Past the pilot stage for off-grid energy

We are poised on the brink of a unique moment the history of electricity supply where decentralised networks are set to rapidly expand, fulfilling the needs of the worlds poor. This is the bold conclusion from a group of researchers based at Berkeley, lead by Dr. Dan Kammen. Their recent perspective piece, published in Nature Climate Change, takes a comprehensive look at the prospects for off-grid solutions in the developing world.

1.3 billion people worldwide lack access to electricity and in many places and there is little prospect of national grid extensions serving their needs in the near future. Aside from the evident injustice, there is a real human cost, with strong links established between access to energy and the Human Development Index (HDI).

The team argue that there is cause for optimism, pointing to disruptive technologies such as new super-efficient appliances and low-cost photovoltaics. Kammen compares today’s situation with that in the late 1800s, when much of the world’s electrification took place. They describe a convergence of forces that  drove the staggeringly rapid advance of domestic electricity supply at the time, including a ready availability of capital,  strong institutions and good access to information.


The trend in electric light source efficacy for a range of technology including LED solid-state lighting (Decentralized energy systems for clean electricity access, Nature Climate Change).

A similar phenomenon may be under way again in the developing world, driven by innovative payment models for home solutions and new technologies. As cost barriers continue to fall, poor people are better able to buy into new energy schemes and support a burgeoning industry.

The authors suggest that energy supply should be seen as a continuum, with different technologies providing steps on the ladder towards full access. Technologies such as pico-power solar systems, while inadequate for most domestic uses can lead to high marginal benefits for households.

This is because the ‘first few watts’ are sufficient to provide for the two most demanded uses; mobile phone charging and lighting. In particular,  they eliminate the need for kerosene (paraffin) lighting, improving health and providing more high quality light for the same price. Kammen invokes a hypothetical person spending US$100 per year for lighting. New LED technology means he/she could swap a mere 100 ‘lumen-hours’ of light generated by kerosene for 100,000 with high-efficacy LED lighting.

Kammen concludes that, while these options currently provide lower power levels, they often have greater flexibility in deployment and scalability. Experience with historical grid expansion suggests that the current suite of tailored public, private, and hybrid efforts may well be the key to rapid expansion of a new decentralised model.

Dan Kammen has written a key essay for Smart Villages’ upcoming anthology, due to be published in early Summer 2015 by Banson of Cambridge.

Header images shows Pearl Street Station, the first central power plant in the United States.


  1. Peter Alstone, Dimitry Gershenson & Daniel M. Kammen, Decentralized energy systems for clean electricity access, Nature Climate Change 5,305–314

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