Energy Return Ratio (ERR)

There’s little reason to believe that household photovoltaic arrays and wind turbines do much to help the environment. Because of their energy footprint of production, toxins, and numerous limitations, they often merely swap one set of side effects for another. In fact, subsidized household solar cells and wind turbines may spur greater fossil fuel consumption: Alternative energy production expands energy supplies, which places downward pressure on prices, and leads to greater total demand.

- Ozzie Zehner, Author of Green Illusions


Criteria for Sustainability Acceptability

Although technology advocates have promised clean energy solutions, there are more constraints than ever before on what constitutes this. There has been a lot of media exposure given to an endless variety of technological solutions but they often come from a narrow engineering and scientific perspective. To be an authentic solution requires meeting many constraints and conditions. A practical solution would need to satisfy all of these qualities:

  1. Renewable:
  2. Scaleable: If it is biological in nature, it must be produced and harvested sustainably at levels sufficient to meet the projected demands
  3. Nonpolluting: Is must be carbon neutral or carbon negative over its entire lifetime? (including End of Life)
  4. Low EROI: Resource extraction and processing must have low Energy Returned on Energy Invested
  5. Low Emergy: It must have low embodied energy
  6. Cost effective: It must be affordable over it’s lifetime and complete installation,  including all capital, maintenance and operation costs
  7. Cradle-to-Cradle: There must be no waste generated by any of the technologies used to excavate, transport, process it. All technical nutrients equivalent must be recoverable to virgin feedstock

In days gone by, the only criteria that needed to be satisfied were engineering and economic (consumer demand) critieria. The additional criteria are very strict additional sets of design criteria which make the search for viable alternatives challenging.  Manufacturing must be re-engineered with Life Cycle Assessment applied to meet new stringent sustainability standards.


One criteria worth focusing on is scaleability. If we are to assume the worst case of having to replace all of our energy needs today and tomorrow, a chief determining factor to be a viable replacement for cheap hydrocarbons is scaleability. Since scaleabiity always implies economics, we must ask this question at the same time we ask about Cost Effectiveness.


From an energy perspective, we must form a more complete picture of the technologicial picture. To date, we have only focused on operational energy but there can be extremely high embodied energy costs as well. Most technological solutions depend on advanced scientific materials that come out of research labs. There are currently 2 types of products that can provide technological solutions:

  1. semiconductor (including nanotechnology)
  2. biological/genetic solutions
Both of these have serious issues that need to be dealt with before they can be sustainably employed on a massive scale.
Semiconductors are notorious for the amount of energy required to produce them. The manufacturing process can take up to 400 steps, use highly toxic materials and a vast amount of energy. As we shall see below, one of the dirty secrets of Solar and Wind is the vast amounts of energy used to make them, use of exotic raw materials and toxic waste.
  1. Embodied energy of semiconductors
  2. Exotic raw materials – The Rare Earth Metals
  3. Toxic ingredients and E-Waste
Biological and Genetically manipulated technologies cause a lot of worries. Genetically Modified Organisms (GMO’s) are banned throughout the EU due to the findings of scientific studies that show many unanswered questions about their impact on natural ecosystems.

We will apply the above list of criteria to a variety of potential clean energy sources including:

  1. Solar
  2. Wind
  3. Biofuel
  4. Nuclear

Green Illusions – The Dirty Secrets of Clean Energy and the Future of Environmentalism

Ozzie Zehner is author of the book Green Illusions and a researcher in environmental and sustainability issues, particuliarly ones that surround technology and the built environment. This book exposes the dirty secrets of  “clean energy” and shows that in many cases, current technology is just another disguise for unsustainable dirty energy. The message of this book is to trust our gut feeling. If there are a lot of questions that don’t have answers, there’s quite probably something fishy going on. We must learn to pay attention to any feelings of discomfort that may arise because they are often a harbinger of truths that will become clearer with time.

In Green Illusions, Zehner pursues issues of how green is green technology with the authentic spirit of science,  daring to question accepted knowledge and ask the questions that we’ve neglected to. He does all of us a great favor by shining a bright light on the shadow areas of alternative energy. In today’s uncertain climate, it is critical to distinguish between myth from reality so that we can take the right course of action. By taking a holistic and integrated approach, Zehner is able to piece together a picture that most specialists have missed. When the future of human civilization is at stake, we have no time for incomplete knowledge or corporate greenwashing that can lead us terribly astray.


Ozzie Zehner, Author of Green Illusions and visiting scholar at U of C Berkeley STSC