Transmission lines sag. The magnitude of the sag depends on several factors like the distance between the towers or poles, the weight of the conductor and temperature, both the ambient temperature and the heat of the line, which is the function of the load on the line. Sags should not be a problem, since there are defined formulas to calculate the sags as well as rules on required clearance to ground or vegetation. Nevertheless, losing transmission lines due to short circuits caused by tree-to-(power) line contact can be a major reason why blackouts cascade. If the system is already stressed, losing a line results in overloads on remaining lines. The overloaded lines heat up and sag more, maybe beyond emergency ratings or tree trimming has not been kept up, increasing the risk for tree-to-line contact and more lines will be lost. It happens fast, like a cascade, as was the case in the 1996 Western North America blackout, the 2003 Northeast blackout, the 2003 Italy blackout, and many other blackouts.
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In 2017 natural gas fired power plants generated 32 % of the electricity in the United States. Coal fired power plants delivered about 30 % of all power, while nuclear delivered about 20 %. Nearly 20 % came from renewable energy sources, out of which 47 % came from hydro power plants and about 37 % came from wind turbines.
Eight years earlier, 2009, when the shale-gas revolution had started to take off, coal was the number one source, 44 % of all electric generation. Natural gas represented 23 % of the generation and nuclear was at 20 %. Renewable generation, basically hydro and wind, produced 10.5 % of the electric power. (EIA data).
Natural gas has replaced coal as the primary source of power generation. Nuclear is basically unchanged at 20 %, while renewables with the growth of wind and solar generation, has doubled and represents about the same proportion of the power generation as nuclear.
In an industry that traditionally changes slow it is a big shift that has happened fast.
There are about 550,000 school buses in United States and Canada. Each day some 26 million children ride on school buses.
For long school buses have been the ideal candidate to go electric instead of being diesel. Eliminating the exposure of the exhaust from diesel engines would be a significant health benefit. In addition, from the electric grid perspective the battery storage in the school buses could be a valuable resource for balancing the system, thanks to school buses having defined schedules, idle during the middle of the day and parked during the summer.
In January 1972 the Val Verde (now Terrell) natural gas process plant started to capture carbon dioxide (CO2, or, short, “carbon”) and transport it in a pipeline to the Kelly Snyder oil field in West Texas. It was the first commercial use of CO2 for enhanced oil recovery (EOR). EOR had been slow in the making. The first patent for EOR was issued in 1952 and field test had been done in 1964, but in the last three decades EOR has become a well-established technology in the North American oil industry. Most of the CO2 comes from naturally occurring sources.
CO2 is the main anthropogenic (human induced) greenhouse gas (GHG), about 76 %. Consequently, it is the focus when addressing global warming.
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“Resilience and Stability of Ecological Systems” was a paper by the Canadian ecologist C.J. Hollings published in the Annual Review of Ecology and Systematics 1973. The concept of resilience was used to describe the persistence of natural systems in face of changes in the ecosystem. The paper has had a major impact within ecology and the concept of resilience has later been expanded to many other areas, including the electric grid.
The 2003 Northeast blackout and extreme weather events like hurricane Katrina (2005), superstorm Sandy (2012), polar vortex (2014), hurricanes Harvey, Irma and Maria (2017), as well as awareness of new risks, such as physical and cyber-attacks, etc., have contributed to the increased attention to the resilience of the electric grid and ways to strengthen it.
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When summing up 2017, it should be noticed, that it was the first year, when annual worldwide sales of EVs (electric vehicles, both battery only and plug-in hybrid electric vehicles) exceeded 1 million vehicles.
The exact numbers are not yet available, but it looks to be well over 1.1 million EVs. By far most of the EVs, about 580,000 were sold in China. 200,000 EVs were sold in United States, and about 305,000 were sold in Europe.
There is a military saying, when faced with a discrepancy between the map and the terrain, trust the terrain!
In a similar way, when faced with a discrepancy between what a company offers and what the customers want, trust the customers!
According to Utility Dive 71 of Fortune 100 companies and 215 of the Fortune 500 have now defined targets for clean energy or sustainable energy. Many of them seems very determined to achieve their targets.
What looked like a start of a U.S. nuclear renaissance in 2008, when the first new nuclear units to be built in 30 years were announced, now, 9 years later, looks like a renaissance on hold.
The supplier of the four units, Toshiba/Westinghouse is in bankruptcy. Two units at Summer, South Carolina, have ceased construction and the owner consortia, SCANA/South Carolina Electric & Gas (55%) and Santee Cooper (45%) has announced they are abandoning the project. The two units at Vogtle (Vogtle 3 and 4), Georgia, will continue to be built with the owner consortia Southern Co./Georgia Power (45.7%), Oglethorpe Power (30%), MEAG Power (22.7%) and Dalton Utilities (1.6%) taking over the completion. However, instead of the originally planned start of operations in 2016/17 at a cost of $14 B the start of operation has moved out to 2021/23 and at a cost estimated to reach $28-29 B.
In May 584 000 cars and 935 000 light duty vehicles were sold in the United States. Only 1.1 %, or 16,788 to be precise, of these vehicles were electric (EV) or plug-in electric (PEV)s. Not a big number, but in terms of battery storage the numbers get more significant.
For the month of May, the total amount of battery storage in the EVs and PEVs cars is 570 MWh. In comparison, according to GTM Research/ESA US Energy Storage Monitor, for all the first quarter this year 234 MWh of stationary “utility scale” electric storage was added and another 13 MWh of distributed storage was installed behind the electric meter.
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In the last 10 years USA has reduced the carbon dioxide (CO2) by 13 % to the lowest annual level since 1992. During the same time China has become the world’s largest CO2 emitter by far, 28.2% of the global CO2 emissions (2016).