Environmental Engineering Reference
In-Depth Information
potential for energy from sustainable technologies is huge. On the techno-
logical side, renewables have an obvious role to play. In general, there is no
problem in terms of the technical potential of renewables to deliver energy.
Moreover, there are very good opportunities for Renewable Energy Targets
(RETs) to play an important role in reducing emissions of GHGs into the
atmosphere, certainly far more than have been exploited so far. However,
there are still some technical issues to address in order to cope with the inter-
mittency of some renewables, particularly wind and solar. Yet, the biggest
problem with relying on renewables to deliver the necessary cuts in GHG
emissions is more to do with politics and policy issues than with technical
ones [79]. For example, the single most important step governments could
take to promote and increase the use of renewables is to improve access for
renewables to the energy market. This access to the market needs to be under
favourable conditions and, possibly, under favourable economic rates as well.
One move that could help, or at least justify, better market access would be
to acknowledge that there are environmental costs associated with other
energy supply options and that these costs are not currently internalised
within the market price of electricity or fuels [67].
Renewables are generally weather dependent and as such their likely
output can be predicted but not controlled. The only control possible is
to reduce the output below that available from the resource at any given
time. Therefore, to safeguard system stability and security, renewables
must be used in conjunction with other, controllable, generation and with
large-scale energy storage. There is a substantial cost associated with this
provision.
The recent REN21* report (2014) states that renewables have entered the
mainstream as we begin the Decade of Sustainable Energy for All (SE4ALL),
†
mobilising towards universal access to modern energy services, improved
rates of EE and expanded use of renewable energy sources by 2030. In 2012,
renewable energy provided an estimated 19% of global final energy con-
sumption, and it continued to grow in 2013. Of this total share in 2012,
modern renewables accounted for approximately 10%, with the remainder
(estimated at just over 9%) coming from traditional biomass. Heat energy
from modern renewable sources accounted for an estimated 4.2% of total
final energy use; hydropower made up about 3.8%, and an estimated 2% was
provided by power from wind, solar, geothermal and biomass, as well as
by biofuels. The combined modern and traditional renewable energy share
*
REN21 is the global renewable energy policy multi-stakeholder network that connects a wide
range of key actors. REN21's goal is to facilitate knowledge exchange, policy development
and joint action towards a rapid global transition to renewable energy.
†
The UN Secretary-General's initiative Sustainable Energy for All mobilises global action to
achieve universal access to modern energy services, double the global rate of EE and double
the share of renewable energy in the global energy mix by 2030. As the newly launched
Decade for Sustainable Energy for All (2014-2024) unfolds, REN21 will work closely with the
SE4ALL Initiative towards achieving its three objectives.
