Much has been made of “smart growth principles” and “smart energy policy” in California.  But in reality, the assumptions which dominate and drive California’s land use and energy policies are seriously flawed.  Failure to examine the quantitative realities that ought to inform these policies, and adjust accordingly, will condemn Californians to a future much darker than many rational alternatives.

The three primary questions facing California’s policymakers are how best to manage California’s land, water, and energy.  In all three, stark choices are faced, which can be illuminated by comparing four types of land use:  High density new homes, low density new homes, corn ethanol farms, and solar thermal power stations.  In all four areas, elementary quantitative analysis may reveal surprising results.

There are 37 million people in California.  Assume the population will grow over the next 25 years to 50 million people - an increase of 13 million.  There are 158,000 square miles of land in California, and about 40,000 square miles of that area is farmland.  So if 13 million people were settled on new land, not infill, at a high density of 20,000 people per square mile (at 3.5 people per household that is 9 residences per acre - an amount easily achieved according to current “smart growth” principles), it would consume 1.6% of California’s farmland, or a mere 0.4% of California’s total land area.  Even that miniscule expansion is a constant, nearly impossible fight in today’s political environment - the conventional wisdom claims “infill” within the footprint of existing cities is supposed to accomodate all new growth!

If on the other hand, 13 million new Californians all chose to live in very low density developments - something that is extremely unlikely since many people prefer living in urban centers where the population often exceeds 50,000 per square mile - how much land would be consumed?  Again the percentages are underwhelming.  At a density of 2,000 people per square mile (less than one household per acre), literally 1/10th the “smart growth” densities, only 16.3% of California’s farmland will be lost; only 4.1% of California’s total land area.  It is true that losing 16% of California’s farmland is not trivial, but nor is it overwhelming.  And even in a scenario where new low-density developments are encouraged, most new development will not occur on farmland.

When considering land use, however, what sort of farmland is being lost?  If agricultural land growing food crops is being lost, that is arguably a problematic tradeoff.  But California is rushing headlong into development of a subsidized corn ethanol industry.  So what are the water and energy tradeoffs between land for homes and land for biofuel?  Let’s assume low density homeowners use a whopping 2,000 gallons per residence per day per person - an absurdly large amount; four times what the average resident uses in Los Angeles County.  At the population density of 2,000 people per square mile (3.5 people per residence), it would take 3.7 cubic kilometers of fresh water per year to supply 13 million people living on 6,500 square miles of new low density residences.

That sounds like a lot until you consider the water requirements for 6,500 square miles of corn ethanol.  A conservative estimate is that every gallon of corn ethanol - in arid regions like California’s Central Valley - requires at least 1,000 gallons of crop irrigation per season.  Since corn ethanol, very best case, yields 5,000 gallons per acre per year, the yearly water requirement for 6,500 square miles of cornfields, instead of low density housing, is 5.2 cubic kilometers of fresh water - nearly twice as much as for housing!

And how much energy would allocating all this land and water to corn ethanol buy us, anyway?  Californians consume 29 billion gallons of petroleum per year.  Planting 6,500 square miles of corn ethanol will yield, best case, 1.4 billion gallons of ethanol, which at 80% the energy density of gasoline, equates to 3.7% of California’s current petroleum consumption.

On the other hand, utility scale solar thermal electric power can easily yield 5 watts per square foot - including the balance of plant.  Moreover solar thermal power is rapidly becoming competitive with fossil fuel, and decentralized and utility grade electrical storage is almost here.  At this energy density, 6,500 square miles of solar thermal installations would yield 123 gigawatt-years of energy per year, which is easily more than 100% of California’s current electricity and petroleum production combined.

So be careful what you want, policymakers, as you continue your ongoing destruction of every beautiful outlying suburb in our beautiful state with ultra high density “infill” developments, and at the same time subsidize corn ethanol - all in the name of being green.