Overall efficiency electricity pricing

In the unit price of electricity (Kk) derived in Section B.2, the dominant factors are the capital cost per kilowatt (CJW), which generally decreases inversely as the square root of the power (i.e. as the fuel price the overall efficiency tjq, the utilisation H hours per year) and to a lesser extent the operational and maintenance costs (OM). 

The non-diffusional methods of bringing D and A together may also result in payment of an ultimate price of diminished overall efficiency since BET within contact ion pairs is usually more rapid than in solvent separated ion pairs (see below). Indeed, the most important aspect of the forward electron transfer is that it presets the conditions for the competition between BET and the fragmentation reaction. The reactive intermediates (ion pairs) are generated in specific solvation and spin states. That state can be controlled or at least influenced by a selection of the excited state component, the ground state component and solvent [20], as well as by magnetic and electric fields [36]. 

Hydrogen production by the electrolysis of water is currently less important, accounting for less than 3% of the hydrogen produced, due to the low overall efficiency of 20 to 25% including the electricity production. Large plants are only constructed where favorable conditions obtain, mainly near dams e.g. in Egypt (a plant at the Assuan dam has an ammonia capacity of 33 000 m- /h), India, Peru and in countries with low electricity prices or where there is a favorable demand for the byproduct oxygen e.g. in Norway. 

But for power station applications, the thermal efficiency is not the only measure of the performance of a plant. While a new type of plant may involve some reduction in running costs due to improved thermal efficiency, it may also involve additional capital costs. The cost of electricity produced is the crucial criterion within the overall economics, and this depends not only on the thermal efficiency and capital costs, but also on the price of fuel, operational and maintenance costs, and the taxes imposed. Yet another factor, which has recently become important, is the production by gas turbine plants of greenhouse gases (mainly carbon dioxide) which contribute to global warming. Many countries are now considering the imposition of a special tax on the amount of CO2 produced by a power plant, and this may adversely affect the economics. So consideration of a new plant in future will involve not only the factors listed above but also the amount of CO2 produced per unit of electricity together with the extra taxes that may have to be paid. 

A once-through process will be used in combination with tri-generation as in this way the product output of the plant can be optimised for market prices or needs. The co-production of electricity, heat, and liquid fuels leads to higher efficiencies and lower overall costs. 

The combination of high value outputs, scale-effects and flexibility in general, may lead to a very efficient, cost-effective and clean overall system. Cost-effective means that the electricity produced has to compete with electricity from coal. For fair comparison the cost of clean electricity generation must be considered with a similarly low environmental burden. For instance, costs for removal or storage of the emitted carbon dioxide from coal plants have to be included. For electricity this inches an allowable cost price of 0.05 Euro/kWh. This value is the EU strategic goal and seems achievable for large advanced systems [5] where electrical efficiencies between 50 and 60% can be obtained [6]. In the case of the produced liquid fuels, cost-effective means that the cost price must correspond to the cost prices of fossil fuels, which will be used in the future in cars with low or very low emissions. For the liquid fuels FT diesel is taken as example and the cost price would have to be 0.34 Euro/litre (of diesel). 

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