Photovoltaic for Australia

Tom Wayburn

Introduction

In the United States, which is the only country I know enough about to suggest policy, which is not to excuse jingoism of any stripe, the applicability of photovoltaic solar cells (PV) is limited by the total area suitable for PV divided by the number of people.  Australia has an area nearly as large as the area of the US and a much smaller population; therefore, enough area per person can be devoted to solar to satisfy the personal energy budget of every person, provided the political will can be found to overcome the huge energy debt that must be incurred before payback begins and, possibly, to accept a complete change in political economy to keep the EROI as high as 3.0, a number that might not include the costs of commerce.  This is explained in “Energy in a Mark II Economy”.

Coping with Peak Oil is like fighting a war – not like fighting insurgents in Iraq but like fighting World War II.  Therefore, drastic measures should be taken, including austerity, rationing strictly enforced, and public debt.  The results, after a long time should be unprecedented prosperity free of the environmental problems associated with fossil fuels.  If, in addition, political changes occur that return the Australian people to Earth as a Garden, as discussed in the copy of my wiki, a happy, sustainable future is expected.  I hope it is understood that the problems associated with the low EROI of PV would be experienced for any alternative energy technology with a low EROI; and, they all have low EROIs.  Thus, the conclusions of this study apply to almost any Peak Oil remediation method considered.

The reference to wartime measures should not be construed as an endorsement of the use of violence to resolve conflicts in living.  Nor do I wish to disparage the many fine people of the great nations of Germany, Japan, Italy, and Finland.  The reason I refer to war at all is that I was seven years old when the US entered World War II; and, I remember vividly the rationing, victory gardening, food canning, and other unusual, total, all-out efforts that the entire nation sustained for nearly four years.  I realize that I am asking Australia to adopt a policy of strict conservation, not for four years but several decades.  Finally, the political change I call for in “The Demise of Business as Usual” is too ambitious for Australia and out of the question for the United States; however, strict conservation measures must be adopted regardless of what else is done.

Dave Kimble’s Normalized Units

In the first two spreadsheet models we needn’t concern ourselves with energy units or with the actual energy requirements of the Australian economy.  The purpose of the following exercise is to determine if anything can be done to prevent the disqualifying deficit incurred by straight-forward exponential growth for solar cell production.  It occurred to me that a one-time subsidy of energy – or, more likely, completed solar cells produced elsewhere – would be sufficient to jumpstart new production facilities powered by the output of the existing cells.  The results are summarized in Table 1 below.

 

Table 1.  A comparison of Kimble’s Idea and Wayburn’s Idea (Problems 1a & 1b)

Clearly, the deep deficit incurred by Dave’s method out-produces Wayburn’s facility; but, we have not assigned an electrical quantity to the normalized units yet.  The results obtained in http://dematerialism.net/pv.xls are portrayed in Figures 1 – 4.

 

 

 

 

 

The virtues and defects of the two ideas are apparent from Table 1 and the four graphs, especially Figures 1 and 3.  These led to the experiments to be described next.  In particular, I wished to recapture some of the fast ramp-up of Kimble’s Idea without incurring the intolerable cumulative deficit.  From now on, I deal in specific energy units, which are explained in the next section.

Energy Units

 In http://dematerialism.net/pv.xls, the current energy budget for Australia is taken to be 5.14 quads, which corresponds to 5.14·10¹⁵ British Thermal Units (BTU) of thermal energy such as one would get by burning coal.  One assumes that it takes 2.98 joules of thermal energy to produce one joule of electricity.  (The joule is an absolute energy unit, whereas quads and kilowatt-hours reported may depend upon the technology under consideration.)  Normally, when one refers to quads per year as the rate of consumption of energy, the “per year” is suppressed; i. e., an energy budget of 5.14 quads means 5.14 quads per year.  Finally,

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In the rest of the paper I will omit the units on the 2.98 factor, and kWh is always electrical; therefore, we can write the above as 5.05 · 10¹¹ kWh, which means 5.05 · 10¹¹ kilowatt-hours/year (kWh/y).

Early Work on the First Spreadsheet

My friends will not be surprised if I admit that I have had a bit of a scare:  I could not find these computations anywhere.  Finally, I found my earlier efforts on  http://dematerialism.net/pv070711.xls where they can still be found.  Sheet 2 has a very nice drawing of energy flows in the US economy, all denoted in quads; Sheet 4 has Dave Kimble’s original computation; and Sheet 1 has most of my original work on this problem:

In Columns A – S, I took ER from the first year to be EI in the second year; but, so as to deliver something to the economy, I switched to about 9.25% growth in the third year.  Important events are noted in yellow cells.  Columns T – AI hold Kimble’s Idea converted to electrical units beginning with a subsidy of 5% of the Australian energy budget for 2003.  Columns AF –AR hold Wayburn’s Mistake converted to electrical units.  It’s easily fixed but to what purpose?  Sheet 3 is Wayburn’s Idea converted to electrical units except that in the 60^th year I switched to the moving average of the last N years with N = 1 in the 60^th year and increasing by 1 every year thereafter.  This brings the energy profit into a steady state equal to the 2003 energy budget in the 81^st year.  Crucial events are noted in yellow cells.  The charts are interesting but not important enough to describe in detail, as I will now move on to better things in Problem 2 of http://dematerialism.net/pv.xls.

Problems 2, 3, and 4

If the Australians will reduce their export of energy and their consumption of energy for tasks other than building photovoltaic cells by about 3.5% for one year, and if they will divert manufacturing assets to that task, an Apollo-like project for renewable, sustainable energy can commence by the year 2009.  This is a first-year subsidy of 1.752 · 10¹⁰ kWh that will be paid back by the year 2036.  I am assuming that solar cells have a lifetime of 24 years; but, with an EROI of only 3.0, require 8 years of electrical output or the equivalent in thermal energy to construct.  Part of this is energy interest on the capital costs of building or converting manufacturing facilities and the energy costs of running the economy – hopefully planned.  (See “Energy in a Mark II Economy”.)  With a subsidy of 1.752 · 10¹⁰ kWh, we can generate 0.219 · 10¹⁰ kWh in the first year provided only that suitable manufacturing facilities can be found.  The government will take care of the money.  It is important to note that the results of this study apply to any alternative energy project with an EROI of 3.0.

The number of new cells manufactured each year is to increase at the rate of about 9.4% per year.  To do this, it is necessary to continue the subsidies, that is, to run deficits, for eleven more years to make up the difference between the energy investment requirement mandated by the 9.4% increase and the energy generated by the cells that have already been produced, possibly off-site, and immediately deployed in suitably large areas surrounding each of the facilities to generate power for the manufacture of additional cells.  It is unlikely, especially at the beginning, that electricity generated on-site could support more than a small fraction of the operation’s energy needs.  After all, much of the energy invested will be energy embodied in the countless items that need to be accounted for in the energy investment term, not the least of which is the commuting costs of the employees.

More cells are in operation each year.  In this idealized model, they operate for 24 years and then fail.  Nevertheless, the number of cells in operation increases every year until 2056, after which it remains constant.  All of this depends upon the scheme that is employed to increase cell production by the moving average of the last N years, where, in 2057, N = 1 with N increasing by 1 every year thereafter.  The effect of this is to hold productivity constant without a transitional period of slower growth.

In 2054, the model delivers, after investment costs, 262.4 billion kWh, which exceeds Australia’s electricity budget; therefore, for every year thereafter, 262.4 billion kWh is subtracted from the energy delivered and the rest is converted to liquid fuels at a great disadvantage.  The factor of 2.98 kWh thermal/kWh electrical may not be used.  Moreover, the value of the electrical energy produced must be reduced by a factor of 3.0 to account for the inefficiencies inherent in any scheme to produce liquid fuel from electricity.  This is an example of a poor solution to the matching problem.  If I had not agreed to consider photovoltaic solar only, a better match could have been selected from a broader slate of renewable energy technologies.

Finally, in 2079, the 2003 energy budget in quads is recovered from the process.  Austerity is over!  I have assumed that Australia will have adopted a sustainable steady-state political economy in time to prevent the worst effects of Peak Oil; therefore, no further growth is built into the model.  The principal results are tabulated in Table 2 and Figures 5 and 6.

 

Table 2.  Three and a half percent of E budget in initial subsidy (Problem 2)

 

 

 

In Problem 3, an attempt was made to speed up the process by starting with a much larger subsidy.  I claim that even a very large subsidy is within the capability of a population that has been suitably indoctrinated into the manifold virtues of conservation.  We see that happening in the United States where parents dare not look like social pariahs to their own children.  The principal results are tabulated in Table 3 and Figures 7 and 8.

 

Table 3.  12.2% ramp-up rate (Problem 3)

 

 

 

 

Below, we see what can be done with a large subsidy and an exponential ramp-up rate close to 12.5%, the rate that holds the deficit constant until the first cells quit.  Or, if we insist upon a constant subsidy until we are ready to switch from exponential increase in energy invested to the moving average, we may adjust the value of the normalized unit to set the subsidy to only 9.6% of the total 2003 energy consumption.  As Dave Kimble has pointed out, even though the additional fossil fuel can be taken from exports, Australia would have to build refining and generating facilities to make use of it.  As I said, a 10% improvement in conservation measures across the board is not unreasonable nowadays.  The government could enact more stringent vehicular mileage requirements for example.

 

Table 4.  12.5% growth  and constant subsidy (Problem 4)C

 

 

 

Houston, Texas

June 29, 2007

Revised July 18, 2007

Addendum on CO2 Emissions

I found the following data on the internet for 2003:

1.         207.6 billion pounds of carbon dioxide emissions per quad of electricity generated from coal in US

2.         6.6 billion metric tons of carbon from greenhouse gases (GHGs), which amounts to 5.335E13 pounds carbon dioxide emitted into the atmosphere in the US

I added two more columns to Scenario 1b on Sheet 1 of pv070711.xls and Scenario 4 of pv.xls for yearly GHG deficits corresponding to the energy deficits and for the cumulative GHG deficits.  I found:

1.         4.668E10 pounds of carbon dioxide deficit in first year of Scenario 1b, which corresponded to the maximum cumulative deficit

2.         1.097E12 pounds of CO₂ for the maximum cumulative deficit for Scenario 4, which comes in the eighteenth year of the project and is 23.5 times the maximum deficit for Scenario 1b

Not all electricity is generated from coal, which corresponds to the worst case; and, not all of the energy invested in the production of photovoltaic solar cells is electrical, but electrical generators are responsible for more carbon dioxide than other energy sources because of inefficiencies; therefore, the numbers computed by me represent absolute upper bounds on greenhouse gas production.  Since neither of the above maximum deficits is appreciable compared to annual US GHG emissions, there is no compelling reason why Australia may not replace all of its fossil fuel consumption with renewable solar energy according to one or the other startup scenario depending upon conditions on the ground.  As I have stated repeatedly, energy and GHG deficits should be made up by conservation and “normal” demand reduction.  Of course, the real reason why this scheme or another scheme to replace fossil fuels will probably not be implemented is political intransigence.

Houston, Texas
July 29, 2007

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