Here’s a biggie. List all the places we can get energy.
If you know physics, you’ll know that there are many possible sources. But, right here and right now, most kinds of energy we can harvest are ultimately solar. Solar power? Of course! But wind, HEP, biomass and biofuel, oil and coal too, all derive from the sun.
Wind turbines catch air currents driven by solar heat. Hydroelectric dams collect energy from rainfall that the sun evaporated from the ocean. Biomass boilers and biofuel cars run on energy that green plants stashed from light. Oil and coal is just biomass with a million-year latency.
The exceptions are tidal, geothermal and nukes.
Most people now accept that burning oil and coal is bad for the planet, so the hunt is on for alternative energy sources. But what exactly makes energy ‘alternative’?
There’s a lot of debate about this, but here are two basic criteria that I find useful:
1. Is it renewable?
Renewable energy sources are replenished naturally. Pretty much everything on our list scores better than oil and coal. Solar and wind do best.
2. Is it scaleable?
Scaleable technologies are usable big or small. Nuclear power is pretty hard to deploy on anything smaller than a national infrastructure, so even though its advocates say it’s non-polluting most commentators don’t class it as ‘alternative’. Tidal doesn’t do so well either, and the jury is still out on windmills.
Now, the thing about solar power is that it scores really well on both tests.
If you choose the right production methods, solar power is easy on the planet. The panels are long-lived, and they won’t pollute in any of the decades that they’re quietly trapping energy. Plus you can deploy them at any scale you like, anything from a glow-in-the-dark walkway light up to a gigawatt desert solar array.
With panel technology advancing all the time, we think the future is solar.