I wrote:
> And I do agree with almost everything you say about costs. The point is: >> how long does it take? >> > > That's easy to estimate. It takes 10 years for automobiles, and 20 years > for heating and cooling equipment (HVAC -- "heating ventilation and air > conditioning"). > Naturally, some cars last longer than 10 years. I have one that is 17 years old. I think the half-life for automobiles is around six years. There are a few antique ones that are 40, 50 or even 100 years old. These are collector's items rather than practical machines. If you look around you will find some buildings with HVAC equipment older than 20 years. However, running such equipment is not cost effective. It is cheaper to replace it with modern equipment. In countries such as China you sometimes see old, obsolete factory equipment and coal fired furnaces. A few years ago they were still using coal-fired locomotives. This is a terrific waste of money. They cannot afford to replace the equipment with more modern machinery. that is why Chinese energy efficiency with was much lower than the US or Europe decades ago. I believe it is catching up now. It is a horrible thing that Chinese and Third World energy efficiency is so low. They end up paying more for goods and services than we do, in some cases. The worst thing by far is the cost of illumination (lighting). In the Third World, many people use kerosene lamps. These are horrible for the environment, for the people. They are dangerous. The cost per lumen for the light is astronomically more than electric lighting, even Edison-style incandescent lights. They use kerosene lamps because they have no electric power service, obviously. Fortunately, nowadays LED lighting and solar battery systems are beginning to replace kerosene. - Jed
