.

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Renewables are cleaning the grid. They’re also messing it up

Photo, posted July 5, 2017, courtesy of Sue Thompson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Saving Energy At Data Centers | Earth Wise

February 17, 2020 By EarthWise Leave a Comment

A data center is a building, dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and data storage systems. Data centers are the backbone of internet services and cloud computing, which together are increasingly dominant elements of modern life.

Energy use is a central issue for data centers. Power used by them ranges from a few kilowatts for a rack of servers in a closet at a local business to several tens of megawatts for large facilities. Some data centers have power densities more than 100 times that of a typical office building and use as much electricity as several thousand homes. For such facilities, electricity costs are a dominant operating expense and account for over 10% of the total cost of ownership of a data center.These centers, with their numerous racks of computer servers, consume 90 billion kilowatt-hours of electricity each year in the United States, as much as all of our residences use for lighting.

A research group at Princeton University is developing a family of devices that can dramatically reduce power consumption at data centers. The team’s technology focuses on the process by which the AC power from the grid is converted to the low-voltage direct current used by computer equipment. With existing technology, this power conversion takes place in each individual computer, which ends up wasting about 40% of the original energy. The new device aggregates power conversion into a single unit, which then distributes the power to the individual computers and storage units.

As data centers get bigger and more numerous, the opportunity to save a lot of energy becomes increasingly important.

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New technology boosts energy eﬃciency in data centers

Photo, posted June 8, 2007, courtesy of Sean Ellis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Breathe Better With Air Conditioning

September 15, 2017 By EarthWise

For many people, commuting to and from work is a time-consuming, stressful part of their lives. In fact, the average American spends nearly an hour a day facing traffic jams and congested highways. There are direct health hazards in commuting as well. Drivers are exposed to increased amounts of air pollutants that have been linked to a wide range of medical problems including cardiovascular disease, respiratory issues and even lung cancer.

The Perils Of Air Conditioning

September 12, 2017 By EarthWise

The battle to reduce greenhouse gas emissions is heavily focused on replacing fossil fuel power plants with renewable energy and replacing internal combustion engine autos with electric cars. But there is another elephant in the room: air conditioners.