Roviyas

Energy not just Electricity

Implementing nuclear power on a grand scale will not secure an energy supply for the U.K., nor will it significantly reduce our CO2 greenhouse gas emissions. The reason is simple, but is seldom rendered explicitly, that only 18% of the total final energy consumption is provided by electricity. 78% (430% more) of the U.K.s total energy is produced by burning coal, natural gas and oil directly, and this burden would not be influenced at all by any amount of nuclear development. The maximum change that might be made - at least in principle - is the substitution of all fossil fuel (mostly coal and gas) fired power stations by nuclear.

Exactly how monumental an undertaking this would be may be gauged from the fact that the current 17% of total electricity produced by nuclear is generated from 18 reactors, which are housed in 10 separate power stations. On this basis, to substitute for the 80% of electricity currently produced from coal and gas, using nuclear, would require building around 100 new reactors, and that is on top of the new ones that will be required in any case, to replace all but one of the existing reactors, which will come to the end of their working lifetimes by the year 2023. This clearly is a colossal undertaking which does not solve the major issues of "security of supply" or CO2 emissions in any significant degree. We will still need to import oil and gas from politically maverick regions, mainly Russia and the Middle east, and is the uranium fuel required for nuclear to be found on our doorstep? Hardly. Most of it comes over from Canada.

What about renewables? It is thought that in the longer run (say, by 2050) around 40% of the U.K.s electricity might be provided using wind/wave/hydroelectric/ solar power. A significant proportion of this would be produced by "microgeneration" devices, rather than a large scale "grid", though any excess electricity generated beyond the local demands of each "micro" community, could be fed into the central network. This still only addresses "electricity" as a final fuel, and the question of providing the greater bulk of "energy" persists.

In simple economic terms, on the level of an individual or a country, the degree of security depends on the gap between income and expenditure. More can be earned or less spent. As far as the U.K.s energy earnings are concerned, the limit is in sight. We cannot realistically "earn" more fuel, and we may well have to endure a pay-cut. It is thus a matter of economy, and of economising. That we spend the precious resources of oil and gas only where it is essential to do so. This will involve schemes of energy efficiency, for example the "40% House" being researched by Dr Brenda Boardmans group in the Environmental Change Institute at Oxford University and the Passivhaus concept.

Such advances in building design could make huge savings in energy use for "space heating" across both the domestic and commercial sectors (each of which accounts for around 30% of the national total energy demand). Transport, which uses another 26%, mainly in the form of oil, is another area where savings could be made, both through more efficient combustion engines (or fuel cells, if the costs can ever be made realistic), and simply by eliminating all unnecessary use of cars (especially the military style "road wagons" - 4x4s, SUVs, depending on which side of the Atlantic you are - that have more to do with symbolising status than any practical transportation issue) .

To a reasonable mind it all seems straightforward, but I suspect there are too many people making too much money to allow any attention more than lip-service to be paid, until it is too late and there is no longer any choice.

Available link for download

Energy Institute Potential for Hydropower on the River Thames

The following is cobbled together from some notes taken at this event, hosted at the Energy Institute (London) on January 28th (2013): http://www.energyinst.org/events/view/909

The thread is, that since we have the river (Thames) close to us, surely we can use its flow of water to produce energy. Thus, weirs in particular, might be considered as assets, of which there are 44 on the Thames, owned by the Environment Agency. Each weir has been screened for its potential in hydropower generation, with consideration to: the "head" (i.e. the drop between the flowing water at the upper and lower parts), and the prevailing flow of the river there. Along the Thames, the head range is 0.7--2.7 metres, with an average of 1.8--1.9 metres. Since this is in the region of the 2 metres reckoned to be viable for power generation, the prospects appear favourable; however, environmental impacts must be considered too. It is the duty, after all, of the Environment Agency (EA) to protect the environment.

Interestingly, it is developers rather than the EA who build hydropower installations, to whom the EA grant a lease for their use of the weir. Romney weir - work on which started in September 2011, and is due to be completed in March 2013 - has some spare capacity for water flow as a flood relief channel (most weirs still need to be kept for flood defence).

Here are some points of consideration taken from, the Environment Agency - Consultation on river flow and water abstraction standards for hydropower : https://consult.environment-agency.gov.uk/portal/ho/br/standards/hydro

*Flows, constraints and water abstractions

*Monitoring of environmental impact - In Europe some schemes taken out because of environmental damage.

*Impoundment licence - authorises holder to obstruct or impede flow.

*Flood risk assessment - flood defences.

*Planning permission.

*Fish pass approval from national panel - there are both sea trout and salmon in the Thames.

*Hydropower is possible at Teddington, for which an application is close to being placed. The anticipated output is 450--490 kW, from 3 screws.

*The most fish-friendly kind of turbine is the Archimedes screw, which accordingly is the preferred technology.

*The existing Thames weirpools, especially gravels, are valuable for fish spawning, and the cumulative impact on spawning grounds mist be considered.

*Since there is no such thing as a "typical year", the impact on wildlife will be monitored over 15 years, to get a kind of "average".

*The proposed installation at Goring (and Streatley) http://ergobalance.blogspot.co.uk/2011/11/further-proposed-hydroelectric-power-on.html was mentioned, over which there is apparently some concern from local residents about noise. I believe that to install the three turbines needs and investment of £2.5 million, hardly a trivial sum! The Goring scheme has taken years to get moving, and is intended to be funded by sale of shares (e.g. 500 investors putting in £5,000 each?). The maximum power output is reckoned at 300 kW, with an average of probably 140 kW. A 3 blade screw is envisaged for Goring, a design on which tests have been made with live fish - most of which survived. Goring is a community led project, as is that at Osney.

*At Romney, a 5 blade screw is planned, which computer models suggest should be fish friendly, but the proof of this will be with actual fish, once it has started. If it proved to be a fish-shredder, it would have to be shut down, as is the case for all such schemes, should they prove to result in damage to the environment

*20-22 sites are being pursued, but because weirs were not designed to be used as hydropower installations, they are subject to a lengthy approval process.

Useful sources of info: Hydropower: A guide for you and your community / Generating energy / Publications / Home (England) - Energy Saving Trust England : http://www.energysavingtrust.org.uk/Publications2/Generating-energy/Hydropower-A-guide-for-you-and-your-community

Setting up a low carbon community group: from kitchen table to willing & able | Low Carbon Hub : http://www.lowcarbonhub.org/advice/2011/12/05/setting-up-a-climate-change-community-group-from-kitchen-table-to-willing-able

Protecting the environment by promoting the use of hydropower: British Hydropower Association : http://www.british-hydro.org/index.html
 
And a few final points (some from the lectures, and some of my own):

Hydropower is a critical feature of electricity generation in many countries http://en.wikipedia.org/wiki/Hydroelectricity, most notably Norway which gets 98+% from its water systems, closely followed by Brazil (86%) and Venezuela (69%); hydropower provides 61% of Canadas electricity, while for the United States it is a little under 6%, and the U.K. nearer 1%.

On the Thames, a working facility exists at Mapledurham http://ergobalance.blogspot.co.uk/2011/11/100-kw-hydroelectric-turbine-at.html although this is privately owned, rather than by the EA. The head is 2.05 m. Once all the planning permission, licenses etc. have been secured, practical challenges remain: e.g. it is not easy to undertake construction on a river, since access to the work area is often difficult. In the case of Teddington, the river is tidal as well as fluvial and hence it flows up and down continually. To avoid environmental contamination, biodegradable oil is recommended to lubricate the hydraulics in plant machinery.

Impacts on wildlife must be considered, i.e. protected species, invasive species, fish rescue. In the event of an emergency, contingency plans must be in place, e.g. in the case of a flood, plant & coffer damns should be removed, then simply move out & let it flood! The final weir in the line is at Richmond, and is owned by Port of London authority, with a half lock and barrage. It is tidal and is left open for part of the day. Caversham weir has too low a head and is not suitable for hydro. A facility with Sunbury proposed 4 screws is proposed at Sunbury. Although, 3 screws would be the most efficient, it has been decided that having 2 fixed speed plus 2 variable turbines is the best compromise for the overall prevailing river conditions there. The EA is considering the prospect of removing some of the weirs that are not needed for navigation, as part of the overall strategy.

Other documents:
Goring & Streatley Hydro-electricity project (PDF slides) http://www.chilternsaonb.org/uploads/files/ConservationBoard/PlanningDevelopment/Dave%20Holt.pdf

Small scale hydropower rejected sites https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/47952/755-wag-report-annex-4.pdf

Available link for download

Endangered Elements Threat to Green Energy

A list of "endangered elements" [1] has been published in a new report, including the rare earth elements (REEs) in particular neodymium, production of which, it is reckoned [2], will have to increase five-times to build enough magnets for the number of wind-turbines deemed necessary for a fully renewable future. Nonetheless, my rough calculations indicate that this would still take 50 - 100 years to implement, depending on exactly what proportion of the renewable electricity budget would be met from wind-power, and if the manufacturing capacity and other resources of materials and energy needed for this Herculean task will prevail.

Neodymium is a rare earth metal used extensively to produce permanent magnets found in everything from computer hard disks and cell phones to wind turbines and cars. Neodymium magnets are the strongest permanent magnets known, and a neodymium magnet of a few grams can lift a thousand times its own weight. The magnets that drive a Toyota Prius hybrid’s electric motor use around 1 kilogram of neodymium, while 10 - 15 kg of lanthanum is used in its battery [1]. Interestingly, neodymium magnets were invented in the 1980s to overcome the global cobalt supply shock that occurred as the result of internal warfare in Zaire (now Congo). Around one tonne of REE based permanent magnets is needed to provide each MW of wind-turbine power.

Of the other REEs, demands for dysprosium and terbium, which are harder elements to extract than their lighter relatives, are such that supply will be outpaced within a decade.The latter have been described as "miracle" ingredients for green energy production since small quantities of dysprosium can result in magnets with only one tenth the weight of conventional permanent magnets of similar strength, while terbium can be used to furnish lights that use as little as 20% of the power consumed by normal illumination. By alloying neodymium with dysprosium and terbium, magnets are created that more readily maintain their magnetism at the high temperatures of hybrid car engines [1].

However, far more dysprosium relative to neodymium is required than occurs naturally in the REE ores, meaning that another source of dysprosium must be found if hybrid cars are to be manufactured at a seriously advancing rate. 97% of REEs come from China, and it appears that China will run out of dysprosium and terbium within 15 years, or sooner if demand continues to soar. The joker in the pack, is that Chinese hegemony for its own future energy projects may mean that the current amount of REEs being released onto the world markets will be severely curbed.

Peak oil may already be with us, and peak coal in 10-15 years, while peak lithium remains a subject of speculation. Peak neodymium is the latest threat to green-energy, while doubt emerges over the security of many other element groups including the rare earths, the platinum group metals, and elements such as antimony, beryllium, gallium, germanium, graphite, indium, magnesium, niobium, tantalum and tungsten. Helium (used to cool superconducting magnets in hospital MRI scanners) and phosphorus (in agricultural fertilizers) are also under threat.

If even "renewables" cannot save us from waning fossil fuel depletion, the only solution is to begin seriously the deceleration of consumption to a lower-energy society based around local communities immediately, with vastly reduced inputs of energy and all kinds of "mined" resources. Recycling must be key to this most difficult transitional step, in hand with a new concept of a "circular economy", that aims to model nature where nothing is wasted.

Related Reading.

[1] "Critical Thinking," By Emma Davies. http://www.rsc.org/chemistryworld/Issues/2011/January/CriticalThinking.asp

[2] "Going "All The Way" With Renewable Energy?" By Mason Inman. http://news.nationalgeographic.com/news/energy/2011/01/110117-100-percent-renewable-energy/

Available link for download