Why Go Solar?
Because there's no other alternative ....
Tell all your Doubting Thomas friends to stop complaining about having to move away from their internal combustion engined cars. Electric motors, ultimately powered by solar energy, are the only realistic solution. And saving the planet isn’t the only reason.
The alluringly informative picture below, first published by Marc and Richard Perez, summarises why.
The diagram compares World Energy use with that available from all main sources: both renewable and finite. The areas of the circles tell you how much in each. In 2015, we used 18.5 Terrawatt (TW) of energy, represented pictorially by the brown circle at top left. Solar energy is represented by the biggest yellow circle. As you can see, the available energy from sunlight far exceeds our current demands - by more than a factor of 1000. And the sum of the other renewables together also contribute more than our current consumption.
With solar PV efficiencies of 20 percent, you’d need to install solar cells covering 0.5 percent of the planet’s surface area (equivalent to about one quarter of the area of the Sahara desert) to satisfy all of our energy needs. That’s not impossible, and harvesting solar energy has to be a major part of the future energy solution because we’ll never be able to harness all the “available” energy from other renewable sources, and the non-renewables won’t cut the mustard either.
The reserves for non-renewables - shown to the right - do appear larger, but remember these are not replenishable (as their name says), so the units are slightly different. For example, the petroleum reserve is 335 Terrawatt-years (TWy). At current consumption rates, that’s enough for only a couple of decades without other sources. Nuclear fission isn’t a silver bullet either. If that were our only source of energy, it would last only a decade or two.
Sunlight, on the other hand, will be there for the next 5 billion years. And, as shown by the figure below - from a recent report* on future energy transitions - it’s rapidly homing in on becoming the cheapest viable option.
* Thanks to Bill McKibben for highlighting the report in his recent posting at The Crucial Years on Substack. You should seriously consider signing up for those.
The paper argues that a rapid transition to renewables will result in a net saving of many trillions of dollars (compared with keeping our heads buried in the sand) and such a transition would also enable us to meet the target 1.5 degree temperature threshold set by the Paris Agreement.
It’s a no brainer to move to solar energy. Tell your friends.
Thanks for reading this. Previous posts on the intersection between Ozone, UV, Climate, and Health can be found at my UV & You area at Substack. Click below to subscribe for occasional free updates.