Renewable Energy. David ElliottЧитать онлайн книгу.
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Acknowledgements
Thanks for some criticism, advice and input from Tam Dougan, editor of the long-running Renew newsletter, previously based at the Open University and now run independently.
Abbreviations
BECCSbioenergy with carbon capture and storageBECCUbioenergy with carbon capture and utilizationCCScarbon capture and storageCCUcarbon capture and utilizationCHPcombined heat and powerCO2carbon dioxideCSPconcentrated solar powerDACSdirect air capture and storageEROEIenergy return on energy investedGDPgross domestic productIEAInternational Energy AgencyIRENAInternational Renewable Energy AgencyLNGliquid natural gasLUT/EWGLappeenranta University of Technology/Energy Watch GroupNETnegative emissions technologyNGOnon-governmental organizationP2Gpower-to-gasPVphotovoltaic solar powerREN21Renewable Energy Network for the 21st CenturyWECWorld Energy Council
Preface
The use of renewable energy is spreading rapidly, and some claim that wind, solar and other renewables can and will become the dominant global energy sources within a few decades, thus avoiding major climate change problems. Concerns about climate change have been a key driver, leading to growing government support. However, the falling cost of renewable energy has also become a major driver. Some renewable energy technologies are now competitive across the board and costs continue to fall, with a new commercial dynamic adding impetus to their uptake. This book asks whether that trend will be sufficient to ensure that renewables expand fast enough globally to limit climate change to survivable levels without imposing high costs.
There are certainly many who doubt that this is possible. Some critics argue that renewable energy systems are inherently unreliable and expensive, and they look to nuclear power as an alternative non-fossil option, and possibly also to cleaning up fossil fuel use. This book seeks to meet these claims head on and asks to what extent renewables can deliver a technologically and economically viable energy future, and whether other technical options and energy policies to support them are also needed. It explores how important renewable energy technology might be by looking at its progress so far and at its future potential and problems in a context where other approaches are also on offer. Much has been promised from renewables and, so far, they seem to be living up to the promises as they accelerate ahead. This book looks at whether that can and will continue.
1 Introduction: All Change?
Renewables are no longer marginal but have become mainstream. This introductory chapter asks what has driven their recent success – and can it continue?
The dynamics of technological change
The way in which we have used technology to meet energy needs in the past has been a key cause of many environmental problems, including air pollution and climate change, but new technology, and new patterns of development based on it, may offer possible solutions to some of these problems. That said, while there is a strong case for looking at technology as a key factor in the attempt to move towards a more environmentally sustainable global future, technology is only one factor and possibly not the leading one. We may also need social and economic change.
However, there are interactive processes at work. The development and adoption of new technology is usually driven by social and economic forces, including profit. Environmental issues have also increasingly come to the fore and are having a direct effect. For example, climate concerns have been a stimulus for rapid recent renewable energy growth, along with air pollution issues, notably bad of late in some Asian cities. Something had to be done, and a switch to cleaner technologies was one option.
Some of these changes have been led by governments, nationally and internationally. In addition to supporting global climate actions designed to reduce carbon emissions, most countries have backed the rapid expansion of renewables, with more than 50 countries having signed up to ‘100% by 2050’ renewable power targets (REN21 2018). Clearly, concerns about climate change have translated into policy changes and action programmes (see Box 1.1 for an overview of the key energy-related climate issues).
Box 1.1 Energy use and climate issues – an overview
Around 80% of the energy used globally comes from roughly equal amounts of coal, oil and natural gas, hydrocarbon materials which were laid down in geological fossil strata eons ago. We are about halfway through extracting and burning off the easily available fossil fuels, but it seems unlikely that we can burn off the rest without causing major environmental and social problems. A key issue is that the combustion of coal in power stations, gas for heating in homes and oil products in vehicles, along with other activities like cement making, produces carbon dioxide (CO2), a so-called ‘greenhouse’ gas that, rising into the upper atmosphere, acts like the windowpanes of a greenhouse, trapping incident solar heat inside. So the greenhouse – in this case the earth – heats up. We are headed for maybe a 4–5 degrees Celsius (°C) initial average global temperature rise over the next century, and possibly more if the polar region permafrost zones thaw out, releasing trapped methane gas, a much more potent greenhouse gas than carbon dioxide. Even without that, the climate models suggest that we are likely to face progressively worsening threats to the already badly (pollution-) stressed environment and ultimately perhaps to ecosystem stability and survival (IPCC 2019).
Current global climate policy, as agreed in Paris in 2016, looks to holding the temperature rise below 2°C, and ideally below 1.5°C, but even holding it to 2°C may not be possible. As the weather/climate system changes and becomes more erratic, we are therefore likely to experience more major storms, floods, droughts and worsening wildfires and thermal stress. As the icecaps melt and the seas warm and expand in volume, sea levels will rise, threatening many coastal cities and food-growing areas. It may be too late to avoid some of this, so we have to be prepared, but there is also an overwhelming case for taking urgent action to reduce carbon dioxide (and methane) emissions so as to avoid it all getting very much worse (Carbon Brief 2018).
To some extent, while, in part, a response to physical threats to the environment and to human health, the political actions being taken around the world are also based on assessments of the likely economic impacts of climate change and pollution. It has been argued that the economic cost of inaction would vastly outweigh the cost of responding to the threat by maybe a factor of ten or more (Stern 2007).
This type of argument laid the base for much that has happened until relatively recently. It might be costly, but a change had to be made. The main policy issue was therefore how the cost of ‘decarbonizing’ could be met, with there being no shortage of political resistance to proposals that would, it was assumed, increase energy costs. That was in a context where the threat of climate change was sometimes seen as longer term, whereas there were arguably more pressing short-term economic and political concerns. So there was some resistance.
Renewable energy, often promoted as the main way forward, was seen as expensive, even more so than the nuclear alternative, usually seen as its main rival, so that the cost of the change might be prohibitive and politically difficult to impose. However, there have been new developments which may change the situation. While nuclear costs remain high, and even seem to be rising (WNISR 2019), it may now be the case