Hydro-power: Watt’s the Current Situation?

Humans’ use of hydro-power began with the invention of the waterwheel, which have been used in Europe for the last 2000 years. (Paish 2002). Modern hydro-power traces its roots to France as the first hydro-turbine was developed by Benoît Fourneyron in 1820 and towards the end of the 19^th century, plans for wide scale use of hydro-power were being developed. The hydro-power industry then boomed in the early 1900s as Europe and America began to build dams and stations very quickly. However, as of 2011, the UK only produced approximately 1.5% of its total power from hydro-electricity (UK Government 2013). What has caused the collapse of British hydro-power?

The rise of fossil fuels went a long way in thwarting the development of large scale hydro-power. Figure 1 (DECC 2009) shows the electricity generation by fuel type in the UK from 1950 to 2008. Hydro was the second largest contributor to our nation’s electricity supply in 1950 (albeit still dwarfed by coal). After this, we see asynchronous rises in oil, gas and nuclear but a steady decline in hydro-power’s contribution. Nuclear energy was on the rise due to the vast amount of research carried out during the Second World War and fossil fuels were inexpensive at the time. Hydro-power simply couldn’t keep up with the vast reserves of fossil fuels that were available very cheaply throughout the latter half of the 1900s or the growing nuclear industry, thus it fell away.

Figure 1 - Electricity Generation by Fuel Type in the U.K. from 1950 to 2008

Despite hydro-power being a renewable and low-carbon energy source, it has the ability to adversely affect the environment. Dams involved in large scale hydro-stations can be huge. Reservoirs created by dams have the ability to alter river ecosystems upstream and downstream. These alterations are a product of anthropogenic changes to variables such as river flow and water quality (Boon 1988). The largest artificial reservoir in the UK is the Kielder dam in Northumberland, which holds 200 billion litres of water. The waters affected by the Kielder dam are home to many species of fish such as brown trout and salmonids. Many of whose life-cycles are synchronised to seasonal variation in river flow. It has been found that water pulsed out of the dam may upset the life cycle of some species as it is of an unnaturally short-term variation (Gibbins et al. 2001).

So, it would seem that hydro-power has been held back due to our preference for other fuel sources and also its own environmental constraints, but what does the future hold?

Small scale projects such as run-of-river schemes seem to be the way to go for hydro-power. These usually involve the use of a small weir and no water storage and therefore do not pose some of the larger threats to wildlife as big projects such as Kielder. Personal hydro-power projects are included in the UK government’s feed-in tariff (see December solar energy post for details) and this seems to be how our government views the future of hydro-power, at a small scale.

The government has stated that the UK has a potential 850 to 1550 megawatts left to exploit, this would account for 1-2% of our energy production (UK Government 2013). In my eyes, hydro-power is moving in the right direction and I feel that on a large scale, we should continue to develop technologies such as wind and nuclear.

Gone Fission

The science behind nuclear power was first developed in the late 1800s. During WWII the focus of scientists in the field was to create and develop the atomic bomb. However, since that time, focus has been on the development of nuclear power as a source of electricity generation (World Nuclear Association 2013). Due to climate change, nuclear energy has been the subject of much debate over the last decade or so. The period has even been described as the ‘Nuclear Renaissance’ (Marshall 2005).

Figure 1 - Map of UK Nuclear Sites

Nuclear power has been subject to much criticism throughout its history, in no small part due to disasters such as Chernobyl in 1986 and Fukushima in 2011. Disasters such as these have led to widespread scepticism and have hindered the development of nuclear power in many countries, including our own. The UK has fallen behind other countries such as France in terms of nuclear power production. The two countries have very similar populations but in 2012, France produced 405 billion kilowatt hours of nuclear energy compared to the UK’s 64 (NEI 2013). Figure 1 (UK Government 2013) is a map showing the UK’s nuclear sites. The new build site at Hinkley Point C has been criticised in the news recently as some believe the power generated will be too expensive (BBC 2013).

Aside from the fact that nuclear power stations have been the (very) occasional cause of meltdown disasters, nuclear power is relatively environmentally friendly compared to coal, oil and gas powered stations. Figure 2 (UK Government 2006) shows the CO₂ emissions per kilowatt hours for several energy sources. Notice that the carbon footprint of nuclear is negligible when compared with those of coal and gas and is as small as hydro power and wind power. Due to the nature of nuclear fuels such as uranium, disposal of waste fuel can be a tricky business. I won’t get into this in huge detail here but I have included a link at the bottom of the page in case anyone is interested on how this is done.

Figure 2 - Bar chart showing relative carbon footprints of several fuel sources

I believe that nuclear power will need to play a substantial role in the future production of the UK’s energy. I could well see nuclear energy acting as a like for like replacement for coal, oil and gas fuelled plants as it boasts a constant supply of energy. I feel that potential hazards such as waste disposal can be avoided by appropriate management. The threat of a nuclear disaster will however, remain lodged in many people’s minds. Nuclear energy is an asset that we need to take advantage of but do so with extreme caution. The development of new fuels (see Thorium post) and techniques such as fusion may well hold the key to unlocking the full potential of nuclear power.

The link to waste disposal info is here,

Thanks for reading. 

Hey guys,

I found this article on the BBC about a potential new energy source involving hydrogen. The process of extraction mimics one that happens in nature and requires doesn't require as high temperatures as current methods of hydrogen extraction. Another major benefit over current methods is that this new process doesn't require the use of any fossil fuel. Could this be the shot in the arm that hydrogen power needs?

The link to the article is here

Thanks for reading.

Hi everyone, 

Just in case you weren't feeling in the Christmas spirit, here's a cartoon to get you in the festive mood.

Happy Holidays.

Shedding Light on Solar Power

Solar energy has been in the news recently as last week our government announced plans to cut funding for onshore wind energy and solar power. (Landale 2013). Figure 1 (DECC) shows us that solar energy has been on the rise in recent years.

Figure 1- Graph showing the growth in renewable electricity generation since 1990

However, compared to wind energy, the growth of solar power has been relatively small. In 2012, solar energy contributed 11% of renewables production capabilities. Onshore and offshore on the other hand, boasted 57% between them (DECC). Why is this?

Figures 2 (Solar Gis 2013) and 3 (Solar Gis 2013) show the amount of annual irradiation in the UK and Spain respectively.^th windiest region in Europe by a Met Office Wind Review. 

Figure 2 - Map of irradiance in the UK

Figure 3 - Map of irradiance in Spain

As you can see from the maps, the amount of irradiation is much lower in the UK than it is in countries of lower latitudes such as Spain. This results in a lower potential for solar power production. On the other hand, the UK has been ranked as the 4th windiest region in Europe by a Met Office Wind Review. Figures 4 (Met Office 2013) and 5 (Met Office 2013) display the monthly average wind speed for a site in England and a site in Spain respectively. The wind speed in the UK site ranges between 6 to 8 m/s as where the Spanish site stays around 5 m/s (Met Office 2013). It is clear that our country’s climate dictates which renewable source we invest in. It would therefore seem that the UK’s heavy investment in wind energy is grounded in logic and we should continue as such.

Figure 4 - Monthly average wind speed in a UK site

Figure 5 - Monthly average wind speed in a Spain site

What is the Future of British Solar Power?

I believe the future of British solar power will be the use of personal solar power devices. The government offers a ‘feed-in tariff’ in order to promote this. This allows people that have renewable systems installed to power their home will receive money from the government for every kilowatt hour of energy they produce. Producers are also able to sell any excess energy that they produce back to the power grid (UKGovernment 2013).  Due to the fact that our country receives a saddening amount of sun, I believe that on a large scale, we should continue to develop wind power more than solar power. However, I do still feel that solar energy has a role to play in the energy mix.

I’ve included a link to the government’s solar energy cashback calculator here in the event that anyone wants to know how much they could make. Thanks for reading and comments are welcome.

Hi everyone,

Seeing as it's Friday i'll keep this post short. The BBC have produced an article discussing the issues surrounding different energy supplies. The article includes an 8 minute video that takes a look at contrasting views towards different modes of power generation. The article gives a nice summary of how people view different energy supplies and raises a valid point that no matter which energy sources we choose, someone will be offended. I believe that in order to power our country, we will have to make sacrifices such as constructing wind farms on previously undeveloped countryside. Whilst the use of different energy sources may anger certain people, I see this as justified by the need to quench our thirst for energy. 

The link to the article is here

Bioenergy

Bioenergy refers to the energy stored in biological sources (biofuels). Bioenergy is released from biofuels by a number of different methods. Figure 1 (UK Government 2012)

Figure 1 - Biomass conversion routes

 outlines the large number of sources of bioenergy and the vast array of techniques used to harness energy from them. Bioenergy can be used on different scales; from being used to heat a home to being used to produce large quantities of electricity.  The coalition government views bioenergy as a major player in the future of the UK’s energy industry. A 2012 government report states that excluding bioenergy from the energy mix would increase the cost of decarbonizing our energy system by £44 billion. Figure 2 was taken from the study and shows the government’s projections for bioenergy production over the next few decades. The graph shows that the government expect more energy production from biofuels in the future, why do they think this to be the case?

Figure 2 - Future reliance on bioenergy

There are several advantages of bioenergy. In my view, one of the biggest advantages of bioenergy over other renewable energy types is the ability to produce a constant supply of energy, making it a potential substitute for fossil fuels (Slade et al. 2010). This would complement other renewable energy forms such as wind power, which only produce energy intermittently (see wind power post). Other benefits of bioenergy include disposal of waste biological material (Cantrell et al. 2008) and the fact that biofuels are a virtually inexhaustible fuel source, which leads bioenergy to be extremely sustainable.

So far, it would seem that bioenergy is a near perfect method of producing power. There is however one pitfall, that skeptics may well be quick to bring up: the production of greenhouse gases. Whilst the burning of biofuels does cause the emission of greenhouse gases, it must be noted that in comparison to those produced by the burning of fossil fuels, the amount is very small. A 2009 study by Rowe et al. shows us that bioenergy could provide large carbon savings over fossil fuels. However, the question remains, should these emissions be overlooked? Or should we stick to renewable energy sources that cause no emissions?

Conclusions

Whilst I do not feel we will ever be close to relying on bioenergy to provide us with the majority of our energy, I do feel it should be continued to be developed and used as part of the ‘energy mix’ in order to power the UK in the future. In my opinion, we can overlook the emissions as biofuels present a ubiquitous source of energy. The government’s projections seem fairly reasonable to myself, although I do think the lower proportional estimates shown in the range of figure 2 are more realistic. Your comments on the matter are welcome as usual, do you feel the emissions should be overlooked? Thanks for reading.