As we saw earlier, many scenarios have been developed about how the future could be shaped. One of the more ambitious scenarios is the mentioned 2⁰-scenario (a 2-degree temperature increase by 2050, compared to pre-industrial level). Not only the IPCC, but also the International Energy Agency (IEA) uses this scenario as a vision of a sustainable energy system of reduced greenhouse and CO2 emissions. But how will this target be reached? Here is a short overview of the main options.
With regard to the renewable energy options, photovoltaic solar power (PV), hydropower, and onshore wind are the technologies that are progressing rapidly. Concentrated Solar Power (CSP) is only growing slowly and nuclear capacity is stagnating worldwide. Seen from a regional perspective, the emerging economies are becoming leaders in the deployment of low-carbon technologies. For example, Asia accounts for over half of globally installed PV added in 2013 and China currently has 150 million electric 2-wheelers on the road.
On the other hand, the continuing increase in coal use is counteracting the emission reductions coming from this increased renewable integration. Therefore, improvement in the efficiencies of coal plants and a scaling up of Carbon Capture and Storage (CCS), is needed. In general, fossil fuel use will have decreased by 2050 in the 2⁰-scenario, but remains above a 40% share of the primary energy supply. Thus, it still fulfils a very important role in industry, transport and electricity generation. For industry, the possibility to integrate renewables in their processes is heavily dependent on the final product and operational aspects. By adopting the best available technologies, a greater penetration of less-energy intensive processes and by recycling materials, the 2⁰-scenario estimates the cuts in energy use by 25%. In the transport sector, the only alternatives for non-grid-connected, long-distance travel modes (e.g. road transport, aviation and shipping) are biofuels and hydrogen. However, those technologies are currently not competitive enough to phase out fossil fuels. And in the electricity generation sector fossil resources also still play a significant role: in the 2⁰-scenario, 20% of the generation relies on fossil fuels.
The largest contributor to global emission reductions however is energy efficiency. Comparing the business-as-usual pathway and the aimed 2⁰-scenario, energy efficiency improvements covers 38% of the reductions, renewable integration for 30%, CCS for 14%, and fuel switching and nuclear power the rest. One specific potential for energy efficiency improvement is by integrating heat pumps in buildings. Heat pumps can be used for heating and cooling of water and space, and could thus reduce the need for natural gas. For example, the EU gas share could possibly fall from 34% to 25% in 2050 by applying heat pump technology.
The growth in electricity demand globally is the largest of all final energy carriers. This provides an opportunity to radically transform both energy supply and end use. But in reality, this transition to ‘electrification’ is not straightforward. Recent trends show a continued large dependency on fossil fuels for energy generation, and the main resources are still coal and gas. Although a shift from coal to gas would mean a (relatively) cleaner energy system, the outcome of the competition of the two will depend more on the economics of the CO2 emissions and the fuel price than on technology improvements. Moreover, natural gas should be seen as a bridging fuel to cleaner energy technologies. Only when CCS is deployed efficiently, natural gas has the potential to remain dominant. Because to reach the emission targets for 2050, the carbon dioxide emissions per unit of electricity have to decrease by 90%. Besides, the growth in electricity demands is different for Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. But overall, the trend is an increased share of electricity in the energy mix.
The share of renewables globally added up to 20% in 2011, and the 2⁰-scenario shows the potential of renewables to add up to 65% by 2050. Solar is the single largest electricity source by 2040 and provides 26% of global electricity by 2050. One purpose of this electricity generation is supplying the transport sector. By switching from oil-dependent vehicles to electric transport, significant emission reductions can be realized. Since the current transport sector is relying on oil so heavily, even small steps in electrification have relatively big impacts. Although adding up to only 11% of the transport energy demand by 2050, it will account for around 50% of the transport efficiency gains.
Although all the sectors have different characteristics and (future) developments, it is important to stress that optimised integration of the sectors is also key. “Systems thinking” is an important tool to apply during a transition towards a wind and solar dominated power generation, because investments have to be optimised and future systems have to be managed efficiently. We will delve deeper into this systems thinking next week with Gerard Dijkema.
In sum, we have seen the main options to reach the pathways addressed yesterday. Wind and solar power are the most promising technologies in order to reach the 2050 targets, but the largest contribution will be by energy efficiency improvements. Since electricity generation by fossil resources will remain important over the next decades, increased deployment of CCS is essential. For a more extensive description of the issues addressed in this article, we refer to the Executive Summary of the Energy Technology Perspectives 2014 by the IEA. To delve more into (technical) details of the separate renewable technologies, take a look at the Technical Summary of the Renewables Report by the IPCC. In the following steps we will examine how the opportunities for an energy transition differ per region.
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