Rural electrification without power grids

By Timothy O’Leary

This article originally appeared in the September 2007 issue of IEC e-tech.

Not only is it technologically feasible to provide electricity to isolated rural communities using photovoltaic systems, wind turbines and small hydropower plants, but it is also affordable.

These technologies can help people in rural villages in Africa, Asia and Latin America obtain electricity relatively inexpensively. It shouldn't actually cost them much more than they'd already pay for kerosene lamps, candles, dry cell battery-powered torches and diesel generators.

Those same rural villagers can use their newfound electricity to obtain a host of desirable ends – refrigeration to preserve antibiotics and vaccines, illumination to increase residential safety and to allow children to study at night, modern communications to reduce social marginalization, and machines to pump water and to drive mills and sewing machines.

High demand for renewables
The demand for rural electrification is enormous. Just ask the World Bank, which says that 1.6 billion people lack access to electricity in their homes. That’s more than one-quarter of the world’s population.

Just ask IEC Technical Committee 82, Solar photovoltaic energy systems, which during the past four years has produced 13 technical specifications in the IEC 62257 series – seven of them in just the past 15 months – and is in the process of drafting four more. This series of standards is intended specifically for rural electrification needs in developing countries.

And just ask such companies as Isofotón, Fortis Windenergy, SMA Technologie and BP Solar, which are providing renewable energy systems for developing and transitional economies. This market is estimated at about USD 220 billion annually for overall electricity.

Since most customers are poor and the scale of individual projects is small, most of the financing for rural electrification comes from governments, foreign donors and international financial organizations.

In meeting the demand for rural electrification, renewable energy providers have certain advantages over traditional providers. Not only do they provide rural dwellers with cheap and reliable electricity, but they also provide clean and cost-effective alternatives to carbon-based energy sources, such as coal and petroleum, which pollute, cause climate change and cost countries with developing and transitional economies high proportions of their foreign trade earnings.

"Decentralized solutions may be cost competitive when you compare them with the extension of the power grid and with conventional electricity options like kerosene and diesel, which also have heavy social and environmental costs that aren’t taken into account," said Paula Llamas, secretary general of the Alliance for Rural Electrification, a Brussels-based nonprofit organization comprising European renewable energy providers.

IEC standards play key role
The IEC has an important role to play in helping the rural electrification industry to develop. As a World Bank report about off-grid rural electrification points out, "Poor-quality equipment and installation, and exaggerated performance claims, hurt markets." Enforceable standards are necessary to ensure quality, safety and customer satisfaction.

"We consider it important that rural electrification of this nature be top quality and perform optimally," says IEC General Secretary Aharon Amit. "That means looking after safety and performance of equipment and systems and it means providing electricity where it’s needed in an efficient and effective way."

Sun? Wind? Water? A world of choices
Before starting to build an off-grid rural electrification system using renewable energy, analysis must be done to determine what kind of system would be best.

• How many homes have to be served? If the answer is many, then it may be necessary to build a so-called "minigrid", which would connect each home to the power source, or sources.

• Does the wind blow consistently enough and with enough force? Wind becomes exploitable where average annual wind speeds exceed four to five metres per second.

• Is the monthly average of daily sunshine hours enough to justify the use of photovoltaics? Excessive clouds, fog and dust can reduce their efficacity.

• Is a hybrid system required, one that uses, for example, wind turbines and photovoltaic cells working in tandem? It can make sense to put one’s eggs into more than one renewable energy basket. In particular, a hybrid system can meet demand more consistently.

• Should the hybrid system include a diesel generator to handle peak loads? "If you have a high peak load, it’s advisable to have a diesel generator as well to guarantee that you get power all the year round," said Johan Kuikman, managing director of Fortis Windenergy.

• Is flowing water an option? If so, does the water have a big enough "head" and do enough litres per second flow to drive a hydro turbine? With an average head of 3,95 metres and a maximum flow rate of 0,800 m3/s, the small hydropower plant in Todomé, in rural Togo, in West Africa, provides 25 kVA to power computers, lamps, machine tools and a refrigerator. Not only does the plant not hurt the environment, but it replaced a lung- and sinus-scorching diesel generator.

• Will inverters be necessary? And batteries to store the electricity like a silo stores grain? And protection against lightning strikes? And noise abaters?

Only after such questions are asked and answered should equipment be procured and installed.

Improving lives in rural China
Netherlands-based Fortis Windenergy makes small wind turbines that provide 200 watt- to 30 kilowatt-rated capacity, are virtually maintenance-free and have an average working life of 20 years. The turbines look like airplane propellers perched on tall metallic pylons. Low-speed permanent magnet alternators convert the rotational energy of propeller-like blades into electricity.

In June 2006, the company installed a hybrid system in a floating school on Hong Hu Lake in western China, where 500 families live on house boats, Mr Kuikman said. The big school boat has six classrooms, a clinic and an administrative office. Besides the five kilowatt wind turbine, they installed a two- to three-kilowatt photovoltaic system on the boat’s roof. The budget for the project was nearly EUR 6 million, with 90% provided by the government of the Netherlands, the rest by the China Association of Rural Energy Industry. The result has been clean, cheap and convenient electricity to power lights, computers, medical equipment and Internet routers.

"Nobody doubts that the era [of renewable energies] has arrived," said Alvaro Ybarra Zubria, executive chairman of Madrid-based Isofotón, who added that the problems of international and institutional aid for energy development "can only be solved in realistic terms with a model based on renewable energy."

Source: International Electrotechnical Commission (IEC).