Composites Design and Manufacture (Plymouth University teaching support materials) Energy considerations in sustainability.

Lecture PowerPoint

Reading Lists

Review papers

Subject Index

Any (re-)processing of materials will require energy. That raises issues of collection and transport, fuel efficiency and the ethics of global sourcing.  Unnecessary use of energy costs money and potentially contributes to climate change.  A European project, RECIPE: Reduced Energy Consumption In Plastics Engineering, aims to help the plastics processing industry to reduce their energy consumption.  The RECIPE best practice guide [i] provides a structured and practical approach to improving energy efficiency in the processing of plastics.

Reference

1. Best Practice Guide for Low Energy Plastics Processing from the European Community funded RECIPE project
    (supported by the Intelligent Energy Europe programme) contract no. EIE/04/153/S07.38646.

Further reading

• Selected review papers on energy
• DNV-GL renewables certification: guidelines and technical notes for wind turbines, wind farms and other renewables
• DNV-GL renewables certification: list of publications
• DNV-GL renewables certification: standards and guidelines
• Green Resources: home energy guides
• S Yao, S Zhang and X Zhang, Renewable energy, carbon emission and economic growth: a revised environmental Kuznets Curve perspective, Journal of Cleaner Production, 20 October 2019, 235, 1338-1352.

The generation of energy may contribute to degradation of the planets ecosystems.  The energy may come from a variety of sources, including:

• ammonia
• biomass
• fossil fuels
• geothermal
• hydroelectric
• hydrogen
• nuclear
• ocean thermal energy conversion (OTEC)
• solar
• tidal barrage
• tidal stream
• waves
• wind

• nuclear

• James Lovelock [1] believes "nuclear power is the only source of energy that will satisfy our demands and yet not be a hazard to Gaia and interfere with its capacity to sustain a comfortable climate and atmospheric composition" [page 67] while "not recommending nuclear fission as the long-term panacea for our ailing planet or as the answer to all our problems [but] as the only effective medicine we have now" [page 11].
• Jack Harris [2] (using data from David Fleming in the June 2005 issue of Prospect)  states that "to make a significant impact on global warming nuclear would have to supply 100% of all the world's electricity requirements.  However, to do this, he calculates that the planets total quantity of viable uranium ores would last just six years".

1. The Sustainable Nuclear Energy Technology Platform
2. James Lovelock, The Revenge of Gaia: why the Earth is fighting back – and how we can still save humanity, Allen Lane, London, 2006. ISBN 978-0-713-99914-3.  PU CSH Library.
3. Jack Harris, Material matters: availability of uranium, Materials World, January 2006, 14(1), 56.

• The generation of energy by combustion of hydrogen offers a clean energy source with emissions limited to water molecules, albeit that the production of hydrogen can be energy intensive.  Hydrogen has an energy density/kg of 33.6 kWh/kg (compared to diesel at 12-14 Kwh/kg), but due to low density occupies a large volume.
• Hydrogen is classified by different colours according to source (Table 1).
• The Liebreich Clean Hydrogen Ladder attempts to put use cases for clean hydrogen into some sort of merit order.
• Hydrogen storage systems review papers

1. JOM Bockris, T Nejat Veziroglu and Debbi Smith, Solar Hydrogen Energy: the power to save the earth, MacDonald Optima, London, 1991. ISBN 0-356-20042-6.
2. T Nejat Veziroglu and Frano Barbir, Hydrogen Energy Technologies (UNIDO Emerging Technologies Series), UNIDO, Vienna, 1998.
3. D A J Rand and R M Dell, Hydrogen Energy - Challenges and Prospects, RSC Publishing, 2007. ISBN: 978-0-85404-597-6.
4. WJ Martinez-Burgos, E de Souza Candeo, A Bianchi, P Medeiros, J Cesar de Carvalho, V Oliveira de Andrade Tanobe, CR Soccol and EB Sydney, Hydrogen: current advances and patented technologies of its renewable production, Journal of Cleaner Production, 1 March 2021, 286, 124970.

• Ammonia (NH₃) has been identified as a sustainable fuel for mobile and remote use [1].  Like hydrogen, it is a synthetic product that can be synthesised from fossil fuels, biomass or other renewable sources.  Zamfirescu and Dincer [1] claim the "advantages of ammonia with respect to hydrogen are [lower] cost per unit of stored energy, higher volumetric energy density that is comparable with that of gasoline, easier production, handling and distribution with the existent infrastructure, and better commercial viability".  The same authors state that ammonia is the least expensive fuel when measured in US$/GJ, is ranked third after gasoline and liquid petroleum gas when measured in GJ/m³, and has a refrigeration by-product!
• Yapicioglu and Dincer [2] have reviewed the use of ammonia as a potential fuel for power generation.
• Li et al [3] have reviewed the combustion characteristics of ammonia as a "carbon-free fuel".
• While ammonia is a carbon-free fuel (i.e. potentially Net Zero CO₂ if synthesised using renewable energy), combustion will generate nitrogen oxides (NO_x) with environmental burdens including (i) global warming potential >100x higher than for CO₂, (ii) acidification, (iii) eutrophication and (iv) human toxicology [4, 5] (see Adisa Azapagic et al's environmental impact classification factors (EICF).

1. C Zamfirescu and I Dincer, Using ammonia as a sustainable fuel, Journal of Power Sources, 15 October 2008, 185(1), 459-465.
2. A Yapicioglu and I Dincer, A review on clean ammonia as a potential fuel for power generators, Renewable and Sustainable Energy Reviews, April 2019, 103, 96-108.
3. J Li, S Lai, D Chen, R Wu, N Kobayashi, L Deng and H Huang, A review on combustion characteristics of ammonia as a carbon-free fuel, Frontiers in Energy Research, 2021, 9:760356.
4. A Azapagic, A Emsley and I Hamerton, Polymers, the Environment and Sustainable Development, John Wiley & Sons, March 2003, ISBN 0-471-87741-7.  PU CSH Library.
5. A Azapagic, S Perdan and R Clift (editors), Sustainable Development in Practice - Case Studies for Engineers and Scientists, John Wiley & Sons, May 2004. ISBN 0-470-85609-2.  Second edition, 2011: ISBN 978-0-470-71872-8.  PU CSH Library.
6. Anon., Ammonia Technology Roadmap Executive Summary, accessed 31 May 2023.
7. BC Tashie-Lewis and SG Nnabuife, Hydrogen production, distribution, storage and power conversion in a hydrogen economy - a technology review, Chemical Engineering Journal Advances, 15 November 2021, 8, 100172.
8. C Tornatore, L Marchitto, P Sabia and M De Joannon, Ammonia as green fuel in internal combustion engines: state-of-the-art and future perspectives, Frontiers in Mechanical Engineering, 22 July 2022, 8, 944201.
9. Anon., Technology Collaboration Programme on Advanced Motor Fuels: Ammonia, accessed 31 May 2023.

• Burning coal without increasing global carbon dioxide levels is a major technological challenge.  The most promising "clean coal" technology involves using the coal to make hydrogen from water, then burying the resultant carbon dioxide by-product and burning the hydrogen.  The greatest challenge is bringing the cost of this down sufficiently for "clean coal" to compete with nuclear power on the basis of near-zero emissions for base-load power [1].
• Linc Energy Limited (Australia) has produced diesel from a demonstration coal-to-liquid (CTL) facility using underground coal gasification (UCG) [2].
• "Capturing and storing carbon dioxide in a cost competitive and safe way is a significant challenge that could achieve significant reductions of CO₂ emissions in the atmosphere" [3].
• The International Energy Agency Greenhouse Gas R&D Programme (IEA GHG) has a series of publications available to download including:
  natural releases of CO2, the Weyburn CO₂ Monitoring & Storage Project, Putting Carbon Back in the Ground, and Ocean Storage of CO₂.
• The Higher Heating Value (HHV) (also known as the gross energy or upper heating value or gross calorific value (GCV) or higher calorific value (HCV)) indicates the upper limit of the available thermal energy produced by a complete combustion of fuel, and the HHV for methane is 55.5 MJ/kg [4].  Liquid Natural Gas (LNG) is produced by cryogenic refrigeration of natural gas at about -162°C at atmospheric pressure. This is a high energy process, with estimates suggesting that production of 1 kg of LNG, assumed to be all methane CH₄, at a high process pressure of 55 bar (the critical pressure of CH₄ is 46 bar) requires a compression work of about 800-860 kJ/kg is necessary (considering a compression efficiency in the range between 0.8 and 0.85) [5].  Liquifying natural gas requires ~1.5% of the methane gross calorific value!
• "Bamboo is the fastest growing canopy for the re-greening of degraded lands with stands releasing 35% more oxygen than wood trees.  Some bamboo can absorb up to 12 tons of carbon dioxide per hectare from the air" [6].

1. "Clean Coal" Technologies, Briefing paper, Uranium Information Centre Limited Briefing Paper #83, May 2006.
2. Mark Hull, Underground coal gasification, Materials World, January 2009, 17(1), 18.
3. Ian Fells and John Horlock, Carbon capture and storage, Ingenia, June 2006, 27, 36-41
4. https://en.wikipedia.org/wiki/Heat_of_combustion]
5. A Franco and C Casarosa, Thermodynamic and heat transfer analysis of LNG energy recovery for power production, 32nd UIT (Italian Union of Thermo-fluid-dynamics) Heat Transfer Conference/IOP Journal of Physics: Conference Series, 2014, 547, 012012.
6. M Doney, M Wroe and D Pratt, Top floor/Bamboo: the ecological wonder plant, Developments (DFID), 2006, 36, 25.

• The European Environment Agency [1] is currently assessing an environmentally-compatible primary bioenergy potential in Europe for 2010, 2020 and 2030. This work will provide input to the policy debates on both the upcoming Biomass Action Plan and proposed post-2010 renewable energy targets.  In a subsequent report, the EEA [2] has considered whether there is a limit to the quantity of biomass which can be grown without damaging the environment.
• Biodiesel can use most animal fats and vegetable oils as raw materials [3].  The triglycerides are converted to methyl esters by transesterification with methanol.  The fuel has a lower energy content than conventional diesel resulting in a 6% increase in volumetric fuel consumption.  A significant disadvantage is the ~10% yield by mass of glycerol (also known as glycerine) produced as a currently saleable by-product for use in resins, polyols, food, cosmetics, drugs, explosives, tobacco, paper making, adhesives and textiles.  Oversupply of glycerol can cause a sharp reduction in its price: of particular relevance for biodiesel production as the volumes of this by-product are high relative to most other production sources.
• a review of the scientific literature [9] suggests that the widespread production of algal biofuels may solicit several types of impacts and that broader international dialogue on the global impacts of algal production and processing technologies is necessary.
• NNFCC (the bioeconomy consultants) have briefly reviewed [10] the controversy around the EU decision to classify crop-based biofuels according to their risk of incurring land use change, taking into account several factors in the context of palm oil: indirect land-use change (ILUC), loss of biodiversity (via deforestation) and greenhouse gas emissions.
• Abbasi et al [11] have reviewed the state-of-the-art for microalgae-based biofuel supply chain modeling.

1. How much biomass can Europe use without harming the environment?, EEA Briefing 02, European Environment Agency - Copenhagen, 2005.
2. T Wiesenthal, A Mourelatou, J-E Petersen and P Taylor, How much bioenergy can Europe produce without harming the environment?, European Environment Agency report 2006/7, Copenhagen, 2006. ISBN 92-9167-849-x. ISSN 1625-9177.
3. J Duncan, Costs of biodiesel production, Report for Energy Efficiency and Conservation Authority, May 2003.
4. N El Bassam, Energy Plant Species - their use and impact on environment and development, Earthscan, March 1998. ISBN-13: 978-1-87393-675-7.  PU CSH Library.
5. M Walsh and M Jones, Miscanthus For Energy and Fibre, Earthscan, September 2000. ISBN-13: 978-1-9029-1607-1.
6. Sjaak van Loo and Jaap Koppejan, The Handbook of Biomass Combustion and Co-firing, Earthscan, December 2007. ISBN-13: 978-1-844072491.
7. F Rosillo-Calle, S Hemstock, P de Groot and J Woods, The Biomass Assessment Handbook - bioenergy for a sustainable environment, Earthscan, January 2008. ISBN-13: 978-1-84407-526-3.
8. J Constable, Biofuels: the future?, Ingenia, March 2009, (38), 12-18.
9. D Benson, K Kerry and G Malin, Algal biofuels: impact significance and implications for EU multi-level governance, Journal of Cleaner Production, 1 June 2014, 72, 4-13.
10. Palm oil- fuelling bioeconomy controversy, NNFCC, 10 June 2019, accessed 10 June 2019.
11. M Abbasi, MS Pishvaee and S Mohseni, Third-generation biofuel supply chain: a comprehensive review and future research directions, Journal of Cleaner Production, 10 November 2021, 323, 129100.

• The core of planet Earth is at a temperature of ~5000 degrees C, still cooling from its formation billions of years ago whilst insulated from the openness of space by the mostly solid mass of the earth's crust.  This heat can be tapped, as geothermal energy, to yield both warmth and power without polluting the environment.
• Allahvirdizadeh [1] presents the most common issues in geothermal well drilling operations and introduces potential future research areas.

1. P Allahvirdizadeh, A review on geothermal wells: well integrity issues, Journal of Cleaner Production, 1 December 2020, 275, 124009.
2. MH Dickson and M Fanelli, Geothermal Energy - utilization and technology, Earthscan, April 2005. ISBN-13: 978-1-84407-184-5.  PU CSH Library.
3. K Ochsner with introduction by R Curtis, Geothermal Heat Pumps - a guide for planning and installing, Earthscan, November 2007. ISBN-13: 978-1-84407-406-8.
4. M-C Suárez-Arriaga, J Bundschuh and F Samaniegod, Assessment of submarine geothermal resources and development of tools to quantify their energy potentials for environmentally sustainable development, Journal of Cleaner Production, 15 November 2014, 83, 21–32.

• All known commercial renewable energy systems, with the exceptions of geothermal and tidal, are driven by the solar radiation which the earth receives [2].  This sub-section will focus on energy derived from the direct conversion of sunlight to heat and/or power.
• The maximum power density at the top of the atmosphere on the side of the earth directly facing the sun is ~1395 J/s.m² (2 cal/min.cm²) although this varies by about 7% primarily due to the changing distance between the earth and the sun [2].  Around 47% of this reaches the ground (24% by direct radiation, 17% by diffuse scatter from clouds and 6% by down-scatter from the atmosphere).  The balance is up-scattered by clouds (25%), absorbed by clouds (10%), absorbed by the atmosphere (9%) or up-scattered from the atmosphere (9%).
• Solar energy can be captured by design of buildings to trap the heat (passive solar) or focussing the energy onto fluids for heating of onto photoelectric cells for the generation of electricity.
• Ristinen and Kraushaar [2] state that "passive heating of buildings is generally not included in tabulations of solar energy usage because every building gains some solar energy through its windows, even those that are not directly south-facing [and hence] the actual importance of solar energy to the natural energy budget is understated in most accounts of energy sources".
• "Artificial photosynthesis is based on the concept of a dye analogous to chlorophyll absorbing light and thus generating electrons which enter the conduction band of a high surface area semiconductor film and further move through an external circuit, thus converting light into 'green' power" [3].  In consequence, biomass is essentially driven by solar energy.
• Ganesh [4] has reviewed the use of solar energy in the conversion of CO₂ to methanol or to other chemicals using catalytic, thermal, biological, electrochemical or photoelectrochemical (PEC) techniques.
• The embodied carbon in solar PV may be of concern [5, 6].
• Kazem et al [7] conducted a comprehensive review of solar photovoltaic dust problems and cleaning methods, proposed a new dust cleaning methodology and compared the systems boyh technically and economically.
1. Jeff Johnson, Power from the sun, Chemical and Engineering News, 21 June 2004, 82(25), 25-28.
2. RA Ristinen and JJ Kraushaar, Energy and the Environment - second edition, Wiley, 2006.  ISBN: 978-0-471-73989-0.  PU CSH Library.
3. How It Works: Artificial Photosynthesis, http://www.dyesol.com/index.php?page=HowItWorks, accessed 12:26 on 08 March 2008.
4. I Ganesh, Conversion of carbon dioxide to methanol using solar energy - a brief review, Materials Sciences and Application, October 2011, 2(10), 1407-1415.
5. GP Hammond, HA Harajli, CI Jones and AB Winnett, Whole systems appraisal of a UK Building Integrated Photovoltaic (BIPV) system: Energy, environmental, and economic evaluations, Energy Policy, January 2012, 40, 219-230.
6. Embodied carbon of solar PV: here's why it must be included in net zero carbon buildings, Circular Ecology, accessed 22 January 2020.
7. HA Kazem, MT Chaichan, AHA Al-Waeli and K Sopian, A review of dust accumulation and cleaning methods for solar photovoltaic systems, Journal of Cleaner Production, 10 December 2020, 276, 123187.

• Xiong Gong, Toward high performance inverted polymer solar cells, Polymer, 9 November 2012, 53(24), 5437-5448.

• Wind turbines are becoming a feature of the landscape, but they do not always run smoothly!:
• Wind turbine going wild and finally breaking, alternative view and slow motion sample (YouTube)
• By borrowing the best practices of composites blade design from the aerospace industry, wind turbine blade manufacturers can avoid costly errors and significantly reduce the time and cost of design, analysis and testing - while manufacturing stronger products with higher energy outputs.
• There is increasing interesting in locating larger wind turbines offshore on floating platforms.
• Limiting blade lengths are of the order of 25 m for natural fibre blades [1], 45 m for glass fibre blades [2], and currently 143 m for carbon fibre blades [see below].
• Vestas has installed the V236-15.0 MW prototype turbine at the Østerild National test centre for large wind turbines in Western Jutland ~ Denmark [3].  The mould for the 115.5 m blades were developed at Vestas factory in Lem ~ Denmark and prototype blades were manufactured at Vestas offshore blade factory in Nakskov ~ Denmark.  The prototype has successfully produced its first kWh of power and will now undergo an extensive test and verification programme to ensure reliability before full type certification and serial production begins.
• Their 2021 MingYang Smart Energy (Guangdong, China) MySE 16.0-242 platform had 118 m blades. MySE recently announced the MySE 18.X-28X wind turbine with 140 m blades taking it beyond the 18 MW threshold for offshore wind turbines [4].  The turbine is designed to operate in extreme ocean conditionsup to Level-17 typhoon.  The first 143 m MySE292 offshore wind blade (swept diameter 292 m) rolled off the production line in February 2024 [5].

1. Z Belfkira, H Mounir and A El Marjani, New investigation of mechanical properties of a horizontal axis wind turbine blade based on a hybrid composites with kenaf fibers, SN Applied Sciences, 2020, 2, 233.
2. P Brøndsted, H Lilholt and A Lystrup, Composite materials for wind power turbine blades, Annual Review of Materials Research, 2005, 35, 505-538.
3. Anon., Vestas’ V236-15.0 MW prototype wind turbine produces first kWh, Vestas, 30 December 2022.
4. G Nehls, MingYang reveals 18-MW offshore wind turbine model with 140-meter-long blades, CompositesWorld online, 19 January 2023.
5. G Nehls, Hengshen carbon fiber contributes to 143-meter-long MingYang wind blade, CompositesWorld online, 03 April 2024.

References for disposal of end-of-life composite wind turbines blades (also see end-of-life boat hulls).

1. A Yazdanbakhsh, LC Bank, K-A Rieder, Y Tian and C Chen, Concrete with discrete slender elements from mechanically recycled wind turbine blades, Resources, Conservation and Recycling, January 2018, 128, 11-21.
2. K Kalkanis, CS Psomopoulos, S Kaminaris, G Ioannidis and P Pachos, Wind turbine blade composite materials - end of life treatment methods, Energy Procedia, January 2019, 157, 1136-1143.
3. A Lefeuvre, S Garnier, L Jacquemin, B Pillain and G Sonnemann, Anticipating in-use stocks of carbon fibre reinforced polymers and related waste generated by the wind power sector until 2050, Resources, Conservation and Recycling, February 2019, 141, 30-39.
4. P Liu, F Meng and CY Barlow, Wind turbine blade end-of-life options: an eco-audit comparison, Journal of Cleaner Production, 01 March 2019, 212, 1268-1281.
5. J Chen, J Wang and A Ni, Recycling and reuse of composite materials for wind turbine blades: an overview, Journal of Reinforced Plastics and Composites, 01 March 2019, 38(12), 567-577.
6. O Prakash, G Glivin, N Kalaiselvan and V Mariappan, A strategic study on the environmental impacts of wind turbine blade materials, their improvements, economics and end-life-options, Energy Research Journal, 2020, 11, 36-44.
7. C Mattsson, A André, M Juntikka, T Tränkle and R Sott, Chemical recycling of End-of-Life wind turbine blades by solvolysis/HTL, IOP Conf. Series: Materials Science and Engineering, 2020, 942, 012013. 41st Risø International Symposium on Materials Science.
8. G Nehls, GE announces U.S. blade recycling contract with Veolia, CompositesWorld online, 11 December 2020.
9. L Mishnaevsky, Sustainable end-of-life management of wind turbine blades: overview of current and coming solutions, Materials, 27 February 2021, 14, 1124.
10. L Bank, R Gentry, E Delaney, J Mckinley and P Leahy, Defining the landscape for wind blades at the end of service life, CompositesWorld online, 14 May 2021.
11. M Lewis, Wind giant Vestas says it can now fully recycle turbine blades, Electrek, 17 May 2021.
12. G Nehls, Ørsted to recover, reuse or recycle wind turbine blades, CompositesWorld online, 07 June 2021.
13. G Nehls, European partnership drives forward novel process development for GFRP recycling, CompositesWorld online, 11 June 2021 [Aker Offshore Wind, Aker Horizones and the University of Strathclyde].
14. M Rani, P Choudhary, V Krishnan and S Zafar, A review on recycling and reuse methods for carbon fiber/glass fiber composites waste from wind turbine blades, Composites Part B: Engineering, 15 June 2021, 215, 108768.
15. G Nehls, Partnership integrates recycled turbine blade materials into energy storage system, CompositesWorld online, 08 July 2021.
16. İM Eligüzel and E Özceylan, A bibliometric, social network and clustering analysis for a comprehensive review on end-of-life wind turbines, Journal of Cleaner Production, 20 December 2022, 380(1), 135004.

additional resources

1. European Wind Energy Association, Wind Energy - The Facts: a guide to the technology, economics and future of wind power, Earthscan, London, March 2009. ISBN 978-1-84407-710-6.
2. P Brøndsted, Advances in wind turbine blade design and materials (Woodhead Publishing series in energy #47), Woodhead Publishing, Oxford, 2013. ISBN 978-0-85709-426-1.  PU CSH Library.
3. Joao Cruz and Mairead Atcheson (editors), Floating Offshore Wind Energy: the next generation of wind energy, Springer International Publishing, 2016.  ISBN 978-3-319-29396-7.
4. MOL Hansen, Aerodynamics of Wind Turbines - second edition, Earthscan, December 2007. ISBN 978-1-84407-438-9.  PU CSH Library.
5. R Harrison, Erich Hau and Herman Snel, Large wind turbines: design and economics, John Wiley & Sons, 2000. ISBN 978-0-471-49456-0.  PU CSH Library.
6. J Johnson, Blowing green, Chemical and Engineering News, 24 February 2003, 81(8), 27-30.
7. GR Kirikera, M Sundaresan, F Nkrumah, G Grandhi, B Ali, SL Mullapudi, V Shanov and M Schulz, Wind Turbines, In C Boller, F-K Chang and Y Fujino (editors), Encyclopedia of Structural Health Monitoring, John Wiley & Sons, Chichester, 2009.
8. R Lacal-Arántegui, Materials use in electricity generators in wind turbines – state-of-the-art and future specifications, Journal of Cleaner Production, 15 January 2015, 87, 275-283.
9. T Loveday and B Byrne, Harnessing Offshore Winds, Ingenia, June 2014, 59, 24-30.
10. JF Manwell, JG McGowan and AL Rogers, Wind Energy Explained, John Wiley, Chichester, 2002.  ISBN 0-471-49972-2.  PU CSH Library.
11. BB Nalukowe, J Liu, W Damien and T Lukawski, Life Cycle Assessment of a Wind Turbine, KTH School of Architecture and the Built Environment, 22 May 2006.
12. B Palomo, C Michaud and B Gaillardon, First life cycle assessment of a French wind plant, JEC Composites magazine, June-July 2014, 90, 36-40.
13. Wen Zhong Shen (editor), Wind Turbine Aerodynamics, MDPI Books, September 2019.  ISBN 978-3-03921-524-9 (pbk);  ISBN 978-3-03921-525-6 (FREE PDF)
14. J Trewby et al, Wind Energy: implications of large-scale deployment on the GB electricity system, Royal Academy of Engineering, London, April 2014.  ISBN: 978-1-909327-07-8.
15. J Walker and N Jenkins, Wind Energy Technology, John Wiley, Chichester, 1997.  ISBN 0-471-96044-6.  PU CSH Library.
16. Wind Energy Handbook, Gurit, 2014.
17. Some additional references
18. Wind turbines (review papers).

• The earth's natural water cycle provides rain (and on higher land seasonal snow and hence runoff when it melts).  The water flows downstream via streams, rivers and lakes and can be contained by dams en route. This head of water can then be channelled to a turbine which generates electricity.
• See also Dinorwig Power Station under energy storage and transmission below.

1. West Webburn River: 90kW of renewable electricity is generated on Dartmoor and excess sold to the National Grid. http://www.waterleat.co.uk/

• Wave energy is due to movements of water near the surface of the sea [1].  Waves are formed when wind blows over the water surface, making the water particles adopt circular motions.  This kinetic energy is determined by the speed and duration of the wind, the length of sea over which it blows, the depth of water, the sea bed conditions and also any interactions with the tides.
• The bioWAVE^TM wave energy system [2] has long vertical blades which sway back and forth in response to oscillating wave forces.  This motion is partially resisted by an electrical generator mounted at a pivot near the sea floor.  In excessive wave forces, the device lies flat against the seabed to avoid damage.
• The WaveCat [3] is a floating WEC designed to operate by oblique overtopping in 50-100 m of water.  It consists of two converging hulls attached to a single point mooring.  The bows are "held to sea" so that incident waves propagate into the decreasing space between the hulls, then flood reservoirs in the hulls before the water drains back to sea through turbine generator groups.
• Pérez-Collazo et al [4] have reviewed the options for combined wave and offshore wind energy.
1. Guide to Marine Energy: an overview of marine energy generation, Marine Energy Challenge News issue 1, accessed 13:18 on 04 April 2006.
2. Biomimetics To Harness Ocean Power, Warren Centre for Advanced Engineering, November 2006.
3. H Fernandez, G Iglesias, R Carballo, A Castro, JA Fraguela, F Taveira-Pinto and M Sanchez, The new wave energy converter WaveCat: concept and laboratory tests, Marine Structures, December 2012, 29(1), 58-70.
4. C Pérez-Collazo, D Greaves and G Iglesias, A review of combined wave and offshore wind energy, Renewable and Sustainable Energy Reviews, February 2015, 42, 141–153.
5. Guide to Marine Energy: the description of real seas and how wave characteristics affect device design, Marine Energy Challenge News issue 2, accessed 13:40 on 04 April 2006.
6. Jeff Johnson, Power from moving water, Chemical and Engineering News, 04 October 2004, 82(40), 23-30.
7. Marine Renewables: Wave and Tidal Stream Energy Demonstration Scheme, DTI Energy Group, January 2005.
8. T W Thorpe, A Brief Review of Wave Energy, ETSU Report ETSU-R120 for The UK Department of Trade and Industry, May 1999.
• Joao Cruz (editor), Ocean Wave Energy: current status and future perspectives, Springer-Verlag, Berlin Heidelberg, 2008.  ISBN 978-3-540-74894-6.

• Water near the surface of (sub-)tropical seas is kept at higher temperatures than water at greater depths or at higher latitudes.  Some effort has been dedicated to trying to harness this temperature difference.

• Tidal energy occurs due to large movements of water in the sea. As tides flow and ebb (come in and go out respectively), water near the coast is raised and lowered and the potential energy of this tidal range can be exploited [1]. The environmental and ecological impacts of such systems are complex.
• The largest tidal barrage power station is La Rance in France where 24 x 10 MW turbines extract power from a 22 km² basin with a tidal range up to 8 m.

1. Guide to Marine Energy: an overview of marine energy generation, Marine Energy Challenge News issue 1, accessed 13:18 on 04 April 2006.
2. Jeff Johnson, Power from moving water, Chemical and Engineering News, 04 October 2004, 82(40), 23-30.
3. Marine Renewables: Wave and Tidal Stream Energy Demonstration Scheme, DTI Energy Group, January 2005.
4. UK Hydrographic Office, Admiralty Tide Tables, 2003.  http://www.ukho.gov.uk/admiralty_tide_tables.html.

• Tidal-stream energy is the direct extraction of kinetic energy from the motion of water in naturally occurring tidal currents in the sea.  Black & Veatch [2] suggest that the UK resource may be about half the entire European resource (and one of the most concentrated tidal stream resources in the world) which could generate 22 TWh/year without causing significant changes to flow momentum or significant environmental impacts.
• The bioSTREAM^TM tidal current system mimics the shape and motion characteristics of highly efficient Thunniform-mode swimming species (such as shark and tuna) but is fixed in a moving stream and converts the motion of the fluid into energy to drive the device against the resisting torque of an electrical generator.
• Wood [3], Sloan [4] and Walker and theis [5] have presented a useful reviews of composites in tidal energy devices.

1. Guide to marine energy: the nature of the tidal stream resource and aspects of generation device design, Marine Energy Challenge News issue 3, accessed 13:15 on 04 April 2006.
2. Focus on tidal stream: a summary of work by Black & Veatch Consulting on the tidal stream resource, Marine Energy Challenge News issue 1, accessed 13:20 on 04 April 2006.
3. K Wood, Composites tap tide energy, Composites Technology, October 2010, 16(5), 28-36.
   Wave-energy conversion (side-bar article accompanying the above).
4. Jeff Sloan, Turbulent salt seas, Composites Technology, December 2012, 18(6), 46-48.
5. S Walker and PR Thies, A review of component and system reliability in tidal turbine deployments, Renewable and Sustainable Energy Reviews, November 2021, 151, 111495.
6. Biomimetics To Harness Ocean Power, Warren Centre for Advanced Engineering, November 2006.
7. Jeff Johnson, Power from moving water, Chemical and Engineering News, 04 October 2004, 82(40), 23-30.
8. Marine Renewables: Wave and Tidal Stream Energy Demonstration Scheme, DTI Energy Group, January 2005.
9. UK Hydrographic Office, Admiralty Tidal Stream Atlases, 2003. http://www.ukho.gov.uk/admiralty_tidal_stream_atlases.html.

A more complete description of the relative merits of each option is beyond the scope of this module.  A number of authors [1, 2] have considered life-cycle assessment for the energy sector.

1. Malgorzata Góralczyk, Life-cycle assessment in the renewable energy sector, Applied Energy, July-August 2003, 75(3-4), 205-211.
2. S Walker and R Howell, Life cycle comparison of a wave and tidal energy device, Proc. IMechE Part M: Journal of Engineering for the Maritime Environment, November 2011, 225(4), 325-337

Relevant technologies associated with energy generation include:

• Sustainability assessment
• Santoyo-Castelazo and Azapagic [1] proposed a new methodological framework for integrated sustainability assessment of energy systems. The framework was applied to the electricity system in Mexico with consideration of the key energy drivers and of climate change targets in 2050. The proposed methodology and the research outcomes may provide a decision support framework for planning future electricity supply.
1. E Santoyo-Castelazo and A Azapagic, Sustainability assessment of energy systems: integrating environmental, economic and social aspects, Journal of Cleaner Production, 1 October 2014, 80, 119-138.
• carbon capture and storage
• Fells and Horlock [1] have reported that "capturing and storing carbon dioxide in a cost-competitive and safe way is a significant challenge that could achieve large-scale reductions of CO₂ emissions into the atmosphere.
• Hester [2] has described the current options and the potential of future CCS strategies.
• Pervaiz and Sain [3] have shown that the use of natural fibre reinforcements in thermoplastic matrix composites has potential as a "sustainable" sink for atmospheric carbon dioxide.
• Zhang et al [4] reviewed the advantages and disadvantages of a variety of remote sensing monitoring technologies in the context of the safety of different CO2 injection stages.
• SaskPower's $1350M flagship Boundary Dam Integrated Carbon Capture and Storage Project first went operational on 03 October 2014.
• The European Technology Platform for Zero Emission Fossil Fuel Power Plants (ZEP) has recognised that public acceptance of the role of CO₂ Capture and Storage (CCS) technology in mitigating climate change will be a prerequisite to its large scale deployment [5].
1. Ian Fells and John Horlock, Carbon Capture and Storage, Ingenia, June 2006, (27), 36-41.
2. RE Hester and RM Harrison, Carbon Capture and Storage, RSC Books, 2009. ISBN-13: 987-1-84755-917-3.
3. Muhammad Pervaiz and MM Sain, Carbon storage potential in natural fiber composites, Resources, Conservation and Recycling, November 2003, 39(4), 325-340.
4. T Zhang, W Zhang, R Yang, Y Liu and M Jafari, CO2 capture and storage monitoring based on remote sensing techniques: a review, Journal of Cleaner Production, 25 January 2021, 281, 124409.
5. A vision for zero emission power plants, EC DG for Research: Sustainable Energy Systems, Brussels, 2006. EUR 22043. ISBN 92-894-0545-7.
6. John Oakey, Containing carbon — carbon capture and storage, Materials World, October 2008, 16(10), 26-27.
7. James Meadowcroft and Oluf Langhelle (editors), Caching The Carbon: the politics and policy of carbon capture and storage, Edward Elgar Publishing Limited, Cheltenham, 2009. ISBN 978-1-84844-412-6.
8. What Happens When CO₂ is Stored Underground? Q&A from the IEAGHG Weyburn-Midale CO2 Monitoring and Storage Project, Global CCS Institute and the Petroleum Technology Research Centre, 2014.  ISBN 978-0-9871873-3-1.
9. M Carus, P Skoczinski, L Dammer, C vom Berg, ARaschka and E Breitmayer, Hitchhiker’s Guide to Carbon Capture Utilisation (CCU), nova paper #11 on bio- and CO2-based economy, Huerth (D), February 2019.
• A Dubey and A Arora, Advancements in carbon capture technologies: a review, Journal of Cleaner Production, 1 November 2022, 373, 133932.
• J Wang, Y Zheng, S He, J Yan, X Zeng, S Li, Z Tian, L Lei, Y Che and S Deng, Can bioenergy with carbon capture and storage deliver negative emissions? A critical review of life cycle assessment, Journal of Cleaner Production, 1 January 2024, 434, 139839.
• energy storage and transmission
• Dinorwig Power Station (1728 MW), commissioned in 1984, is the largest pumped storage hydroelectric scheme of its kind in Europe [1]. It consists of Europe's largest man-made cavern, with 16 km of underground tunnels, deep below Elidir mountain in Wales.  Off-peak electricity is used to pump water from the lower reservoir up to Marchlyn Mawr reservoir (location map and photograph).  The six reversible pump/turbines are capable of reaching maximum generation capacity in less than 16 seconds.
1. Dinorwig Power Station Llanberis, First Hydro Company, undated, accessed 11;25 on Saturday 16 February 2008.
2. Bent Sørensen, Renewable energy conversion, transmission and storage, Academic Press, November 2007. ISBN-13: 978-0-12-374262-9.
3. EUR 21240 European CO2 Capture and Storage Projects (Sixth Framework Programme Project Synopses), European Commission, Luxembourg, 2004. ISBN 92-894-8002-5.
4. EUR 22574 CO2 Capture and Storage Projects (Project Synopses), European Commission, Luxembourg, 2007. ISBN 92-79-03724-2.
• Trans-Mediterranean Renewable Energy Cooperation (TREC)
• TREC is an initiative to campaign for the transmission of clean power from deserts throughout Europe, the Middle East and North Africa. It was founded in 2003 by The Club of Rome, the Hamburg Climate Protection Foundation and the National Energy Research Center of Jordan. TREC aims to boost the generation of electricity and desalinated water by solar thermal power plants and wind turbines in the Middle East and North Africa (MENA) and to transmit the clean electrical power via High Voltage Direct Current (HVDC) transmission lines throughout those areas and from 2020 into Europe.

Other resources on these issues include:

• David Mackay, Sustainable Energy - without the hot air, UIT Cambridge Limited, 2009. ISBN 978-0-9544529-3-3 (paperback), ISBN 978-1-906860-01-1 (hardback).   PU CSH Library.
• VVN Kishore, Renewable Energy Engineering and Technology: principles and practice, Earthscan, London, April 2009. ISBN 978-1-84407-699-4.
• RA Ristinen and JJ Kraushaar, Energy and the Environment - second edition, Wiley, 2006.  ISBN: 978-0-471-73989-0.  PU CSH Library.
• Janet Wood, Local Energy: Distributed Generation of Heat and Power, IET Publishing, Stevenage, 2008. ISBN-13: 978-0-86341-739-9.  PU CSH Library.
• ETDE: Energy Technology Data Exchange (also known as the Energy Information Library)
    ..  free access to almost 4 million articles and papers on energy research and technology.
• DTI Energy Policy and Strategy
• NERN: National Energy Research Network
• UK Energy Research Centre  Energy Research Atlas
• Cornwall Sustainable Energy Partnership

... and for climate change the following may be of use:

• California Climate Change Extension
• Interview with Dan Kammen on Alternative Energy
• Interview with Dan Cayan on Climatology
• Interview with Kelly Redmond on Climatology
• Interview with Michael Hanemann on Economics
• Interview with Dan Sperling on Transportation