g  e  n  u  i  n  e  i  d  e  a  s
  home   art and
science
writings biography   food   inventions search
let the sun shine in

Viewpoint (originally appeared in Business Week Online   August 1 , 2007. This longer version is a bit more discursive, but expands on the more tightly edited version in BW)

Sometimes the best solutions are discovered by leaving well-enough alone. Consider one small corner of the energy crisis- what offers the smallest energy footprint- paper or plastic cups? Well, here my father-in-law cuts through all the debate and calculations with a simple trick. When we visit, he marks a paper cup with each of our names, then hands them out for one day’s worth of use.  In so doing, he renders moot the seemingly never-ending debate among environmental purists about which cups are more energy-efficient—ones of paper (renewable resources, lots of water to manufacture) or ones of plastic (fossil fuels, may or may not be properly recycled).

Assuming five drinks per cup per day, my father-in-law reduces, in one fell swoop, a paper cup’s environmental impact by a factor of five.  Which swamps any difference between paper and plastic. The point is, if you don’t muck around with what you’ve already got and use what you already have without further changes or conversion, you can side-step a lot of esoteric issues, while still doing good.

Energy conservation is great, higher efficiencies are even better, but doing nothing is sometimes best of all.

Take the use of solar power to light a home.  Even the most advanced photovoltaic solar panels convert just 20% of the available sunlight to electricity.  The resulting direct current then must undergo conversion to alternating current, losing another 20%.  If that AC goes on to light an incandescent bulb, which is only 5% efficient, you end up using a fraction of 1% of the original sunlight as room light. (Even switching to compact florescent bulbs, which are 15% efficient, makes little difference in overall energy efficiency).

But, if you were to simply leave sunlight as light- via proper skylights, window orientation and louvers, nearly 80% of the light ends up as illumination. A 100x improvement, by leaving well enough alone.

Or take the multiple conversions required to produce alternative biofuels. The efficiency of converting sunlight into plants such as corn and switch grass and then into ethanol or biodiesel is one-tenth of 1% or less. Algae looks like it will perform slightly better, but at these rates, why bother? The best way to convert plants to energy, frankly, is to eat them.

The more links we put in the energy conversion chain the more the losses and the more improbable and inappropriate the solution.  We need, wherever possible, to keep light as light and heat as heat and food as food. 

Fortunately, a number of much more straightforward solutions are emerging.

We could begin by siteing new buildings for optimal exposure to sunlight and properly designing them to best capture daylight via skylights and windows.  Though still a rarity in the U.S., such design practice has become much more common in Europe. With proper insulation, such structures also require very little energy to heat. 

Similarly, we could install heat exchangers--simple, low tech devices which operate with 90% efficiency--much more widely.  Office building architects, for example, increasingly use heat exchangers to help separate sources of heat and cold, thus eliminating double heating and cooling.  Banks of server computers, now routinely walled off from office space, use heat exchangers to transfer the hot air they generate out of the building during summer and into the building during winter.  Less expensive versions for the home, can do the same for refrigerators or stoves (why use electric energy to cool food when the outside temperature is 30° F?) and hot water generated for showers (why lose all that heat down the drain?).

Many such innovations lend themselves best to new structures. But even older homes in shady neighborhoods, where solar power is impractical, could reduce their energy consumption through more efficient community-based solutions.  We could put solar thermal collectors in open parks or even in the hot tar of streets, then distribute the hot water via pipes to the surrounding neighborhood. Heat left as heat.

Even if you can’t avoid conversion entirely, there are ways to minimize the number of conversions. For example, we could also find more opportunities to break the DC/AC conversion cycle. Refrigerators and other appliances that operate on DC are becoming available and, with the certain arrival of economical LED lighting, which operates on DC, direct DC solar-power-to-DC-end-use will shortly become much more practical.

As some European towns already do, we could build community windmills and distribute energy locally from there, avoiding the energy losses associated with high voltage transmission lines.  Both solar and wind energy collection systems operate most efficiently on a slightly larger scale than that used by individual homes. (Such off-the-grid, locally-based energy solutions offer the added advantage of making communities less vulnerable to terrorist attacks.)

Applying the doctrine of minimizing energy conversions to automobiles is more problematic, but still doable. Going from sunlight to biofuels to mechanical engines to hybrid electric is a non-starter. Staying all electric is the answer, but the main problem lies in battery technology, which has yet to see a breakthrough. Over the last 100 years, battery improvement has invariably tracked the same, slowly increasing logarithmic curve.  Even proposed battery advances using nanoparticles would just keep the rate of improvement on the same pace.  It’s simply too hard to jumpstart the chemical processes inherent in battery technology.

Still, battery-operated cars are just a factor of two or three away from attaining the range and horsepower required to become popular with consumers. By substituting light composite materials for steel and by installing the latest generation electric motors, we could effectively close the gap.  All are readily available.  Then it would just be a matter of plugging our car into solar-generated power and we’d be off, as it were, to the races.

With rare exceptions, energy security and an improved environment don’t generally require startling leaps in new technology.  Nor do they require massive deprivation through conservation or insurmountable acts of political will. They do require, however, a clear focus on what works most simply and directly. Fewer energy conversions should become our watchword whether we’re government policymakers or whether we’re investors.

If we were to apply that principle more broadly, we could make a huge difference in the U.S.’s energy consumption.  I think greater efficiency alone would enable us to cut energy use by as much as 30% in 10 years and eliminate our dependence on uncertain petroleum imports.

All by doing nothing at all.

___________________________________________________________________
Greg Blonder is a partner at Morgenthaler Ventures, a venture capital firm that invests in energy as well as other technology and life sciences opportunities. He is based in Princeton, NJ.

 


Contact Greg Blonder by email here - Modified Genuine Ideas, LLC.