Technology Required

Batteries, and fuel cells, essentially comprise two electrodes immersed in a chemical solution (usually) termed an electrolyte, while externally the electrodes are connected to an electrical circuit. An electrolyte is any substance containing free ions (an atom or molecule having lost or gained one or more electrons relative to its normal complement) and thus behaves as an electrically conductive medium. Because they generally consist of ions in solution, electrolytes are also known as ionic...

Thermal Storage Storage Principles

Energy may be stored in one of six primary mechanisms namely potential energy (gravity, elastic), kinetic energy (dynamic), thermal energy, chemical energy (batteries), magnetic and electric fields. However, since in so much of our present day economy, energy is produced and transferred as heat, the potential for thermal energy storage (THES) merits serious examination as a facilitator for a future economy based on renewables. Thermal energy storage generally involves storing energy by heating,...

Potential for Providing Intermittency Correction

In renewable energy storage terms, interest in flywheel technology is further boosted by other key features such as minimal maintenance, long life (at least 20 years or tens of thousands of accelerating decelerating cycles), and environmental neutrality. It is clear that modern low friction flywheels exhibit the potential to bridge the gap between short term smoothing and long term electrical storage applications with excellent cyclic and load following characteristics. The choice of using...

Storage Principle

It has been known for centuries that it is possible to store energy in kinetic form, for short periods of time, in the motion of a heavy mass. The movement commonly used to do this is that of a spinning disc or flywheel. Rather surprisingly, since it is not obvious that a flywheel could be made to spin for hours, or even days, it is a storage method that is now being re-evaluated in the light of advances in material and bearing technology, for roles more commonly associated with batteries....

The End of an Illusion

One does not have to delve too deeply into the seemingly vast output of the green-wash industry, to find overly optimistic statements, bordering on 'flights of fancy', about the potential of renewables to satisfy all of mankind's energy needs. On the basis of the claims of advertising copy alone, the switch from our fossil fuel past, to a renewable power future, could happen painlessly, and now, apparently In both its written and electronic form, and in the guise of consultancy reports,...

Potential as a Source of Green Energy

In global terms the contribution of geothermal sources to electrical power generation is quite small at just over 9 GW in 2005. Where local conditions are favourable it is clear that electricity generated from geothermal sources is an attractive option, and capacity could, with proper encouragement, be increased fifteen-fold. However, the evidence emanating from authoritative reports 45 on renewable energy, is that few plans are in place in 2008 to significantly increase electricity generation...

Where the Power Comes From

The current estimate for the solar constant is 1367 W m2. At the beginning of this chapter it is noted that the solar constant is a measure of the radiant power from the sun that is intercepted by the Earth's disc. However, the surface area of the Earth is four times that of its disc 27 , and if we assume that the radiant power is reduced by half both through reflection at the boundary of the Earth's atmosphere and space, and in absorption by passing through the atmosphere, we have to divide...

How the Power Is Extracted

The primary rotational force on the blades of a wind turbine, which aerodynami-cally have much in common with the wings of an aircraft, is due to 'lift' and the lift force increases with blade speed. Once the blades are rotating, velocities are high in large machines, particularly near the tips, even for moderate rotational speeds. While this is advantageous for the desired lift force, the blades become increasingly subject to 'drag'. In much the same way as a jet aircraft has thin small wings...

Power from the

The source of all renewable energy on planet Earth is predominantly the solar system. In pondering this bountiful energy provider, it is humbling to contemplate the elegance of the physical insights that have evolved by dint of human effort over the past 200 years, allowing us now, to fully comprehend it all. Quantum theory enables us to understand the nuclear processes in the sun electromagnetic theory tells us everything we need to know about radiation from the sun, while the general theory...

The Power Leakage Dilemma

Losses in the grid are estimated to be of the order of 7 in USA and Europe. Consequently, at the point where electricity is distributed to end users, only between 30 and 50 of the original power supplied to the system, in the form of heat from steam in a conventional generating station, is available. The two figures depend on whether an estimate of 36 or 60 is adopted for turbine efficiency. This implies that at best only half of the energy in the coal or oil burned in a modern fossil fuel...

Electricity

The electrical systems (generators, transformers and power lines) which we will encounter in this book are constructed from two types of material, namely metals (conductors) and dielectrics (insulators). To understand what follows it is sufficient to know that in metals, the bound atoms (e.g., copper atoms which have a tiny but 'heavy' nucleus comprising 29 positively charged protons, embedded in a 'cloud' of 29 electrons I am ignoring neutrons, which seldom make themselves known to electrical...

Dearth of Engineers

A paradigm shift in the energy supply infrastructure for the planet is being hesitantly postulated. It will entail, if implemented properly, the abandonment by mankind of fossil fuels in favour of renewable energy sources to generate electricity for all our energy needs. This is a potentially massive undertaking that cannot possibly be implemented without huge engineering effort. We are, in effect, going to have to create an industrial goliath, of similar proportions to the current automobile...

Eye of the Beholder

Scotland, a small ancient nation to the north of England, and a part of the United Kingdom, generates a relatively high proportion (13 ) of its electricity from renewable sources, predominantly taking the form of hydro-electric generation. However, most Scots, and many of the visitors to Scotland, and to the remote places where the hydro-schemes have been sited, would hardly complain that the scenery is tarnished by their presence. Some might think that a few of the Scottish dams actually add...

Chapter

1 World Energy Consumption www.solcomhouse.com worldenergy.htm 2 Brockris, J.O'M., Energy Options. Taylor Francis Ltd., London 1980. 3 Tickell, O., Kyoto 2 How to Manage the Global Greenhouse. Zen Books, London, 2008. 4 Breaking the Climate Deadlock. G8 Report, Japan 2008. 5 The Future of Nuclear Power. Massachusetts Institute of Technology, 2003. web.mit.edu nuclearpower 9 Bressand, F. et al., Curbing global energy demand growth the energy productivity opportunity. McKinsey Global Institute,...

The Unknowable

From the miniscule scale of nano-engineering, where molecules are massaged to form novel materials, to electrical engineering on the macroscopic scale where massive components are manipulated to build power stations and other large electrical systems, in general the technical problems that are encountered by scientists engineers, have known or knowable solutions. Because of this most technologists would probably aver that engineering in the physical world is largely 'child's play', by...

Towards a Wired World

There is probably a multitude of possible routes that governments could follow in attempting to hasten the transition to renewable energy. From a rational standpoint, if maintaining modern standards of living is the goal, it seems inescapable that their obligation is to do everything possible to achieve sustainability. In the event that politicians and governments are brave and wise enough to make the huge commitment that is called for, their deliberations about how they may intervene to...

Diverging Supply and Demand

If one could imagine, and this is probably quite easy for many people, that 'business-as-usual' were possible to the end of the century, and that population numbers were to plateau at 10.5 billion, as is generally predicted, then consumption trends 1 suggest that we will require to find 25-30 TW of power in 2050 to feed the seemingly 'unquenchable thirst for energy' of industrialised, and modernising, societies. The trend is shown in Fig. 5.1, where the uppermost curve (solid line + diamond...

The Ecogrid

This gentle trawl through the highways and byways of massive energy storage has, if nothing else, clearly underlined one stark fact. Namely this - because of the piecemeal approach to renewable energy, there has been a negligent lack of commitment to MES from governments around the world, and a serious absence of investment from business. Consequently, a significant range of technologically challenging solutions to the renewable energy storage dilemma still exists, despite the best efforts of...

Nuclear Backup

The expending of serious and meaningful research and development time and money is clearly needed to bring MES systems up to a level which matches the progress that has been made in establishing the technology for renewable power generation. From a strictly engineering standpoint, it is difficult not to accept that the lag between storage and generation can be ameliorated by employing nuclear power generated electricity, to furnish base load when MES systems are found wanting. However, as is...

Technofix Junkies

The obvious, but uninformed, response to the 'warming' dilemma, which is being strongly pushed by the financial community and by our political leaders, is a switch away from our reliance on fossil fuels through the agency of a market led expansion of power generation from so called renewables, such as wind power, wave power, tidal power, hydro-electric power, solar power and geo-thermal power. Nuclear power is usually included in the mix but it is not really renewable unless scientists can...

The Transport Crunch

As our freedom to burn fossil fuels becomes increasingly constrained by critical levels of CO2 in the atmosphere, travel by road and air, in vehicles and aircraft that are wholly dependent on these fuels, represents an activity, which eventually and unavoidably, will be possible no longer, in its present form. It is taken for granted, in saying this, that with a global population in excess of 10 billion the use of land area for bio-fuels is unlikely to be tolerated by hard pressed humanity....

The Grid

The final element in the electricity supply 'jig-saw' is transmission and distribution. In the electricity supply industry transmission and distribution are viewed as quite separate activities. In the industry, when they talk of transmission, the bulk transfer of electrical power from several power stations to towns and cities is being considered. Typically, power transmission is between one or more power plants and several substations near populated areas. The transmission system allows...

Energy Storage

Products that use tiny amounts of electrical power, supplied from energy stored in batteries, such as radios, hand-held phones, laptop computers, watches, toys, etc., are commonplace, but as consumers and users will know well, this is a very expensive way to energise electrical gadgets. In fact cost effectively harnessing and storing electrical power remains a major challenge to science, particularly when very large quantities of electrical energy are involved 1 . Current generation and...

Pump Storage Storage Principle

Pump storage is in essence a system for enhancing the operation of hydro-electric power plants, by assisting nature in refilling the reservoir. In particular, it is applicable to those schemes that operate with more than one reservoir. In these circumstances, it becomes possible, at periods when demand for power from the grid is low, to use excess generation capacity to move water from a lower reservoir to a higher one, for future use when demand is high. Water is then released back into the...

Power and Entropy

An ideal pendulum, which is not subject to air friction e.g., pendulum in a vacuum , and which also possesses frictionless hinges perfect bearings , would oscillate in perpetuity, if allowed to do so, with perfect transference of energy between the potential and kinetic forms. The total energy the sum of the instantaneous potential and kinetic energies for the ideal isolated pendulum is, however, fixed. No matter how long it is in motion there is no change in the total energy for this closed...