Figure SPM.2
Shares of energy sources in total global primary energy supply in 2008 (492 EJ).
Modern biomass contributes 38% of the total biomass share. …
(IPCC, Special Report on Renewable Energy Sources and Climate Change Mitigation, 2011, p 6)
Climate Council
Despite pledging in 2009 to phase out fossil fuel subsidies, all G20 countries continue to subsidise fossil fuels, collectively spending an estimated US$ 452 billion annually on fossil fuels.
The amount spent by G20 countries subsidising fossil fuels is nearly four times the amount spent to encourage the uptake of renewable energy. …
(p 14)
Despite global growth in renewable energy for power generation, fossil fuels continue to make up 77% of global electricity production, with coal contributing the largest share (40%). …
In 2014, coal plant closures in OECD countries were offset by capacity increases in the rest of the world, leading to a net increase of 66 GW in coal power capacity …
(p 18)
(Andrew Stock, Petra Stock and Martin Rice, A Whole New World: Tracking the renewables boom from Copenhagen to Paris, 2015)
The 6°C Scenario
International Energy Agency
The 6°C Scenario (6DS) is largely an extension of current trends.
By 2050, primary energy use grows by almost two-thirds (compared with 2012) and total GHG emissions rise even more.
In the absence of efforts to stabilise atmospheric concentration of GHGs, average global temperature rise above preindustrial levels is projected to reach almost 5.5°C in the long term (by 2500) and almost 4°C by the end of this century.
Already, a 4°C increase within this century is likely to stimulate severe impacts, such as sea level rise, reduced crop yields, stressed water resources or diseases outbreaks in new areas.
The 6DS is broadly consistent with the World Energy Outlook Current Policy Scenario through 2040.
The 4°C Scenario (4DS) takes into account recent pledges made by countries to limit emissions and step up efforts to improve energy efficiency, which helps limit long-term temperature rise to 4°C (by 2500).
The 4DS is, in many respects, already an ambitious scenario that requires significant changes in policy and technologies compared with the 6DS.
This long-term target also requires significant additional cuts in emissions in the period after 2050; yet with average temperature likely to rise by almost 3°C by 2100, it still carries the significant hazard of bringing forth drastic climate impacts.
(p 17)
[For] the first time since the IEA started monitoring clean energy progress, not one of the [clean energy technology fields (ie renewable power and heat, nuclear power, gas-fired power, coal-fired power, CCS, industry, iron and steel, cement, transport, fuel economy, electric and hybrid-electric vehicles, buildings, building envelopes, appliances and equipment, co-generation and district heating and cooling, smart grids, energy storage or hydrogen) was on track to meet its objectives under the 2°C Scenario.]
(p 4, emphasis added)
[Within the renewable power field, solar] PV is the only technology on track to meet its 2DS power generation target by 2025.
Its capacity is forecast to grow by 18% annually between 2014 and 2020. …
If these medium-term trends continue, solar PV could even surpass its 2025 target.
Improvement Needed
(p 24)
Low-priced coal was the fastest-growing fossil fuel in 2013, and coal-fired generation increased in all regions. …
Natural gas-fired power, a cleaner and more flexible generation fuel than coal, slowed markedly on global markets in 2013-14, unable to compete against low coal prices. …
Total electricity generation in 2012:
- 40% coal-fired
- 21% renewable [— wind and solar 2.8%]
- 11% nuclear …
[The] first commercial-scale coal-fired power plant (CFPP) with CO2 capture [was opened] in October 2014.
(p 9)
… 90% of CO2 emissions from the unit … will be captured and stored underground through enhanced oil recovery … without storage-focused monitoring. …
To meet the 2DS, the rate of CO2 being stored per year will need to increase by an order of magnitude.
(p 32)
[Enhanced oil recovery currently] remains the only commercial driver for carbon capture projects.
(p 12)
In 2014, global renewable electricity generation rose by an estimated 7% (350 TWh) …
OECD non-member economies continued to dominate global renewable generation, with their share increasing to around 55%.
China remained the largest market, accounting for an estimated 23% of overall renewable electricity generation in 2014.
In 2014 … over 45 gigawatts (GW) of new [onshore wind, and 40 GW of new solar photovoltaic] capacity was installed globally …
(p 17)
Renewable Power Generation by Technology — 2°C Scenario(Adapted from Figure 1.7) | ||
| On Track | Improvement Needed | Not On Track |
| Solar PV | Hydropower | Solar Thermal Electricity |
| Onshore wind | Offshore Wind | |
| Geothermal | ||
| Bioenergy | ||
| Ocean | ||
(p 25)
At the beginning of 2014, 72 [nuclear] reactors were under construction, the highest number for more than 25 years. …
[Gross installed capacity is] currently at 396 GW [and] is projected to reach 438 GW to 593 GW by 2025 …
[Under the 2°C Scenario] global nuclear capacity would need to reach 585 GW by that time.
(p 26)
Last year China overtook the United States in annual investment in smart grid technologies.
(p 56)
By 2020 the average lifetime emissions intensity of all new-build plants in China, India and the United States will need to fall to levels near half that of current gas-fired plants …
(p 64)
The average CO2 intensity of electricity generation has fallen since 2000 in [China, the United States and the European Union. …]
Policies to phase out inefficient coal plants and wider deployment of wind and solar power helped to cut emissions intensity by 17% in China between 2000 and 2012.
The development of cheap shale gas in the United States triggered a switch from coal to gas-fired generation that lowered average emissions intensity by 19%.
In the European Union, reductions in emissions intensity have been more modest as policies to phase out nuclear power, combined with ongoing use of coal, have partially offset rapid expansion of renewable generation.
[By contrast,] the emissions intensity of electricity generation in India has risen slightly (by 2%) because rapid growth in electricity demand has been mainly satisfied by subcritical coal plants and because existing coal capacity is ageing and poorly maintained.
(p 69)
Each 1% reduction in electricity consumption in the buildings sector … can help to reduce emissions from power generation by 60 MtCO2, equivalent to an installed capacity of 45 GW of wind power (15,000 turbines) or 23 GW of coal-fired power (46 plants).
(p 75)
(Tracking Clean Energy Progress 2015)
Contents
Introduction
Climate Change
Technologies and Markets
Integration into Present and Future Energy Systems
Renewable Energy and Sustainable Development
Mitigation Potentials and Costs
Policy, Implementation and Financing
Advancing Knowledge About Renewable Energy
Intergovernmental Panel on Climate Change
- IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation, Working Group III, 2011.
Ottmar Edenhofer, Ramón Pichs-Madruga, Youba Sokona, Kristin Seyboth, Patrick Matschoss, Susanne Kadner, Timm Zwickel, Patrick Eickemeier, Gerrit Hansen, Steffen Schloemer, and Christoph von Stechow: Editors.
Introduction
The Working Group III Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) presents an assessment of the literature on the scientific, technological, environmental, economic and social aspects of the contribution of six renewable energy (RE) sources to the mitigation of climate change.
Renewable Energy and Climate Change
Demand for energy and associated services, to meet social and economic development and improve human welfare and health, is increasing. …
(p 2)
Greenhouse gas (GHG) emissions resulting from the provision of energy services have contributed significantly to the historic increase in atmospheric GHG concentrations. …
Recent data confirm that consumption of fossil fuels accounts for the majority of global anthropogenic GHG emissions [56.6%].
Emissions continue to grow and CO2 concentrations had increased to over 390 ppm, or 39% above preindustrial levels, by the end of 2010.
There are multiple options for lowering GHG emissions from the energy system while still satisfying the global demand for energy services. …
As well as having a large potential to mitigate climate change, RE can provide wider benefits. …
Under most conditions, increasing the share of RE in the energy mix will require policies to stimulate changes in the energy system.
Renewable Energy Technologies and Markets
RE comprises a heterogeneous class of technologies.
Various types of RE can supply electricity, thermal energy and mechanical energy, as well as produce fuels that are able to satisfy multiple energy service needs.
Some RE technologies can be deployed at the point of use (decentralized) in rural and urban environments …
[Others] are primarily deployed within large (centralized) energy networks.
Though a growing number of RE technologies are technically mature and are being deployed at significant scale …
[Others] are in an earlier phase … or fill specialized niche markets.
The energy output of RE technologies can be- variable and — to some degree — unpredictable over differing time scales (from minutes to years),
- variable but predictable,
- constant, or
- controllable
Box SPM.1
Renewable energy sources and technologies considered in this report.
[Bioenergy]
[Can] be produced from a variety of biomass feedstocks, including- forest, agricultural and livestock residues;
- short-rotation forest plantations;
- energy crops;
- the organic component of municipal solid waste; and
- other organic waste streams.
[Technical Maturity]
[Commercially] available technologies include- small- and large-scale boilers,
- domestic pellet-based heating systems, and
- ethanol production from sugar and starch.
Advanced biomass integrated gasification combined-cycle power plants and lignocellulose-based transport fuels are examples of technologies that are at a pre-commercial stage …
[Liquid] biofuel production from algae and some other biological conversion approaches are at the research and development (R&D) phase.
[Deployment]
[Technologies] have applications in centralized and decentralized settings …
[The] traditional use of biomass in developing countries [in the residential sector is] the most widespread current application.
{[This involves] the often unsustainable use of wood, charcoal, agricultural residues, and animal dung for cooking and heating.
All other biomass use is defined as modern.}
[Output]
[Typically] constant or controllable …
[Solar]
[Harness] the energy of solar irradiance- to produce electricity using photovoltaics (PV) and concentrating solar power (CSP),
- to produce thermal energy (heating or cooling, either through passive or active means),
- to meet direct lighting needs and, potentially,
- to produce fuels that might be used for transport and other purposes.
[Technical Maturity]
[Ranges] from- R&D [—] fuels produced from solar energy …
- relatively mature [—] CSP) …
- mature [—] passive and active solar heating and wafer-based silicon PV …
[Deployment]
Many … of the technologies are modular in nature, allowing their use in both centralized and decentralized energy systems.
[Output]
[Variable] and, to some degree, unpredictable, though the temporal profile of solar energy output in some circumstances correlates relatively well with energy demands.
Thermal energy storage offers the option to improve output control for some technologies such as CSP and direct solar heating.
[Geothermal]
… Heat is extracted from geothermal reservoirs using wells or other means.
Reservoirs that are naturally sufficiently hot and permeable are called hydrothermal reservoirs …
[Reservoirs] that are sufficiently hot but that are improved with hydraulic stimulation are called enhanced geothermal systems (EGS).
Once at the surface, fluids of various temperatures can be used to generate electricity or can be used more directly for applications that require thermal energy …
[Technical Maturity]
[Power] plants and thermal applications … are mature technologies …
… EGS projects are in the demonstration and pilot phase while also undergoing R&D.
[Output]
[Typically] constant …
[Hydro]
[Encompasses] dam projects with reservoirs, run-of-river and in-stream projects [at a range of scales.]
[Deployment]
[Can] meet large centralized urban needs as well as decentralized rural needs.
[Technical Maturity]
[Mature]
[Output]
[Projects] exploit a resource that varies temporally.
However, the controllable output provided by … reservoirs can be used to meet peak electricity demands and help to balance electricity systems that have large amounts of variable RE generation.
[Ocean]
[The] potential, kinetic, thermal and chemical energy of seawater … can be transformed to provide electricity, thermal energy, or potable water [using]- barrages for tidal range,
- submarine turbines for tidal and ocean currents,
- heat exchangers for ocean thermal energy conversion, and
- a variety of devices to harness the energy of waves and salinity gradients.
[Technical Maturity]
[Technologies,] with the exception of tidal barrages, are at the demonstration and pilot project phases and many require additional R&D.
[Output]
[Variable] energy output profiles with differing levels of predictability [—] wave, tidal range and current …
[Near-constant] or even controllable operation [—] ocean thermal and salinity gradient …
[Wind]
[Produces] electricity from large wind turbines located- on land (onshore) or
- in sea- or freshwater (offshore).
[Technical Maturity]
Onshore wind energy technologies are already being manufactured and deployed on a large scale.
Offshore wind energy technologies have greater potential for continued technical advancement.
[Output]
[Is] both variable and, to some degree, unpredictable, but experience and detailed studies from many regions have shown that the integration of wind energy generally poses no insurmountable technical barriers.
(pp 4-5)
Deployment of RE has been increasing rapidly in recent years. …
[Capacity] continued to grow rapidly in 2009 …- wind power (32% increase, 38 Gigawatts (GW) added),
- hydropower (3%, 31 GW added),
- grid-connected photovoltaics (53%, 7.5 GW added),
- geothermal power (4%, 0.4 GW added), and
- solar hot water/heating (21%, 31 GWth added).
Biofuels accounted for 2% of global road transport fuel demand in 2008 and nearly 3% in 2009. …
Of the approximate 300 GW of new electricity generating capacity added globally over the two-year period … to 2009, 140 GW came from RE additions.
[Developing] countries host 53% of global RE electricity generation capacity.
(p 6)
The global technical potential of RE sources will not limit continued growth in the use of RE.
[Studies] have consistently found that the total global technical potential for RE is substantially higher than global energy demand.
(p 7)
Climate change will have impacts on the size and geographic distribution of the technical potential for RE sources, but research into the magnitude of these possible effects is nascent.
(p 8)
The levelized cost of energy for many RE technologies is currently higher than existing energy prices, though in various settings RE is already economically competitive. …
{The levelized cost of energy represents the cost of an energy generating system over its lifetime …
[It] is calculated as the per-unit price at which energy must be generated from a specific source over its lifetime to break even. …}
Many of the other RE technologies can provide competitive energy services in certain circumstances, for example, in regions with favourable resource conditions or that lack the infrastructure for other low-cost energy supplies.
[However, in] most regions of the world, policy measures are still required to ensure rapid deployment of many RE sources.
(p 9)
The cost of most RE technologies has declined and additional expected technical advances would result in further cost reductions. …
[Important] areas of potential technological advancement include:- new and improved feedstock production and supply systems, biofuels produced via new processes (also called next-generation or advanced biofuels, eg, lignocellulosic) and advanced biorefining;
- advanced PV and CSP technologies and manufacturing processes;
- enhanced geothermal systems (EGS);
- multiple emerging ocean technologies; and
- foundation and turbine designs for offshore wind energy
[Opportunities] exist to make hydropower projects technically feasible in a wider range of locations and to improve the technical performance of new and existing projects.
(p 11)
A variety of technology-specific challenges (in addition to cost) may need to be addressed to enable RE to significantly upscale its contribution to reducing GHG emissions.
Integration Into Present And Future Energy Systems
Various RE resources are already being successfully integrated into energy supply systems and into end-use sectors. …
Figure SPM.7
Pathways for RE integration to provide energy services, either into energy supply systems or on-site for use by the end-use sectors.
The characteristics of different RE sources can influence the scale of the integration challenge.
(p 13)
Integrating RE into most existing energy supply systems and end-use sectors at an accelerated rate — leading to higher shares of RE — is technologically feasible, though will result in a number of additional challenges. …
The costs and challenges of integrating increasing shares of RE into an existing energy supply system depend on the current share of RE, the availability and characteristics of RE resources, the system characteristics, and how the system evolves and develops in the future.- RE can be integrated into all types of electricity systems, from large inter-connected continental-scale grids down to small stand-alone systems and individual buildings. …
- District heating systems can use low-temperature thermal RE inputs such as solar and geothermal heat, or biomass, including sources with few competing uses such as refuse-derived fuels.
District cooling can make use of cold natural waterways. - In gas distribution grids, injecting biomethane, or in the future, RE-derived hydrogen and synthetic natural gas, can be achieved for a range of applications but successful integration requires that appropriate gas quality standards are met and pipelines upgraded where necessary. …
- Liquid fuel systems can integrate biofuels for transport applications or for cooking and heating applications.
There are multiple pathways for increasing the shares of RE across all end-use sectors.
The ease of integration varies depending on region, characteristics specific to the sector and the technology. …- For transport, liquid and gaseous biofuels are already and are expected to continue to be integrated into the fuel supply systems of a growing number of countries.
- In the building sector, RE technologies can be integrated into both new and existing structures to produce electricity, heating and cooling. …
- Agriculture as well as food and fibre process industries often use biomass to meet direct heat and power demands on-site.
The costs associated with RE integration, whether for electricity, heating, cooling, gaseous or liquid fuels, are contextual, site-specific and generally difficult to determine. …
In order to accommodate high RE shares, energy systems will need to evolve and be adapted.
As infrastructure and energy systems develop, in spite of the complexities, there are few, if any, fundamental technological limits to integrating a portfolio of RE technologies to meet a majority share of total energy demand in locations where suitable RE resources exist or can be supplied.
However, the actual rate of integration and the resulting shares of RE will be influenced by factors such as costs, policies, environmental issues and social aspects.
(p 15)
Renewable Energy And Sustainable Development
Historically, economic development has been strongly correlated with increasing energy use and growth of GHG emissions, and RE can help decouple that correlation, contributing to sustainable development (SD). …- RE can contribute to social and economic development. …
- RE can help accelerate access to energy, particularly for the 1.4 billion people without access to electricity and the additional 1.3 billion using traditional biomass. …
- RE options can contribute to a more secure energy supply, although specific challenges for integration must be considered. …
- In addition to reduced GHG emissions, RE technologies can provide other important environmental benefits.
Maximizing these benefits depends on the specific technology, management, and site characteristics associated with each RE project. - Lifecycle assessments (LCA) for electricity generation indicate that GHG emissions from RE technologies are, in general, significantly lower than those associated with fossil fuel options, and in a range of conditions, less than fossil fuels employing CCS. …
- Most current bioenergy systems, including liquid biofuels, result in GHG emission reductions, and most biofuels produced through new processes (also called advanced biofuels or next-generation biofuels) could provide higher GHG mitigation.
The GHG balance may be affected by land use changes and corresponding emissions and removals. … - The sustainability of bioenergy, in particular in terms of lifecycle GHG emissions, is influenced by land and biomass resource management practices. …
- RE technologies, in particular non-combustion based options, can offer benefits with respect to air pollution and related health concerns.
Improving traditional biomass use can significantly … lower associated health impacts, particularly for women and children in developing countries. … - Water availability could influence choice of RE technology. …
- Site-specific conditions will determine the degree to which RE technologies impact biodiversity. …
- RE technologies have low fatality rates.
(pp 16-18)Figure SPM.8
Estimates of lifecycle GHG emissions (g CO2eq/kWh) for broad categories of electricity generation technologies, plus some technologies integrated with CCS.
Mitigation Potentials and Costs
A significant increase in the deployment of RE by 2030, 2050 and beyond is indicated in the majority of the 164 scenarios reviewed in this Special Report.
(p 18)
RE can be expected to expand even under baseline scenarios. …
RE deployment significantly increases in scenarios with low GHG stabilization concentrations.
(p 19)
Many combinations of low-carbon energy supply options and energy efficiency improvements can contribute to given low GHG concentration levels, with RE becoming the dominant low-carbon energy supply option by 2050 in the majority of scenarios. …
The scenario review in this Special Report indicates that RE has a large potential to mitigate GHG emissions. …
Scenarios generally indicate that growth in RE will be widespread around the world.
(p 20)
Scenarios do not indicate an obvious single dominant RE technology at a global level; in addition, the global overall technical potentials do not constrain the future contribution of RE.
[Modern] biomass, wind and direct solar commonly make up the largest contributions of RE technologies to the energy system by 2050. …
[In] the four illustrative scenarios less than 2.5% of the global available technical RE potential is used.
(p 21)
Individual studies indicate that if RE deployment is limited, mitigation costs increase and low GHG concentration stabilizations may not be achieved. …
A transition to a low-GHG economy with higher shares of RE would imply increasing investments in technologies and infrastructure. …
The four illustrative scenarios analyzed in detail in the SRREN estimate global cumulative RE investments (in the power generation sector only) ranging from USD2005 1,360 to 5,100 billion for the decade 2011 to 2020, and from USD2005 1,490 to 7,180 billion for the decade 2021 to 2030.
The lower values refer to the IEA World Energy Outlook 2009 Reference Scenario and the higher ones to a scenario that seeks to stabilize atmospheric CO2 (only) concentration at 450 ppm.
The annual averages of these investment needs are all smaller than 1% of the world’s gross domestic product (GDP). …
The higher values of the annual averages of the RE power sector investment approximately correspond to a five-fold increase in the current global investments in this field.
Policy, Implementation and Financing
An increasing number and variety of RE policies—motivated by many factors—have driven escalated growth of RE technologies in recent years.
(p 22)
Policies have promoted an increase in RE capacity installations by helping to overcome various barriers. …
- institutional and policy barriers related to existing industry, infrastructure and regulation of the energy system;
- market failures, including non-internalized environmental and health costs, where applicable;
- lack of general information and access to data relevant to the deployment of RE, and lack of technical and knowledge capacity; and
- barriers related to societal and personal values and affecting the perception and acceptance of RE technologies.
Public R&D investments in RE technologies are most effective when complemented by other policy instruments, particularly deployment policies that simultaneously enhance demand for new technologies. …
Some policies have been shown to be effective and efficient in rapidly increasing RE deployment.
However, there is no one-size-fits-all policy. …
- Several studies have concluded that some feed in tariffs have been effective and efficient at promoting RE electricity …
- An increasing number of governments are adopting fiscal incentives for RE heating and cooling. …
- In the transportation sector, RE fuel mandates or blending requirements are key drivers in the development of most modern biofuel industries.
‘Enabling’ policies support RE development and deployment. …
- by addressing the possible interactions of a given policy with other RE policies as well as with energy and non-energy policies (eg, those targeting agriculture, transportation, water management and urban planning);
- by easing the ability of RE developers to obtain finance and to successfully site a project;
- by removing barriers for access to networks and markets for RE installations and output;
- by increasing education and awareness through dedicated communication and dialogue initiatives; and
- by enabling technology transfer.
Two separate market failures create the rationale for the additional support of innovative RE technologies that have high potential for technological development, even if an emission market (or GHG pricing policy in general) exists.
- The first market failure refers to the external cost of GHG emissions.
- The second market failure is in the field of innovation: if firms underestimate the future benefits of investments into learning RE technologies or if they cannot appropriate these benefits, they will invest less than is optimal from a macroeconomic perspective. …
Advancing Knowledge About Renewable Energy
Additional knowledge related to RE and its role in GHG emissions reductions remains to be gained in a number of broad areas including …
- Future cost and timing of RE deployment;
- Realizable technical potential for RE at all geographical scales;
- Technical and institutional challenges and costs of integrating diverse RE technologies into energy systems and markets;
- Comprehensive assessments of socioeconomic and environmental aspects of RE and other energy technologies;
- Opportunities for meeting the needs of developing countries with sustainable RE services; and
- Policy, institutional and financial mechanisms to enable cost-effective deployment of RE in a wide variety of contexts.
