How Much Primary Energy Is Wasted Before Consumers See Value from Electricity?
by Bob Shively, Enerdynamics President and Lead Facilitator
Ever wonder how much of the primary energy that goes into creating electricity actual provides useful work to us as consumers? Well the answer is not much – depending on the device using electricity it’s anywhere from 30% to as little as 5%. So, where does all that wasted energy go and what can we do about it? Or is it even worth trying? To address these questions, let’s look at where electricity is lost in the delivery chain.
Losses in generation, transmission, and distribution
First, let’s consider the primary energy that enters the electric delivery system at the input to the generator and examine how much of the primary energy is delivered to the customer. According to the Energy Information Administration (EIA), the answer is 34%. In other words, 66% of the primary energy used to create electricity is wasted by the time the electricity arrives at the customer meter.
U.S. primary energy consumption by source and sector:
Source: Graphic from Enerdynamics’ Energy Industry Overview course developed using data from the Energy Information Administration (EIA)
Where does all this waste go? It is primary energy that is converted to heat and then lost as waste heat. Here is where losses occur:
Generation
It is estimated that of the 66% lost, 59% of it is lost in the generation process. This includes:
- Waste heat occurring due to inefficiencies in the process of converting primary energy to electricity. This makes up about 54% of the overall losses.
- Electricity used internally by the power plant during operations. This makes up about 5% of overall losses.
Transmission and distribution grid
Another 5 to 7% of the original primary energy is lost during the delivery of electricity through the T&D system. The energy becomes waste heat released in the air due to line losses and conversion losses in transformers and other line equipment.
After the electricity arrives at the consumer premise, there are additional losses due to line loss within the building and inefficiency in converting the energy to useful services (heat, light, electronic processing, etc.). While amounts wasted within a consumer’s premises vary widely depending on the type of consumer and the type of equipment being used, looking at typical losses for various end-use processes can give us an idea of how much more energy is being lost within our buildings and factories:
| End use |
Estimated energy lost |
| Industrial boilers |
20% |
| Industrial process heat |
15% |
| Pumps and fans |
40% |
| Motors |
5% - 10% |
| Incandescent light bulb |
90% |
| LED light bulb |
10% |
Losses through the electric delivery system:
Learning that losses are so large is likely to make you ask “does it matter and, if so, what should we do about it?” Certainly, there are negative implications of energy losses. Power plants and T&D facilities have to be oversized since so much of the energy is lost. For thermal power plants more fuel is needed. This results in both capital and expense dollars that ultimately are paid by consumers.
Losses also increase environmental impacts of using electricity since more fuel must be mined or produced, more emissions are put in the air, and, in the case of renewable generation, more land is used for larger power plants. As for what we can do about it – our society can put more focus on efficiency of power generation and end-use devices. In many cases, energy efficiency investments are the cheapest way to control electricity costs.
To learn even more about primary energy, where it comes from and how much is lost before it gets to you, feel free to browse our online energy learning courses to sign your team up for advanced learning options. Enerdynamics is your #1 source for energy education, so sign up for more classes today!
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