Friday, April 12, 2024

Is The U.S. Power Grid Truly Unsustainable Without Fossil Fuels, Nuclear Energy?

                                                                                 






The March 29 WSJ editorial (The Coming Electricity Crisis) made a bold claim, specifically that the combination of A.I. and climate rules are pushing the U.S. power grid to "the breaking point."  The Journal's Pooh-Bahs quoted former Obama Energy Secretary Ernest Moniz to the effect: 

"We're not going to build 100 gigawatts of new renewables in a few years."  

In other words, utilities will have to rely more on coal, gas and nuclear plants to even get us to 2030.  Failing that look for massive blackouts and power grid snafus - and that's assuming there are no violent 'extracurricular' events from the Sun as it ramps toward sunspot maximum.

There are, in the lower 48, three major interconnected systems that comprise the power grid — one covering everything east of the Rocky Mountains (the Eastern Interconnection), one for everything west of the Rocky Mountains (the   Western Interconnection), and  one for Texas- governed by ERCOT.   The power system that serves 95 percent of the state is intentionally isolated from the rest of the country.   This has been deliberate given a severely deregulated energy system is incongruent with regulated ones.  In this case Texas features a competitive wholesale power market but which offers scant incentives for investment in backup power. 

Given this background, how accurate is the WSJ editorial claim?  In fact, it is more spot on than many on the left may wish to acknowledge. As long ago as 2012, , Matt Savinar (Life After the Oil Crash) showed that NONE of the renewable sources usually cited: from wind to geothermal to solar will do squat to totally replace the energy now being consumed for our entire infrastructure, from powering a military-industrial complex with umpteen bombers, and now missile defense, plus more tanks for occupations and wars, not to mention sustaining growth in industries (e.g. aircraft and car manufacture), new computers, maintaining the electrical power grid.  And that was way before bit coin mining which consumes gigawatts each year.   (And the WSJ editors inform us:  "About 20 gW of fossil fuel power are due to be retired over the next two years.")

For reference, current yearly U.S. energy consumption is roughly 97 EJ. To put the numbers in a harsher perspective, any serious major effort to "decarbonize" the planet will require an amount of clean energy on the order of 100 trillion kilowatt-hours per year  or 360 EJ. To reach this target even within 3 decades the world's nations would need to add 3.3 trillion more kwh of clean energy every year. Solar and wind simply cannot scale up to that level in that time, so the only remaining form of energy - apart from fossil fuels - is nuclear and at least one climate scientist (James Hansen)  has recommended such incorporation . 

As Jay Hanson (www.dieoff.org) has pointedly noted:

“The fact that our society can‘t survive on alternative energy should come as no surprise, because only an idiot would believe that windmills and solar panels can run bulldozers, elevators, steel mills, glass factories, electric heat, air conditioning, aircraft, automobiles, etc., AND still have enough energy left over to support a corrupt political system, armies, etc. Envision a world where freezing, starving people burn everything combustible -- everything from forests (releasing CO2; destroying topsoil and species); to garbage dumps (releasing dioxins, PCBs, and heavy metals); to people (by waging nuclear, biological, chemical, and conventional war); and you have seen the future. “

But how accurate is he? One needs to process that different kinds of energy resources have fundamentally different "qualities". For example, a BTU of oil (oil before it is burnt) is fundamentally different than a BTU of coal. Oil has a higher energy content per unit weight and burns at a higher temperature than coal; it is easier to transport, and can be used in internal combustion engines. A diesel locomotive wastes only one-fifth the energy of a coal-powered steam engine to pull the same train. Oil's many advantages provide 1.3 to 2.45 times more economic value per kilocalorie than coal.
This means you need that factor increase in coal to equal a similar amount of oil, to get the same work done.

Ditto with solar. Unlike energy derived from fossil fuels, energy derived from solar power is diffuse and also extremely intermittent: it varies constantly with weather or day/night. If a large city wants to derive a significant portion of its electricity from solar power, it must build fossil-fuel-fired or nuclear-powered electricity plants to provide backup for the times when solar energy is not available. Solar power has a capacity of about 20 percent. This means that if a utility wants to install 100 megawatts of solar power, they need to install 500 megawatts of solar panels. This makes solar power a prohibitively expensive and pragmatically poor replacement for the cheap and abundant fossil fuel energy our economy depends on, especially if one intends to use it operate missile factories.

Back to the grid, what are the key components and issues?

  The primary problem with the U.S. power grid is the lack of volt-amp-reactive (VAR) dynamic compensation elements. Instead, an array of conventional methods are employed to give a rough equivalence to true VAR-compensation. If instead of this approach, HTS dynamic synchronous condensers (see Fig. 1) were more generally used many advantages would accrue, including:

i) Large Q (imaginary) power output
ii) Rapid dynamic response
iii) Minimizing of switching transients
iv) Long term reliability from the stable operating temperature (of HTS coils)


To better grasp the HTS condenser’s remarkable abilities, a basic inductive physics set-up (often employed to teach physics students) is useful. We obtain a U-shaped magnet wrapped with n turns of conducting wire. Then the magnetic flux induced in the gap is proportional to nI (product of no. of turns n by the current I) and inversely proportional to the gap length, x. Thus:

Flux ~ n I/ x

Note as x is decreased, the flux gets larger. In like manner, the closely spaced iron teeth in rotor and armature of a conventional motor are closely spaced precisely to enhance the flux by minimizing the gaps. Logically then, a machine with HTS rotor coils and no iron teeth has much greater effective gap between the armature coils and magnetic components in the core.

This lowers the flux, but this is compensated for by the fact the high current density HTS wire is so fine that many more turns n are allowed. This enables any HTS device to generate a much greater flux than its conventional counterpart.

When d.c. HTS rotor coils spin they generate a time –varying flux that induces an rms excitation voltage  V exc   according to Faraday’s law such that: 
V exc    = - d(F)/dt

Where 'F' is the magnetic flux.

Meanwhile, the a.c. armature current  I a  induces a back emf ( V B) in the armature coils that is proportional to I a but out of phase with it. The proportionality constant is denoted as X S the synchronous reactance. Then:

V exc    =  X S I a   - V B

Now, the sum of the two voltages induced in the armature coil must equal the grid voltage: V G  so the out of phase reactive armature current coupled to the grid is given by:

I a    =  X S  (V exc     -   V G) 

Note what happens above if the grid voltage  drops below the level set by V exc  say to  V exc /10 or 0.01 (V exc).   Then the HTS synchronous condenser injects capacitative current into the grid. If the converse holds, and V G > V exc, the condenser injects inductive current. (Since recall the current lags behind the voltage). Most importantly, the magnitude of V exc can be adjusted in seconds by changing the HTS rotor coil current.

It is precisely the "hair-trigger" control over V exc  that allows a dynamic response to the VAR-compensation needs of the grid.

Thankfully, first generation HTS wire-based dynamic sychronous condensers have already been field tested by the TVA (Tennessee Vallee Authority), and additional orders have been placed. This is good, but such technological enhancements need to be made throughout the U.S. grid to bring us up to date, as electrical power needs ramp up. In addition, we simply cannot take nuclear power off the table prematurely.

In the meantime, lack of transmission capacity remains  a bugbear and one of the major obstacles to expanding clean energy in the U.S.  Replacing existing power lines with cable made from state-of-the -art materials could approximately double the capacity of the electric grid in many areas of the country, making room for much more wind and solar power.  

This technique is known as "advanced reconductoring" and is widely used in other nations, but many U.S. utilities have been slow to embrace it. This is because of unfamiliarity with the technology but also regulatory and bureaucratic hurdles.  

But the climate stakes are high.  In 2022 Congress approved hundreds of billions of dollars for solar panels, wind turbines, electric vehicles and other non-polluting technologies to tackle global warming (as part of the Inflation Reduction Act).  But if the U.S. can't add more transmission capacity more rapidly about half the emission reductions expected from that law may never materialize.

This will be especially important as global warming is exacerbated, with mean global temperatures` expected to increase by a further 3 degrees Celsius by 2100, which actually may be an underestimate.  See e.g.


See Also:


And:


at

No comments:

Post a Comment