Using Lean Six Sigma to cut down your Electricity Bill

Lean Six Sigma can help you to cut down your energy consumption at home. Want to save money on your energy bill? Let’s have look how to do that!

What To Know Before Getting Started

  • Kilowatt Hour, kWh: Is a unit of energy equal to 1000 watt hours or 3.6 mega joules. All wattage measures in this study are in kWh(s);
  • Usage Meter: This device is used to measure the actual power usage of a appliance in kWhs;
  • Major Appliances: For this study are the following:
    • Refrigerator, Oven, Stove, Dishwasher, TV, DVR
    • Washer, Dryer, House Heater Fan, Air Conditioner
    • Pool pumps
  • Smart Meter: Elecrtic Ireland SmartConnect® smart meters are designed to transmit usage information within a secure wireless network every hour. This data used in tandem with its supporting S/W gives the customer access to a much greater set of information, programs and tools that can be sued for greater control over his/her energy use and budget;
  • Billing is from the 19th thru 19th of the next month

Project Summary

  • Reduced monthly electricity cost by 35%, 10% greater than the target goal;
  • Improved alignment of max power usage with least cost time frames thus reducing the cost of electricity used;
  • Improved awareness by all house mates on their own power usage habits.

Problem Statement

  • Monthly cost of electricity used has gone up every year for the last 6 years. Now it is more than $260/month.

Goal Statement

  • Understand the required use of electricity and identify those devices or activities that contribute the most to the overall bill. Reduce the overall electricity usage & cost by 20%


In Scope:

  • Upgrading of major appliances with more efficient devices
  • Redefine the usage models for major appliances to reduce use frequency and when used

Out of Scope:

  • Changes to house environment standards (Air and Water Temp, etc.)

Business Case & Benefits

  • Currently the customer is in job transition. Household budget has been greatly reduced. Also being at home more has increased the monthly utility bills.
  • Reducing this monthly expense will reduce the monthly drain on savings.

Voice Of the Customer

  • Customers are those living in our house
  • Requirements based on interviews:
    • Home temperatures need to be comfortable
    • Adequate hot water available
    • Laundry kept clean
    • Yard lights in place for safety
    • Pool kept clean
    • Changes approved by all

Team Members

  • Self
  • Wife
  • Daughter
  • Son

DMAIC Approach

  • Identified a baseline of electricity usage (over 1 year)
  • Identified appliances and how much electricity is
    used and when during the day
  • Audit the number of times room lights and computers are left unattended and powered on


  • The customer is currently unemployed and needs to reduce monthly costs in order to meet budget constraints

Project Timing

  • Start Date: October 07, 2014
  • End Date: December 20. 2014


  • December 2010: €350
  • December 2011: €320 (- €30 from previous year)
  • December 2012: €215 (- €105 from previous year)

Analyze Phase



Room Light Audit:

  • Potential Issue: People leave the lights on to often expense
  • Hypothesis Statement: Lights left on in unattended rooms greatly contribute to the over monthly electricity
  • Audit Results: It was determined from the baseline data that there was a real issue with how we manage our habits with regard to turning the light off when we leave a room


  1. Held a family meeting to review the baseline results and to agree upon possible improvements. See below:
    • Install automatic light switches in rooms that we all can agree on. Of the 12 rooms in our house 6 were selected. Automatic light switches operate on detecting motion. Each was set to turn off after not detecting motion for 8 minutes.
    • A incentive plan for people was adopted. Every time anyone saw a light on in a empty room the last person to use the room would put €1.00 in a Electric Ireland fund. If we went 1 month without any contributions then we would have a family movie night.


  • Each automatic light switch cost €11.99 (6 for €77.69 including Taxes)
  • Each room has at least 200 watts of lighting and I decided to allocate 2 hrs for each event.
  • Kilowatts / month = 103 events/month x 400 watts/event = 41,200 watts / month = 40.2 kWs / month Savings: (40.2 kWs/month x €.30/kW = €12.06 per month x .806 = €9.72/month

Return on Investment = €77.69 / €9.72/month = 7.9 months


  • Improvements were selected based on the ease of implementation and the return on investment;
  • Improvements were also agreed to by the customers;
  • The improvements were as follows:
    • Update the 20 year old single speed master pool pump with a variable speed pool pump;
    • Reduce the frequency of lights being left on in unoccupied rooms;
    • Alignment of our peak electricity usage with Electric Ireland least expensive time frames;
    • Turn off the dryer mode in the Dishwasher;
    • Keep the Freezer 90% full at all times.


  • Monitor Lights Left On agreed to process;
  • Audit electricity usage each week for 1 year, checking on daily use metrics provided by Electric Ireland;
  • Perform a energy usage audit every year and maintain records for all major appliances;
  • Slowly convert all household lights to LED lighting, target goal 100% in 2 years.

Monitoring Plan

Key Process measures:

  • Bi-monthly communication to customers with data provided by Electric Ireland
    • Provided by wife in a monthly family meeting
  • Average daily/weekly usage should not exceed that of the usage from 1 year ago minus process improvement estimates from Dec. 2014
    • Provided by Michael in a monthly family meeting
  • Monthly “Lights Left On” process fees should not exceed €21.00 / month
    • Provided by wife in a monthly family meeting

All indicator measures are lagging and will be evaluated monthly.