It's all about the blinking...
One of the complaints in regards to Christmas Lights has been their environmental footprint. Yes they look pretty, but 10KW of power (Just over 2008's maximum power draw) used for 4 hours a night for all of December can produce a LOT of CO2. 1,250 KWhr from black coal can produce over a tonne of CO2 during the month of December. Add to that the testing, powered up time for repairs etc, which can easily add another 10 to 20% to the total time the lights are powered up.
Because of this, Lithgow Lights has reduced its overall load by a number of means as shown below. In the last 2 years Lithgow Lights has more than doubled the number of lights in the display, while reducing maximum power consumption by almost 50%. All Computers, controllers and power supplies are switched off when not in use, so as to further minimise the standby current draw.
The replacement of 240V floodlights with energy efficient 24V DC LED Floodlights has continued in 2010. With all the floodlights on in 2008 they would draw close to 3000 Watts, but the 12 replacement LED floodlights drew less than 140 Watts when all on. 2010 will see the floodlight numbers increase to 26, including uplighting in trees and better coverage on the house, and drawing just 340 Watts.
After the replacement of the floodlights in 2009, the largest source of power usage is now 240V ropelight used for outlining the house. The house outline had 90 meters of ropelight totalling over 2200 Watts when all on, or roughly 25 Watts per meter. In 2010 this has been replaced with 90 meters of LED ropelight which draws a maximum of 909 watts. Because the led's are run at much lower intensity, and only 1 color is usually on at a time, the actual power usage is less than 200 watts, a saving of 90% on power usage. Because the 240V ropelight was 2 channel, Green/Blue and Red/Orange, the replacement ropelight for 2010 will actually be a 4 color ropelighte in White, Red, Blue and Green.
Instead of 2 channels in each of the three 30 meters sections, there are now 4 channels on each of 15 sections, so rather than lighting up one 30 meter section, I can often just illuminate a few much smaller sections to give a much better result, and using substantially less power.
Some of the 240V ropelight items have also been upgraded to LED Ropelight. As the incandescent ropelight items fail they will be restrung with LED ropelight to continue saving energy and increase life expectency of the items. One item that has been restrung for 2010 has dropped energy usage from 264 watts (1.1 Amps at 240V AC) to 63 watts (2.6A at 24V DC), which is less than 25% of the original power usage! One additional bonus, like the house outline, is that there will be less 240V gear outside in the weather.
One of the final energy saving items is the display itself. Rather than having all the lights burning all the time, the nature of animated lighting is that only a small part of the display is on at any time. The LED floodlights for instance, were used for a little over one full minute out of the entire 15 minute show in 2009, and even then they were not always on at full brightness, and not all of the 3 colors were used at any one time. Many of the incandescent lights were used in the same manner, so on average only 25% or less of the lights were on at any one time. In fact only once in the 2009 show did all the lights come on at once, and that was for a whole 1.3 seconds!
While the peak power usage may have been close to 7,000 watts, the real average power usage was measured at less than 1800 watts averaged out over the entire 15 minute show. All the wattages used here are worst case, meaning all the lights are on with 100% intensity, but when doing colors other than white, the RGB items are up to 2/3 lower than that stated, and many items now have 2 through 4 sets of different colored lights on them, and normally only 1 set is on at any one time, making the real power just 25% of the peak power shown. To put that in perspective, a clothes dryer or bar radiator will draw between 1800 and 2400 Watts when on.
In 2007 we had no LED lights, in 2008 we introduced 1536 LED's in the Ledtriks Panel. 2009 saw a 3072 LED Ledtriks Panel and 1944 Led's in the floodlights, and in 2010 we expect 3072 LED's in the Ledtriks, 4860 LED's in the floodlights and about 12,000 LED's in ropelight, totalling close to 20,000 LED's. These LED's draw a fraction of the power that a conventional incandescent bulb does, but give similar brightness. This power saving through the use of LED's will continue over the next few years here at Lithgowlights, and hopefully one day we will get to 100% LED.