electricity

Trouble On The Colorado

April 4, 2019 By EarthWise Leave a Comment

The 1450-mile-long Colorado River begins in the Rocky Mountains and wends its way to the Gulf of California, creating the Grand Canyon along the way, and providing water to some 40 million people. The amount of Colorado River water promised to users is far more than actually flows between its banks, and that amount is dropping.

An unrelenting drought since 2000 has resulted in the water levels of the two largest reservoirs of Colorado River water – Lake Mead and Lake Powell – being at all-time lows.

Lake Mead, just outside of Las Vegas, is the reservoir of Hoover Dam, which provides power for millions of people in Southern California, Nevada, and Arizona. The last time Lake Mead was full was in 1983. It has slowly declined and now is 40% full.

If the lake level drops another 7 feet to 1075 feet above sea level, it will trigger a Tier 1 declaration, mandating cuts to water allocations to Arizona and other states. If the level drops to 1050 feet, it would reach Tier 2 at which point Hoover Dam would have to stop generating electricity because water levels would be too low to flow through it. If the lake level drops all the way to 895 feet, it would be below the level at which water can be piped out of it. This is known as the “dead pool”.

These scenarios are no longer doomsday fantasies. Water managers in the Southwest see the writing on the wall and are busy making contingency plans and developing ways to use less water from the Colorado River. The booming city of Phoenix in particular is hard at work finding alternative ways to provide water for its millions of citizens. On the Colorado, drought in the new normal.

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On the Water-Starved Colorado River, Drought Is the New Normal

Photo, posted October 24, 2016, courtesy of Sharon Mollerus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Changing Face of Electricity

March 15, 2019 By EarthWise Leave a Comment

The New York Times recently published an article on how electricity is made in the United States on a state-by-state basis and how it has been changing over the past two decades. Two conclusions to draw are that the mix of energy sources is wildly different from one state to another and that the mix has been changing rather dramatically in many places.

Overall, the past two decades have seen the dramatic rise in the use of natural gas and a dramatic drop in the use of coal. Coal plants used to account for over half of the electricity produced in the U.S. at the turn of the 21st century. Now natural gas has passed coal as the largest energy source at roughly 1/3 of the total generated.

Switching from coal to natural gas is a good thing since modern gas power plants emit only about half the carbon dioxide as modern coal plants. But industry spin about “clean gas” is just spin. Gas is not really clean; it is just cleaner than coal. So, having the electric grid powered by gas is not really going to solve our emissions problems.

That being said, there are still states that make nearly all their electricity with coal. Indiana, Kentucky, Missouri, Utah, Wyoming, and West Virginia are on that list. Meanwhile, Delaware, Massachusetts, Mississippi, Nevada, and Rhode Island are powered mostly by gas. Idaho, Oregon, Washington, and Vermont rely heavily on hydropower.

Newer renewables like solar and wind are starting to make major contributions in many states. Wind contributes only 6% nationwide but is much bigger in places like Iowa, Kansas, Minnesota, the Dakotas, Oklahoma and Texas.

The face of electricity continues to change.

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How Does Your State Make Electricity?

Photo, posted March 5, 2010, courtesy of Tennessee Valley Authority via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Renewables Taking Over In Britain

March 14, 2019 By EarthWise Leave a Comment

A year-and-a-half ago, we reported on the steep decline in the use of coal in Britain, including the conversion of the giant Drax Power Station from burning coal to running on wood chips. Since then, Britain has been steadily moving away from fossil fuels and towards renewable energy sources. The transformation is being driven by a surge in offshore wind farms currently under construction or about to begin operating. Britain is in the process of adding over 6 GW of offshore wind to its current total of 8 GW. Renewables generated one-third of the UK’s electricity last year, and half of that came from wind power.

In 2018, coal- and gas-fired power stations generated about 131 terawatt-hours of electricity in Britain. Renewable energy plants – including wind, solar, biomass, and hydropower – produced about 96 terawatt-hours. Based on the new projects coming online, renewable sources could generate 121 TWh by 2020 and fossil fuel plants are likely to fall to 105.6 TWh as more coal plants are retired. Thus, within the next year or so, renewables in Britain are likely to surpass fossil fuels in electricity generation.

The transformation in Britain has been rapid and dramatic. In 1974, the country generated 80% of its electricity using coal. By 2016, that number had dropped to 9%. Last April, the British power grid went three days in a row without burning any coal. The UK is expected to shut down its remaining coal plants by 2025, if not sooner.

At the same time, Britain’s renewable energy capacity has more than quadrupled since 2010, jumping from 21 TWh that year to 96 TWh last year. Britain’s energy mix is changing fast and getting significantly cleaner every year.

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Renewables Could Surpass Fossil Fuels in Britain by 2020

Photo, posted August 2, 2008, courtesy of Richard Allaway via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Renewables Without Storage In Texas

February 27, 2019 By EarthWise Leave a Comment

Texas has a Texas-sized appetite for electricity and relies most heavily on natural gas, coal and nuclear power to get it. But in recent times, wind power has grown tremendously in the Lone Star State and it has already leapfrogged past nuclear power. Coal could be the next domino to fall.

In the past few years, solar power has become competitive with wind in terms of price. Texas is a large, coastal state in the sunny southwestern U.S. and has significant solar resources. As a result, the amount of solar power in Texas is now growing rapidly.

In order for a combination of solar and wind power to address the bulk of electricity demand in Texas, there needs to be a way to provide reliability that these intermittent sources don’t necessarily provide. Energy storage is a solution that ultimately is likely to be part of most electricity grids, but currently it is still expensive on a utility scale.

A new study from Rice University looked at the complementarity of solar and wind power in Texas. Complementarity refers to balancing the output of solar and wind systems. The peak performance of wind and solar occurs at very different times in different regions of the state. The study suggests that the right mix of solar and wind systems in the right parts of Texas could provide a continuously reliable energy system. On both a yearly and daily basis, wind and solar power resources in Texas complement each other in terms of peak performance. It is a matter of locating the solar power and wind farms in the right places.

With the Texas solar industry really starting to boom, there is a real opportunity to integrate far more renewable energy into the Texas grid.

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More Renewables with Less Energy Storage: Texas Shows How

Photo, posted June 8, 2018, courtesy of Laura Lee Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Liquid Fuel From The Sun

February 21, 2019 By EarthWise Leave a Comment

Most forms of energy we use ultimately come from the sun in one way or another. Even fossil fuels are the end product of millions of years of plant life that captured solar energy. The advantage fossil fuels have over direct solar power is that they are, in fact, fuels and therefore can be stored for use when needed.

Scientists in Sweden have now developed a specialized fluid that absorbs some of the sun’s energy, holds it for months or even years, and then releases it when needed. This solar thermal fuel is like a rechargeable battery for heat rather than electricity.

The special fluid is pumped through transparent tubes where ultraviolet light from the sun excites its molecules into an energized state. A compound called norbornadiene is converted into quadricyclane. The quadricyclane is a quite stable substance until it is passed over a cobalt-based catalyst, which causes it to turn back into norbornadiene and release copious amounts of heat.

Such a solar thermal fuel could be stored in uninsulated tanks in homes or factories or piped or trucked to where it was needed. It could then be used for water heaters, dishwashers, or clothes driers. The room temperature fluid quickly warms to about 183 degrees when passed over the catalyst, plenty warm enough for heating a home or office. Both the fuel and the catalyst are damaged very little by the reactions, so the process can be recycled many times.

There is much development work needed to optimize shelf life, energy density, good recyclability and other properties before this technology can be commercialized but there are at least 15 groups around the world now studying this intriguing way to get liquid fuel from the sun.

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Scientists transform sunlight into a liquid fuel that can be stored for 18 years

Photo, posted August 17, 2009, courtesy of Hiromichi Torihara via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Electric Cars In Norway

February 18, 2019 By EarthWise Leave a Comment

Norway has long been a world leader in sales of electric vehicles. The country only has 5.3 million people, so the absolute numbers cannot compete with those of large countries. Despite that, it wasn’t until the first quarter of last year that Germany became the leader in number of electric cars sold in Europe and Germany has 15 times the population of Norway.

In percentage terms, almost one-third of all new cars sold in Norway last year ran on batteries. The country offers generous subsidies for buyers who opt to go electric. The government has set a goal of having all new cars be emission-free by 2025. Last year, three of the top five most popular new car models were electric: the Nissan Leaf, the BMW i3, and the Tesla Model X.

Tesla’s Model 3, which has shattered all records for electric car sales in the United States, has yet to go on sale in Norway. When the car becomes available there in the next few months, it is expected to generate very high sales figures.

The 31% market share for electric cars in Norway far exceeds that of most other countries. In the United States, for example, plug-in cars account for only about 2% of new car sales. Only Hong Kong and Iceland are also currently above 5% electric.

Norway’s role in all of this is rather convoluted. The country has copious hydroelectric power resources that provide virtually all of its electricity. Thus, electric cars in Norway are truly clean, green vehicles. On the other hand, Norway is the 15th largest producer of oil in the world and gets about 17% of its GDP from oil exports. Tackling climate change must ultimately deal with the emissions Norway continues to export.

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Photo, posted October 3, 2018, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bigger Is Better For Wind Energy

February 13, 2019 By EarthWise Leave a Comment

Bigger is almost always better for wind power. Bigger wind farms are better than smaller wind farms and bigger wind turbines are better than smaller ones.

The biggest turbines currently available produce nearly 10 MW of power, which is enough to supply over 2,000 homes with electricity. A wind farm with just a few of these turbines could produce enough electricity for a small town. A big wind farm, like the giant 1,550 MW Alta Wind Energy Center in California can generate enough power for a small city.

Vestas Wind Systems, an industry leader based in Denmark, has announced a 10 MW turbine that will be ready for installation in two years. The rotor diameter of the giant machine is 538 feet and the blades sweep out an area of 227,000 square feet, the size of nearly 4 football fields.

Not to be outdone, General Electric is developing a 12 MW offshore wind turbine that will stand 850 feet tall and sweep out an area of more than 400,000 square feet. GE estimates that its 12 MW turbine will achieve nearly twice the capacity factor of its 6 MW turbine.

Companies are building bigger and bigger wind turbines because they are more cost effective. The capacity factor, which is the actual energy production divided by the potential energy production, goes up as the turbines get bigger and more efficient. In terms of dollars spent to produce a given amount of power, larger windfarms are less expensive to build than smaller ones. A wind farm of 200-500 MW capacity is about 40% cheaper per MW capacity than a 25 MW wind farm.

When it comes to wind energy, there is no doubt that bigger is better.

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Wind Energy — Where Bigger Is Better

Photo, posted February 14, 2012, courtesy of Aaron Warner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Misconceptions About Electric Cars

February 8, 2019 By EarthWise Leave a Comment

Tesla’s Model 3 was one of the best-selling cars in the United States last year, eclipsing all but a handful of sedans. This was the first time that an electric car had that honor and is indicative of how electric cars are finally becoming mainstream. A host of other new electric models from multiple manufacturers will be the entering the market over the next couple of years.

Despite all of this progress, there is still a great deal of misinformation about electric cars. A new study commissioned by Volkswagen revealed some of the widespread misconceptions about the vehicles.

Some people believe that electric cars can’t be driven through puddles. Nearly one in five people believe that electric cars slow down as the battery depletes. Many people believe that electric cars are fundamentally less safe than gas-powered cars.

More generally, people are unaware of how far current electric cars can drive on a charge. More and more models can go 200 and even over 300 miles between charging sessions. People also don’t know how quickly cars can charge up either. Fast chargers like Tesla’s Superchargers can add 200 miles worth of charge in about 20 minutes. And people don’t know what it costs to charge electric cars. In most places, it is only a fraction of what it costs to drive the same distance using gasoline.

Despite their limited knowledge about electric cars, the 2,000 people surveyed in Britain were positively disposed towards them with nearly 6 in 10 saying that they would like to own an electric car some day and would even consider one as their next vehicle.

Electric cars will become more familiar and less exotic as more and more of them are on our roads and highways.

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Major misconceptions prevent drivers from buying electric cars, study claims

Photo, posted April 6, 2018, courtesy of Brian Doyle via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

https://www.independent.co.uk/news/uk/home-news/electric-cars-misconceptions-battery-charging-safety-volkswagen-study-results-a8700536.html

Droughts And Hydropower

February 7, 2019 By EarthWise Leave a Comment

Recent droughts in several western states have led to well-publicized problems including wildfires, loss of trees, and damage to crops. A lesser-known impact of drought conditions has been increases in emissions of carbon dioxide and harmful air pollutants from power generation.

When hydropower runs low in a drought, western states tend to ramp up power generation – and therefore emissions – from fossil fuels. According to a new study from Stanford University, droughts caused about 10 percent of the average annual carbon dioxide emissions from power generation in California, Idaho, Oregon and Washington between 2001 and 2015.

Water is used in electricity generation both directly for hydroelectric power and indirectly for cooling in thermoelectric power plants. When water for hydropower comes up short because of drought conditions, natural gas or coal-fired power plants are brought online to pick up the slack.

These drought-induced shifts in energy sources led to an estimated 100 million tons of carbon dioxide across 11 western states between 2001 and 2015. That is the equivalent of adding 1.4 million vehicles to the region’s roadways. California, whose legislature has mandated that the state be carbon-free by 2045, contributed about half of this total. Washington, which is considering a similar mandate, contributed nearly a quarter of the total.

Western states in recent years have suffered intense droughts that scientists expect to become more common as global warming continues to intensify. The new study indicates that in regions where clean, reliable hydropower has been an important part of the energy mix, it will be increasingly necessary to provide clean backup energy sources in order to meet emission reduction targets.

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Droughts boost emissions as hydropower dries up

Photo, posted March 7, 2016, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Wildfire Pollution

January 24, 2019 By EarthWise Leave a Comment

California’s record-breaking wildfires this past season have been an unmitigated disaster with respect to loss of life, property, impact on human health, and in multiple other ways. And as if all of that was not bad enough, the impact on carbon emissions into the atmosphere was equally catastrophic. The wildfires were deadly and cost billions of dollars but were also terrible for the environment and for the public’s health.

According to estimates from the U.S. Department of the Interior, the California wildfires released emissions equivalent to about 68 million tons of carbon dioxide into the atmosphere. That is equal to the emissions from generating one year’s worth of electricity in the state, or about 15% of the total annual emissions in the state of California.

It is a vicious circle in which the changes to the climate that have lengthened the fire season and shortened the precipitation season are creating additional contributions to the warming of the climate.

Over the past century, California has warmed by about 3 degrees Fahrenheit. That extra-warmed air sucks water out of plants and soils, resulting in trees, shrubs, and rolling grasslands that are dry and primed to burn. That vegetation-drying effect compounds with every additional degree of warming. Plants lose their water more efficiently as temperatures get higher.

The result is that wildfires are increasing in size both in California and across the western United States. Fire experts at Columbia University estimate that since the 1980s, the warming climate has contributed to an extra 10 million acres of burning in western forests – an area about the size of Massachusetts and Connecticut combined.

It’s a bad situation that is getting worse.

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California’s 2018 Wildfires Have Emitted A Year’s Worth of Power Pollution

Photo, posted October 11, 2017, courtesy of Bob Dass via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Smog And Solar Power

January 22, 2019 By EarthWise Leave a Comment

China has been struggling with some of the worst air pollution in the world. Beijing frequently sits under a brown blanket made of exhaust gases from industry, cars and coal fires, which dump harmful particulate matter, soot, sulfur dioxide and nitrogen oxides into the air.

The human health consequences are severe. According to the World Health Organization,air pollution contributes to about 1.6 million premature deaths in China each year. World-wide, air pollution is implicated in over 7 million deaths annually.

Faced with this air pollution crisis, China has undertaken a wide variety of measures to improve its air and curb carbon dioxide emissions alongthe way. Among other things, China has invested heavily in the deployment of solar power and has plans for ever greater expansion of solar power in the future.

A study by researchers at ETH in Zurich looked at the impact of China’s air pollution on the production of solar energy. The smog in China’s cities reduces the amount of solar radiation that reaches the ground and therefore significantly reduces the power output of solar energy systems. According to the study, solar radiation would increase by an average of 11% nationwide as a result of strict air pollution control measures. In some places, cleaning up the air would result in 26% more energy production.

China’s electric power industry is the world’s largest electricity producer, having passed the United States in 2011. Two-thirds of the electricity in China still comes from coal, which, apart from the serious climate and health consequences associated with its use, continues to make it more difficult to switch to clean solar power. Much work remains to be done.

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Fighting smog supports solar power

Photo, posted February 7, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Remove Enough CO2 From The Air?

January 9, 2019 By EarthWise Leave a Comment

As atmospheric carbon dioxide levels continue to set new records and the effects of climate change grow stronger, humanity has continued to procrastinate on reducing emissions. As a result, it is increasingly clear that any strategy to avoid runaway climate change will have to involve the use of “negative emissions”- techniques or technologies that actually remove CO2 from the air.

There are both low-tech and high-tech methods for removing carbon dioxide from the atmosphere and both are likely to be needed.

On the low-tech side, afforestation (planting trees where there were none before), reforestation, changes in forest management, rebuilding the carbon backbone in agricultural soils, and the use of energy from waste biomass are all ways to take carbon out of the atmosphere.

On the high-tech side, direct air capture technologies that take CO2 out of the air and store it in the ground are making rapid progress. Right now, they are still very expensive,but that is changing. There is an analogy to wind and solar technology. Not very long ago, both of those technologies were quite expensive but now their costs have plummeted to the point where they are often the cheapest way to make electricity. With sufficient development effort and deployment, direct air capture technology could become quite affordable.

Some people advocate geoengineering as a solution for climate change. While removing carbon dioxide amounts to tackling the root cause of the warming climate,geoengineering would address the problem by changing the climate again in some other way. It is at best an extremely dangerous approach.

Removing CO2 using a combination of natural and man-made techniques is an important part of mitigating the effects of climate change.

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Climate Solutions: Is It Feasible to Remove Enough CO2 from the Air?

Photo courtesy of Climeworks.

Earth Wise is a production of WAMC Northeast Public Radio.

Big Success From A Big Battery

January 1, 2019 By EarthWise Leave a Comment

In the fall of 2017, Tesla took on the challenge of installing a 100-megawatt battery storage system in South Australia in under 100 days, promising that the system would be free if it was not built in time. The project was actually completed in 54 days.

The system is located at the Hornsdale Wind Farm, which consists of 99 wind turbines with a generation capacity of 315 MW. The Hornsdale Power Reserve installation is the world’s largest lithium-ion battery system and, after a year of operation,has proven to be a smashing success. Estimates are that the project has reduced costs associated with stabilizing the energy grid by about $29 million. The cost of the system was about $87 million, so it is paying for itself quite rapidly. The wind farm and battery systems are owned and operated by a French renewable energy company.

The battery storage system provides a variety of different services to the electric grid. The primary motivation for it was to achieve system security and reduce the risk of blackouts and load shedding. Having the battery system in place protects the regional interconnection from tripping,which reduces the risk of separation of South Australia from the National Electricity market. The system also provides so-called ancillary services such as frequency control and other forms of electricity supply regulation.

The most significant contribution of the Hornsdale Power Reserve is that it has raised the profile of energy storage technology and demonstrated its unique capabilities. Based on the success of the system, there are now about 2,500 MWh of new storage projects announced by the public and private sectors in Australia.

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