原创 Can we all afford energy-saving designs?

We all know about the push for implementing diverse energy-saving technologies, and with good reason: They pay off in the long run. A few recent examples you may have read about include:

- Ford is switching the body panels of the F-150 pickup, its most popular truck, from steel to aluminum. This will reduce weight by several hundred pounds and increase gas mileage by a few mpg, but it will also raise the vehicle cost by a few thousand dollars. The switchover is not trivial; it requires huge changes in the supply chain, body panel design, production tooling, and manufacturing techniques. In addition, aluminum is much harder to repair in the field. Only a few body shops can handle it.

- Cars are being designed for "start-stop" operation, where the engine shuts off when the vehicle stops (no matter how briefly) and restarts when the gas pedal is depressed. Again, the objective is to save fuel. The cost is the need for a far more rugged design in the entire starter subsystem, as well as a very different internal construction of the vehicle battery. The need for frequent bursts of starting current (around 100 A) puts a very different battery charge/discharge curve and chemistry into play.

- To squeeze a little more operating efficiency and mileage out of the power train, the traditional three-, four-, and even five-speed transmission is being replaced in some vehicles with seven or more forward speeds. The penalties are the increased weight and size of the transmission, unknown long-term reliability, and, of course, higher initial cost.In a non-automotive application, we have the use of CFLs and LED-based lamps in place of the incandescent bulb, as dictated by building codes and other government mandates. Certainly, these newer technologies are much more efficient and last longer, but they are also more costly. An LED lamp costs between $5 and $10, while an incandescent bulb is less than $1 in many cases.

- In all these cases, the message is the same: Regardless of the up-front cost to the consumer, it's worth it because it will save energy and thus money in the long run. Economists call this ROI, for "return on investment."

But the dilemma is this: Not all consumers can afford to think in terms of that virtuous long run, nor can they measure the value of their expenditures in terms of cold, rational ROI. For many people, spending a few hundred extra dollars now -- to save that amount and more later -- is just not a viable option. They don't have the money, period. You could argue that it is somewhat presumptuous of those who have the funds available to insist that those who may not have them to do this for their own good, if only they could think of the long term and act accordingly.

That's why I am of two minds whenever I see yet another energy-saving product or program that says we need to invest (also known as "spend") money now in order to get recurring savings later. Certainly, the ROI may be favorable, but not everyone has the ability to make that up-front investment, regardless of how much sense it makes in the ideal world. In some ways, it's yet another manifestation of the many corollaries to the basic engineering design rule, "The perfect is the enemy of the good."

Have you seen an energy-saving design or strategy that assumed too much about the end user's situation? Which aspects do you consider unrealistic, and why?