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RE: Solar, hydrocarbons, EROI & life cycles

Most people seem to believe that so-called "renewable energies" will help us to fight climate change, and simultaneously create a "sustainable" source of energy that will alllow us to maintain modern life styles.

This belief does not consider that
- These "renewable energies" are predominent electricity, which in many areas cannot replace conventional fossil fuel technolgy;
- The capacity to produce more electricity is limited, for ecological and technical reasons;

The below post in a discussion group highlights the life cycle aspect. Installations must be replaced afer wear and accidents.

Wind generators as well as solar panels have caught fire and were destroyed by mere technical failures after a very short life span.

How does one repair a hydraulic dam without conventional technology and fossil fuel dependent equipment?
Hi Rex,
When I was working in building control systems, the PLC’s (computerised components for operating automated air conditioning in buildings) were failing in less than 15 years, in most cases, meaning that we were running systems that were comprised of a patchwork of different generations of controllers. This raised issues of compatibility between generations and compromised reliability, requiring a full time maintenance team. These systems were commercial grade. As a soldier driving a tank, I noticed similar rates of failure with our military grade systems for firing control and optics and I’m wondering what the mariners on the list have noticed.

This leads me to extrapolate that the effective service lives of renewable energy systems will be similarly limited, and that the energy generation systems that rely most heavily on digital switching and control systems are the most vulnerable. Once a particular microprocessor is no longer being fabricated (usually in The East) the failure of any components reliant on this chip could necessitate the replacement of the entire controller, an increasing expensive proposition as the economy “unwinds”. The most robust systems are those that rely least on electronic control components. (Rick, this is exceptionally important to bear in mind for the Biochar processing facility – All critical control components require manual overrides and all digital measurements need to have an analog backup).

I’ve created the following analogy to explain the importance of critical materials and components while a civilisation “unwinds”: When we’re building a tower in the game of Jenga, it makes no difference which wooden block goes where in the tower. However, when we’re removing the blocks one by one, the removal of a critical block will cause the entire tower to crumble and the person who causes the collapse loses the game.

As Pink Floyd sang in The Wall: And night after night, We pretend it's all right…

Philip Be’er - Home Harvest Farms
We manufacture durable and movable Container Gardens and Urban Farms and we Teach Sustainability Phone: 778.235.2990 Online Store: E-mail: Website: Facebook: Twitter:!/HomeHarvestFarm Blog:
Begin forwarded message:
From: "Rex Weyler" Date: 2013.05 .01 9:01:06 AM PDT
Subject: Solar, hydrocarbons, EROI & life cycles Reply-To:

Friends & colleagues ..

Thank you for the great dialogue re: energy transition. Indeed, this appears to be a critical discourses of our age: Can we replace the hydrocarbon energy bonanza with renewable energy systems?

It is a mistake to think that those who warn of peak oil or complex system collapse don’t understand the renewable energy alternatives. Most of the serious commentators on these issues do understand and desire renewable energy systems. However, there exist very real limits on any scenario to build out a renewable energy infrastructure for 7+ billion humans, with any advances in social justice and any significant portion of those humans living a modern consumer lifestyle. Among those limits discussed – net energy, material limits, land-use limits, infrastructure replacement time, cash subsidies, hydrocarbon energy subsidies (to mine & transport the materials & energy needed), intermittent flow, liquid vs. electricity, transmission losses, and so forth (+ the political and financial limits created by an entrenched petroleum status quo) – I’d like to emphasize one more, as yet unspoken limit:

Life cycle.

All physical energy infrastructure has life cycle limits, generally in the decades to 1-century range. The life cycle of a wind turbine or solar array appears in the magnitude of 30-60 years. Yes? Some of you likely have better data. Please refine or correct me, as I’m speaking in orders of magnitude. I’ve read reports as low as 10-20 years for some systems, and reports in the 50-80 year range, and I assume we can improve this. Hydro dams and geothermal systems also have life cycle limits. The point is: Life cycle limits exist.

If we assume a 50 year life cycle for solar & wind, then we would have to build out the entire array to “replace” hydrocarbons within that life-cycle period, fifty years, at which point, we would have to begin decommissioning, recycling, and replacing the early arrays.

Consider Lester Brown’s “Plan B” scenario, first proposed a decade ago, of developing 3,000 gigawatts of wind generating capacity by 2020. That would have been about 1.5 million wind turbines at a cost of $4.5 trillion. But we’re not anywhere near that pace, and this will not happen.

To replace hydrocarbons, we are contemplating 10s of millions of turbines and solar panels, in the range of 1000 new systems per day, non-stop, for 50 years. Plus transmission infrastructure and conversions to electric power. Even if this was achievable, our progeny would then have to begin the process again: decommission (takes energy), recycle (takes energy), mine new replacement resources, rebuild, re-install, and so forth, again in 50 years. This is a scenario for building forever with finite resources.

The required materials and energy, rare-earth metals, copper, steel, silicon and so forth are not mined with solar energy, but with hydrocarbons. Try operating a copper mine, for example, with solar po wer. When we see that, we can recalculate.

It appears as if most of us in this debate want the best for humanity, and would love to see a world of renewable energy and happy people living reasonable lives, but our optimism has to be based on biophysical reality, which includes very real limits on materials, energy, supply chains, political and economic resources, and even availability of skilled workers.

We need to appreciate the magnitude of the transitions we contemplate. Today, the rich 15-percent of Earth’s people consume about 85-percent of the resources. Meanwhile, our population grows at about 1% and nations expect their economies to grow by 3-to-4-percent annually. Projecting these growth rates to 2050, a world of 9-10 billion people with social justice and better living standards, powered w ith renewable energy, would require about 30-times more resources than we consume today. We would be fair and wise to ask: Is that possible?

Resource peaks do not manifest as “running out” of oil, or copper, but of declining quality, declining EROI, and escalating costs to recover lower quality resources. J. Tainter refers to this correctly as diminishing returns on investments in complexity.

We tend to approach sustainability backwards. In nature, desire, optimism, and good engineering do not equal capacity. To be serious about sustainability, we have to start with Earth’s material and energy (solar) capacity and design our cultural transition based on that capacity.

Therefore, the key policy of a ny ecological energy plan must be conservation, the only solution that does not require material growth. Conservation has to start with wealthy nations. If rich consumers reduced energy consumption by half – possible since rich economies waste so much energy – then the rest of the world could double energy use, and we could still reduce total world energy use. But if we attempt to power the wasteful, consumer culture built on fossil fuel for 10-billion people, we encounter some inconvenient laws of physics, thermodynamics, and ecology.

Beware efficiency: Remember Jevons, who got this right: Human enterprise never leaves the efficiency gains in the ground, in nature; humans have always taken it out in cash profits, cheaper prices, and/or less physical work. Historically, efficiency leads to greater resource use, not less. Remember when computers were going to save paper? This never happened. In 1950, humanity used about 50 million tons of paper each year. We now use 300 million tons, six times the paper. Growth swamps efficiency. Computers stimulated growth and more uses for paper. Meanwhile, during that period, the earth lost over 600 million hectares of forest. Computers did not, and will not, save paper. Technology does not save energy. Technology consumes energy.

Beware energy success: Given what humanity has done with the hydrocarbon energy bonanza, one of my worst fears is that 10 billion people would have all the energy they could ever want. Without transforming society, this could be a disaster. I support a massive renewable energy build-out, such as the recently published Jacobson scenarios, at the most aggressive pace & scale possible, but I venture to say that there exists no renewable energy scenario that will supply current per-capita energy consumption to 10 billion people, sustainably, without some combination of:
  1. End of wasteful and vanity energy use by the rich
  2. Massive energy conservation programs in every sector of human enterprise (Not just “efficiency” but actual conservation).
  3. The end of cars (including electric cars), and a build-out of low-energy, public transit.
  4. The end of massive energy use in warfare
  5. Population stabilization and reduction
  6. Some reasonable advancement in social justice to help avoid wasteful human conflict
If we achieved all or most of this, then we might have a chance to build a sustainable renewable energy array, perhaps, over centuries of careful transition and massive social transformation.

Rex Weyler
April 2013
Copyright: Contribution to TheGreatChange discussion list.
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