INSIGHTS BY DAVID M. DELANEY

This is for those who enjoy playing around with numbers.  David emailed this calculation to the Dieoff group in April, 2005. He calculates how many square kilometres of photovoltaic panels would be required to replace the energy loss that a 2% annual drop in oil production would generate.

To keep the sum of wind electricity power, solar
electricity power, and oil power constant at its
2017 value (somewhat less than today) during the first 40 years
of decline of oil production would require 1000 square
kilometers of solar panels *and* 87,000 very big (3 MW) wind
turbines to be installed in every year of the decline.

Calculation:

In this calculation I use the form of scientific notation for numbers
found in several well known computer programming
languages, in which "xey" means "x times 10 raised to the power y".
For example 1e9 = 1 times 10 to the 9 = 1 billion.

ASPO says we can expect a decline of world oil production (all
liquids) of 2% per year in 2017 when production is
passing downward through 25 billion barrels per year (25e9
bbl/yr), and that the volume rate of decline (not the percentage
rate)
of the maximum possible production will be fairly constant
for decades. (This assumes, of course, that we will maintain
sufficient social cohesion to be able to maintain maximum
possible production.)

This rate of production decline is 0.02 x 25e9 = 0.5e9 = 0.5 billion
bbl/yr/yr.  (1.4 million bbl/day/yr)  (For data I measured the graph
in the
ASPO Newsletter.)

This rate of oil production decline is equivalent to a rate of
energy production decline of
0.5e9 bbl/yr/yr x 6e9 joule/bbl = 3e18 joule/yr/yr.

Expressing this rate of decline of energy production in watts/yr: 
3e18 joule/yr/yr /(365 x 24 x 60 x 60)= 1e11 joule/s/yr
= 100 gigawatt/yr.

To maintain a flat energy availability to humans (no
decline *and* no growth) would require, for example, the
commissioning of 100 1 GW nuclear plants per year, or
400 gigawatt/year (400,000 megawatt/year) of solar
electric panel nameplate capacity or wind turbine
nameplate capacity. This does not include the effects
of the decline of natural gas production. The US, as
the user of 25% of the world's oil production, would,
sooner or later, need to build 25% of the replacements.)

ASPO projects that oil production will be down to 25e9 bbl/yr
(the data point used for the calculations above) in
2017, and that production will then have been declining at about 0.5
billion bbl/yr/yr for about 10 years, and will continue to decline
at about the same rate for another 30 years.

So, how big is the required ongoing construction project if 
solar and wind electricity are used to replace the power
loss from the decline of oil?

An article at
http://www.utilityweek.com/utilityweekv1/weeklynews/FeaturesDetail.as
p?nLinkID=39662

lists the following countries three and their total
installed solar electric capacity (nameplate) as being the
countries with the greatest installed capacity.

Japan     1.13 GW
Germany  0.7 GW
USA         0.37 GW

Total        2.2 GW

Let's guess that the rest of the world has almost as much
again, for an approximate world total of 4 GW installed
solar electric nameplate capacity.

This means that to offset the decline of oil with solar
electric power would require the installation *each year for
forty years*  of 100 times as much solar electric capacity
as has ever been installed to date. (Assumes 100 GW/yr
required, capacity factor of 0.25, giving a required
nameplate solar panel capacity of 400 GW/yr)

An article at
http://www.windenergy.org.nz/FAQ/global04percap.htm

Lists the global installed wind turbine capacity (nameplate)
by country, giving a total of 7.5 GW.

Again assuming a capacity factor of 0.25 and therefore a
requirement of 400 GW wind turbine nameplate capacity per
year. To offset the decline of oil with no growth of energy
use would require the installation *each year for forty
years* of 400/7.5 = 53 times as many wind turbines as have
ever been installed to date.

Let's assume a combination of the two kinds of renewable
energy, solar electric and wind, installed in the same
proportion as to date, total 11.5 GW, we would have to
install renewable energy generating facilities *each year
for forty years* equalling 400/11.5 = 35 times as much
renewable generating capacity as has ever been installed.

With current technology, the solar electric nameplate
capacity of 1 square meter of solar panel is about 130
watts.  Assuming that solar electric panels are installed
with wind turbines in the ratio 4:7.5, the area of solar
electric panels required each year is 35 x 4 GW/yr / 130
W/m2 =  1e9 m2 = 1000 square kilometres of solar panels per
year for forty years. (1000 square kilometres is a square 32
kilometres on a side).

Assuming 3 MW per wind turbine (the biggest current
designs), we would need to install  35 * 7.5 GW/yr / 3MW =
87,000 wind turbines per year for forty years.

To keep the sum of wind electricity power, solar electricity power,
and oil power flat during the 40 year decline of oil
production would require 1000 square kilometres of solar
panels and 87,000 very big wind turbines to be installed
every year of the decline.

David Delaney, Ottawa