embracing

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

Steel was first made thousands of years ago. The discovery that heating up iron ore in a hot enough charcoal fire could purify the iron into a strong and valuable material was the start of the Iron Age. In many ways, things have changed very little since then.

Global iron and steel production accounts for 7% of society’s carbon emissions. Making steel generally involves burning coal in a blast furnace to produce the very high temperatures required to turn iron into steel. The coal is used both as a feedstock and as a fuel. Steel is made from iron and a substance called coke, which is basically coal that has been carbonized at high temperatures. Coal itself is burned to provide the high temperatures needed.

A new analysis from the Global Energy Monitor think tank shows that the global steel industry is slowly embracing electric-arc furnaces to produce the necessary heat, which is a cleaner alternative. The analysis found that 43% of forthcoming steelmaking capacity will rely on electric-arc furnaces, up from 33% last year.

According to the study, the shift to cleaner steel is not happening fast enough. To meet the emissions reductions goals of the Paris Climate Agreement, electric-arc furnaces must account for 53% of global steelmaking capacity by 2050. Based on the current plans, those furnaces would only account for 32% of total capacity by that year.

In order to meet these goals, the steel industry will need to retire or cancel about 381 million tons of coal-based manufacturing capacity and add 670 million tons of electric-arc furnace capacity.

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Steel Industry Pivoting to Electric Furnaces, Analysis Shows

Photo, posted March 3, 2012, courtesy of Jeronimo Nisa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning the grid can create messes

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Electric Steel Furnaces | Earth Wise

Steel was first made thousands of years ago. The discovery that heating up iron ore in a hot enough charcoal fire could purify the iron into a strong and valuable material was the start of the Iron Age. In many ways, things have changed very little since then.

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