Solar Energy Perspectives - IEA

Chapter 3: Solar electricity
Kenya and Nigeria, and 5 MW (each) for Senegal and Sri Lanka. Each megawatt of solar home
systems with an average size of 50 W offers basic solar electricity to 20 000 households, but these
numbers pale when compared to the considerable demand in the developing world.
Indeed, electricity has yet to change the lives of 1.4 billion people who have no access to it
today – more than was the case when Thomas Edison first popularised the electric light-bulb
in the 1880s. Many more people suffer frequent shortages or voltage fluctuations, whether
through insufficient generation capacities or weak distribution networks or both.
Fuel-based lighting is expensive, inefficient and the cause of thousands of deaths each year
from respiratory and cardiac problems related to poor indoor air quality. It severely limits any
visually oriented task, such as sewing or reading (IEA, 2006). Small quantities of electricity
would provide light and power for education, communication, refrigeration of food and
pharmaceuticals. More electricity would allow the development of economic activities.
The rate of electrification of the world population has increased dramatically in the last 25 years,
mostly due to grid extensions in China. Where grids do not exist, there should be no systematic
preference either for off-grid distributed systems or for grid extensions. The choice must rest on
an analysis of the density of the population, lengths of cables, foreseeable demand, and the
various generating means at hand, including their investment and running costs, and fuel
expenditures (for a good example of such analysis, see e.g. Raghavan et al., 2010).
Throughout most of the world, lack of access to grid electricity need not last forever.
Electricity grids have many advantages. Grids require much less generation capacity than if
each electricity usage had to be fed directly from an individual generating system. In most
countries the total capacity subscribed by all customers is three to five times the total installed
generating capacity, because not everyone makes use of all their available electric devices at
the same time. Savings on the generation side usually more than offset the cost of building,
maintaining and strengthening the electricity networks. It is not by accident that this model
has spread all around the industrialised world.
Nevertheless, off-grid and mini-grid electric systems, totally or partly based on solar energy,
whether PV or small-scale STE, offer, in many cases, a shorter route to electrification. This is
especially true for low-density rural population in sub-Saharan Africa and Southeast Asia,
where many of those lacking access to electricity live. As solar electricity costs go down,
these markets will open further.
Policies
A wide range of policies might be considered for the support of large-scale deployment of
solar electricity. Many have been spelled out in the Technology Roadmaps for solar PV and
solar thermal electricity. The rationales and potential advantages and disadvantages of
a number of them are discussed below.
• Support for research and development remains indispensible before new devices and
approaches, such as those described in chapters 6 to 9, can reach their markets. Support
for deployment drives considerable research effort from private companies, with private
R&D expenditure growing sharply between the initiation of support and actual on-grid
deployment, as the PV example shows (Figure 3.14).
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© OECD/IEA, 2011