Page 345 - ISES SWC50

12.2.4 Overview of Assumptions in the Three Studies

The three studies presented here (all developed prior to the outbreak of the coronavirus pandemic) have
many common elements for achieving the Paris Climate goals through an energy transformation to 100%
renewables. However, based on assumptions related to technology costs, political will, and technology
innovation, they offer somewhat different pathways, resulting in differing outcomes in terms of technology
mixes, deployment rates, overall costs, etc. The outcomes differ in the level of decarbonization achieved by
2050, and they all require further actions to continue to be taken during the remainder of the century. But all
studies ultimately achieve 100% renewables, and all reflect a very positive future for renewable and related
clean energy technologies.

IRENA Global Renewables Outlook 2020 [1]: Since 2014, the International Renewable Energy Agency
(IRENA) has been undertaking studies to determine how the world can achieve sustainable energy and
mitigate climate change, known as the Global Energy Roadmap, or REMap. Initially their analyses went out
to 2030, using a pathway that doubles the share of renewable energy. In 2018 they extended the outlook to
2050 and have elaborated on their analysis most recently in their first Global Renewables Outlook 2020 [1].

The Roadmap examines in detail a “Transforming Energy Scenario”, which is described as an ambitious, yet
realistic transformation pathway based largely on renewable resources and energy efficiency measures aimed
to keep the rise of global warming to well below 2ºC and towards 1.5ºC by the end of this century. This scenario
contrasts to their “Planned Energy Scenario”, which is their reference case and is based on governments’
current energy plans, targets, and policies, including the NDCs established by individual countries under the
Paris Agreement. An even lesser-ambitious scenario, the Baseline Energy Scenario, is predicated on policies
and commitments in place just prior to the Paris Agreement.

The Transforming Energy Scenario is achieved through a number of factors and assumptions. First and
foremost, the costs of solar PV and other renewables will continue to decline, and policies that currently
support subsidies to the fossil industry will shift to renewables. The scenario specifically assumes the following:
1) a major shift towards the electrification of the transport and heating and cooling sectors, resulting in more
than a doubling of the current contribution of the power sector, so that electricity supply represents 49% of
total energy demand; 2) the percentage of renewables providing this electricity supply will grow from 25%
(2017 levels) to 86% by 2050, with solar and wind representing the majority of this supply due in large part to
their falling prices (solar PV will provide 25% of total electricity demand, compared to its current contribution
of ~3%);. 3) hydropower will continue to provide important synergies to a future energy system; 4) besides
increased electrification, renewables will also contribute significantly to the heating and cooling and mobility
sectors; 5) the energy intensity of the global energy demand will fall by 2/3 due to electrification, renewables,
and energy efficiency measures; 6) modern bioenergy and biofuels, and the emergence of green hydrogen,
will also provide key roles in meeting a transformed energy supply. The energy mix resulting from these
assumptions is shown in Figure 103.

The Transforming Energy Scenario does not bring carbon emissions down to the level recently recommended
by the IPCC [4], which requires a fully decarbonized energy system by md-century in order to achieve the
1.5ºC Paris Climate Agreement target. The Transforming Energy Scenario, albeit ambitious, cuts 70% of
the world’s energy-related CO emissions by 2050, 90% of which is accomplished through renewables and
2
energy efficiency measures. By 2050 this scenario still shows annual CO emissions of 9.5 Gt, although this is
2
more than 80% below current levels. The study does offer additional recommendations to cut CO emissions
2
beyond 2050 to zero or net-zero, especially with the emergence of cost-competitive green hydrogen utilisation.

ISES SWC50 - The Century of Solar-Stories and Visions | 327