## "How To" Energy Savings Calculations

Recently we took a good hard look at what articles we had written generated the most interest. It was clear that most people were interested in the "how to" of calculations.

This article will focus on the basics of energy calculations, more specifically it will be on how to put everything together so you can get a very close estimation on energy savings.

## Useful Energy Calculations:

Not everyone knows the exact wattages of the lights over their head. For the sake of ease I am going to give you the industry standard wattages of the more common fixtures. You can download the table here.

OK now that you have that lets look the calculations. Let's use a very common 2X4, 4 lamp fixture that consumes 148 watts. Here's the scenario:

- 70 fixtures (Fixture Quantity)
- .10 KWH rate (Per Kwh Cost of Electricity)
- 4,000 hrs annual operation (Number of Hours Per Day x 365)
- Replaced with 28W T8 lamps and ballasts (Possible Upgrade)

**Demand KW = (fixt. wattage X fixt. qty.) /1000**

(148 X 70) / 1000 = 10.36KW.

**KWH = (Demand KW X hours of operation)**

10.36KW X 4,000 = 41,440 KWH.

## What Are the Energy Savings?

Now using the table lets look at how much electricity the new T8 lamps and ballast will use:

**Demand KW = (fixt. wattage X fixt. qty.) /1000**

(92W X 70) /1000 = 6.44KW.

**KWH = (Demand KW X hours of operation)**

6.44KW X 4000 = 25,760 KWH.

## What Are Your Annual Energy Savings?

Now that we have our old and new KWH let's calculate what our savings will be.

**KWH Savings = Original KWH - New KWH **

41,440KWH - 25,760KWH = 15,680KWH

**Annual Energy Savings = KWH Savings X Electric Rate**

15,680KWH X .10 cents per KWH = $1,568.00 dollars.

## Hovey Energy Savings Group Can Do the Calculations For You

Don't want to go through all the headache of being your own calculator?

Let the Energy Efficiency experts help you determine the best energy efficiency investments for your facility. We help you determine energy savings, find all available incentives, calculate maintenance savings, calculate payback period and determine your ROI from each energy efficiency recommendation that we make.

Leave a comment and we'll take all the hassle out of the equation!