File talk:Available Energy-2.jpg

A volume graph was probably used so the wildly disparate scales would fit together and still be visible. Its worth noting that using volume to represent quantity is a technique to reduce the apparent difference between various amounts. It seems the amount of solar energy available isn't much more than total consumption, maybe 4 or 5 times at a glance. This is because a casual user expects the only relevant axis to be height and that it is linear. But with a volume graph a doubling of the height means an eight times increase! I was caught out by this until I read the attached text on World_energy_resources_and_consumption#Wind_power_2. See How_To_Lie_With_Statistics for more fun. --[[User:Schwer 07:04, 22 May 2007 (UTC)

I'll tell you how to lie with statistics, use the amount of solar power absorbed by the earth instead of the amount usable by solar plants. The solar number is complete BS, only 1/3 of the available area is land area and at best we can convert maybe, MAYBE, 1/5th of the absorbed energy into electrical energy, then only if you deforested the entire earth and replaced all land available at all with solar panels, the number would only be like 3,000 TW. That amount of solar power that would ever be thinkable to use would be far less than the 15 TW block, not even considering intermittency and other problems. Yes, the graph is deceptive, very. -Theanphibian ^{(talk • contribs)} 04:39, 7 September 2007 (UTC)[reply]

The graph is not attempting to convey any of that. It's a representation of the upper bound of available renewable energy to illustrate how much is potentially available vs our current consumption and to show that there's potentially plenty of solar power. "89,000 TW is the amount of sunlight that falls on the Earth's surface." Furthermore, because solar power ultimately powers all renewable sources, it is too narrow to think of the available usable power as being just that harnessed by solar collectors. Solar power also powers wind, biomass (via photosynthesis) and ocean thermal power (ie. taking advantage of thermal differences between cold and hot water) to name a few. Wallpapering the world with solar collectors is not the only way to get at the energy.

To put it another way, we're quite sure how much solar energy is reaching the Earth. How much power we can usefully extract from it is rather speculative. The graph is only intended to convey that, yes, it is possible to run the Earth just off of renewable resources and to show the scale of the difference.

Also the math does not hold up the statement that "the amount of solar power that wold ever be thinkable to use would be far less than the 15 TW block" is a bit wonky as 15 TW is about 1/6000th of 890000 which is quite a ways from 1/15th (1/3 the Earth's surface times 1/5 conversion rate). You'd have to throw in an additional fudge factor of 400 to break even. That's a lot of fudge. mmmm, fudge. --Schwern 22:28, 31 October 2007 (UTC)[reply]

Of course other energy sources are powered by the sun. The only energy source that is not powered by the sun ultimately is nuclear power. You say that this is a comparison of how much energy hits the Earth and what we're using, but it's not taken that way. People look at this, and even caption it as a comparison of what could be obtained by solar electric power versus other sources. To say that we could start producing an average output of 15 TW from solar PV is not right. The entire GDP of the world isn't enough to theoretically buy all those solar panels. How's that for the extra 400 fudge factor? -Theanphibian ^{(talk • contribs)} 20:35, 11 November 2007 (UTC)[reply]

I see no way to edit the description, but shouldn't it refer to power instead of energy? -- Whitepaw (talk) 22:38, 28 June 2010 (UTC)[reply]