Renewable hope for the South

Sustainable development requires sustainable energy. And sustainable energy will have to include sustainable electricity. As yet, we do not know what sustainable electricity looks like. But we have a pretty clear idea of what unsustainable electricity looks like. It looks like the traditional form of electricity that has spread over much of the planet through most of the past century.

The traditional electricity system is shaped by the economies of scale associated with water turbines and steam turbines. Large remote central stations based on these machines generate electricity in the form of synchronised alternating current, and deliver it to users over a network including long high-voltage transmission lines. This technical configuration has been spectacularly successful, so much so that most people in OECD countries take electricity completely for granted.

But traditional electricity systems have failed to reach more than two billion people, one-third of humanity. Moreover, the three most important traditional generating technologies hydroelectric dams, coal-fired stations and nuclear stations now face severe challenge, not only for their environmental impacts but also for their daunting capital cost.

Gas turbines

Traditional electricity systems are franchised monopolies. Traditional planners can order enormous plants, costing billions of dollars, taking six years or more to complete and at least another twenty years to pay off, because captive customers pay all the costs and bear all the risks. However, as electricity systems are freed from government control, shareholders and bankers have to share the risk; and long-term investments in traditional generating technologies become seriously risky.

At the same time, new generating options are emerging, more attractive both financially and environmentally. First comes the gas turbine, fuelled by cheap and abundant natural gas. Wherever natural gas is available, gas-turbine generation is now the option of choice.

Gas-turbine generation is economic at a smaller scale. It exhibits economies of series manufacture, with a rapid learning curve. It is modular, expanding capacity by adding more modules. It can be ordered, built and brought into service in less than three years. It is easier to site, cleaner and more convenient than the traditional technologies. It can therefore be located close to or indeed on the premises of electricity users.

The rise of gas-turbine generation is changing the technical configuration of electricity systems, from centralised towards decentralised, with more and smaller generators closer to users. Other innovative generating technologies with similar attributes are reinforcing this new trend, for example, mini- and micro-turbines, fuel cells, and a portfolio of renewable energy technologies including micro-hydro, wind, biomass and photovoltaics.

The traditional synchronised AC system demands large-scale centralised dispatching and control; power electronics, however, now allows systems to be much less tightly integrated and more flexible. The capabilities of new data-handling and system management technologies are likewise burgeoning.

Local systems

If communities, companies and other local users generate their own electricity close to where they use it, they will want to make sure it is used as effectively as possible, with high-performance buildings, lights, motors, electronics and so on. They will think in terms of the whole local system, not just the 'energy source'. They will want to optimise the whole system to deliver the services they want comfort, illumination, motive power, information not just the electricity. Optimising the whole local system thus makes sense both financially and environmentally.

The implications are profound. Much of this Energy sub-site of People & the Planet has focused on local systems where people are still awaiting the benefits of electricity. Where the traditional large-scale centralised model faces insuperable obstacles, only local systems have any hope of delivering electricity services. The remarkable fact, however, is that even in the rich countries of the OECD, the shape of electricity is now evolving in the same direction, away from the traditional model towards a much looser network of local systems.

By a powerful irony, where people do not now have traditional electricity, they are also free of its technological and institutional inertia. They will be able to establish the innovative model much faster. As we enter the new millennium, today's emerging countries will lead the way towards sustainable electricity.

Walt Patterson, Senior Research Fellow in the Energy and Environmental Programme of the Royal Institute of International Affairs, London, is the author of Transforming Electricity, Earthscan, 1999.

For more details of how you can help, click here.