21 December 2011


The light emitting diode (LED) was invented decades ago, but it is the 21st century that is now gobbling up this technology en masse. Everywhere we look, flashlights, cell phones, the tiny light on your computer’s battery plug, even clothes and accessories are sporting these tiny gas-burning bulbs of wire and epoxy. And with good reason: LED are extremely energy efficient and since they do not use heavy metals or other contaminants, they produce very little waste at the end of their long life cycles. A standard, white LED runs on about 3.2V of electricity (20mA consuming 0.064Watts), 95% of which is channeled into light with only about 5% lost as heat, and produces on average 30,000 hours of light. Part of its efficiency is that electrical current only travels in one direction through the tiny semiconductor, positive to negative, and of the two metal terminals that protrude from the bulb, the longer one is always positive. Working with LED makes the physics of electrical circuitry very easy, plus with low voltage there is no threat of shock or burns. Of course the light produced by LED is very concentrated, but there are myriad ways to diffuse their light using simple household materials or even by recycling trash. Water is a great way to diffuse light and just one white LED placed inside the cap of a 2-liter bottle of water can create soft ambient lighting for a patio, a garden path, or an isolated dry toilet. And the water in the bottle can be dyed any color to create different moods or atmospheres.

Here in Los Brujos we are fast trading-in our expensive candle dependency for the luminescence of LED. We have experimented with two systems of battery: the 12V deep cycle charged by our solar panels and a 5V cell phone battery. Since LED are sensitive to higher voltage, which will drastically cut their lifespan or just burn them out, it is best to design your circuits with less voltage per LED than more (reminder: their maximum voltage is 3.2V on average). Here’s where you have to remember back to physics class: in series the voltage per LED adds up, in parallel the voltage remains constant. What that means is to use 12V energy for my 3.2V LED’s, I connect 4 LED’s in series (energy flowing from one to the other, positive to negative) which gets my system as close to 12V as possible without going over voltage per LED. For the 5V cell battery, we connected 2 LED’s in series. All other LED connections to our systems are placed in parallel (complete circuits of LED’s in series of 4 for 12V and of 2 for 5V connected back to the battery source). So far we have not found a limit for how many series can be placed in parallel, but transitioning from candles to electrical light, our lighting needs are probably far less ambitious than the average household. In the puppeteers’ illuminated house, they are running at least 6 series of 2 LED in parallel to their 5V cell phone battery without impunity. I only have 2 series of 4 LED in parallel in my house (the kitchen and altar), but it is mostly on account of not making the time to run more wire and my easy pace of transitioning myself to this new technology.

After nearly 5 years of life among candles there is something romantic that one loses by replacing the daily presence of flame with electrical light. But candles are extremely expensive and their light, though soft and inspiring, is typically petroleum-based. It has been a process of wonder to come home and literally click-on the lights, the kitchen counter and stove spot-lit by inversed metal cans punctuated with LED, the altar a-glow from bottles of Kikkoman and mineral water with LED’s inside. The puppeteers placed LED’s between old compact discs, giving their mud-house the look of what I imagine the Ewok village might have transitioned to after the rebel forces arrived to the Endor moon with all their laser technology. I suppose we invent and imagine our own romance to replace that which we set-aside in our personal evolutions. Fire will always remain a sacred element to Los Brujos life, heating our houses, cooking our food, creating a space for reflection in ritual, but it will no longer be placed on precarious stands besides flammable curtains asking to be forgotten, leaping up the walls, devouring precious things in its wake. Here we now celebrate the LED-volution as we continue exploring technologies and designs that fit our scale of life and literally keep illuminating the creative process.

All my knowledge on LED was supplied by Fernando Becerra who gave an interesting talk at a reunion of Permaculturists from Latin America (Encuentro PermaSur) at El Manzano in November 2011. Please visit his website http://www.lapuertadelsol.com for more information on LED or if you live in Chile and would like a professional consultant to design and install an LED-lighting system for your house.