Hydroelectric Power Potential

Hydroelectric power has huge potential to produce electricity at specific sites where water traverses a large height difference, and therefore loses gravitational potential energy. Through the driving of turbines this energy can be converted into electricity. 

From purely a renewable electricity production view point hydroelectric has huge potential to form part of a sustainable future electricity mix. WorldWatch Institute state that 16.1% (3427 terawatt-hours) of global electricity production is currently from hydroelectric power. Five countries produce 52% of this 16.1%: China, Brazil, the United States, Canada and Russia. There are currently three hydropower dams larger than 10GW: The Three Gorges (China), Itaipu (Brazil) and Guri (Venezuela).

Guri Dam, Venezuela (Source)

The Three Gorges Dam, China (Source)

Itaipu Hydroelectricity Power Plant, Brazil (Source)

Four countries, although small, produced 100% of their electricity from hydroelectric power as far back as 2008! The countries leading the way on the hydroelectric front? Albania, Bhutan, Lesotho and Paraguay. Fifteen other countries generated over 90% from hydroelectric power. Unsurprisingly, the most hydroelectric power produced per/capita are countries with mountainous terrain and significant snow melt to drive the dam, New Zealand, Iceland and Norway.

So why are countries already opting to go full throttle on hydroelectric powers? Firstly, it's relatively cheap costing between 6-10p per kilowatt-hour for a hydro plant larger than 10MW. Hydro power also provides electricity security and it is produced 'in-house', unlike fossil fuels where many states rely on others for their electricity production. Hydropower also enables very fast increases in power production to deal with peaks in demand, whereas fossil fuel power stations can take hours and some other renewables cannot increase production at all.  Due to these characteristics Kosnik concludes that a strong case can be made for using hydroelectric power in USA to fight global warming.

However, it's not all plain sailing for hydroelectric power. Damming majorly interrupts local and national ecosystems preventing the migration of fish. For rivers with multiple dams, this practically destroys any hope of a healthy ecosystem as species became increasing dispersed with ever-decreasing gene pools. Building of dams also displaces people and terrestrial wildlife, see the Three Gorges Dam for an example of this on a huge scale. A further issue with the Three Gorges especially is it flooded mines which results in leakage of toxic chemicals into the water. Dams also trap sediment. Firstly, this means that the capacity of the dam will decrease if it is not regularly dredged. Secondly, it deprives downstream communities of silt which is vital to keep land fertile. Furthermore, dams can stop flooding downstream (unless a natural flood regime is mimicked), which may be vital to local economies downstream. The immobility of hydroelectric dams is also an issue. As explored by Whittington and Gundry hydroelectric plants are often justified on long-term economic calculations. With global climate change altering precipitation patterns, it is worth considering in a proposal what might happen to such rainfall patterns in the future. Given the huge development of dams across the world it seems inevitable there will be abandoned dams where rains have moved on. For example, see how many dams have been constructed in the USA alone:

Amid all the above local impacts, I'd like to focus on a global impact of hydroelectric dams, and that's the emissions from dams. Dams flood vast areas of land that was not previously flooded. This newly created water-land interface is the location of chemical reactions and decomposition. Fearnside explains that carbon dioxide is emitted from the decay of trees left standing in the newly formed water mass, whilst methane is emitted from the decay of soft vegetation at the bottom of the lake (this is especially prevalent for macrophytes and plants in the drawdown zone which floods when the water level rises). Fearnside ascertains that because of this dissolved methane levels are highest at the bottom of the reservoir. Some methane is released through bubbling, but mainly from the water traversing the turbines and spill way. As water is drawn from sufficient depth, this results in large methane concentrations. Fearnside studied the Curuá-Una dam in Brazil. He found that in 1990 after 13years of production the Dam had 'emitted 3.6 times more greenhouse gases than would have been emitted by generating the same amount of electricity from oil'. Rudd et al. found similar patterns of high Carbon Dioxide and Methane emissions from a Quebec reservoir. At most sampling sites, Rudd et al. found that Carbon Dioxide were 2-3times equilibrium levels, whilst Methane levels had 'concentrations higher than in natural, stratified Canadian shield lakes'.

This is only two dams, so covering Barros et al.'s research in Nature on 85 globally distributed dams accounting for 20% of total hydroelectric dam area gives a broader perspective. Total reservoirs from hydroelectric dams cover 3.4×10⁵ km², about 20% of global reservoirs. Previous research from St Louis et al. suggests that 321Tg of Carbon/year are emitted from such reservoirs. Barros et al. estimate that 48Tg of Carbon as Carbon Dioxide is emitted from hydroelectric dams, and 3Tg of Methane. More limited data is cited as the reason for lower estimates than previously produced by St Louis et al. Barron et al. found that the highest emissions were from Amazonia, understandable for the mass of vegetation/biomass that will have been flooded to create dams. 

Such evidence is damning (intended) for the case of hydroelectric power. Hydroelectric power plants are often marketed as positive for the environment, but this is not the case on a global scale. The common opinion that dams reduced greenhouse gas emissions, and hence global warming, is clearly misconceived. Dams produce significant amounts of Carbon Dioxide and Methane, whilst also having a very long list of negative impacts as listed above. The positives of dams for a single country however do remain larger, they produce electricity within the state at a low cost and production can be ramped up quickly. Hence, dam construction is likely to continue as governments place economic and energy security high on the agenda.

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COP21 Focus

Recently my blog has focused more on COP21, rather than explicitly examining how to produce enough electricity for the future. Firstly, I've done this because of the huge importance of COP21 to anyone interested in anthropogenic climate change. Secondly, because the outcome of COP21 would define future electricity production, and the extent of the governments' commitment to greener electricity production. 

A large proportion of the emission reductions are likely to come from shifting towards renewable electricity sources. This is because switching away from oil as our primary fuel for transportation is decades away, whereas we can switch electricity production now. 

Given the huge success of COP21 in Paris, we have illustrated our commitment to switching to low emission alternatives for electricity production. This is a huge statement of intent from global leaders, and will undoubtedly shape the power production landscape of the future

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Why are students not protesting?

On December 12th was a march organised by Friends of the Earth in Paris. I interviewed one of my friends who attended the march, Issy. Although the rally declared it would no long be official due to the security situation in Paris, thousands still turned out to voice their opinion.

Given the outcome of COP21 Issy obviously felt very positive about Paris. Being part of the group of activists to pressure global leaders and achieve such a result must've been exhilarating (plus you get to go to Paris!). 

One of the most interesting observations Issy made was the age of people who were marching. The vast majority were in their 40s and above, with hardly anyone Issy's age outside of her university friends. Yet it's our generation who have been educated about, and grown up around, climate change. Furthermore, per capita far more 18-25year olds vote for the Green Party than other age groups. So why are they not represented? Perhaps it's a money and time issue, young people can't afford to go to Paris whereas older generations can. Issy also got the impression that many of her fellow protestors weren't just marching for climate change, as she was. Many had been marching since the 1970s, whether that's for a green movement, anti-war or global equality. Such a demographic wasn't expected, and neither would I have predicted. Maybe our generation is more complacent and hasn't experienced the same repeated disappointment of failed climate change talks that out elders have.

Some protesters said to Issy "It's so nice to see students protesting again", as if they hadn't seen students at marches since they themselves were. The older protestors had the impression that students don't have the enthusiasm that they had. 

Maybe it is money, or perhaps we are more complacent and less enthusiastic. I know a lot of friends who marched in London, so maybe that was considered enough. 

But, the march in Paris among many other pressures have worked, and an extremely positive outcome has been achieved without students turning out! 

Alternative to reducing emissions? Geoengineering

What are the alternatives to not reducing emissions with climate change? Either, you accept the temperature increase and deal with it, or you stop the temperature increasing. This post concerns the latter; how we can geoengineer the climate to stop the temperature increasing. Geoengineering is deliberately changing, or engineering, planetary-scale processes.

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In their paper, Geoengineering the Climate: Science Governance and Uncertainty, the Royal Society accepts immediately that the most reliable method of controlling temperature increase is to reduce greenhouse gas emissions, and that geoengineering should not be seen as an alternative. But, if greenhouse gas emissions are not sufficiently controlled then geoengineering could be useful to mitigate climate change and effectively buy us more time to reduce emissions. 

There are two types of geoengineering, Carbon Dioxide Removal (CDR) and Solar Radiation Management (SRM). 

CDR methods include (from Royal Society paper):

• Land use management to protect or enhance land carbon sinks;
• The use of biomass for carbon sequestration as well as a carbon neutral energy source;
• Enhancement of natural weathering processes to remove CO2 from the atmosphere;
• Direct engineered capture of CO2 from ambient air;
• The enhancement of oceanic uptake of CO2, for example by fertilisation of the oceans with naturally scarce nutrients, or by increasing upwelling processes.

Caldeira, Bala and Cao provide this graphic showing the different methods CDR.

Caldeira, Bala and Cao

The science behind CDR is removing the quantity and hence reducing the concentration of CO2 in the atmosphere, which reduces the effectiveness of the greenhouse effect. This counteracts the pumping of CO2 into the atmosphere from burning fossil fuels. The main issues with CDR are the cost, scale and the time required for it to be effective. Hence, the scale at which CDR is used will probably rely on the cost. Planting trees to remove CO2 as well as other carbon capture methods are expensive relative to the amount of carbon they remove from the atmosphere.

Unlike SRM methods, CDR geoengineering is relatively uncontroversial as taking CO2 out of the atmosphere has few unknowns. The exception is ocean fertilisation. Ocean fertilisation involves deliberate eutrophication (see here for explanation of eutrophication) of the ocean, meaning algae will grow which will absorb CO2 (similar to afforestation, but in the ocean). In his edited book Coastal Systems, Haslett describes how eutrophication can occur with influxes of nitrogen and phosphorus, usually from fertilisers or human waste. The algae blooms that occur can eliminate all bottom-living organisms. As such, deliberately causing eutrophication in the ocean has been met with stern opposition regarding our lack of understanding of the potential impacts on wider ecosystems. 

Now for SRM. Again, from the Royal Society paper the methods of SRM include:

• Increasing the surface reflectivity of the planet, by brightening human structures (eg by painting them white), planting of crops with a high reflectivity, or covering deserts with reflective material;
• Enhancement of marine cloud reflectivity;
• Mimicking the effects of volcanic eruptions by injecting sulphate aerosols into the lower stratosphere;
• Placing shields or deflectors in space to reduce the amount of solar energy reaching the Earth.

Caldeira, Bala and Cao

SRM is increasing the albedo of the Earth. Hence, less of the Sun's energy will be withheld and instead reflected back out to Space. This will reduce temperatures. 

As explained by Caldeira, Bala and Cao, and perhaps unsurprisingly, in contrast to CDR SRM has many more issues associated with it. There are problems relating to global scale environmental management, whereas CDR generally only has local impacts. With this, comes global scale governance challenges. As mentioned the main issue with CDR is the efficiency of reducing temperature, both in terms of investment and time taken. CDR can take decades to be effective, whereas SRM can have almost instant impacts. The issue with SRM is the risk. Predicting the impacts of pumping particulates (aerosols) into the atmosphere to increase reflectivity seems almost impossible. The climate system is complex enough as it is, such that only in the last few years have any weather forecasts began to get predictions right. Therefore, understanding the risk involved with SRM (both potentially to human health and by how much it would actually reduce temperatures) is a challenge, and in the event of uncertainty should be assumed to be high.

Regarding methods other than pumping aerosols into space; massive mirrors in the sky? To me, that's something that'll probably stay in sci-fi movies. Brightening of clouds to make them more reflective is more plausible. Crutzen suggested this would be done by filling balloons with sulphur, and when they reached high altitudes shooting them with artillery guns. The cooling effect would be felt within six months, and the sulphur would last two years. However pumping sulphur into the atmosphere was something my GCSE Chemistry teacher taught me wasn't a good idea.  But, if the alternative was temperatures rising five degrees then it could be considered. Increasing the albedo of the sea is plausible, but as with ocean fertilisation the impacts of attempting to engineer such a complex system as the World's oceans requires near certainty of the effects before being carried out. Painting buildings white and planting more reflective crops is a much less controversial idea. But it falls short, as many of the CDR do, considering how effective it would actually be at reducing global temperatures.

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The effectiveness of SRM is very high though. Caldeira, Bala and Cao modelled the effect of reflecting 1.84% of the Earth's incoming radiation away, whilst doubling CO2 concentrations.

Modelling by Matthews and Caldeira suggests that within months temperatures could start to fall and be reduced by multiple Kelvin within 10years using SRM. Cooling of this magnitude could prevent catastrophic events, such as retreating Antartic glaciers and the collapse of the Greenland Ice Sheet. Irvine et al.'s work focuses on how we can keep the Greenland Ice Sheet and not make drastic changes to our energy mix by using geoengineering, and specifically SRM.

The Economist

In conclusion, both CDR and SRM have some large flaws. CDR's issues surround how effective it would be and hence, the temporal scale and financial investment required to actually meaningfully reduce global temperatures. That's not to say we shouldn't do it, we should. The CDR methods, with the exception of ocean fertilisation, have almost no side effects, so why not? The same goes for painting buildings white and planting reflective crops (unless the crops are genetically modified to be reflective... definitely a discussion for a different blog). 

SRM is much more effective. It can bring about significant changes within a decade and cool down our planet. But whether it's whitening the clouds, putting aerosols into the outer atmosphere or increasing the albedo of the ocean, the unknowns regarding the consequences are huge. Therefore, the shortcoming of SRM is the risk of making such changes to our planet. The Royal Society conclude by saying 'it would be highly undesirable' for geoengineering to take place that had influences beyond national borders without correct government mechanisms and clear knowledge of potential impacts. As such, further research into geoengineering is definitely required to even make a guess at potential impacts. 

But the risks of climate change are also potentially huge, whether it be changing rainfall patterns, higher temperatures or rising sea levels. It may be that to buy ourselves more time to reduce our greenhouse gas emissions we will require geoengineering. Hopefully, this will not be the case and we can just reduce greenhouse gases emissions, keep temperature increase below 1.5degrees, and so scrap the need to geoengineer the climate. 

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Stop Being So Negative?!

In my post on Friday, I summarised our mock negations mimicking COP21. Having simulated the contributions countries would have to give, especially developing countries, to keep temperature rise to 2°C.

However, based on BBC's analysis of progress, keeping temperature rise to 2°C now seems almost likely. Announcements from COP today suggest that temperature increase could even be kept to 1.5°C! In his analysis Matt McGrath does point out that there is still uncertainty as to how this will be met, but the sounds coming out of COP21 are fantastic.

So why was my opinion of the keeping temperature rise to 2°C two days ago so relatively pessimistic? There are one of two options. Firstly, I greatly underestimated the ability of undeveloped countries to not further increase their emissions and even start to decrease them relatively soon, even with huge amounts of money from the developed world. Secondly, that the climate model used for these predictions is different to the one we used in our seminar, and hence the huge contributions that were required in our seminar to keep to a 2°C increase are not the same magnitude as in the model whose results are being reported. As with all climate modelling, the immense complexity of the system and our relatively poor knowledge of responses mean different modelling techniques can produce different results.

Regardless, whichever of the two reasons for my misplaced opinion on the success of COP21, I would love to be wrong and have countries sign a deal to stop dramatic impacts being felt worldwide from climate change by keeping to the seemingly golden 2°C target.

It would certainly keep these guys happy...

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Fossil Free UCL

This week the UCL arm of the political movement Fossil Free took over a building in the UCL Quad in perhaps the world's first ever COPupation. Having broken into the De Vere building, which controversially costs UCL £500/day to use, on Tuesday the COPupation lasted until Thursday. On Thursday, the Fossil Free group left for Paris to join the march pressurising global leaders to reach a deal.

So what were the students protesting about? It's UCL's involvement with oil companies. UCL currently has £14million invested in oil companies. On these investments, it has actually lost £1.25million over the last financial year! On top of this, UCL has a policy of not investing in companies that conflict with research undertaken at UCL. Given the number of climate related papers published from UCL, particularly made academics in the Geography department, that highlight the role oil companies have in causing climate change, this policy promise is not being kept.

With this is mind, UCL Fossil Free is committed to pressuring UCL until they drop fossil fuel investments. Almost as expected, UCL has refused to comment on the issue. Furthermore, UCL Fossil Fuel cannot become a society within the union, as wanting to end UCL's association with Fossil Fuels is deemed 'too political'. 

If UCL ended its relationship with fossil fuels, as many other universities have done, it would be a powerful statement from a huge research institution that we are committed to a more sustainable future. Renewable electricity production is a more ethical investment on whichever scale you chose, so it would be great if UCL divested into that as an alternative.

But, given the refusal to make a statement and the continued investment in fossil fuel, this unfortunately seems unlikely. 

EDIT:

If you want to find out more, UCL Fossil Free held a debate last year, click here to read

If you're interesting in signing the petition 'UCL, DIVEST FROM FOSSIL FUELS' written to Michael Arthur (UCL Provost) then click here. Thanks to Ben Ayre for these resources. 

UCL COP21

A few days ago our Global Environmental Change module did a 3hour practice run through of COP21. As mentioned in the previous post, the current contributions countries are making will keep temperature increase to 2.7°C... Not enough to avoid serious implications.

After multiple rounds of negotiation between China, India, USA, EU, Other Less Developed Countries, Other More Developed Countries, Climate Activists and Oil Companies. The result was better than the INDCs, but only slightly keeping temperature increase to 2.5°C.

Now comes the worrying part, we simulated what contributions each party would have to make to limit temperature change to 2°C. The measures required are huge. Along the lines of developed countries reducing emissions by 3.5%/year now, and developed countries stopping emissions rising by 2025 and starting to reduce by 2030.

Unfortunately, the likelihood of this seems slim. To expect developing countries to stop increasing emissions by 2025 seems unreasonable and unrealistic. Perhaps evidence towards why in my previous post academics have said a temperature rise of 2°C is completely unrealistic. So should we judge COP21 against such an aim? When we consider whether it's a success, maybe a higher target is more feasible? If we are to criticise COP21 for not meeting a 2°C temperature rise then I think the negotiations will only ever be seen negatively. If the countries were to reach a deal that kept temperature increase to 2.5°C, which involves huge contributions, I would see that as a success.

The seminar really illustrated the challenges of negotiation, and that was with 8 parties not 195! Furthermore, it showed to me that serious climate change is going to happen, but it is still up to us to keep it to a minimum.

COP21

COP21

You may have heard of COP21; the 2015 UN Climate Change Conference. It is the 21st annual meeting since the 1992 UN Framework Convention on Climate Change (UNFCCC) of the Conference of the Parties (COP), and the 11th since the 1997 Kyoto Protocol of the Meeting of the Parties (CMP).

The aim of COP21 is to reach an agreement to tackle climate change. Such agreement will be agreed in 2015 and implemented by 2020. For an agreement to be reached every single of the 195 members must sign, a value which has been a hurdle in previous meetings. The key measure that COP21 hopes to achieve is to limit global warming to 2°C by 2100, with the pre-industrial era the starting point. Any temperature increase above 2°C is predicted to result in serious climate catastophese.

In 2013 Anderson and Bows summarised 'there is now little to no chance of maintaining the global mean surface temperature at or below 2°C'. Furthermore, 'the impacts associated with 2°C have been revised upwards, sufficiently so that 2°C now more appropriately represents the threshold between ‘dangerous’ and ‘extremely dangerous’ climate change'. Stocker puts this into numbers. For a 2°C rise in temperature we can emit 790billion tonnes of Carbon. Currently, we have emitted 535billion tonnes already, leaving us with another 255billion before climate change dramtically changes our planet. Stocker estimates 10billion tonnes of Carbon are emitted/year. This gives us another 25years at current emission rates. But, emissions are still rising as Less Economically Developed Countries from around the world continue to develop and demand more electricity and fuel in pursuit of a higher quality of life.

Before the conference all parties sumbitted Intended Nationally Determined Contributions (INDCs). These outline commitments they would be prepared to make and any aid they would need to achieve such commitments. Analysis of these by the UN predicted such contributions would limit climate change to 2.7°C, significantly higher than the aim.

For COP21 to be branded a success I think significantly higher contributions will have to be realised and adopted by all. The contributions made my states directly impacts the electricity production mix they will adopt in the future. Hence, the larger the contributions are for reducing Carbon emisssions, the larger the commitment to renewable electricity sources will be.

WiFi Trees?

Reddit

This image is currently being ciruclated on Reddit, Facebook, Twitter and the rest. It makes an interesting point about how humans prioritse elements of their life. I think it also illustrates how disconnected we are from the impacts of climate change.

Given that... it's not strictly true, as explained by National Geographic.

Natural Gas and Renewable Energy - Shell

'The Beautiful Relationship' - Shell

In October Shell released this video depicting Natural Gas as the perfect partner for renewable energy. It's cheap, it's reliable and there's a large supply. 

So why all the fuss? As said, the potential supply is huge (Shell say there is 200years worth), and this can be extended by using natural gas-hydrates.  Makong et al.'s research displays the even larger potential of natural gas if hydrates can be used successfully. At present, research is required regarding converting natural gas-hydrates into natural gas safely and efficiently as well as work on their properties. 

Furthermore, natural gas is significantly less polluting than other fossil fuels, so if we have to use fossil fuels we may as well use natural gas. In fact, on the website 'Alternative Energy', it even lists Natural Gas as an alternative energy alongside Solar Energy, Hydroelectric and others. To this end, it is a relatively new fuel compared to other fossil fuels.

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So why the opposition to natural gas? It still pollutes the environment, both in terms of greenhouse gases and smog as well as locally (especially when produced through fracking). Natural gas production can seriously impact surface waters as well, illustrated well by Entrekin et al. Water is required in significantly quantities (millions of litres) is used for drilling as well as 'a suite of chemicals that may be toxic to aquatic biota'. As such, concern is growing that although the natural gas is there, obtaining it has large negative impacts. As optimists should we not opt for completely green technologies rather than half-heartedly using natural gas because it is 'not as bad', whilst still being very bad? 

Interestingly, the ratio of likes to dislikes is roughly 1:5 on Shell's video, and they wisely decided to disable comments on the video (you can't disable liking/disliking on youtube). Shell's PR team must have known what the backlash from the public would be to this suggestion. And maybe we shouldn't be considering continuing to use fossil fuels, but realistically maybe Shell do have a point. Maybe, we will need to continue to use fossil fuels to fund renewable energies shortcomings. 

Then again there are other issues associated with Natural Gas, such as where it comes from... whereas renewable energy is produced within country...

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Oh, and I haven't even touched on how the video presents a woman us unstable renewable energy, needing a strong man that is reliable... good one Shell.