From reading comments on EnergyDSM.com and LinkedIn, I get the sense that there is a bit of misunderstanding about energy efficiency and energy conservation. Here are the explanations that I use. Please comment on how this compares and contrasts with your understanding of energy efficiency, energy conservation and the difference between the two.
What is Energy Efficiency?
Energy efficiency involves technology that produces the same end product while using less energy. For example, an energy efficient air conditioner produces the same level of cooling capability while using less energy than the average air conditioner on the market. This technology is always changing because a device that was energy efficient 30 years ago is probably not energy efficient today.
Energy efficiency programs have become increasingly popular as global warming has become more of a threat. As many people in the industry say, “the cleanest energy is the energy never used.” For example, consider a business that installs solar panels on its office buildings, but does not replace its inefficient light bulbs and air conditioners. If the inefficient devices were replaced by efficient ones, there may not have even been a need for the solar panels in the first place. Clean energy powering dirty devices does the world no good. For this reason, Barack Obama calls energy efficiency “the cheapest, cleanest, fastest energy source.”
What is Energy Conservation?
Although energy conservation is often confused with energy efficiency, it is quite different. Both involve a reduction in overall energy use, but achieve that goal in different ways. Conservation involves cutting waste of energy whereas energy efficiency does not. For example, I can replace my old air conditioner with an energy efficient one, but can still waste energy by running it while I’m not home. I may have been able to save more energy by changing my behavior or programming my thermostat as opposed to replacing my air conditioner.
Energy conservation has not been as popular as energy efficiency because it is often associated with sacrifice. If I do not have my air conditioner on while I’m not home, I might be uncomfortable for a few minutes while the house cools down when I get home and turn it on. If I buy an energy efficient air conditioner instead, I save energy without changing my behavior. For utilities, it is also much easier to measure the impact of installing an energy efficient device because the energy savings do not depend on human behavior.
Is Energy Conservation Gaining Popularity?
Fortunately, there are many companies out there that are trying to create interesting solutions so that we can conserve energy without having to change our behavior as much. Sensors can be used that know when someone is in the room and leaving the room. In the near future, we should be able to use our phones to control home energy use. If my home is unbearably hot when I arrive, I will be able to turn on the air conditioner when I’m 15 minutes away. Once these technologies become more widely available, energy conservation will likely gain popularity. Just remember… it’s not energy efficiency. It’s energy conservation.
So, I open the windows at night and allow my home to cool down as much as possible. In the morning, I close all the windows to prevent the warming air from coming inside. As a result, I don’t run my air conditioner until late in the afternoon, and then for only a portion of the time I would have run it otherwise.
Efficiency or conservation?
For me the end result is the same (comfortable home) and I’ve used less energy (conserved power). However, I’ve done so without upgrading to energy efficient equipment.
Why not strive for both? New technologies will potentially allow us to achieve both. However, it starts with our attitude and behavior, and more importantly education. If we can demonstrate all of the potential values and benefits to the consumer they will embrace change.
Good points. Although touched on several times, it is worth emphasizing that the broad goal is twofold: to minimize spending on energy and to cut use of fossil fuels, the latter either because you are concerned about CO2 evolution and other pollution, depletion of fossil fuels, or dependence on other countries for supply.
This can be done by some combination of
1. generating energy more efficiently – more usable work, heat, cooling, light, transportation, comfort, etc. from the same amount of energy source (coal, oil, hydro, etc);
2. generating energy more sustainably by using a renewable, non-polluting, indigenous resource – solar, geothermal, wind, etc. (Note that this may actually be less efficient than burning a fossil fuel. Solar conversion is inefficient, but solar is so abundant and renewable that, capital costs aside (a big aside), that may not be critical.)
3. Using the energy more efficiently to do the work, generate the light, cool the room, travel to work, etc. (an efficient air conditioner);
4. Waste less of the generated work/light/heat, etc., through
a. using less of it where it brings no advantage, other than convenience (leaving the lights on, heating an empty house);
b. using less of it where cutting back is acceptable from a cost/benefit, ethical, moral or other perspective (turning down the thermostat and putting on a sweater, using public transportation);
c. using less of it by decreasing waste without giving up comfort or convenience – better insulation, tight, energy efficient windows and more of them, designs to capture solar gain in winter and shield it in summer, lower weight car with regenerative braking, efficient power supplies for electronic items.
As always, the costs of changing to something different are a combination of the real and the perceived expenditures of capital, operating cost, convenience, comfort, performance, status, and freedom.
Thanks for bringing this to the attention of everyone. I understand it but it was nice to see it explained in plain English
I agree with this distinction and would like to add to it. Energy Efficiency is about the conversion of energy from one form to another. So the air conditioner converts electrical energy to cool air. A car converts energy in fuel to distance travelled. At 100% efficiency all the energy is converted from one form to another by the machine, but this never happens, as there are always losses and the goal of an efficient machine is to minimise those losses. So I would say that in fact energy efficiency is about reducing wasted energy but that waste is in the conversion from one energy form to another.
Energy conservation is about making energy last longer through careful use and as you say that involves turning things off when they are not required.
So for me efficiency is about the conversion of energy, conservation is about the use of energy. Conservation is becoming more popular as it is cheap and quick to implement. You can monitor electricity use in the home and it is easy to turn off lights in rooms that are not being used and to turn off equipment that is sitting in standby modes. There is no investment required!
Good writeup. Energy Conservation seems to be gaining more popularity for 2 reasons :
1. Retrofit solutions mean affordability and lesser work rather than replacement of an entire unit.
2. Users tend to pay from savings for Energy Conservation solutions to safeguard their interests. This is generally not encouraged in case of Energy Efficient solutions where the replacement costs are higher and the service provider may be more interested in complete transaction at one.
Moreso with advancement in technology and human tendency to spend less on lesser known solutions or products re-emphasizes the belief that Energy Conservation is better than Energy Efficiency in several aspects.
The point is very clear for the difference in energy efficiency and energy conservation. Energy efficiency is technological up gradation of particular equipment or utility while energy conservation involves optimum usage of energy according to the actual requirement and avoid any wastage due to unnecessary running of the device or utility……
the purpose of both is same to save energy (by technical up gradation its improving efficiency and by demand side management its conservation)
Hi Josh,
I like the analogy, and I think you’ve hit on an important point. Very often it’s the change in behaviour that gets the real benefits, but that’s almost always the most difficult change to make.
Whilst a change of behaviour is obviously the cheapest thing to do, in terms of cash-in-pocket, people look for the ‘gadget’ instead of looking to modify their behaviour.
Efficiency and conservation are different, and interrelated. You can indeed have efficient products, yet use them in a way that is not. This is where conservation plays a roll. Conversely using inefficient products in a conservative way can be more productive. Let me get this out of the way, I do not like flourescent lights. They give me a head ache. Incandescents have a warmer glow and in my opinion better light. This is my gut reaction to them. Thinking about them, they are more efficient in the light they do produce, more light for each watt they use, but they rely on mercury to do so. The label gives elaborate disposal procedures which are scary in thier own right. Now that that’s out of the way, there is an alternative, ie using mirrors. Sunlight strikes the earth at around 800 Watts per square meter. Special mirrors can split the infrared (the heat) portion from the visible light, and
concave mirrors can be used to adjust this level to say 80 Watts per square inch, which can then be directed throughout the building with flat mirrors, and dispersed at the final destination with convex mirrors. The hot portion can be directed to a storage center in the same way.
With a little forethought a structure can be planned out to take advantage of the local neighborhood. The way I would do it; Starting with the foundation, I would dig a trench 25′deep x 4″wide around the perimeter, filling it with concrete to make a skirt to trap the ground heat. This has the effect of keeping the floor at about 55 degrees year around. Next using styrofoam loaded concrete for an R-32 insulation value build the walls, floors, cielings and roof. Tracking mirrors divide and concentrate the light portions to be used for lighting and thermal storage. The heat can then be used for power generation and heating as needed. Silvered mylar curtains go a long way to preventing overheating in summer and direct light. Judiciously designing the thermal mass of the bottom floor the building, it can be designed to maintain a constant 70 degrees without further active control. Lighting on days with overcast will rely on storage for power to augment the lighting with electricity. The skirt can also help keep roads and driveways free of ice. I would also escavate the grounds 3-4 feet deep and lay down heavy plastic sheet then gravel and sand then top soil to control ground water for feeding and watering the grounds with a pump station.
I like this differentiation between energy efficiency and conservation and like the way it is explained with examples of sensors.With the time, specifically in case of buildings, these devices play a major role . Do we have the figures how energy efficiency and energy conservation measures go hand by hand and impact the system and what is their individual contributions.