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Renewables can't save the planet from a mathematical point of view. For example, to satisfy the current energy demands of Germany with wind energy alone, one wo

Renewables can't save the planet from a mathematical point of view. For example, to satisfy the current energy demands of Germany with wind energy alone, one would need more area of land to build turbines, than Germany actually has (and as the article states, there is still the problem of storage for renewable energy). I didn't do the math, but I'm pretty sure that many other developed countries simply burn more energy, that they have space available to host renewables. To attain some kind of equilibrium, they would need to import renewable energy from other countries, or to degrowth their energy consumption (and therefore there economy).

chewz 8y ago
Wind turbines work close to Betz limit [1]. Worlds demand for energy grows by circa 2,000 terawatt-hours per year. Two-megawatt turbine can produce about 0.005 terawatt-hours per annum. With 50 acres per megawatt we would fill land area greater than the British Isles, including Ireland every year. In 50 years it would amount to land area of Russia. And this is just new demand. Plus wind turbines are just concrete and steel which requires coal and produce CO2. Hardly green energy. A two-megawatt wind turbine weighs about 250 tonnes. Globally, it takes about half a tonne of coal to make a tonne of steel. Add another 25 tonnes of coal for making the cement and you’re talking 150 tonnes of coal per turbine. Now if we are to build 350,000 wind turbines a year (or a smaller number of bigger ones), just to keep up with increasing energy demand, that will require 50 million tonnes of coal a year. That’s about half the EU’s hard coal–mining output. This game of green energy is just a sideshow. Opportunity to make big money for some, tax great unwashed and keep the game of demand/consumption/subsidies going on. [1] https://en.wikipedia.org/wiki/Betz%27s_law#Economic_relevance https://en.wikipedia.org/wiki/Betz%27s_law#Economic_relevanc...

chewz 8y ago

Wind turbines work close to Betz limit [1]. Worlds demand for energy grows by circa 2,000 terawatt-hours per year. Two-megawatt turbine can produce about 0.005 terawatt-hours per annum. With 50 acres per megawatt we would fill land area greater than the British Isles, including Ireland every year. In 50 years it would amount to land area of Russia. And this is just new demand. Plus wind turbines are just concrete and steel which requires coal and produce CO2. Hardly green energy. A two-megawatt wind turbine weighs about 250 tonnes. Globally, it takes about half a tonne of coal to make a tonne of steel. Add another 25 tonnes of coal for making the cement and you’re talking 150 tonnes of coal per turbine. Now if we are to build 350,000 wind turbines a year (or a smaller number of bigger ones), just to keep up with increasing energy demand, that will require 50 million tonnes of coal a year. That’s about half the EU’s hard coal–mining output. This game of green energy is just a sideshow. Opportunity to make big money for some, tax great unwashed and keep the game of demand/consumption/subsidies going on. [1] https://en.wikipedia.org/wiki/Betz%27s_law#Economic_relevance https://en.wikipedia.org/wiki/Betz%27s_law#Economic_relevanc...