http://sunweber.blogspot.com/2011/01/energy-in-real-world.html
go to the blog to see the pictures
Solar and Wind are not renewable. The energy from solar and from wind is of course renewable but the devices used to capture the energy of the sun and wind is not renewable. Nor are they green or sustainable.
An oak tree is renewable. A horse is renewable. They reproduce themselves. The human-made equipment used to capture solar energy or wind energy is not renewable. There is considerable fossil fuel energy embedded in this equipment. The many components used in devices to capture solar energy, wind energy, tidal energy and biomass energy – aluminum, glass, copper, rare metals, petroleum in many forms to name a few – are fossil fuel dependent
Aluminum comes from bauxite. It takes considerable energy to refine the bauxite. When I was fourteen, I worked loading trucks in an aluminum extrusion plant. The ingots of aluminum would be heated, pushed through a die to shape, then cut and put on carts. We would take these carts and move them into a small room heated to around 400 degrees Fahrenheit where they were baked.
The history channel on “Modern Marvels” had an excellent show on mining and producing copper. Huge machines the size of a two-story house running on fossil fuels gouge out the earth. The rock being only a very small percent copper must be processed using chemicals and more fossil fuels. Then depending on whether it is the plate for the absorber in the panel or wire for the blower further fossil fuels are needed to create the final product. These products must be transported various places for further manufacturing, again using additional fuels.
There are consequences to the manufacture of solar and wind equipment; including serious air and water pollution, release of deadly chemicals into the environment as well as misuse of humans in mining and processing applications. There is pollution of the air and water that arises from the chemicals used in the manufacturing of the glass, copper, aluminum and other sundry materials in these panels. It does not include the debris from the mining of low percentage ore. From glass can come various noxious chemicals plus particulates in the air of arsenic and lead. Copper and aluminum manufacture (or recycling) also creates water and air pollution problems. To call these “renewable” energy capturing devices and processes green is not correct.
It is also blind to call these devices sustainable. As indicated above, it takes massive amounts of fossil fuels in the mining, extraction, purifying, basic manufacture, final product manufacture and transportation to get the materials to assemble this equipment. Often the electricity used to manufacture these products is powered by coal brought in by 100-car coal train run by a diesel/electric engine. There is simply no way that the energy captured by these devices can be use to reproduce the devices in a sustainable manner.
There is an important accounting system connected to energy decisions. Any system must give more energy than it takes to create/generate. This accounting system is Energy Invested on Energy Returned (EroEI). When it costs more to pull oil from the ground than we get back, then it is over for that well. On any technology, this has to be a main consideration. Many have heard that it takes as much energy to make ethanol as it provides. This makes it a dead end street.
How many units of energy does it take to make a hot air solar collector or a hot water solar collector or a wind generator or a solar electric panel? Each of the components (aluminum, glass, insulation, wires, pumps, blowers, solar cells, etc.) needs to be computed for the accumulated energy cost of the particular technology. This must be compared to life span energy output of the technology. It is important to realize we are talking about the ENERGY output. The financial payback cost is actually secondary in this perspective. Perhaps these energy devices need an energy content label like food has a calorie label.
There are tremendous stresses politically, environmentally, geographically and geologically for fossil fuels. Our money, energy and mineral resources must be used judiciously to repair and upgrade the infrastructure of water, sanitation, and buildings. Energy conservation by insulating, weather stripping, and cutting back are the first line of defense toward energy independence and self-reliance. It is important for the future of energy use to be clear on these matters.
These technologies (solar air panels, solar electric panels, wind, etc.) can be looked at as transitional. This means they can help this generation and maybe the next generation ease down the slope to minimal fossil fuels. I am not saying don’t use these devices. I am suggesting we use them sparingly and wisely.
As fossil fuels become less available, judicious use of the remaining reserves becomes even more important. We must come to realize that fossil fuels (as well as concentrated sources of minerals) are a gift from the earth and previous to life. To mistakenly call solar or wind energy renewable and include the capturing mechanisms leads to both false hopes and perhaps poor allocation of limited fossil fuels and funds.
John Weber
Rising Rock Orchard
Northern Minnesota
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Permalink Reply by Jack Driscoll on March 28, 2011 at 4:59pm Hi John, this was a thought-provoking essay for me; in fact, it brought me all the way back to the origins of our universe and the currently-understood laws of thermodynamics. For instance, the chemical elements that make up all forms of life and nearly all forms of matter are formed in processes like stellar supernovae. Imagine the embodied energy of even a single atom of Copper, believed to have been formed by the birth and death of likely hundreds of stars involved in large-scale fusion reactions for billions of years. There are millions of those in even the cheapest electronic trinkets. Think of all of the energy the universe invested in creating us and everything around us. According to many scientists it will never get more energy back than it invested, and is in fact destined to a long slow heat death.
"Solar and Wind are not renewable. The energy from solar and from wind is of course renewable but the devices used to capture the energy of the sun and wind is not renewable."
This is an often-overlooked part of renewable energy. Certainly, in a planet with finite resources, we will have to make choices about our utilization of those resources. I think your dictum that "we use them sparingly and wisely" is a good way to look at it. If all of our copper is bound up in consumer electronics, we will be unable to use it to manufacture generators. Then again, if all of our copper is bound up in generators, we will have nothing to provide power for. It seems the best we can do is make wise decisions on the use of the resources we have. I do think, however, you are being overly generous in your assertion that the wind and sun themselves are renewable. The sun will likely run out of matter for fusion, enlarge, and consume the earth. Even assuming our atmosphere would still be intact, once the earth has been consumed by the sun, wind will no longer exist. While the timeline for these events is on the order of millions of years, it's not infinite. There is an end.
Permalink Reply by John Weber on March 29, 2011 at 2:55pm Jack - thanks for responding. You of course are right about long term sustainability. More important only living lightly on the land with far less people will allow even short term (decades) sustainability because of that nasty second law.
You might find this other essay of interest:
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