18th April 2024
How Renewable are Renewables?
Many things are renewable as in they can be naturally replaced – timber is a renewable resource in that for every tree used/ consumed, another tree can be grown. Water is a renewable resource in that once used it can be recaptured and reused: this might be through the natural water cycle of evaporation, transpiration, condensation and rainfall, or through collecting and cleaning waste water for further use. Fish for use as food is a renewable resource – this supply of food is maintained through the natural reproductive processes of the fish.
However the renewability of things isn’t necessarily limitless.
If oceans are overfished, the rate at which new fish are born and mature will not keep pace with the rate at which fish are caught. Eventually there will be no fish.
If trees are felled faster than the rate at which new trees reach maturity – which can be 40 to 150+ years depending on the species – the landscape will become deforested.
If an ecosystem is not maintained, more can be lost through evaporation in a locality than falls as rain. Without forests in the middle of large continents, rainfall in these areas would be negligible reducing the landscape to desert. If rainforests are cleared, rainfall in those areas will be diminished reducing the landscape to bare earth.
Solar energy is a renewable energy source – the sun is constantly producing heat – as is wind, as the earth’s weather system continues to be generate wind. (Sometimes resources such as sunshine, wind, tides and geothermal energy are known as perpetual resources).
But whilst solar and wind energy are constant/ renewable, the means by which we capture that energy may not be as readily replaced. Solar panels that convert the sun’s energy into electricity are made of non-renewable minerals – silicon, silver, aluminium, and copper. Wind turbines that capture the wind’s energy converting it into electricity are made of large amounts of non renewable materials such as steel and carbon fibre.
The source of the energy is renewable but not always the means by which we capture the energy.
Here is an interesting blog describing how solar panels are made – https://blog.ucsusa.org/charlie-hoffs/how-are-solar-panels-made/
and wind turbines – https://blog.ucsusa.org/charlie-hoffs/how-are-wind-turbines-made/
The Green Tau 