lpetrich
Contributor
Over the last decade, renewable-energy sources have been emerging as good alternatives to fossil fuels for powering industrial economies. Preindustrial technology was all powered in renewable fashion, except for coal burning here and there. But that proved inadequate for powering industrial technologies, and for a long time, the main renewable source has been hydroelectric generation.
Fossil fuels have three problems: (1) they won't last for more than about a century at current consumption, (2) much of the more easily-exploited resources have already been used up, and (3) using them puts a lot of carbon dioxide into our planet's atmosphere, and that has already been causing global warming. For these reasons, development of additional renewable energy sources has been actively pursued over the last few decades, and that effort is now bearing fruit.
Wind power -- present-day wind turbines are not your ancestors' windmills. They look much like 3-blade airplane propellers on tall posts -- and recently very tall ones, over 100 m (300 ft) high. The installed capacity has been growing by a factor of around 10 every 10 years since the 1990's, and the worldwide value is now around 500 gigawatts.
Growth of photovoltaics -- a big surprise for me, for these reasons: (1) photovoltaic cells are made much like computer chips, and I expected that to keep them relatively expensive, and (2) I expected concentrated solar power with thermal generation to be the solar winner, but it has not been.
But photovoltaic cells' installed capacity has also been growing by a factor of around 10 every 10 years since the 1990's, and is now around 400 gigawatts worldwide.
A big problem with wind and solar generation is that they are intermittent, and that has provoked a lot of work in electricity-storage technologies like improved batteries.
Another problem is the inadequacy of synthetic-fuel technology. This is for transport, where battery storage is often inadequate, and where liquid fuels are a great convenience. One makes synfuels with electricity by electrolyzing water and then combing the resulting hydrogen with carbon dioxide from the air -- the Fischer-Tropsch reaction. It has been used to make synfuels by nations with relatively little oil, like Germany and South Africa, and it is nowadays used to make synthetic motor oil. But in most places, synfuels are still more expensive than their petroleum-derived counterparts.
Cleantech News — Solar, Wind, EV News (#1 Source) | CleanTechnica is a renewable-energy enthusiast site (EV = electric vehicles, mainly electric cars). But it is revealing that that site seldom discusses synfuels.
Fossil fuels have three problems: (1) they won't last for more than about a century at current consumption, (2) much of the more easily-exploited resources have already been used up, and (3) using them puts a lot of carbon dioxide into our planet's atmosphere, and that has already been causing global warming. For these reasons, development of additional renewable energy sources has been actively pursued over the last few decades, and that effort is now bearing fruit.
Wind power -- present-day wind turbines are not your ancestors' windmills. They look much like 3-blade airplane propellers on tall posts -- and recently very tall ones, over 100 m (300 ft) high. The installed capacity has been growing by a factor of around 10 every 10 years since the 1990's, and the worldwide value is now around 500 gigawatts. Growth of photovoltaics -- a big surprise for me, for these reasons: (1) photovoltaic cells are made much like computer chips, and I expected that to keep them relatively expensive, and (2) I expected concentrated solar power with thermal generation to be the solar winner, but it has not been.But photovoltaic cells' installed capacity has also been growing by a factor of around 10 every 10 years since the 1990's, and is now around 400 gigawatts worldwide.
A big problem with wind and solar generation is that they are intermittent, and that has provoked a lot of work in electricity-storage technologies like improved batteries.
Another problem is the inadequacy of synthetic-fuel technology. This is for transport, where battery storage is often inadequate, and where liquid fuels are a great convenience. One makes synfuels with electricity by electrolyzing water and then combing the resulting hydrogen with carbon dioxide from the air -- the Fischer-Tropsch reaction. It has been used to make synfuels by nations with relatively little oil, like Germany and South Africa, and it is nowadays used to make synthetic motor oil. But in most places, synfuels are still more expensive than their petroleum-derived counterparts.
Cleantech News — Solar, Wind, EV News (#1 Source) | CleanTechnica is a renewable-energy enthusiast site (EV = electric vehicles, mainly electric cars). But it is revealing that that site seldom discusses synfuels.
