Bjorn Lomborg on German solar subsidies

Bjorn Lomborg (The Skeptical Environmentalist and Cool It) has an interesting article (Goodnight Sunshine) describing the late realization in Germany that their massive investment in solar energy is “a massive money pit” and “a threat to the economy.”   They have subsidized 1.1 million solar photovoltaic installations to the tune of $130 billion, which provide a whopping 0.3% of the nation’s energy.

If you are worried about anthropogenic CO2 induced global warming (a.k.a. climate change, a.k.a. climate disruption), he points out

“This sizeable investment does remarkably little to counter global warming. Even with unrealistically generous assumptions, the unimpressive net effect is that solar power reduces Germany’s CO₂ emissions by roughly 8 million metric tons—or about 1 percent – for the next 20 years. To put it another way: By the end of the century, Germany’s $130 billion solar panel subsidies will have postponed temperature increases by 23 hours.”

And as to “green jobs” boosting the economy of Germany…

“[E]ach job created by green-energy policies costs an average of $175,000… And many ‘green jobs’ are being exported to China, meaning that Europeans subsidize Chinese jobs, with no CO₂ reductions.”

I have one large quibble with his Lomborg’s numbers.  He says

“Even with the inefficiency of current PV technology, we could meet the entire globe’s energy demand with solar panels by covering 250,000 square kilometers.”

It would really take closer to a million square kilometers.

Why a million square kilometers?

Because even good solar panels (say, rated for 150 Watts/m2) will yield much less than their name plate power for a variety of reasons.

1. A one square meter solar panel in a huge array actually requires a land area of at least 1/cos(latitude) meters.  This is the land area shaded by the one meter panel by the sun at noon.  It is larger at other times of day.

2. Extra area is required for infrastructure, such as service roads

3. The capacity factor for solar energy is about 20%.  This means that if a solar panel’s name plate says that it is 150 watts,  then on the average it will yield about 30 Watts because sometimes it is night, sometimes it is cloudy, and even during a sunny day the incident angle is optimal for only several hours before and after noon.

In Berlin, for example, where the latitude is 52 degrees, a one square meter panel in a huge array will require closer to 1.7 square meters of land.  A typical good quality one square meter panel with a name plate wattage of  150 Watts at peak averages out to about 30 watts over the course of a year because of the 20% capacity factor.  This translates to an average of about 18 Watts per square meter (30 Watts divided by 1.7 meters).

World energy consumption is about  5×10¹⁷  BTUs per year (about 1.5×10¹⁷ watt-hours/year).  That is an average power consumption of  about 1.7×10¹³ watts (1.5×10¹⁷ watt-hours/year divided by 8760 hours/year)

Therefore, it would take about a million square kilometers of solar arrays (1.7×10¹³ watts divided by 18 Watts per square meter).

This all assumes that the energy impoverished of the world are happy to stay that way.  Oh well, we all have our crosses to bear.

You can see Lomborg’s complete article here.

Comparing the Interstate Highway System to Scientific American’s “A Path to Sustainable Energy by 2030″

In the November, 2009 issue of Scientific American, Mark Z. Jacobson and Mark A. Delucchi propose a plan to supply the world’s energy needs entirely by solar, wind and water sources by 2030. They conclude that the cost would be $100 trillion. My calculations show the cost to be more like $200 trillion.

This post dissects their comparison between the construction of the Interstate Highway System and their Energy system.

Cost

Interstate Highway System (2009 dollars):  $0.453 trillion
Jacobson’s and Delucchi’s Energy system (2009 dollars): $200 trillion

Jacobson and Delucchi say…

“Our plan calls for millions of wind turbines, water machines and solar installations. The numbers are large, but the scale is not an insurmountable hurdle; society has achieved massive transformations before… In 1956 the U.S. began building the Interstate Highway System, which after 35 years extended 47,000 miles, changing commerce and society.”

The Interstate Highway System is “largest public works program in history.” The concept was first approved by congress in 1944. But it was more than a decade until President Eisenhower signed the Federal Aid Highway Act of 1956. The plan evolved to building 42,500 miles of “super-highway” by 1975.  40,000 miles were completed by 1980.

The expected cost in 1958 was $41 billion. By 1995 the total construction cost amounted to $329 billion (in 1996 dollars). This translates into $58.5 billion 1957 dollars. That is not too far off from the original estimate.  Converting the $329 billion 1996 dollars to 2009 dollars gives $453 billion.

So if Jacobson’s and Delucchi’s estimate for the cost of their energy system is correct, then their energy plan would cost over 200 times as much ($100 trillion / $453 billion) as the Interstate Highway System to which they like to compare it.

If my calculations for the cost of their energy system are correct, then it would cost more than 400 times as much ($200 trillion / $453 billion) as the Interstate Highway System! And since they propose building their system in just 20 years, then it would be like building 20 interstate highway systems (which took about 30 years to build) every single year for twenty years.

Required surface area

Interstate Highway System – paved area: 3,500 km²
Jacobson’s and Delucchi’s Energy system (solar portion only): 500,000 km²

Another interesting comparison is the amount of land required. The image at the left (click to enlarge) shows a spot check of interstate highway widths using Google Earth.  A liberal estimate of the average paved width of the Interstate Highway System is about 150 feet (about 45 meters, or 0.045 kilometers).  So, roughly speaking, the 47,000 mile (76,000 kilometer) Interstate Highway System paved over about 3,500 square kilometers ( 0.045 kilometers X 76,000 kilometers).

The area covered by solar panels in the Scientific American plan would be on the order of 500,000 square kilometers, or 150 times larger than the Interstate Highway System. (See calculated land required for Concentrated Solar, PV power plants, and rooftop solar, here)

Let’s rip up the Interstate Highway System and build a new one.

Jacobson and Delucchi claim that the expense of their energy system “is not money handed out by governments or consumers. It is an investment that is paid back through the sale of electricity and energy.” This is a soothing argument that overlooks an obvious fact: We already have a power energy system that pays for itself “through the sale of electricity and energy.”   

This is like pointing out that an Interstate Highway System would have great benefits for us, and then suggesting that we could reap those benefits by tearing down the system we have now and then rebuilding it.

It’s almost like swallowing poison so you can reap the benefits of good health after you recover.