Dominion Energy’s recent announcement to make all school buses in Virginia electric by 2030 is most likely the step necessary to cross the chasm from diesel school buses to EV school buses. Crossing this chasm is a big deal considering there is about 550,000 school buses in United States and Canada.


More variable resources, wind and solar, will require more electric transmission. It will be needed to balance the variability over larger areas, and to bring remote generation like offshore wind to the load.

The main challenge to building more transmission lines is the difficulty to get necessary permits to build. Added to the challenges is that in the most electrically congested areas it tends to be the most difficult to take existing transmission lines out-of-service for any extended time.


September 17, 1964 President Lyndon Johnson addressed the Intertie Victory Breakfast in Portland, Oregon. It was the closure of more than a decade of multi-dimensional political controversies and challenges, and the start of probably the largest electric infrastructure project in the United States after the US Government built the Bonneville and Grand Coulee dams and power stations on the Columbia River in the 30s and 40s.

The Pacific Northwest/Pacific Intertie is the transmission lines that enabled hydro power from the Columbia River to flow to California. The Intertie consists of both HVAC (High Voltage Alternating Current) and HVDC (High Voltage Direct Current) lines, which after expansions now have a combined capacity of 7,900 MW.

Pacific Intertie. 500 kV HVAC transmission line to the left. ±400 kV HVDC transmission line to the right. Photo: michael1111.blogspot.com


….. and the 2018 EV winner is Tesla Model 3.



















All numbers are not yet reported, but all indications are that worldwide EV (both all electric and plug-in hybrid electric vehicles) sales in 2018 will be over 1,9 million. It is a 70 % growth over 2017. Impressive, but in relation to all 81 million cars sold in the world in 2018 the EVs represent about 2.4 %, which is up from 1.4 % in 2017.

China continues to be the leader with some 850,000 EVs (estimated based on the first 9 months) in 2018. EV sales in the U.S. will exceed 350,000 vehicles. It is an increase with almost 80 %. Europe saw a slower growth than the U.S., about 23 %, but still reached more EVs, an estimated 375,000 (based on the first 11 months).


Marcellus shale gas-drilling site in Pennsylvania.
Photo: Nicholas A. Tonelli.



















“Prediction is very difficult, especially if it is about the future.” Niels Bohr, the Nobel laurate in Physics, is credited with this line. It is always possible to develop a model that fits the past, but much more difficult to have the same model to correctly forecast the future.

Recent analysis by EIA (Energy Information Agency) and Lazard find that the lowest cost power generation is natural gas, wind and solar. It looks clear, going forward, what to invest in, but before doing so, there may be some lessons to be learnt from the past about making predictions.



Photo by Egor Kamelev from Pexels.

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.


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.


“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.