Читать книгу Renewable Energy - David Elliott - Страница 11

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 that the newly emerging renewable energy technologies can be taken up without imposing extra costs. They may even deliver a system that is actually more economically viable than the present one. Moreover, renewables are now getting so cheap that their uptake may accelerate under market pressures, regardless of whether climate change or pollution is taken seriously (PEI 2018).

That opens up some interesting possibilities. Although the environmental and climate benefits are still obviously important, some renewable energy proponents have suggested that renewables no longer need to use climate change as a justification. They can now prosper on their own economic merits. Indeed, for many countries, it is claimed, the direct economic benefits, and their role in fuel-cost saving, have become, or will become, the main motivation for investment in renewables. Thus it has been argued that ‘renewable generation will stand on its own commercial feet and cutting down emissions will become a fortuitous side-effect’ (Swift-Hook 2016).

That may be going too far, but it is certainly clear that the cost of renewables has fallen dramatically, in particular for PV solar (Lazard 2018a). According to the International Monetary Fund, ‘between 2009 and 2017, prices of solar photovoltaics and onshore wind turbines fell most rapidly, dropping by 76% and 34%, respectively – making these energy sources competitive alternatives to fossil fuels and more traditional low-carbon sources’ (IMF 2019).

That trend also extends to offshore wind, initially seen as one of the most expensive renewable energy options, with ‘strike prices’ under the first round of the UK’s CfD capacity auction system in 2015 reaching nearly £120/MWh. In the 2019 CfD round, strike prices for some successful project bids fell to just under £40/MWh, around a third of the earlier figure (New Power 2019).

These cost falls have been important in propelling renewable energy to the fore, and they are likely to continue. So it has become very hard for opponents to maintain resistance to what seems likely to be an unstoppable change dynamic. However, they do sometimes try. For example, it is ironic that the incumbent fossil and nuclear interests, which often initially dismissed the renewable energy options as totally irrelevant, now have to fight to protect their market shares as opposition to fossil fuel use mounts, nuclear costs rise (Portugal-Pereira et al. 2018) and renewables win out across the board. They already supply more than 26% of global electricity (REN21 2019), compared to nuclear power at around 10%, and are displacing fossil fuels in many markets.

Interestingly, under increasing pressure from renewables, some of the fossil and nuclear lobbies have therefore changed tack a little and are now arguing that renewables are still problematic since they cannot expand fast enough to deal with climate change (BP 2018a), with some climate change sceptics joining in (Lyman 2019), this after they have all resisted change and spent so long trying to stop renewables from getting started. Some of the incumbents may continue to resist, but over 185 companies so far have signed up to ‘100% by 2050’ renewable electricity targets (RE100 2019).

As argued above, what has changed things is not a sudden extra concern about climate or air pollution (although, as noted, that has happened and has helped) or even what some see as a collapse of nuclear power as a future option (WNISR 2019) but the fact that the cost of renewables has fallen dramatically. Arguably, a new economic dynamic has, at least partially, taken over, with renewables well placed to become the dominant option.

However, while the case for renewables does look strong, they are up against a set of well-established energy technologies, well entrenched in lucrative markets. The fossil fuel-based incumbents look to new carbon capture technology to allow them to stay in the game, and the nuclear lobby similarly looks to new technology to improve its economics. To set the scene, Box 1.2 provides a short summary of the main impacts of the options on offer, and I will be looking at the options, and at the issues raised by them, in more detail later.