Light Bulb Moment
Dr Barry Manor, Sustainability Consultant, looks at the technology of lighting and how it can be used to achieve energy efficiency in domestic and commercial situations.
Lighting technology has been revolutionised in the last few years as LED lighting has become available. LED lights last a very long time in service. People can choose a warm (orangey) light, or a harsher cool (white) light for places like kitchens and factories. There is virtually an LED light for any application at home or at work.
The old incandescent bulbs are now illegal to sell in Australia, a result of the federal government initiative known as the Minimum Energy Performance Standard (MEPS). MEPS is applied to items such as light bulb, fridges and electric appliances and each year the threshold for energy efficiency if increased. For lighting, this means the minimum number of lumens (units of light output) for each watt of electricity used by the lamp goes up. Incandescent bulbs are extremely inefficient as 95% of the electricity is converted to heat and only 5% is converted to light. The present lumen per watt threshold is way above what incandescent lamps can provide, so they are illegal to sell.
Before LEDs were available there was the interim technology of compact fluorescent lamps (CFLs, also known as “energy saver” bulbs) that fitted into incandescent lamp fittings. There were government energy saving schemes which encouraged businesses to spring up and provide efficient CFL lighting to households, in many cases for free. Unfortunately people often didn’t install them, as they had a few issues that people didn’t like. They took a few minutes to ramp up to full brightness and they contained a small amount of mercury which created a problem for landfill. Thus, the scheme was not particularly successful.
An incandescent lightbulb puts out about 10 lumens per watt of electricity consumed whereas an LED puts out over 100 lumens per watt, 10 times more energy efficient. There has been a steady increase in output from 70-80 lumens per watt and in labs they have achieved 230 lumens per watt. This is considerable given the service life of an LED bulb is typically around 14 years (in use 10 hours per day). The electronics in unbranded products are often poorly designed, so those LED bulbs are less likely to last 14 years. Cheaper bulbs may buzz or flicker, due to compromised electronic design. Incandescent bulbs provide about 1,000 hours of use compared to 50,000 hours for LEDs. Electricity use in Australia actually went down for 4-5 years in a row, forcing providers to bump up charges to recoup their multi-billion dollar investment in poles and wires.
Lots of people have downlights in their ceilings but these are nasty! Most downlights are low-voltage ones that run off transformers hidden in the roof space. Each downlight is usually around 60 watts (50 watts for the bulb and 10 watts for the transformer). One down light can be replaced by an 11 watt LED. The cost ($12-15) will be paid back in less than a year and there are the added benefits of producing less heat (so less need for air conditioning) and lower maintenance.
Currently, there is big business supplying LED lighting to the commercial, industrial sector and domestic sectors. It might cost a factory $35,000 to upgrade to LED but that amount is often paid back in 4-5 months, a return on investment of over 200%. Many factories and warehouses use high intensity discharge lighting which falls in between incandescent and LEDs. A 460 watt high bay light fixture can be replaced by a 110 watt LED fixture, a substantial saving.
Unfortunately this federal government appears wedded to old technology, particularly in electricity generation. They are not pro-active in sustainability; they’re still approving new coal mines and blaming power system failures on renewable energy. Individuals and businesses can make a difference by implementing energy efficiency improvements, especially in lighting.
Changing to LEDs is a win/win as it reduces pollution, saves on resources and saves money. LEDs really are a light bulb moment.
Dr Barry Manor was interviewed for A Question of Balance by Ruby Vincent. Summary text by Victor Barry, May 2017.