Lights that are turned ON when they aren't needed is wasting energy and your money.
Lights that are turned OFF when they aren't needed is saving energy and your money.
Turning the lights OFF in an area no matter how big or how small when there is nobody around to use them is always going to give you energy savings.
Exactly how much energy you will save in a day, a week or a year depends on a number of factors; the application type, the area usage by time; as well as ambient light levels during the day to name a few. The idea to save energy is straight forward - automatically turn the lights on when needed and turn them off when not.
The more areas of lighting you can turn on only when needed and turn off when not needed for the longest amount of time possible = more energy and money savings.
With an energy savings strategy and a little bit of planning you can maximise your energy savings with a range of products and techniques.
Energy Savings Example
Consider a warehouse with 5 bays and twenty 40W lights per bay. The warehouse hours are 7am – 5pm operating Monday – Friday with a 1 hour lunch break. The electricity tariff for this example is 20cents per kWh.
Without sensors the yearly electricity consumption is 10,400 kWh at a total cost of $2,080.
Now include an energy saving mySmart Sensor that will turn off the lights during the 1 hour lunch break. Immediately the consumption drops by 10% and $208 per year.
In many warehouses there are both slow and fast moving stock lines. A well designed warehouse will have fast moving stock lines closer to the front of the warehouse and slow ones towards the back. This saves time and costs by allowing the faster and more efficient fulfilment of orders.
So imagine if the lights in each bay were split 50:50 with sensors controlling each half. Assume now that because the slower stock lines are only accessed half as often as the fast ones it means that lights in the back are only turned on for 50% of the time.
This would give a further saving of 25% over and above turning the lights off at lunchtime and a 33% and $676 saving over the lights being on all day!
But, there are even more energy savings that could be had.
Energy Savings with Light Level (Lux)
Many warehouses have transparent roof panels to let in more natural light. So let's use this to our advantage to save even more energy and money with dimmable lighting. This technique is often referred to as daylight harvesting or light levelling and it is rather surprising just how much energy can be saved by controlling lighting to make the most use of natural light.
As an example Sydney has an average of 6 hours of bright sunshine per day and only 133 cloudy days per year **.
So during the period 9am to 3pm we can dim the lights to 50% output on 64% of the operating days whilst still keeping in place our previous energy saving strategies. This gives a further saving of 18% from the 50:50 split and a 44% and $924 saving over the baseline electricity consumption.
**Source: Bureau of Meteorology