So, I’ve been thinking some more about energy, inasmuch as I haven’t had any this last week.  Fortunately, my Vagus nerve is beginning to hum again with good gut bacterias taking over from the bad, and I’ve finally got the rice and toast to write an article.

I wanted to continue the post from a couple of weeks ago to flesh out the proposal of supplanting coal power with solar power.  First off, I’ve taken a closer look at the numbers and see that it would only take 7 quads of energy from solar to replace all natural gas and coal fired power plants in production.  This assumes that coal, nuclear, and natural gas electricity production are only 26% efficient, and that all other modes are 90% efficient.  I arrived at those numbers by looking at the 32% efficiency of electricity generation from the flow diagram helpfully provided by Lawrence Livermore Laboratories.

2013USEnergy

Just that one change would reduce our energy consumption from 97 quads to 79 quads.  Almost a 20% reduction in energy consumption and a much greater reduction in greenhouse gases.

So, by the helpful calculations of the otherwise completely wrongheaded article of Mr. Dowd, We see that we would need an PV panel of about 18,000 sq. mi. To do this.  Still bigger than Maryland, but only 16% of the land area of Arizona, where it would most likely be located.  A far cry from the 210,000 sq. mi. Mr . Dowd presented.

The only other bit I’d nibble at this point, without touching transportation, is the residential sector.  Much of the rejected energy there is from natural gas and incandescent light bulbs used for heating.  I’m not sure about that however, and will look up stats as the topic evolves.  The rejected energy from the residential sector is 35% of the energy input.  Much less wasteful than the 68% of electricity generation, but still a waste.

Assuming the average household has a roof of 1,000 SF, there are almost 4,800 sq. mi. of residential roof to convert into solar.  Or about 2 quads worth of solar energy.  This is a significant, but not complete part of the residential budget, with over 7 quads of useful energy supplied by 5 quads of electricity and 5 quads of natural gas, along with sundry sources.  With advances in zoned and room-specific heating and lighting, residences could soon be energy efficient enough for the energy from regional and household electricity to be entirely sufficient for the energy needs of residences

There’s a lot of variation in house footprints, encompassing ranch homes, bungalows,, townhouses, garden apartments and high rise condos.  Commercial buildings are equally variable, but tend to be larger with more stories.  It is harder for an average commercial building to supply all its energy needs from its roof area in solar panels.  But with modifications to the energy supply away from coal and natural gas, they might not have to to significantly reduce our energy needs.

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German Energy Flow Diagram, 2011

No trees were harmed in the making of this post, but a large number of electrons were inconvenienced

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