Showing posts with label variability. Show all posts
Showing posts with label variability. Show all posts

Sunday, April 26, 2015

Renewable Energy Cannot Sustain a Consumer Society


We live in a fantasy world.  We have blind faith that we’ll be able to sustainably feed nine or ten billion people in 2050, a wish-based belief.  We have blind faith that technology will vaporize all challenges that appear in our path over the coming centuries.  Economic growth will continue forever.  We’ll celebrate a glorious victory over climate change by switching to safe, clean renewable energy, in a smooth and painless manner.  Our high standard of living will keep getting better and better as we zoom toward utopia.  The best is yet to come!

Australian professor Ted Trainer is not entranced by blind faith, and he explained his heresy in Renewable Energy Cannot Sustain a Consumer Society.  Attempting to transition to a future powered only by renewable energy, while maintaining our current mode of high waste living, would be the opposite of smooth and painless.  Indeed, it’s impossible, he says.  Renewables simply can’t produce as much energy as we currently get from burning enormous amounts of sequestered carbon (fossil fuel).

In modern societies, electric power is highly reliable for both households and industries.  Power companies generate electricity, feed it into their distribution grid, and send it to consumers.  Excess electricity cannot be stored, and insufficient electricity leads to brownouts.  So, utilities must be very careful to generate electricity at levels that closely match the swings in demand.  Today’s centralized power systems are designed to do a good job of this, but they are not designed to reliably distribute electricity generated by decentralized sources, like wind farms or solar facilities.

Coal-powered plants can run at full capacity all the time, and they can be built anywhere.  Solar and wind facilities can run at full capacity only during ideal conditions.  For example, a solar thermal plant can run at peak on a hot summer day, but its average annual production is just twenty-five percent of peak.  The capacity of solar and wind facilities is highly dependent on location.  They cannot be built anywhere, and the ideal locations are chosen first.  The potential for future expansion is limited.

Photovoltaic panels convert sunlight directly into electricity.  They produce little or no energy at dawn, dusk, night, or during cloudy periods.  For large-scale generation, solar thermal is better, because it generates heat, which can be stored for use during off-peak periods.  Ideal locations for solar thermal are deserts, like the Sahara, or the U.S. southwest.  The drawback is that ideal locations are typically distant from population centers, and significant energy is lost when power is sent thousands of kilometers away.  Even in ideal locations, output during summer is five times higher than winter.

Wind power is even less consistent.  Wind velocity varies from year to year, from season to season, and from minute to minute.  For 54 days in 2002, a wind farm in Denmark had zero production.  A farm in Australia was nearly windless for five straight days.  Winds can suddenly go calm over a wide region.  Ideal locations are on hills and ridges.

This hard-to-predict variability is a serious obstacle to a renewable energy future.  Neither wind nor solar can produce electricity sufficient to meet current demand, in a dependable manner.  To provide dependable power, backup capacity is needed.  One mode of backup is to use the surplus power, generated during peak hours, to pump water uphill into reservoirs, where it can later be used to generate hydroelectric power.  For most regions, this is not an option.

Surplus electricity can also be used to generate hydrogen, to be stored for later use.  Storing energy in hydrogen is highly inefficient, expensive, and problematic.  Putting one unit of hydrogen energy into a fuel cell requires at least four units of wind or solar energy.  Hydrogen atoms are tiny, which makes them especially prone to leakage.  A big tanker truck can only carry 288 kilograms (634 pounds) of hydrogen.  Hydrogen does not make economic sense.

Backup electricity can also be generated by burning sequestered carbon, but this would result in undesirable greenhouse gas emissions.  In a renewable energy future, for each megawatt of wind or solar capacity, systems would also need almost a megawatt of backup.  The backup systems would be expensive, and they would be idle much of the time.  They cannot be quickly cranked up to respond to demand surges, or to supply shortfalls due to clouds or calms.

A number of well-paid respectable-looking nutjobs are preaching that the cure for climate change is nuclear energy.  But eighty percent of the energy used today is not electricity.  Trainer concluded, “If all electricity was generated by nuclear reactors, carbon dioxide emissions might be reduced by thirty percent.”  Uranium is nonrenewable, the supply is finite, and the top quality ores are gone.  All facets of the nuclear industry are designed and operated by accident-prone tropical primates.  Meanwhile, spent fuel remains intensely toxic for more than a million years, and we have yet to discover how to safely store it.  A more mature option would be to focus intense attention on how we live and think.

The variability of wind and solar generation is a huge challenge to a renewable energy future.  A far greater challenge — the death blow — is the issue of liquid fuels.  Liquid fuels are used to power cars, trucks, trains, planes, ships, wars, and our food system.  Under perfect conditions, renewable energy might be able to generate ten percent of the energy currently produced by petroleum.  Options include ethanol, methanol, and hydrogen fuel cells.  Trainer discusses the serious drawbacks.

Clearly, a smooth and painless transition to a renewable energy future that allows us to continue living like crazy is an intoxicating fantasy.  In addition to being impossible, it’s also unsustainable.  The “clean,” high-tech wonderland will continue extracting non-renewable resources for wind turbines, solar panels, transmission lines, roads, tractors, fuel cells, air conditioners, cell phones, and so on.  It will do nothing to wean us from soil mining, water mining, forest mining, and fish mining — or shift population growth into reverse.

The consumer way of life is a dead end path.  While reading, I kept thinking about my four grandparents, all of whom were born into non-electric, car-free households.  They lived good lives.  Food is a genuine need, but unsustainable energy is a devastating addiction — lots of fun at first, but deadly in the long run.

Trainer thought along the same lines.  The big problem is that the dominant culture programs us to be competitive, acquisitive, individualists.  He presented a dreamy vision called The Simpler Way, a joyful utopia of voluntary frugality, stress-free lifestyles, lovely gardens, and small cooperative communities — and we don’t even have to give up modern technology!  Really?

Instead of struggling to continue living like crazy, for as long as possible, by any means necessary, the intelligent option would be to slow down — to really slow down!  That’s the message here.

In 2012, Trainer wrote an updated 22-page summary of his analysis of renewable energy, Can Renewable Energy Sustain Consumer Societies.  In 2011, he helped write a 48-page description of his vision for a happy green future, The Simpler Way Report.

Trainer, Ted, Renewable Energy Cannot Sustain a Consumer Society, Springer, Dordrecht, The Netherlands, 2007.