Can we grow our own energy ?

farmer-plowingSo you think we can grow our own energy?  My first thought was “why not”, but the inner engineer said “do the math”.  OK, inner engineers always win.
Now what facts and numbers are we interested in.  I thought that it would be interesting to take the average American, put him and his average family on a piece of land.  This piece of land would have to provide him with all the direct energy the family uses.  I’ll define direct energy as the energy used for heating, cooling, electricity, and automobile transportation.  For this scenario, we’ll assume that each factory, office, etc. has its own “energy farm”.

The best source for energy statistics is the US department of energy website (

I thought this was going to be hard. In fact the data is all right on this one table:

It seems that the average US household consumes 95,000,000 BTU (equivalent) for electricity, natural gas, and heating oil.The average daily consumption of gasoline for the U.S. is about 9,000,000 barrels (42 gallons.)  I’ll assume that half of that consumption is for individuals (tell me if I’m wrong). There are 127,000,000  dwelling units.

The total energy growing requirements calculate out to about 157,000,000 BTU per year.

On the supply side…How much solar energy do plants absorb ?  According to it’s possible to obtain 10 tons of dry plant material per acre per year.  At an average of 19GigaJoules per ton, this would yield (assuming 50% conversion to useful energy) 45,000,000 BTU per acre.  Doing the division 157,000,000/45,000,000 gives us 3.5 acres.

In reality, you’ll need much more area. Because you have to eat, the horses (or tractors) have to eat, you may have to irrigate your energy crops, and you need manufactured products.

Assuming very little “home grown energy”, we would need: 127,000,000 households x 3.5 acres = 445,000,000 acres of additional cultivation. The US has about 407,000,000 acres of arable land.


Well, maybe this efficiency thing isn’t such a bad idea after all..

Other sources:

  • has conversions from different energy sources and units.

“I have been so happy as by accident to hit upon a method of restoring air which has been injured by the burning of candles and to have discovered at least one of the restoratives which Nature employs for this purpose. It is vegetation.”
Joseph Priestley 1771

We’re keeping plastic out of the dump

landfillThe vast majority of our whole house fans are shipped to the customer by UPS. Now they are a wonderful company, full of energetic 🙂 employees, who find that the best exercise is at work. Translated out of politically correct speak, it means that they throw our stuff as far as they can.

Faced with this athletic problem, we have developed and tested some great packing solutions. What drives us nuts, is that this typically means packaging our WHF’s in wonderful, resilient, polyethylene foam. Not only is the polyethylene foam expensive (it’s worth it), but more importantly it either goes straight to the landfill or at best is ground up and recycled.

Our goal was to go one step better and re-use the packaging foam. Each time that we re-used the plastic foam, that would be less plasic in the landfill. If we were lucky, maybe we could save some money along the way :-).

Since we ship our whole house fans throughtout North America, our first concern was the cost and inconvenience involved in shipping the foam back to us. packaging-reuse

We decided that if we had to provide another box to ship the foam back in that would be counter-productive. However the foam has to be assembled into something resembling a package.  What we came up with is to send a small roll of packaging tape. There is some inconvenience for the customer. They have to tape the foam together, attach the return label, and drop the “package” at a UPS store or truck.  It will be interesting to see how customers react to this.  This is what the returned polyethylene foam looks like after being returned to us.