Solar Energy Perspectives - IEA

Chapter 1: Rationale for harnessing the solar resource
More significantly perhaps, in scenarios that call for a more rapid deployment of renewables,
such as the ETP 2010 “Hi-Ren” (for high-renewable) scenario, solar energy makes the largest
additional contribution to GHG emission cuts, probably because of its almost unlimited
potential. Solar electricity tops 25% of global electricity generation by 2050, more than either
wind power or hydro power. By contrast, most other renewables – with the possible exception
of wind power – may meet some kind of intrinsic limits. If this is the case, in a carbon-lean
world economy solar energy would continue to grow faster than any other energy resource
long after 2050. Solar energy is particularly available in warm and sunny countries, where
most of the growth – population, economy, and energy demand – will take place in this
century. Warm and sunny countries will likely contain about seven billion inhabitants by
2050, versus two billion in cold and temperate countries (including most of Europe, Russia
and parts of China and the United States).
An important implication of these scenario analyses is that, if other important technologies or
policies required to cut emissions fail to deliver according to expectations, a more rapid
deployment of solar energy technologies could possibly fill the gap. Energy efficiency is essential
but growth in demand, the so-called “rebound effect”, 3 might be underestimated; nuclear power
may face greater political and public acceptance difficulties; CCS is still under development.
Furthermore, according to the Intergovernmental Panel on Climate Change (IPCC, 2007),
a reduction of GHG emissions by 2050 of 50% from 2 000 levels is only the minimum
reduction required to keep the long-term increase of global temperatures to within 2°C to
3°C. Reductions of up to 85% might be needed to keep within these temperature rises. This
would imply that CO 2 emissions should be constrained to less than 6 Gt CO 2 in 2050 and
beyond. As ETP 2010 put it, “a prudent approach might be to identify a portfolio of lowcarbon
technologies that could exceed the 50% reduction target in case deeper cuts are
needed or some of the technological options identified do not become commercially
available as originally thought.” This publication therefore outlines an energy future with very
little CO 2 emissions and small contributions from technologies other than renewables.
This is not to say that renewable energies, and solar in particular, will not face expected and
unexpected challenges. They already do. In 2011, policy makers in several European countries
expressed legitimate worries about the “excessive success” of their policies on solar photovoltaics
(PV). Based on incentives per kilowatt-hours (kWh) for long periods of time – typically 20 years –
these policies create long-lasting liabilities for electricity customers and sometimes taxpayers.
The incentives appear too generous, often only months after they have been set. This results from
the very rapid cost decrease of PV – an effect precisely in line with the goals of the policy. Roofmounted
PV modules are now competitive, not only off-grid, but also on grid in sunny countries
with high retail electricity prices. Cost concerns are legitimate, but it would be foolish to give
up at this stage. Market expansion drives cost reductions, and cost cuts expand niche markets,
which sets in motion a virtuous circle. Nothing indicates that this development would meet any
limit soon, but the impetus still requires policy support for a few more years.
Despite the costs, deploying renewables gives policy makers a positive, industrialising, job
creating, and non-restrictive means of action to mitigate climate change. While European policy
3. Energy efficiency improvements reduce energy consumption and thus the costs of doing anything; as a result, people might do
more of it. For example, they may drive longer distances with more efficient cars.
27
© OECD/IEA, 2011