Waste is a terrible thing. At best, it connotes something that has performed no good for anyone. At worst, it is something disgusting that we avoid at all costs. But, nonetheless our lives are filled with waste. It is the rare person or circumstances that allow one to go through a day without creating any unnecessary waste, or even limiting that waste to a small amount. We are so used to some forms of waste that we hardly recognize it. But, waste should be seen as a failure of our system of doing things. Many of our activities are possible with little or no waste, we are just complacent towards it. As part 1 of this series, we will look at heat, how and why it is wasted and what we should do about it.
First, the heat we are talking about is not the heat for our homes in the winter, although that would also be included (in as much as it escapes to the environment without helping us). The term heat in the Physics or Engineering sense refers to all energy that has not been applied to a useful task, which results in this energy being released as heat. How does that work? Well, imagine a electric motor using 1.5 kilowatts that raises a 100 kilogram load of equipment 100 meters to the place of a work site on a tall building in 100 seconds, it has utilized 980 watts in productively moving the equipment, while the other 520 watts has apparently disappeared.
Well, in fact that 520 watts did disappear through being converted into heat, which was eventually lost into the air one way or another. All of the 1500 watts of power was supplied to the motor, but some was lost to heat because of the electrical resistance of the wires and other components in the motor. Some power was lost as heat because of friction in the motor bearings and in the other pulleys used to lift the equipment. Some power was converted to noise, which warms the air a small amount. [ad name="Adsense Small Horz Banner"] The other main way heat is lost is through it being discarded as unusable. Put your hand next to the exhaust of a car or truck; you will feel a very warm stream of gases, and those gases have already been cooled considerably by their path through the exhaust system. The engine of the vehicle burns fuel, and that chemical reaction creates heat and volume expansion that provides power to run the vehicle. If it is during the winter season, some of the heat is then used to warm the passenger cabin. The remainder of the heat is discarded to the environment as unusable by the vehicle, even though it still retains as much as two-thirds of the total energy created by the combustion.
Electrical power plants running a combined cycle (gas turbine, then steam turbine, then water heat exchanger) do a much better job with using the available heat from fuel combustion, but even they will discard at least one-third of the heat to the environment as unusable, and usually much more.
The last category of wasted heat is that of misdirected functions. A fan blowing in a room to cool a person or people who are not present results in 100% of the energy provided to the fan being lost as waste heat eventually. Another example is electric lights utilized in some area where no one is around to see it. While the reason for this lost heat is different, the result is the same, all of the power supplied to that device ends up as heat added to the local environment, with no other end effects.
In all of these things: electrical resistance, friction, noise, thermodynamic discarding, and wasted functionality, we (whether the user, buyer, seller, designer, or regulator) are expending valuable effort (collecting, transforming, and transporting energy) for absolutely no gain to ourselves or the larger society. There is a small amount of this waste that is inevitable given our current technology, but most of it is not. After covering the other problems of waste, we will consider some of the solutions.