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In the previous post we analyzed why renewable energy is the lifeline that is constantly telling us from the media and by companies and parties. As we saw, a major difficulty and was difficult to ignore is that, apart from biofuels (whose limitations have already discussed here ) our renewable energy sources provide us with electricity, which is not what we need most, and that saturation of the market for excess power generation, coinciding with the current economic and financial problems and progress can ever get to deploy. Does that mean that in our future energy descent can not count even with renewable energy? Not at all, but what is requier and is doing, in this as in so many other things, a transition and change our way of thinking. So far our aim has been to maintain an industrial society with specifications similar to the present, and while try to make a transition from current fossil to the post-fossil as will necessarily be a future, we realize that the technical and financial difficulties our company will fail. But is not this, again, a case that what is needed is restate the problem?
Consider for a moment: What do we want renewable energy? Why electricity? Actually, no, electricity is a means to an end. So what we want? Fundamentally, to improve our living conditions, especially in our homes, and more light physical labor. Both of which renewable energy can we seek, and with relative ease, since they overcome the obstinacy of model based on electricity alone.
produce electricity makes sense if you want to transport energy over long distances and then effectively convert this electrical energy into mechanical energy or other (magnetic, radiation, ...) at the site where it is consumed and above managing demand as does our electricity grid (in short, adapting to our whims, to the sum of the vagaries of users of the grid). But Despite the recent conversion efficiency of electricity-in the case of electric motors is used for 85% of the power to make it mechanically there is a 20% loss in the network caused by thermal dissipation and the voltage transformation losses. And this must be added the initial losses in the conversion of sunlight or wind power into electricity. Naturally, many more steps of transformation taking place more energy is dissipated along the way and less effective a process. But we need to move from the mains so much energy? Can not we capture and consume energy locally renewable? Our ancestors did, and our current knowledge we should be able to improve it. Here is a non-exhaustive list of various methods to make more efficient use of renewable energy sources, all share a distinctive feature: the use of energy is distributed, local-global non-centralized.
- solar power Comprehensive use of energy from the sun begins in the very conception of the homes and factories, using passive solar designs . Thus, reduced considerably the needs for heating, cooling and lighting. Although more difficult designs liabilities is to find the optimal formula adapted to the specific climate where the building is situated in countries like Spain that have been inhabited for millennia, no need to reinvent the wheel. On the shores of the Mediterranean traditional houses were low and were whitewashed, to reduce exposure to intense heat and reflect more of the incoming solar radiation. In mountain areas, the roofs are steep to prevent accumulation of snow, and the materials used, other than local, favor the thermal insulation, such as the board, also strongly influences the design (narrow windows, thick walls) and the location (on the sunny side of the mountain in preference to the shade). During the twentieth century, much has been building expertise that will help them greatly improve the design and implementation of housing to accommodate a situation in which no power on. Apart from passive solar, solar concentration devices create simple task is affordable and can provide hot water and, with minor adaptation of electricity to a home in these latitudes but, yes, in a discontinuous manner. Higher concentration systems based on salt cylinders molten allowed to accumulate energy and give a more uniform output, technology not available to a home but simple and robust, and further than photovoltaics.
- Wind: have traditionally been used mills Wind for tasks as varied as water pumping, grain milling, oil extraction from olives and other industrial uses. Direct mechanical transmission of motion of the blades to power a machine has the advantage of saving energy losses by converting torque to electricity (unknown to this author, but that surely are important) and discussed and transmitted over the network (about 20%) and conversion of electricity to mechanical motion (depending on engine type and operating system, and although effective can easily involve losses of 15%). The drawbacks of this design are two main types: local and inflexibility. With regard to locality, the work is performed at the location of the mill, so to avoid losing too much energy transporting raw materials to the mill and converted from the mill as raw material production and consumption of finished product must be in places not too far from the mill. As for inflexibility, if it is coupled to a mill a particular system probably can not be changed easily use (although you can always attach the mill at a PTO as tractors and engage or disengage the relevant equipment as needed.) Be added to that the scale that allow these facilities is smaller than that gives us the power today, or whether they think when the infrastructure has to study in detail what you want done and how volume. As the future looks especially bright for wind power is for marine navigation: the old sailing clippers were capable of reaching speeds of 15 knots in excess of 11 knots that many carriers today do not dare transfer not to spend too much fuel (although much smaller clippers were displaced mass).
- Hydropower: historically had water mills, which are discussed here for purposes similar to those of wind. Although its capacity is much less energy than hydroelectric dams, not suffer from the problem of silting of wetlands (which we'll talk when we discuss the future of hydropower). In addition, there are interesting designs, like the floating mills , allowing better use of current energy and also infrastructure can bring wherever necessary at all times.
- Biofuels: machines probably make the best use of "biofuels" are the animals and men themselves. Versatile, convertible, easily reprogrammable and autoreparantes for limited damage, its energy requirements are moderate, although its power is too. For certain uses of force likely to animal and human is the best option, at last, after all, not so long ago that the machine guns the U.S. Army climbed the mountains on the back of a mule. Nor does while the tram system was moving mules Even in crowded areas such as New York. In urban areas such mobility creates health problems because the testimonies of horses, but who had the advantage to fertilize your garden (see series Valencia full color "of the defunct blog" bargain is running out " .)
- Engineering: Although not strictly energy sources that spoke in this section, it must be noted that good engineering can improve, and by far the performance of the various sources. Of ancient human beings by machines has increased its capacity to do work even at the cost of reducing the speed with which made. Result of this ingenuity are the pulleys, winches and hoists, and highways rope, zip lines and swings and slides of all kinds.
Why this insistence, then, the use of renewable energy for electricity production? Because this pattern of exploitation of renewable energies is a model of large-scale network and supports not only Taylorization work, but also the concentration of capital in equipment and improvement of economic returns. In addition, large network models, with its large facilities, provide great returns to investors. But if the goal is not unbridled economic growth, but have a society in balance, in full, sustainable, growing only in human progress and knowledge, the major networks, as we have discussed today, are first a hindrance than a desirable goal . We are so used to this big network model do not question it, to the point that is all that is discussed in the media that we do not realize that this obsession with a certain type of exploitation is exactly what you can do viable society.
If this post is part of the series "Preparing for the transition" is because in order to harness these energies with great performance and a sustainable and maintainable in a shortage of energy has to begin now to think of something that goes beyond the paradigm of grid-scale distribution and start devise local systems to better use.
renewable energy use, and do it wisely, so distributed and adapted to each application.
Salu2,
AMT
P. Data: During the next two weeks may be less connected than usual. I hope to resume normal activity on May 10.
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