Energy efficiency, not the falling price of solar, has done the heavy lifting when it comes to improving the economics of distributed clean energy for the poor.

LEDs' reduced demand for energy brings down the size, and therefore the cost, of everything in a system, from solar panel to battery. Imagine if we took this lesson -- energy efficiency unlocks distributed energy for the poor -- and applied it to rural electrification as a whole?

What you might come up with is a novel new approach to mini-grids -- dubbed "skinny grids" by my colleague Stewart Craine of Village Infrastructure Angels.

Two of the most pressing basic needs for the poor are lighting and mobile phone charging -- the latter coming from an unprecedented number of unelectrified mobile phone users, which represent an enormous market opportunity for distributed energy. Serving those needs with yesterday’s technology (the incandescent bulb and even CFLs) is very tough. Using those technologies basically meant that the economics to serve these markets with clean energy didn’t work.

Enter the LED. Advances in LED white lighting have revolutionized the amount of power poor households now need. That changes everything from component to system size, which has cut costs dramatically. For example, the light supplied by 100 watts of incandescent bulbs can now be met with just 5 watts of well-designed LED lighting. Since a phone charger requires a similar amount of power, basic services can now be provided with 90 percent less power.

That’s a story many may know. What is far less explored is the impact beyond the individual solar home system. That’s because the drop in demand lowers the current in the "poles and wires" that connect households in conventional grids. This enables companies to use much thinner and cheaper wiring. Combined with smaller poles and longer spans, or locally dug underground trenches, the cost per household for reticulated wiring can be vastly reduced via thin-cable designs not previously imagined -- our aptly named skinny grids.

Combined with innovative 1- to 2-kilovolt transformers designed to use this lower power, these services can reach hundreds of households from existing off-grid sources of distributed generation.

In some countries, over 95 percent of all households are within 5 to 10 kilometers of an off-grid telecom tower, and these towers are often grossly under-loaded compared to the power demand for the tower. That means the power generation to connect 10 to 20 watts of load per household may already exist for the majority of the unelectrified population. Even better, the only investment needed is $1 per meter of skinny-grid connections.

Think about that for a minute. All the talk about the need for massive energy investments and grid expansion to electrify the world may be far overblown. There is massive distributed energy potential yet to be tapped -- all thanks to the LED light bulb.

Skinny grids are just one of the many innovations coming from the off-grid sector that may actually impact the grid itself. Indeed, the future of innovative clean energy deployment in developing countries is off the grid.

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Justin Guay leads the Beyond Coal to Clean Energy work for the Sierra Club’s International Climate Program.

Tags: developing countries, distributed energy, energy access, leds, lighting, rural power