Para empezar, estoy seguro de que no tenemos que medirlo en "unidades de petróleo", sino en vatios de electricidad.
Así que lo que quería cuando empecé a escribir esta entrada para la bitácora, y lo que sigo queriendo, es ver cuántos vatios-hora necesitamos por persona y día en Canarias, y cómo conseguirlos de forma autónoma, sostenible, segura, limpia, barata y pronto. :-)
El caso es que cuando ya tenía guardados unos pocos enlaces, leí algo que gmoke acaba de publicar en globalswadeshi: aquí. Merece la pena leerlo y lo comentaré, espero.
En fin, a lo mío:
http://es.wikipedia.org/wiki/Energ%C3%ADa
Llevo tiempo queriendo entender la energía. "Capacidad para realizar un trabajo", dicen. ¿Y cómo se mide? Lo siguiente es de wikipedia:
¿Y cuánto se consume en Canarias? No me queda claro, porque se consume energía fósil y energía eléctrica, que viene de la energía fósil. Viendo sólo la eléctrica, en el ISTAC:Unidades de medida de energía
La unidad de energía en el Sistema Internacional de Unidades es el Julio, que equivale a Newton x metro.
Otras unidades:
- Caloría. Es la cantidad de energía térmica necesaria para elevar la temperatura de un gramo de agua de 14,5 a 15,5 grados Celsius. Un julio equivale aproximadamente 0,24 calorías.
- La frigoría es la unidad de energía utilizada en refrigeración y es equivalente a absorber una caloría.
- Termia, prácticamente en desuso, es igual a 1.000.000 de calorías o a 1 Mcal
- Kilovatio hora (kWh) usada habitualmente en electricidad. Y sus derivados MWh, MW•año
- Caloría grande usada en biología, alimentación y nutrición = 1 Cal = 1 kcal = 1.000 cal
- Tonelada equivalente de petróleo = 41.840.000.000 julios = 11.622 kWh.
- Tonelada equivalente de carbón = 29.300.000.000 julios = 8138.9 kWh.
- Tonelada de refrigeración
- Electronvoltio (eV) Es la energía que adquiere un electrón al ser acelerado por una diferencia de potencial en el vacío de 1 Voltio. 1eV = 1.602176462 × 10-19 julios
- BTU, British Thermal Unit, 252,2 cal = 1.055 julios
Del orden de 10 millones de megavatios-hora por año para 2 millones de habitantes. Así que 5 megavatios-hora por año y por habitante. Lo que serían 5 mil kilovatios-hora por año y habitante, o 5000/365=casi 14 kilovatios-hora por habitante y día. ¿Encaja?
http://es.wikipedia.org/wiki/MWh 10 céntimos por kilovatio-hora.
Ahora, veamos la promesa de nanosolar. Dicen que 1 gigavatio al año por 1.65 M$. Y que una planta de 2MW en 10 acres da para 1000 viviendas. Konakra dice que 10 céntimos por watio, sin contar cables y baterías.
Habrá que compararlo con http://www.inersol.es/kits_porque.htm
¿Encajan estas cosas? Tengo que hacer más números, y entender los conceptos. Pero este es la típica entrada de bitácora que me quema en las manos, así que la comparto y ya veremos en una entrada que se llamará "Sociedad de 2000 vatios (2)". De momento, ¡tú dirás!
3 comentarios:
http://www.newyorker.com/reporting/2008/07/07/080707fa_fact_kolbert?currentPage=all
Del artículo al que hace referencia gmoke: "One way to think about the 2,000-Watt Society is in terms of light bulbs. Let’s say you turn on twenty lamps, each with a hundred-watt bulb. Together, the lamps will draw two thousand watts of power. Left on for a day, they will consume forty-eight kilowatt-hours of energy; left on for a year, they will consume seventeen thousand five hundred and twenty kilowatt-hours. A person living a two-thousand-watt life would consume in all his activities—working, eating, travelling—the same amount of energy as those twenty bulbs, or seventeen thousand five hundred and twenty kilowatt-hours annually.
Most of the people in the world today consume far less than this. The average Bangladeshi, for example, uses only about twenty-six hundred kilowatt-hours a year—this figure includes all forms of energy, from electricity to transportation fuel—which is the equivalent of using roughly three hundred watts continuously. The average Indian uses about eighty-seven hundred kilowatt-hours a year, making India a one-thousand-watt society, while the average Chinese uses about thirteen thousand kilowatt-hours a year, making China a fifteen-hundred-watt society.
* from the issue
* cartoon bank
* e-mail this
Those of us who live in the industrialized world, by contrast, consume far more than two thousand watts. Switzerland, for instance, is a five-thousand-watt society. Most other Western European countries are six-thousand-watt societies; the United States and Canada run at twelve thousand watts. One of the founding principles of the 2,000-Watt Society is that this disparity is in itself unsustainable. “It’s a basic matter of fairness” is how Stulz put it to me. But increasing energy use in developing countries to match that of industrialized nations would be unacceptable on ecological grounds. Were per-capita demand in the developing world to reach current European levels, global energy consumption would more than double, and were it to rise to the American level, global energy consumption would more than triple. The 2,000-Watt Society gives industrialized countries a target for cutting energy use at the same time that it sets a limit for growth in developing nations.
The last time Switzerland was a two-thousand-watt society was in the early nineteen-sixties. By the end of that decade, energy use had reached three thousand watts, and by the mid-seventies it was up to four thousand watts. This rapid rise could be said to follow from technological advances—the spread of automobiles, the advent of jet travel, the proliferation of appliances and electronic devices—or it could be seen as just the reverse: a failure to apply technology where it is needed. A few years ago, a group of Swiss scientists published a white paper—or, to use the Swiss term, a “white book”—on the feasibility of a 2,000-Watt Society. Relying on widely agreed-upon figures, the scientists estimated that two-thirds of all the primary energy consumed in the world today is wasted, mostly in the form of heat that nobody wants or uses. (“Primary energy” is the energy contained in, say, a lump of coal; “useful energy” is the light emitted by a bulb once that coal has been burned to produce steam, the steam has been used to run a turbine, and the resulting electricity has been transmitted over the grid to heat the bulb’s filament.) This same paper concluded that, with currently available technologies, buildings could be made eighty per cent more efficient, cars fifty per cent more efficient, and motors twenty-five per cent more efficient."
"Very broadly speaking, the average Swiss today uses energy as follows: fifteen hundred watts per day for living and office space (this includes heat and hot water), eleven hundred watts for food and consumer items (the energy that it takes to produce and transport goods is referred to as “embodied” or “gray” energy), six hundred watts for electricity, five hundred watts for automobile travel, two hundred and fifty watts for air travel, and a hundred and fifty watts for public transportation. Each person’s share of Switzerland’s public infrastructure, which includes facilities like water- and sewage-treatment plants, comes to nine hundred watts. Reducing these five thousand watts to two thousand would seem to require a significant reduction in every realm. Assuming that infrastructure-related consumption could be cut to five hundred watts, a person who continued to use fifteen hundred watts for living and office space would have nothing left for food, electricity, and transportation. Similarly, a person who continued to travel and use electricity at current rates would consume two thousand watts without having anywhere to live or work, or anything to eat."
Dices que si encaja. "Casi 14000 kWh por habitante y día" es el equivalente a tener encendidas muchas bombillas de 100 watios durante 24 horas.
Una bombilla de 100 watios x 24 horas son 2.400 watios-hora, o 2'4 kWh.
14.000 kWh / 2'4 kWh = del orden de 6.000 veces más. No un 6% más, ni un 60% más, ni 6 veces más. 6 mil veces más.
Algo está mal en las cifras.
Tienes que contrastarlo por otro lado.
6 mil bombillas en lugar de 20 bombillas, son 300 veces más que el ideal de los suizos.
Sigue sin cuadrar.
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