[Richard Brown]

Richard Brown asked the Naked Scientists:

Hi Chris,

Just been listening to the podcast 'Olympic Science' and about the 'Anaconda' tube and I started to think about the various methods we've invented to convert natural forces into energy (wind farms, wave farms, etc).

As, when it comes to energy, there is no free lunch, are we sapping nature of its energy? If so, what could be the repercussions in the many years to come?

Keep up the good work.
Richard

What do you think?

[bryan]

I think the amount of energy in wind, waves, sunlight etc. is massive compared to the amount we need. For example wind farms must be sapping energy from the wind but only a tiny proportion. Also, remember energy is never created or destroyed so one way or another that energy will still be around. 

[sarah cp]

Wind and Wave energy are certainly very abundant, if only we could harvest them efficiently.

Winds around the Earth are formed by the combination of the spin of the earth and the energy from the sun. Ocean currents are also involved. The different thermal properties of land and water mean that as they are heated up by the sun, the air above them will behave differently. This combined with the Coreolis effect of the world turning in space creates winds. Hopefully, unless the earth stops spinning or the sun goes out, wind energy will never run out! (although if those things did happen, i reckon running out of sustainable energy would be the least of our worries!). Similarly with wave power - waves are driven by ocean currents, the wind and by the tides (which are driven by the moon), so hopefully will not run out.

The bigger problem we face is being able to harvest and convert the energy efficiently and cost effectively.