Greta Thunberg Cannot Count
A young activist with good intentions, remarkably brings vast awareness to real problems, yet then promotes fantastically unachievable solutions.
Greta Thunberg is a well meaning teenager, who transformed herself into an international media darling by initially sitting on a cold granite step with a rugged scrap of cardboard, hand scrawled with the words meaning “school strike for climate.”
While she espouses the truth that carbon-dioxide (CO2) levels are growing alarmingly, she also embraces the fallacy that the simple solution is a world of windmills and solar panels. If she could only examine the mathematics, she would discover this is tremendously difficult.
This article is not about climate change and future predictions. Vast literature exists on the subject. What this is about is actualities, the existing engineering that mankind can unleash, and the costs and benefits thereof. They are both staggering. Whether the reader is an extreme climate-denier or extinction-believer, the numbers behind a future of wind turbines, solar photovoltaic (PV) modules, a.k.a. solar panels, and batteries, are simultaneously mandatory and impossible. That hopelessly conflicting outcome is why the subject is so difficult.
Damned if we Don’t, Damned if we Do.
The first actuality is that CO2 emissions from fossil fuels, apart from any predictions of future climate, are horribly changing the atmosphere. In only 150 years of industrialization we will double the average atmospheric CO2 level that was nearly the past million years. This alone should be cause for concern.
For 800,000 years, the atmosphere has steadily oscillated between 190 and 270 parts per million (ppm) CO2. It never broke that trend until the year 1900. Then it exploded with increasing speed, exceeding 300 ppm by about the year 1950, then above 350 ppm by 1990, and onto 400 ppm by 2020. At the present rate it will be 450 ppm by only 2040. This indisputable fact is what should be the focus, not predictions of various scenarios of fear and dread, of possible or probable effects. It is not a estimate based on disputable models. It is a exact, intrinsic calculation, from immutable equations of chemistry.
The U.S. on recent average, rounded to a simple single-digit, annually consumes 40 Quadrillion BTUs (Quads) of oil, 30 Quads of natural gas (NG, methane), and 10 Quads of coal. That is a total of 80% of U.S. energy consumption, with the other 20% being ½ nuclear and ½ renewables. The chemistry (in lbs. CO2 per MMBTU: 215 coal, 161 oil, and 117 methane) is inextricably about 5,400 million metric tons CO2 annually. Similarly, the global emissions are about 7-times as much, 36,000 million metric tons CO2 per year. Divided by the calculated mass of earths atmosphere, and even after half being absorbed by the oceans alone, the remaining CO2 is 2.5 ppm, the amount the CO2 level has been recently growing by.
The second actuality is the waste of energy when fossil fuels are converted to heat. To generate electricity, and to push vehicles forward for transportation, virtually 2/3rds of the energy burned is unused waste heat, lost to the atmosphere by cooling towers and vehicle radiators. 25% of U.S. energy is lost in electric generation, 20% is lost by motor vehicles, and another 5% is lost up the chimneys of commercial and residential buildings. The total is 50% of the massive amount of U.S. energy, where we get nothing for its consumption. In a fully electrified future, no matter when it is achieved by, most of that waste would disappear. An electrified future would require only ½ the existing energy production.
The third actuality is that wind turbines, while growing so large as to almost become science-fiction objects, take up vast amounts of space by either land or sea. No matter the size, they still deploy at the same impact area, or capacity (power) density. A 15 MW turbine takes the exact same area as ten 1.5 MW turbines. Bigger only means more efficient installation costs.
And the U.S. area required just for converting half the existing electric generation to wind is 10% of U.S. land, the complete area of California, Oregon, and Washington. Or as author Robert Bryce eloquently puts it, “two Californias.”
The fourth actuality is that the hype around the “reasonable” quantity of PV panels needed is all based on annual average output of 20-25% (a number identified as the Capacity Factor, CF) after storms, clouds, and darkness. Unfortunately for PV proponents, there are two numbers rarely disclosed that must be accounted for, the winter-low CF, and the different electrified winter heating vs summer cooling energy load. Combined, a huge amount of PV is required vs comparatively little oil or gas.
Even in the South, from Los Angeles, to Phoenix, Dallas, and Atlanta, on January 1st there is over 14 hours of darkness, making for a 13-16% CF, requiring twice as much PV as the annual average.
Residential energy is measured in Degree-Days, a number as simple as it sounds, multiplying the indoor-outdoor temperature difference by days. The U.S. EIA puts the average household air-conditioning at 1,500 degree-days. The average heating though is 4,500 degree-days.
Combining the two, heating homes with electric heat-pumps instead of gas or oil is awful for PV. When winter’s PV supply is the lowest, half of spring/fall average, demand is the highest, tripled, requiring six times the PV. The shear enormity of PV panels required, 15 Billion just for existing generation, 27 Billion for full electrification, becomes a materials and installation problem instead of an emissions problem.
The fifth actuality is that it doesn’t matter there is tremendous excess summer PV generation, as no economical method of storing energy between seasons exists. Batteries have proven their technical worth storing energy and connecting to the grid. Economically though, they are only worthwhile for a short four hours. An electrified U.S. powered on calm windless nights with batteries would need 5 Trillion batteries. There are only 2 Trillion galaxies in the universe. That’s 5,000 Billion batteries and there are only 400 Billion stars in our Milky-Way galaxy. Even attempting to build that will take 25 Giga-Factories a century to produce. And that’s just for the U.S. The rest of the world uses 5-times as much.
The sixth actuality is that batteries themselves become a precious resource, and therefore must be relegated to use in their most necessary application, that of transportation, not the grid electricity supply. Therefore an alternative means of grid storage is necessary. Pumped Storage Hydroelectric (PSH) has proven itself the world over, and economical for 12-14 hours, unlike batteries. But how to build it everywhere, even where geography simply doesn’t exist, such as Florida?
Another worldwide proven technology uses Tunnel Boring Machines (TBMs) to excavate stormwater overflow tunnels. Building them bigger and deeper proportionally increases the stored potential energy. Tesla might be building large energy storage systems with 200 to 500 of their Megapack(tm) batteries, but the biggest battery in the world is a PSH facility in Bath County, Virginia, is as big as 10,000 Megapacks.
The seventh actuality is the completely unaffordable Capital Expenditure (CapEx) per household.
The U.S. grid is a 1,100 GW miracle. Dividing that 1,100,000,000 kW by 130,000,000 households is a mere 8.5 kW per household. An 8,500 Watt portable generator the size of a wheelbarrow is only $3,000 at a big-box hardware store. True, fuel to the tune of $8,000 per year is sold separately. (Per capita, a pair of $500 1,600 Watt inverter generators the size of a backpack, and $3,000 of fuel.)
By comparison a renewable system for an electrified future will need, per household: over 200 PV panels the size of an 85” jumbo television; the equivalent of a 100’ tall, 40’ diameter, 25kW wind turbine; and almost 40,000 battery cells, at a CapEx of $215,000 per household, ($85,000 per capita.)
Furthermore, this is only for the electric supply. Additionally $80,000 or more for electric vehicles is required household spending, as is a new heating system with heat-pumps, insulation, and air-barriers. Infrastructure improvements to transmission and distribution lines are not included yet, and charging stations are extra. At this point the capital expense per household is $350,000 ($135,000 per capita.) Who is lending the U.S. 50 Trillion dollars , 2 full years GDP, to build this?
Can Greta’s parents easily afford this, giving her a false belief everyone can? Does she not realize Sweden gets 45% of its power from cheap hydroelectric and 30% from nuclear (U.S. <10% hydro., 20% nuclear.) Does she believe those that can’t afford it must go without heat, and without transportation?
Without government subsidies this is wholly unaffordable to both young families and retirees, and would break all but the top 5% of middle-class workers. Worse, 25 years just to breakeven, before interest is even accounted for, is a poor return on investment (ROI), that further exemplifies why houses do not go ‘off-grid.’ And then, instead of earning any positive return, the system is worn out and in need of entire replacement after 25 years. Coal, gas, and nuclear generators have a far, far longer service life.
The eighth actuality is U.S. emissions are about 15% of world emissions. Climate czar John Kerry has admitted reducing U.S. emissions to zero wouldn’t make much of a difference in the global climate fight, “not when almost 90% of the planet’s global emissions come from outside U.S. borders.”
China, India, Brazil, South Africa, and Nigeria are determined to get their large and/or growing populations out of poverty as inexpensively as possible. As shown above, this is not with renewables.
It All Adds Up
Combined, these actualities show that PV and wind turbines can, and do, supply a variable-generation energy load at low prices, and as such should be massively deployed to the extent necessary.
Yet conversion to completely replace existing electric generation, requires 5-times the renewable generation (at 20% average wind and winter PV combined CF), with 4-times the energy storage, a combined 9-times the infrastructure it replaces. Simply put, to replace 1 GW of fossil fuel with 1 GW of renewables is cost effective but requires 1 GW backup generation with fossil fuel, deferring the emissions to when the sun isn’t shining and the wind isn’t blowing. However to completely replace existing fossil fuel and nuclear generation, the required total 9 GW of renewables+storage is dreadfully capital intensive.
And full electrification of transportation and domestic heat will then require 9 GW of renewable generation plus 7 GW of storage, a total infrastructure 16-times what U.S. electricity is now.
Just as conflicting as the simultaneous necessity and impossibility of a conversion to renewables is, are the difficult choices going forward, which will be examined next.
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Megapack is a trademark of Tesla, inc.
Hector E. Joules is the pen-name of a writer with a B.S. degree in Mechanical Engineering from Rensselaer Polytechnic Institute. A report, “Counting (Not) On Renewables: A Million Wind Turbines, Billions of Solar Panels, and Trillions upon Trillions of Batteries©” is forthcoming.