Coal

On the world scale coal provides 23 of its energy. Of that, 69 is devoted to generating electricity. Reserves of coal are estimated to be 560 billion tonnes,4 which would be sufficient for the next 160 years at current rates of extraction. According to the IEA, annual consumption will increase from the present 2.5 billion tonnes to 3.95 billion by 2020. This would reduce the life expectancy of coal to 123 years. However, there will probably be a considerable increase in the use of coal to...

Insulation

There is an increasing demand for eco-insulation materials that are obtained from natural sources. The most popular up to the present is cellulose fibre derived from recycled newspaper. The material is treated with boron to give fire resistance and protect against vermin infestation. It is suitable for wet spray or dry blown application. One of the most popular proprietary brands is 'Warmcell', supplied by Excel Industries which belongs to Fillcrete. It has a thermal conductivity of 0.036 W mK,...

Foreword

With mounting anxieties about climate change and the long-term outlook for energy, the role of renewable energy is becoming ever more critical. This book responds to these concerns by examining technologies ranging from microgeneration of power for individual homes to multi-megawatt technologies for base-load electricity. This second, enlarged edition reviews the latest advances in the technologies, as well as adding new case studies. As the century progresses, the world will increasingly be...

Solar heating

The United Nations Development Programme (UNDP) world energy assessment estimates the global use of energy to heat water to be 10,000 PJ.1 This technology is especially important for rapidly growing cities like Mexico City and Sao Paulo which have a severe pollution problem as well as an energy problem. There are two basic systems for solar heating Flat bed collectors consist of metal plates coated matt black behind glass or plastic. They are tilted to maximize uptake of solar radiation. Behind...

The lightemitting diode LED

Scientists have produced materials which have a photonic band gap, namely a range of wavelengths of light which are unable to pass through the material. This is achieved by structuring the materials in precisely designed patterns at the nanoscopic scale. The result has been called 'semiconductors of light'. Light emitted from traditional forms of illumination is effectively a by-product of heat. The incandescent light bulb operates at 2000 C so clearly much of the energy it uses is wasted....

Notes

New Scientist, 'Inside Science, Fuelling the Future' 16 June 2001 2. US National Renewable Energy Laboratory (NREL) 4. emagazine.com, 'After oil, clean energy from a fuel-cell-driven global hydrogen web' December 2005, p.5 6. Energy Saving Trust, 'A strategic framework for hydrogen energy in the UK' December 2004 7. Peters, M. D. and Powell, J. C., Working Paper 64, November 2004

Beddington Zero Energy Development BedZED

Though this project featured in the first edition, BedZED has still not been surpassed as a pioneer development. It is not just another low-energy housing scheme, it is a prescription for a social revolution a prototype of how we should live in the twenty-first century if we are to enjoy a sustainable future. This project was introduced at the foundations stage in Architecture in a Climate of Change (pp. 76-78). The scheme now has its first residents and it is appropriate in this volume to...

Council offices Kings Lynn

When the Borough Council of King's Lynn in Norfolk was obliged to consider new accommodation there was a commitment to create a building which was exemplary in both aesthetic and environmental terms. The Borough Council took its obligations under Agenda 21 extremely seriously. King's Lynn is a tight-knit town with buildings spanning from the twelfth to twenty-first centuries. The new offices occupy a corner site close to a Grade 1 listed church. Jeremy Stacey Architects were commissioned to...

Vacuum tube collectors

In this technology, evacuated tubes enclosed within an insulated steel casing work by exploiting the vacuum around the collector. This reduces the heat loss from the system, making them particularly suited to cooler climates like that experienced in the UK. They heat water to around 60 C but sometimes significantly higher. This means that domestic hot Figure 2.1 Vacuum solar collectors on Professor Marmont's Farm, Nottinghamshire Figure 2.1 Vacuum solar collectors on Professor Marmont's Farm,...

Microgeneration and combined heat and power

In March 2006 the UK government issued a report outlining a new microgeneration programme called 'Our energy strategy power from the people'. It was prompted by the Energy Saving Trust's (EST) prediction that microgeneration could provided 30-40 of the UK's electricity needs by 2050. The report was mainly descriptive, identifying a range of difficulties faced by potential installers, particularly the problems of contributing to the grid and the feed-in tariffs that are offered. Its main...

CIS Tower Manchester UK

It is still the case that most PV arrays on buildings are installed for reasons that do not include cost-effectiveness. However, that could change if the cost of the PVs is absorbed into the overall cost of a building refurbishment. The fa ades of most commercial offices are of the curtain wall variety, which can be relatively easily dismantled. Re-fa ading presents an ideal opportunity for employing building-integrated renewable energy. Integrating PVs into a curtain wall can be a...

Dyebased cells

The dominance of silicon is being challenged by a new generation of solar cells that mimic the process of photosynthesis. Developed by Michael Gratzel and Brian O'Regan of the University of Lausanne, this cell uses a dye containing ruthenium ions that absorb visible light analogous to chlorophyll in nature. The dye is applied to nanocrystals of the semiconductor titanium dioxide or titania. The titania has the electronic property of being able to draw electrons from the ruthenium and propel...

Flexible solar panels

Shell Renewables and Akzo Nobel in the Netherlands are jointly developing a low-cost process for mass-producing flexible solar cell panels. A special semiconductor coating is applied to rolls of flexible foil substrate on an almost continuous basis. The process is being developed in parallel by the Technical Universities of Delft and Eindhoven, Utrecht University, the Energy Research Centre of the Netherlands, NOVEM the Dutch agency for energy and the environment and the European Union. This...

Amorphous silicon cells

Less efficient but cheaper to produce are silicon-based cells which do not have a crystalline atomic structure. Hydrogenated amorphous silicon (a-Si H) comprising a thin film 0.5 m thick form the basis of highly light-absorbent cells, hence the description 'thin film solar cell'. They are produced by atomic deposition over a large area and consequently much more economical to produce than crystalline silicon cells which involve slicing up slabs of crystalline silicon grown by a slow...

Prospects for the energy infrastructure

The system of generating and distributing electricity is undergoing a slow but radical change. In political science there is a concept called the 'elitist perspective', which describes how individuals and groups assume control over social institutions. Elitist clusters exert power through the manipulation of individuals and governments to achieve their aims and maximize their profits. This is graphically illustrated by the 20 million given by US energy companies between 1999 and 2002 to...

Sustainability on a knife edge

Global warming is taking us by surprise. Scientists are regularly having to recalibrate their predictions for impacts in the face of the accelerating evidence of climate change. The most dramatic example of this occurred in 2005. Before this the definitive prognosis for global average temperature rise to 2100 was the IPCC Third Assessment Report of 2001. It estimated that CO2 emissions were likely to raise average global temperature between 1.4 and 5.8 C. In January 2005 the results were...

Offshore impoundment

An alternative to estuary tidal generation is the concept of the tidal pound. The idea is not new as mentioned earlier. The system is ideal for situations in which there is a significant tidal range and shallow tidal flats encountered in many coasts of the UK. The system consists Phitlng ol tnplfl cells ev Ml I ' gtnera tto n Figure 11.11 The shape and generating phases of tidal impoundment Phitlng ol tnplfl cells ev Ml I ' gtnera tto n Figure 11.11 The shape and generating phases of tidal...

Introduction

In October 2001 the Royal Institute of British Architects hosted a conference on the subject of Sustainability at the Cutting Edge, which inspired the title of this book. The opening address was delivered by Sir John Houghton, a world authority on climate change issues. The aim of the conference was to provide an overview of the science and technology behind sources of renewable energy which would assume prominence in the next decade. This review was placed in the context of increasing concern...

About the author

Sir John Houghton was co-chairman of the Scientific Assessment for the IPCC from 1988-2002. He was previously chairman of the Royal Commission on Environmental Pollution (1992-1998), Chief Executive of the Meteorological Office (1983-1991) and Professor of Atmospheric Physics, University of Oxford (1976-1983). He is currently chairman of the John Ray Initiative, a Trustee of the Shell Foundation and Honorary Scientist at the Hadley Centre. All figures and text copyright Sir John Houghton CBE...

Photonics in communication

Fibre optics are now a familiar feature of long-range communication. An optical fibre consists of a glass core and a cladding layer wrapping around it. The core and cladding are precisely chosen so that their refractive indices (the ability to bend light by specific amounts) ensure that the photons within the core are always reflected at the interface of the cladding (see Fig. 14.2). This ensures that the only way light can escape is through the ends of the fibre. Either an LED or a laser sends...

Central solar heating plant diurnal storage CSHP

In this case, the storage capacity is obviously much less, merely coping with a 24-hour demand. The demonstration project at Ravensburg supplies 29 terraced houses with hot Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month of the year district heating- and solar network tauet heat storage seasonal storage district heating- and solar network tauet heat storage seasonal storage Figure 2.14 Diagram of the Neckarsulm project (courtesy of Renewable Energy World) Figure 2.14 Diagram of the...

Bioenergy

Biomass is the sum total of all the Earth's living matter within the biosphere. It is continually regenerated by the sun through the process of photosynthesis. The energy reaching the planet is equivalent to about seven times its primary energy consumption. If biomass is converted to a fuel when it is at its peak as a store of chemical energy the process is carbon neutral. This means that the carbon emitted when it is burnt is equal to the carbon absorbed during growth. It is not a complete...

Fuel cells and the UK

In December 2004 a research project funded by the DTI and led by Eoin Lees, former Chief Executive of the Energy Saving Trust, examined the prospects for hydrogen in the UK.6 Its final report came to the following conclusions 'The UK's priorities with regard to hydrogen were unclear making them hard to address for the purpose of achieving maximum overall benefit. Hydrogen energy support was provided by several initiatives in the UK but a dedicated programme was not in place. . . The UK had no...

Microhydro

Despite often having access to wind or hydropower, about two billion people or one third of the earth's population have no electricity. Many small communities, especially in the developing world, do not have the resources to embark on a small hydro project, but micro-hydro is another matter. It covers systems providing between 10 and 100 kW of power. A typical case is the Vavanga Community, a village on the south west coast of Kolombangara Island, one of the Solomon Islands. It now has...

Anaerobic digestion from waste

Anaerobic digestion (AD) is becoming increasingly important as a means of disposing of waste. Germany, with 1500 small farm-based digestion plants, and Denmark, with its centralized plants producing combined heat and power, are among the leaders. In this process, wet waste comprising dung or sewage is transformed into a slurry with about 95 water content. This mixture is fed to a sealed digester where the temperature can be controlled. Digesters range in size from a domestic scale holding 200...

Solar buildings

Solar collectors are one of several renewable technologies that together make a solar building. It is essential that, from the earliest design stage, there is a symbiotic relationship between active solar and PVs, heat pumps and possibly small-scale wind turbines. 'Integrated design' is one of the slogans of the new millennium. Figure 2.6 Open loop pumped circulation system (courtesy of Renewable Energy World) Figure 2.6 Open loop pumped circulation system (courtesy of Renewable Energy World)...

Solargas combination boilers

The principle here is that a 240-litre tank is heated by flat plate solar collectors supplemented by a gas burner within the body of the cylinder. A heat exchanger coil in the upper half of the tank heats the central heating circuit. A production solar-gas combination boiler with 2.83 m2 of solar collectors produces 4GJ year 3 a 5.4 m2 collector supplies 5.64GJ year. A test involving 25 units showed boiler efficiency of 90.1 . On average, consumers saved 650 m3 of natural gas compared with...

Largescale tidal energy The tidal barrage

Trapping water at high tide and releasing it when there is an adequate head is an ancient technology. A medieval tide mill is still in working order in Woodbridge, Suffolk. In the first quarter of the last century this principle was applied to electricity generation in the feasibility studies for a barrage across the River Severn. Tidal power works on the principle that water is held back on the ebb tide to provide a sufficient head of water to rotate a turbine. Dual generation is possible if...

National Trust Offices Swindon UK

A cutting edge office building in the UK is the National Trust offices in Swindon by architects Fielden Clegg Bradley. Despite being a 'design and build' contract, the nominated architects were able to deliver a state of the art sustainable building. It is naturally ventilated and daylit, Figure 15.5 National Trust offices, Swindon (courtesy of Fielden Clegg Bradley) Figure 15.5 National Trust offices, Swindon (courtesy of Fielden Clegg Bradley) Air exhausts via ventilation 'snout' Air rises...

Solar thermal electricity

Solar energy is more evenly distributed across the sun belt of the planet than either wind or biomass. The downside is that deserts do not attract centres of population. However, as the world gradually switches to becoming a hydrogen-based energy economy, solar thermal electricity could be the key to substantial hydrogen production by electrolysis. African countries bordering the Mediterranean could greatly boost their economies by exporting solar hydrogen to Europe by tanker or pipeline. This...

Wave and tide

Wave power is a fairly high density form of solar energy since the winds that generate waves are created by heat from solar radiation. Solar power can be transformed into waves with an energy density of 100 kW per metre length of wave crest. The World Energy Council estimates that wave power could meet 10 of world electricity demand. It is regarded as a reliable power source and has been estimated as being capable of meeting 25 or 12 GW of peak UK demand. With an estimated load factor of 50 for...

Micropower and CHP

There is an increasing climate of opinion in favour of 'distributed' or decentralized power generation. This is especially the case in rural locations or where stability of supply is essential, such as for banks, hospitals research facilities etc. Micropower or small-scale generation is the key to this trend. There are several advantages to this alternative to the large-scale grid system served by a few large thermal power plants Small-scale power can be closer to the point of use, overcoming...

Photovoltaic cells

Electricity is produced from solar energy when photons or particles of light are absorbed by semiconductors. This is the basis of the photovoltaic (PV) cell. Most solar cells in current use are built from solid-state semiconducting material. Semiconductors are at the centre of the electronic revolution of the last century and it is worth a moment to consider how they function. Silicon is a typical semiconductor material in that its electrical properties can be influenced in a number of ways....

Monolithic tandem concentrator cells

The Fraunhofer Institute for Solar Energy in Freiburg has developed a PV based on a thin film structure of two semiconductors gallium indium arsenide and gallium indium phosphide. Solar concentrators are incorporated in the cell which increases the solar intensity by factors ranging from 100 to 1000. Because the optical concentrators focus solar energy onto a small area, this reduces the area of cells required for a given output. In the laboratory the cells achieve an efficiency of 29 but...

Point absorbers

As the term suggests, these are systems which are focused on a nodal form of absorbing the energy of the waves to generate electricity. One technology which is on the verge of being market ready is the Interproject Service (IPS) Offshore Wave Energy Converter (OWEC) system. This uses only wave energy and is not affected by tidal or ocean currents (see Fig. 11.1). The system consists of a floating buoy (A) attached to the sea bed by 'elastic' moorings enabling it to exploit the motion of the...

Wind power

The first known windmills were developed in Persia between 500 and 900 AD to pump water and grind grain. They consisted of vertical sails rotating round a central shaft. The first documented example of the technology in Europe dates from 1270. It shows a horizontal-axis machine mounted on a central post with four sails, known predictably as a 'postmill' machine. It took until the nineteenth century for the windmill sails to achieve peak efficiency. These sails had some of the crucial features...

Electricity storage

A technology called 'regenesys' converts electrical energy to chemical energy and is potentially capable of storing massive amounts of electricity. Energy is stored in two concentrated aqueous electrolyte solutions, sodium bromide and sodium polysulphide. On charging the bromide ions are oxidized to bromine while sulphur in the polysulphide anions is converted to sulphide ions. On discharging, the sulphide ions act as the reducing agent and the tribro-mide ion as the oxidizing agent. The system...

The spectre of energy

The second critical threshold advancing inexorably relates to energy. In sharp contrast to the warnings from the climatologists is the optimism of the energy industry based on predictions of unimpeded world economic growth. However, a forecast contained in the International Energy Agency (IEA) World Energy Outlook 2004 report suggests that developed countries will increasingly be at the mercy of OPEC (Organisation of Petroleum Exporting Countries). This cartel is set to provide half of the...

Towards a hydrogen economy

Over the millennia there have been three ages of energy. First there was the epoch of wood burning, lasting up to the eighteenth century when it was gradually supplanted by coal. The early twentieth century saw a gradual shift from coal to oil. The fourth energy age is dawning and will focus on hydrogen. Its drivers will be concern about security of supply of fossil fuels, anxieties about the environment especially global warming and, finally, advances in technology. The concept of a hydrogen...

Barriers to progress

A drawback which affects most renewables is the new electricity trading arrangement (NETA). This requires a provider of electricity to the National Grid to estimate in advance how much electricity they will be exporting. Suppliers who may be subject to quite large fluctuations in output due to the inconsistency of wind or sun are severely disadvantaged by this regulation. Secondly, the UK conforms with the European Union in the way heat and power from CHP are evaluated. It is the heat which has...

Biofuel for transport

Biofuel for transport is a further opportunity sector for biomass. Revisions to the EU Common Agricultural Policy which came into effect in 2005 pose a challenge to farmers as world cereal prices fall. Energy crops are an obvious substitute. The Department of Environment, Food and Rural Affairs (Defra) is currently investigating barriers to energy crop production. Already the EU is the largest producer of biodiesel in the world at 500,000 tonnes with the potential for twice that capacity....

The Intergovernmental Panel on Climate Change IPCC

The IPCC was formed in 1988 jointly by the World Meteorological Organization and the United Nations Environment Programme. I had the privilege of being chairman or co-chairman of the Panel's scientific assessment from 1988 to 2002. Hundreds of scientists drawn from many countries were involved as contributors and reviewers in these assessments. Our task was honestly and objectively to distinguish what is reasonably well known and understood from those areas with large uncertainty. The IPCC has...

Environmental impact

Despite claims to the contrary, it is virtually impossible to produce and transform energy without some carbon dioxide emissions. A survey of over 5000 MW installed capacity of geothermal emitted an average of 65 g CO2 per kWh. This compares with 450 g kWh for gas, 906 g kWh for oil and 1042 g kWh for coal, excluding the embodied energy in plant and equipment as well as carbon miles for the transportation of oil and coal. So, geothermal advocates are justified in their claim that it is one of...

Utilization of biofuels

Short-rotation coppice (SRC) of certain fast-growing trees like willow can provide a bulk fuel for burning in power plants. It can be co-fired with coal to reduce emissions and prolong the life of coal-fired plants. Trees are planted at a rate of 15,000 per hectare and cut back to near ground level after a year. They usually re-grow as multiple stems and after two to four years can be harvested for fuel. The cycle is repeated over a life span of about 30 years. One problem in a liberalized...

Hydrogen storage

This is the final hurdle for the hydrogen economy to negotiate before it reaches the final straight. Fuel cells depend on a steady supply of hydrogen, which means that storage backup is an essential component of the system where reformation is not involved. The conventional storage method for hydrogen is pressurized tanks. The pressure varies according to volume up to 50 litres requires 200-250 bar larger amounts, 500-600 bar. Some very large containers can be as low as 16 bar. It can be stored...

Government Training Centre Germany

Possibly the most ambitious example of building-integrated PV (BIPV) to date is at the heart of the Ruhr in Germany at Herne-Sodingen. The Mount Cenis Government Training Centre, for a time the world's most powerful solar electric plant is a spectacular demonstration of the country's commitment to rehabilitate this former industrial region whilst also signalling the country's commitment to ecological development (see Fig. 15.3). After the demise of heavy industry the Ruhr became a heavily...

Active district solar heating

Flat plate or evacuated tube solar heating collectors are a well-established technology for individual buildings, especially at the domestic scale. The next development is likely to Figure 2.8 Mechanical circulation solar thermal system with back-up boiler (courtesy of Renewable Energy World, March-April 2004) Figure 2.8 Mechanical circulation solar thermal system with back-up boiler (courtesy of Renewable Energy World, March-April 2004) be the scaling up of this technology to help meet heating...

The road ahead

There are two approaches to the adoption of hydrogen as the prime energy carrier of the future. The first is to extract hydrogen from a readily available fuel like natural gas or petrol. As stated earlier, this is done by a reformer unit. The sage of the green movement, Amory Lovins, claims that a reformer the size of a water heater 'can produce enough hydrogen to serve the fuel cells in dozens of cars'. The great advantage of this approach is that there already exists the infrastructure for...

Combined heat and power CHP

From time to time reference has been made in the text to CHP. Since there seems to be strong EU and UK government support for this system of energy distribution it calls for special consideration. First, electricity generation in the UK is the largest single contributor to CO2 emissions, amounting to 26 of the total. Many buildings are responsible for more CO2 from the electricity they use than from the fuel for the boilers providing hot water and space heating. At the same time the heat from...

Stirling combined heat and power

Stirling Engine For Home Use

The alternative system that is already on the market is a micro-CHP (combined heat and power) unit based on the Stirling engine. The UK government is increasingly promoting micro-CHP as part of its strategy to reduce CO2 emissions, especially in the domestic sector. It is interesting how two nineteenth century technologies, the fuel cell and the Stirling engine, are only now coming into their own. Invented by Robert Stirling in 1816, the eponymous machine is an 'external combustion engine'...

Building integrated systems

There is increasing interest in the way that the design of buildings can incorporate renewable technologies including wind turbines. Up to now such machines have been regarded as an adjunct to buildings but a concept patented by Altechnica of Milton Keynes demonstrates how multiple turbines can become a feature of the design. The system is designed to be mounted on the ridge of a roof or at the apex of a curved roof section. Rotors are incorporated in a cage-like structure which is capped with...

Smallscale hydro

Hydropower has a history going back at least 2000 years. The Doomsday book records 5000 waterwheels. One of the earliest hydroelectric schemes and first in the world to power a private home was installed by the First Lord Armstrong in the 1880s at Cragside in Northumberland. This means, of course, that it is not exactly at the cutting edge of progress. The expansion of the National Grid sounded the death knell for many small hydroschemes. However, it is increasingly now being perceived as an...

Airsourced air heat pumps

Instead of drawing warmth or coolth from a ground or water source, in warmer climes it is possible for the external source to be the air. In cooling mode the compressor pumps refrigerant to the outside coil where it condenses into a liquid. The air flowing across the coil removes heat from the refrigerant. It is then transported to the inside coil where it picks up heat from the interior of the building. Internal air is blown across the inside coil where the liquid refrigerant evaporates giving...

Tidal currents

Alderney Tidal Currents

Whereas the tidal fence is appropriate for capturing fast tidal flow between land masses like an estuary or well-defined channel, other technologies can exploit the energy content of tidal currents that oscillate along coasts. These have to be distinguished from large ocean movements like the Gulf Stream, which are thermodynamic phenomena. Horizontal-axis underwater turbines are the favoured technology for offshore tidal currents. They are similar to wind turbines but water has an energy...

Sky Zed

Tower blocks are usually regarded as the antithesis of green building. Bill Dunster Architects have tackled this perception head-on with the concept design for a zero energy tower. The argument is that urban densities will have to increase which will make some high-rise development inevitable, therefore the task is to exploit their height and floor plate to make them net sources of power. The tower could form the focal point of a larger low-rise housing complex on the lines of BedZED (see...

Contents

1 Climate change and sustainable energy The 2005 Prince Philip 1 Lecture at the Royal Society of Arts by Sir John Houghton CBE FRS The Intergovernmental Panel on Climate Change (IPCC) 5 3 Low energy techniques for cooling 31 Groundwater aquifer cooling and warming 31 Desiccant dehumidification and evaporative cooling 36 Solar-assisted desiccant dehumidification with air conditioning 37 Types of small-scale wind turbine 54 Monolithic tandem concentrator cells 70 Photovoltaics cost projections 72...

Acknowledgements

I am indebted to the researchers and construction professionals who readily gave permission for the inclusion of their work in the text. These include Dr Koen Steemers of Cambridge Architectural Research, Arup Associates for BedZED diagrams, Christopher John Hancock for the images of Malmo, Jeremy Stacy Architects for the Council Offices, King's Lynn, Fielden Clegg Bradley for the National Trust Offices, Swindon, XCO2 for the triple helix wind generator image and Pilkington plc for the image of...

Hydrogen the agent of social reform

At present consumers of energy in developed countries are reliant on either an extensive grid of wires or pipes for gas. Both are wasteful of energy and costly in terms of maintenance (Fig. 7.6). Figure 7.6 The National Grid for the UK and Ireland including the inter-connectors with Ireland and the continent Figure 7.6 The National Grid for the UK and Ireland including the inter-connectors with Ireland and the continent One of the most persuasive of hydrogen apologists is Jeremy Rifkin,...

Mode of operation of geothermal heat pumps

In the cooling mode a GHP is transformed into a refrigerator. Water circulating in the earth loop is warmer than the surrounding ground. It therefore releases heat to the ground, cooling in the process. The cooled water then passes through a heat exchanger in the heat pump. Within the heat exchanger refrigerant, gas heated by a compressor releases its heat to the water, which then begins its travel to release heat to the ground. The refrigerant, having released its heat energy, becomes a cold...

Malmo city of the future

Malmo Bo01

The development on the waterfront of this southern city in Sweden was given its initial impetus by exhibition Bo01, masterminded by Professor Klas Tham and aimed at promoting sustainable urban development. The significance of this project is that it seeks to reconcile the goals of sustainable design with the demands of the market. Malmo is set to experience a renaissance in its fortunes with the completion of the Oresund Bridge linking it to Denmark. This project represents an emphatic...

STM 4Piston Double Acting Stirling Cycle Engine

Www Stmpower Com Stirling

Figure 9.6 Axial configuration of cylinders (courtesy of STM Power) Beta Stirling Engine Figure 9.6 Axial configuration of cylinders (courtesy of STM Power) Beta Stirling Engine This has a single power piston in the same cylinder and on the same shaft as a displacer piston. The latter is a loose fit piston which serves to move the working gas from the hot zone to the cold heat exchanger. As the working gas is pushed to the hot zone of the cylinder it expands and pushes down the power piston. At...

Free piston Stirling engines FPSE

Free Piston Stirling Cooler

The second main category of Stirling engine is a version in which the piston floats freely within a hermetically sealed cylinder thus without an external linkage to drive a generator. This elegant development of the Stirling principle is even more silent than the previous examples and is ideal for domestic use. Sunpower Inc., a US company, plans to introduce a system to the UK in 2007 which is based on a Stirling engine which incorporates an alternator within the cylinder which produces 1 kW of...

Types of smallscale wind turbine

Vertical Wind Turbine Blade Design

Most small systems have a direct-drive permanent-magnet generator which limits mechanical transmission losses. Systems under 2 kW usually have a 24-48 V capacity aimed at battery charging or a DC circuit rather than having grid compatibility. Up to the present, horizontal-axis machines are much more in evidence than the vertical-axis type, even at this scale. These machines have efficient braking systems for when wind speed is excessive. Some even tip backwards in high winds, adopting the...