scenario for a future energy supply
Moving from principles to action for energy supply that mitigates against climate change requires a long-term perspective. Energy infrastructure takes time to build up; new energy technologies take time to develop. Policy shifts often also need many years to take effect. In most world regions the transformation from fossil to renewable energies will require additional investment and higher supply costs over about twenty years. However, there will be tremendous economic benefits in the long term, due to much lower consumption of increasingly expensive, rare or imported fuels. Any analysis that seeks to tackle energy and environmental issues therefore needs to look ahead at least half a century.
Scenarios are necessary to describe possible development paths, to give decision-makers a broad overview and indicate how far they can shape the future energy system.Two scenarios are used here to show the wide range of possible pathways in each world region for a future energy supply system:
• Reference scenario, reflecting a continuation of current trends and policies.
• The Energy [R]evolution scenario, designed to achieve a set of environmental policy targets.
The global Reference scenario of the Energy [R]evolution 2012 was based on the Current Policies scenarios published by the International Energy Agency (IEA) in World Energy Outlook 2011 (WEO 2011).15 It only takes existing international energy and environmental policies into account. Its assumptions include, for example, continuing progress in electricity and gas market reforms, the liberalization of cross-border energy trade and recent policies designed to combat environmental pollution.The Reference scenario does not include additional policies to reduce greenhouse gas emissions.
The Reference scenario for this updated US study is based on the Reference case of the Annual Energy Outlook 2013 (AEO2013), prepared by the U.S. Energy Information Administration (EIA). As the EIA’s projections only extend to 2040, they have been extended by extrapolating their key macroeconomic and energy indicators forward to 2050.This provides a baseline for comparison with the Energy [R]evolution scenario.The projections are based generally on federal, state, and local laws and regulations in effect as of the end of September 2012, the Reference case projection is defined as a business-as-usual trend estimate, given known technology and technological and demographic trends.
The global Energy [R]evolution scenario has a key target to reduce worldwide carbon dioxide emissions from energy use down to a level of below 4 Gigatonnes per year by 2050 in order to hold the increase in average global temperature under +2°C.
A second objective is the global phasing out of nuclear energy.The Energy [R]evolution scenarios published by Greenpeace in 2007, 2008 and 2010 included ‘basic’ and ‘advanced’ scenarios, the less ambitious target was for 10 Gigatonnes CO2 emissions per year by 2050. However, the 2012 revision only focuses on the more ambitious “advanced” Energy [R]evolution scenario first published in 2010.
This global carbon dioxide emission reduction target translates into a carbon budget for USA, which forms one of the key assumption for the Energy [R]evolution scenario. To achieve the target, the scenario includes significant efforts to fully exploit the large potential for energy efficiency, using currently available best practice technology. At the same time, all cost-effective renewable energy sources are used for heat and electricity generation as well as the production of biofuels.The general framework parameters for population and GDP growth remain unchanged from the Reference scenario.
Efficiency in use of electricity and fuels in industry and
“other sectors” has been completely re-evaluated compared to earlier versions of the Energy [R]evolution scenarios using a consistent approach based on technical efficiency potentials and energy intensities.
Hydrogen generated by electrolysis and renewable electricity is introduced in this scenario as third renewable fuel in the transport sector after 2025 complementary to biofuels and direct use of renewable electricity. Hydrogen generation can have high energy losses, however the limited potentials of biofuels and probably also battery electric mobility makes it necessary to have a third renewable option. Alternatively, this renewable hydrogen could be converted into synthetic methane or liquid fuels depending of economic benefits (storage costs vs. additional losses) and technology and market development in the transport sector (combustion engines vs. fuel cells).
In all sectors, the latest market development projections of the renewable energy industry16 have been taken into account.The fast introduction of electric vehicles, combined with the implementation of smart grids and fast expansion of super grids allows a high share of fluctuating renewable power generation (photovoltaic and wind) to be employed. In this scenario, renewable energy would pass 50% of USA energy supply just after 2035.
These scenarios by no means claim to predict the future; they simply describe and compare two potential development pathways out of the broad range of possible ‘futures’. The Energy [R]evolution scenarios are designed to indicate the efforts and actions required to achieve their ambitious objectives and to illustrate the options we have at hand to change our energy supply system into one that is truly sustainable.