The increased use of renewable energy is critical to reducing emissions of greenhouse gases in order to limit climatic change. Hydropower is currently the major renewable source contributing to electricity supply, and its future contribution is anticipated to increase significantly. However, the successful expansion of hydropower is dependent on the availability of the resource and the perceptions of those financing it. Global warming and changes in precipitation patterns will alter the timing and magnitude of river flows. This will affect the ability of hydropower stations to harness the resource, and may reduce production, implying lower revenues and poorer returns. Electricity industry liberalisation implies that, increasingly, commercial considerations will drive investment decision-making. As such, investors will be concerned with processes, such as climatic change, that have the potential to alter investment performance. This paper examines the potential impact of climatic change on hydropower investment. It introduces a methodology for quantifying changes in investment performance, and presents preliminary results from a case study. These inform discussion of the implications for future hydropower provision and our ability to limit the extent of climatic change.

One solution to reduce the extent of climate change is to replace fossil-fuelled electricity generation with renewable sources including hydropower.However, simultaneous changes in climate may alter the available hydropower resource, threatening the financial viability of schemes.To illustrate the potential problem, a sensitivity analysis is presented that considers the impact of altered precipitation and temperature on river flows, energy production and financial performance measures of a planned hydro scheme in Sub-Saharan Africa.The behaviour of the river basin was found to amplify changes in precipitation and, while the design and planned operational strategy of the station tended to moderate the impact, the overall financial impact remained significant.Comparison with (non-climate) project parameters indicated that financial performance, not surprisingly, depends strongly on discount rate and electricity sales price and that, importantly, it showed a similar sensitivity to precipitation change and rising temperature.Critical changes in climate were identified in order to indicate the severity of climate change that could be tolerated before the project becomes financially non-viable.

Limiting the emissions of greenhouse gases from power generation will depend, among other things, on the continuing and increased use of hydroelectric power. However, climate change itself may alter rainfall patterns, adversely affecting the financial viability of existing and potential hydro schemes. Previous work developed a methodology for quantifying the potential impact of climate change on the economics of hydropower schemes. Here, the analysis is extended to examine the potential for changes in project risk. A case study is presented that indicates that the applied climate change scenarios alter not only the mean financial performance of the scheme but also the financial risk facing it. Given that investors must balance project risk and reward, this finding has implications for the future provision of hydropower.

The twin requirements of reducing CO2 emission levels and increasing the level of penetration of renewable energy will involve innovative technical and operational solutions. This paper describes a novel but proven process (CO2 + 3 H-2 --> CH3OH+H2O) which could be adapted to use, as input reagents, CO2 emitted from fossil-fuelled power stations and hydrogen from electrolysis of water by a zero-emissions electricity source, e.g. renewable and/or nuclear energy. This approach, in addition to addressing the above two issues, would produce methanol for which, there is a ready and expanding market.A preliminary analysis is presented of the process economics and operational regimes necessary in the UK Electrical Supply Industry to accommodate the methanol plant. Four different designs are assessed, all based on a supply of renewable energy limited to 16 h/day when demand is off-peak. Option 'A' relies on a variable 100-500 MW supply, whereas Option 'B' makes use of a steady 100 MW during the availability period. Option 'C' is identical to 'B' except for the use of pressurised electrolysers at 30 bar instead of conventional ones. Option 'D' departs from 'B' with the use of hydrogen-powered fuel cells for power generation during the period of no availability. In the absence of a market for the electrolytic oxygen, Option 'B' is found to be the most economical, and it should be profitable if a favourable taxation regime applies on zero-emission automotive fuels. However, if the oxygen can be sold to a local industry via pipeline, Option 'C' could be potentially viable, even in the absence of tax breaks.It is claimed that significant benefits might accrue from successful development of a methanol process and that it may ease the absorption of increasing levels of embedded generation into the electricity supply network. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.

The harnessing of renewable energy sources is key to constraining the extent of climate change. Unfortunately, the very fact that such sources are derived from climatic conditions may leave them vulnerable to changes in climate. In particular, their economic performance may be adversely affecting making them a less attractive prospect to investors. The potential for such changes is examined using hydropower as an example. A methodology is introduced that enables quantification of changes in investment performance following from changes in climate. Results of its use on a planned scheme indicate that investment measures show significant sensitivity to changes in rainfall, implying that, hydropower could become less competitive. Other technologies may show similar impacts and the investigation of them should now be a matter of importance.

Gaseous emissions from fossil-fuelled electricity generation are major contributors to climate change. Limiting the extent of such change will depend, among other things, on the continuing and increased use of renewable sources, including hydropower. Paradoxically, climate change itself may alter the availability of this natural resource, adversely affecting the financial viability of both existing and potential schemes. A model is described to assess the relationship between changes in climate and the viability, technical and financial, of hydropower development. A case study is presented, both to validate the model and to predict the impact of climate change on a large potential scheme in Africa.

Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO(2) each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO(2) emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO(2) emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have still to be assuaged. Other approaches include the application of improved combustion technology, the removal of harmful gases from power-station flues and the use of waste heat to improve overall power-station efficiency. These all have a part to play, but many consider our best hope for emissions reduction to be the use of renewable energy. The main renewable energy contenders are assessed in this paper and realistic estimates of the contribution that each could provide are indicated. It appears that, in the time-scale envisaged by planners for reduction in CO(2) emission, in many countries renewable energy will be unlikely to deliver. At the same time, it is worth commenting that, again in many countries, the level of penetration of renewable energy will fall short of the present somewhat optimistic targets. Of renewable options, wind energy could be used in the short to medium term to cover for thermal plant closures, but for wind energy to be successful, the network will have to be modified to cope with wind's intermittent nature. Globally, hydroelectricity is currently the largest developed source of renewable electricity, but future large-scale projects will probably be limited to the less-developed world: the best schemes in the developed countries have already been exploited. Wave and tidal can be looked on as medium- to long-term generators of electricity, as their respective industries are not as mature as competing renewable resources. Municipal solid-waste combustion and landfill gas technologies can also be seen as short term, as can their rural equivalents, agriculture and forestry waste. Any widespread exploitation of renewable energy will depend on being able to transmit the energy from source to point of use, so the implications for the electrical network from the penetration of substantial levels of renewable energy are presented. Effective management of renewable energy installations will require technical assessment of the range of exploitation strategies, to compare local production of, say, hydrogen and the more traditional transmission of electricity. Such resources will have to compete with others in any national, or grid, system and detailed economic analysis will be necessary to determine the deployment that best fits the trading regime under which the energy will be sold. Consideration will also be necessary to determine how best to control the introduction of this radically new resource such that it does not attract punitive cost overheads until it is mature enough to cope. Finally, it is inescapable that nuclear power is a proven technology that could take its place in any future generation portfolio. Unfortunately, suspicion and mistrust surround waste management and radioactivity release. Unless this is overcome, the lack of confidence engendered by this public mistrust may result in few, if any, new nuclear power stations being built. In the event of that decision, it is difficult to see how CO(2) levels can be significantly reduced: the irony is that nuclear energy may emerge as environmentally essential.

The continuing and increased use of renewable energy sources, including hydropower, is a key strategy to limit the extent of future climate change. Paradoxically, climate change itself may alter the availability of this natural resource, adversely affecting the financial viability of both existing and potential schemes. Here, a model is described that enables the assessment of the relationship between changes in climate and the viability, technical and financial, of hydro development. The planned Batoka Gorge scheme on the Zambezi River is used as a case study to validate the model and to predict the impact of climate change on river flows, electricity production and scheme financial performance. The model was found to perform well, given the inherent difficulties in the task, although there is concern regarding the ability of the hydrological model to reproduce the historic flow conditions of the upper Zambezi Basin. Simulations with climate change scenarios illustrate the sensitivity of the Batoka Gorge scheme to changes in climate. They suggest significant reductions in river flows, declining power production, reductions in electricity sales revenue and consequently an adverse impact on a range of investment measures.

Renewable energy will undoubtedly be required to make a significant contribution to electricity supply in the future as fossil fuel reserves are depleted and concerns about the environment increase. The inherent sustainability and low carbon dioxide (CO2) emissions of renewable energy technologies additionally provide the necessary features of a future energy policy goals, however, there are a number of technical and operational problems limiting large scale integration into the conventional electricity network.The most abundant renewable energy resources come from intermittent, often unpredictable and non-despatchable sources such as wind, solar and wave. The integration of such variable power sources into the electricity grid network make the control of strict voltage and frequency limits and the security of supply through reserve capacity management difficult.To secure the contribution of renewables in future electricity supply a novel method of storing renewable energy through electrolytic hydrogen production converted into methanol incorporating CO2 sequestration is being proposed. This method provides a solution to the integration problems through absorbing the variable out put, producing a readily storable and transportable fuel and further contributing to carbon dioxide emissions reductions.

In recent years, most new generating plant installed in the UK electricity supply industry has been gas turbine. In the near future, this trend could change as both environmental pressures and international agreements legislate towards a significant increase in the level of exploitation of renewable energy. Options for new generating plant must be assessed and compared using several bases before a...

The increased use of renewable energy is critical to reducing emissions of greenhouse gases in order to limit climatic change. Hydropower is currently the major renewable source contributing to electricity supply, and its future contribution is anticipated to increase significantly. However, the successful expansion of hydropower is dependent on the availability of the resource and the perceptions of those financing it. Global warming and changes in precipitation patterns will alter the timing and magnitude of river flows. This will affect the ability of hydropower stations to harness the resource, and may reduce production, implying lower revenues and poorer returns. Electricity industry liberalisation implies that, increasingly, commercial considerations will drive investment decision-making. As such, investors will be concerned with processes, such as climatic change, that have the potential to alter investment performance. This paper examines the potential impact of climatic change on hydropower investment. It introduces a methodology for quantifying changes in investment performance, and presents preliminary results from a case study. These inform discussion of the implications for future hydropower provision and our ability to limit the extent of climatic change.

Since privatisation of the UK Electricity Supply Industry, the merit-order for the dispatch of generating plant has undergone radical changes. In Scotland, where the electricity companies have a broad-based generation portfolio, base load is now usually carried by a combination of nuclear and gas-fired generation. Hydroelectricity has nov; moved to a much less well-defined position for generation, partly because of its seasonal variability.However, the major consequence of this arrangement has been that coal-fired generation has slipped in the merit-order from the days of Nationalisation and now occupies a mid-merit position. This changed role for coal has imposed new requirements on engineers involved in the operation of, and generation planning for, coal-fired power stations. (C) 2000 Elsevier Science Ltd. All rights reserved.

Within the privatized E!ectricity Supply Industry (ESI) of the United Kingdom there exist several ways of selling electricity. This paper concentrates on spot trading with an external pool member outside the England and Wales Pool. The operation of the UK ESI is described to identify the role of the spot market tend details are given of the software which has been written to assist operations engineers in the bidding process. A typical software run is presented and its application for the future is discussed.

Bulgaria and Romania started the macroeconomic transition from a command economy to a market economy in 1989, and this involves redefining policy and practice in the electricity sector. The physical supply-side infrastructure has changed little, due to lack of finance, but operation has changed significantly. The need for structural reforms has become clearer, but the process has proved more difficult than expected. This article highlights some of the main issues facing the electricity industry in this transition.

In electricity supply networks, traditional dispatch algorithms are based on features such as economics and plant availability. Annual limits on emissions from fossil-fuelled stations are regarded as a restriction and set a ceiling on generation from particular stations. With the impending introduction of financial penalties on emissions, for example carbon taxation, algorithms will have to be developed which allow the dispatch engineer to assess the cost in real-time of different generation options involving fossil-fuelled plants. Such an algorithm is described in this paper.