Energy prices, relatively speaking

It's instructive every once in while to review various energy prices, to see what "cheap" really means.

Oil is WAY down, at $45 per barrel.  How does this compare to other forms?

Coal is about $45 per ton, for thermal coal.  But that's about 5 barrel's worth of oil energy.  So it's a dirtier, less transportable (but easily stored) energy form, at about $9 per barrel (and it's down more than oil, in the past few years).

Natural gas is less than $3Mbtu today.  That's equivalent to about $18 per barrel oil.

What about solar? That's harder, as solar panels aren't a store of energy (like oil, or for the mistaken greenies, hydrogen), but a converter of solar energy to electrical energy.

Well, installed solar is about $5 per watt, more or less.  The panels alone are less than $1 per watt.  Still, at $5 per watt, and about five hours of generating time per day, and a life of at least 20 years, you get:

1 watt * 5 hrs/day * 365 days/year * 20 years = 36500 watt-hrs for $5, at 3.4btu per watt-hru = 125Kbtu.

That's 1/8MMbtu, or less than 50 cents worth of gas.  So, installed solar is still considerably more expensive, but if you go just on panel cost then it's a lot closer (and with subsidies, cheaper still).  Utility scale is about half the price (8c/KWH, versus about 16 above), especially when you include the generation cost for gas.

Really, energy is terribly cheap.  Solar is cheap.  Gasoline is cheap.  Oil is cheap.  Natural gas is cheaper still.  The trick is to use the form that fits the need best.  Use liquids for transportation, solar PV for electricity, and NG or coal for heating.  Note that today coal is so cheap that even if you sequestered it, it would still be cheap (assuming 2x the cost).   Inject it in depleting gas or oil fields and it would probably help pay for itself.