Since people like the discussion on the collapse of our techno-industrial civilisation once our energy reserves run out, let me cautiously add another 2c. Green energy (solar, wind, hydro, tidal and geothermal) has two major problems:
a) the energy sources aren't available everywhere
Hydro works fine in a place like Norway, where there are plenty of dammable rivers capable of supplying energy to a small population. Thermal works fine in Iceland with plenty of undeground heat that supplies more power than its small population needs. But with larger populations there is a limit on what hydro, tidal and geothermal can supply.
b) the energy sources are erratic
This applies to everything except tidal and geothermal. 80% of Brazil's electricity is supplied by hydroelectric dams thanks to the huge Amazon river system, but in times of drought the water levels drop off substantially and blackouts are the result. Wind and solar are by their nature erratic, solar especially so as there is a big difference not only between night and day or cloudy and clear but also winter and summer.
In consequence one is obliged to create a far bigger infrastructure than one would originally think necessary, in order to collect and store energy for the lean periods. In particular gigantic battery arrays.
So far I haven't come across any serious study of the industrial requirements that will be needed to extract all the raw materials necessary for the quantities of wind turbines, solar panels and batteries we will need, and the further requirements necessary to maintain this huge infrastructure and dispose of its used components. But everything suggests that far, far more energy drawn from green sources will be required to maintain its infrastructure than energy drawn from oil, coal, natural gas and uranium is necessary to maintain their infrastructures. Let's just say that electricity will be come very expensive and you can kiss goodbye to your Tesla. Take an electric tram or walk instead.
a) the energy sources aren't available everywhere
Hydro works fine in a place like Norway, where there are plenty of dammable rivers capable of supplying energy to a small population. Thermal works fine in Iceland with plenty of undeground heat that supplies more power than its small population needs. But with larger populations there is a limit on what hydro, tidal and geothermal can supply.
b) the energy sources are erratic
This applies to everything except tidal and geothermal. 80% of Brazil's electricity is supplied by hydroelectric dams thanks to the huge Amazon river system, but in times of drought the water levels drop off substantially and blackouts are the result. Wind and solar are by their nature erratic, solar especially so as there is a big difference not only between night and day or cloudy and clear but also winter and summer.
In consequence one is obliged to create a far bigger infrastructure than one would originally think necessary, in order to collect and store energy for the lean periods. In particular gigantic battery arrays.
So far I haven't come across any serious study of the industrial requirements that will be needed to extract all the raw materials necessary for the quantities of wind turbines, solar panels and batteries we will need, and the further requirements necessary to maintain this huge infrastructure and dispose of its used components. But everything suggests that far, far more energy drawn from green sources will be required to maintain its infrastructure than energy drawn from oil, coal, natural gas and uranium is necessary to maintain their infrastructures. Let's just say that electricity will be come very expensive and you can kiss goodbye to your Tesla. Take an electric tram or walk instead.
