How is Energy Efficiency Calculated?

The conversion of energy into another form naturally results in dissipation, usually in the form of heat. The energy transmission and transformation process happens all around us, yet we’re unaware of its impact on our lives. There’s reason to be familiar with this process as it governs the rules of energy efficiency.

Energy efficiency is described as the amount of energy produced compared to the amount used in producing it. To calculate efficiency, you must divide the energy obtained by the initial energy. In a residential setting, the conversion efficiency for appliances, heating, and lighting is crucial in figuring out if the entire household is efficient. If that number is high, it means that the building or house is more energy efficient. Nevertheless, there are still other things to be factored in, i.e., quality of insulation.

Energy and Power

Energy, measured in joules (J) or watt-hours (Wh), refers to an object’s capacity to do work. 1 Wh of energy is equal to 3,600 joules. There’s no way of producing 100% efficiency in measuring energy efficiency even with the most advanced or sophisticated equipment.

Meanwhile, power is the amount of work, light, or movement produced over time by an appliance, machine, or energy type—the unit of measurement for power is in watts. Power can likewise be defined as the amount of energy that’s consumed per unit of time. To illustrate how power is measured, observe a standard light bulb. The brighter that bulb is, the more electricity it’ll consume over time.

Value of Energy Efficiency

It’s important to understand energy efficiency since it protects homeowners from the constant threat of rising utility costs. There’s a way to save money even if you’re using electricity at home, provided you know how to adjust. Efficiency savings depend on factors such as electricity rates, financial incentives afforded by the local government or utility company, and your home’s current efficiency. Use your knowledge of calculating energy efficiency to your advantage.

1 – Electricity Rates

Some regions in North America have higher electricity rates than others, particularly in the northeast. If you reside in one of those areas, the only way to up your savings is to perform energy efficiency strategies on your property. Utility companies charge more in some areas because of the high heating and cooling requirements (usually due to the climate and temperature).

2 – Financial Incentives

Local government and utility rebates are designed to help homeowners reduce their out-of-pocket costs of building projects meant for saving energy. Incentives vary from one program to another; but generally, it includes rebates for buying energy-efficient appliances and HVAC systems. You may also get rebates from the local utility company if you improve your home’s insulation and replace leaky doors and windows.

3 – Current Efficiency

This answers the question of how efficient your home or building is. Certain factors affect your property’s current efficiency, including the presence of drafts, two-decade-old appliances, and outdated heating and cooling equipment. Energy efficiency savings are possible once you recognize the need to replace old appliances and upgrade your heating and cooling system. Even if you don’t require an upgrade, the switch to energy-efficient appliances and equipment leads to net savings via reduced utility bills.

Calculating Energy Efficiency Savings

Calculate the energy efficiency of your household in a handful of ways:

  • Read the EnergyGuide label on all your appliances and electronic equipment.
  • Compute your energy use and expenses based on every appliance and electronic equipment’s energy rate and usage.
  • Compare the EnergyGuide label of old appliances to the new ones and then figure out how much you can potentially save.

The EnergyGuide program was borne out of the Energy Policy and Conservation Act of 1975. The law took effect five years later, from which the Federal Trade Commission was commissioned to come up with a compulsory energy efficiency labeling scheme for major appliances. This is how the EnergyGuide came to be. The law applies to the following appliances:

  • Refrigerators
  • Freezers
  • Air Conditioning Systems
  • Washing Machines
  • TVs
  • Furnaces
  • Boilers
  • Dishwashers
  • Heaters
  • Ceiling Fans
  • Pool Heaters
  • Heat Pumps

With the EnergyGuide label data, recalculate annual cost estimates to get accurate figures for your household. Determine the current price per kWh or kilowatt-hour of electricity and estimate how often you use the home appliances.

You can use the EnergyGuide estimate for “average use” for the refrigerator because it remains “on” for the whole day. The same thing can’t be said for other appliances like the air conditioning system.

EnergyGuide estimates how often the typical property owner will use them for other appliances that don’t run all day. Let’s use the TV as an example; the EnergyGuide label on your TV estimates that you’ll be consuming 350 kWh of energy on five hours of usage each day. So, what if your average usage is only four hours per day?

Multiply the EnergyGuide daily estimate (hours) by 365 (days) to get the number of hours per year. So, if you use your TV for five hours on average (based on the EnergyGuide label), then you’ll get 5 x 365 = 1825 hours. Next, divide the EnergyGuide estimated annual energy consumption of your TV by 1825 hours to get the number of kWh per hour of using the appliance. Hence, 350  1825 = 0.1917808 kWh.

This time multiply your estimated daily use of the TV in hours by 365 to get the adjusted annual estimated use. Therefore, 4 (hours) x 365 (days) = 1460. Next, multiply the two figures to get the adjusted annual estimate of your electricity consumption. Hence, 0.1917808 x 1460 = 280 kWh.

Since you now have the estimated kWh to use for your TV consumption, the next step is multiplying it by the kWh rate indicated on your electric bill. This gives you a much better idea of what it’ll cost you to operate a new TV.

Remember that the whole idea of energy efficiency is that older appliances are always less efficient than new ones because of outdated technology. Aside from that, you’ve been using them for a long time, which means efficiency is also affected by wear and tear.

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