Wednesday, October 1, 2014

How much area to devote to algae in order to make a gallon of fuel per day?

If this is any guide, it may 2k square feet.

A gallon of gas contains about the equivalent of 40 kilowatt-hours of energy.  Half of that is 20 kwh, so 1k square feet would produce the half gallon.  Only 500 square feet would be needed to get 10 kwh.

If you don't want to convert to liquid fuel nor electricity, you could probably get by with a lot less algae.  Let's say 250 square feet could get you 10 kwh of heat if burned.

Now, if your demands for heating are even less than this, you can get it all the way down to a small number.  That's what I'd like to do.

Now, LeMar Alexander gets by with only about 3 kwh a day of electricity.  Looks to me that a small amount of algae produced each day and stockpiled over time would give you plenty of energy to fall back on when solar power isn't available and it's cold.

I was thinking that a simple thing like Stirling Engine using algal pellets as fuel would be able to produce about 2.4 kwh per day if it was capable of producing a 100 watts continuously.  That's nearly enough to get to Alexander's level.

Perhaps the amount of land needed for this would be less than 100 square feet because the algae can be produced continually and then stockpiled when needed.  You could supplement the algae with wood chips and waste paper.

The Stirling Engine would allow the burner to operate indoors, which means that it can recycle the water and carbon.  The amount of water would be small, however.

By the way, the water problem may be more easily solved by using a Fresnel Lens.  The Fresnel Lens would evaporate the grey water and then it would be recovered using a dehumidifier.

This will go into the off-the-grid series.

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