Cost-capacity factor

The cost capacity factor (n) has an average value of 0.6 for most plants and equipment but can vary over a wide range. The factor can be obtained from published data or historical records. 

Barrato et al. determined a value of 0.94 for the cost-capacity factor y, however, its value is usually in the region of 0.6 [622]. 

Comparing two or more complex alternatives is more difficult than examining equipment capacity or first cost. Characteristics of alternatives should be weighted for relative importance and measured on a common scale to aEow proper evaluation. Many characteristics such as first cost, capacity, space requirement, and annual energy use can be measured objectively and used for system comparisons. Experience has shown that items such as maintenance expense, component life, and downtime can also be rehably estimated. Other factors, eg, system maintainabEity, flexibEity, and comfort, are more arbitrary. 

Selection of Equipment Packed columns usually are chosen for very corrosive materials, for liquids that foam badly, for either small-or large-diameter towers involving veiy low allowable pressure drops, and for small-scale operations requiring diameters of less than 0.6 m (2 ft). The type of packing is selected on the basis of resistance to corrosion, mechanical strength, capacity for handling the required flows, mass-transfer efficiency, and cost. Economic factors are discussed later in this sec tion. 

The economics of such a system are very complex, and there are many variables that must be considered. Some of the major considerations are total installed cost, the load factor or capacity factor, the... 

The principal factors to consider when comparing the performance of bubble-cap, sieve and valve plates are cost, capacity, operating range, efficiency and pressure drop. 

There are no electrolyzers developed specifically for operation with wind turbines. However, the rapid response of electrochemical systems to power variations makes them suitable "loads" for wind turbines. Industrial electrolyzers are designed for continuous operation, mainly because their elevated investment cost requires high-capacity factors for reasonable payback times, but they are subject to a considerable number of current interruptions through their lifetime due to occasional power interruptions, accidental trips of safety systems, and planned stops for maintenance. Current interruptions are more frequent in specialty applications, where electrolyzers supply hydrogen "on demand." Therefore, the discontinuous use of the equipment is not new, and most commercial electrolyzers may be used in intermittent operation although a significant performance decrease is expected with time. In fact, it is not power variation, but current interruptions that may cause severe corrosion problems to the electrodes, if the latter are not protected by the application of a polarization current when idle. 

For a given wind power installed, the sizing of the electrolyzer is not trivial. In the case of "stand-alone" systems, a one-to-one approach is often proposed, with the electrolyzer power input being equal to the nominal power output of the wind turbine. In this way, the electrolyzer should be able to retrieve all the wind power in the absence of load. In grid-connected systems, the same approach leads to the choice of an electrolyzer with a power supply equal to the power output of the wind turbine minus a "base load." However, the specific capital cost of the electrolyzer being almost equal to the cost of a wind turbine, it is important to take into account the capacity factor of the electrolyzer that will always be smaller than that of the wind turbine. 

Retention times of molecules separated over mesoporous silica are much longer than those obtained by using commercially available silica, this is due to the increased surface area of mesoporous silica, which in turn increases molecular capacity factors. Differences between capacity factors are also enhanced Thus, molecules which elute with similar retention times on commercial HPLC columns, with overlapping peaks, can be successfully separated by using HPLC columns slurry packed with mesoporous silica. The long retention times are somewhat of a drawback in that large amounts of solvent must be used and the peak shapes of molecules with long retention times can be broad. Mesoporous silica may not be ideal for routine analytical separations but provides an excellent and cost-effective preparative separation medium. 

Pumps. Pump base costs were found in Fig. 8.8. Here pump product of capacity, gpm times the respective head, psi, gives a factor that is used to fix each particular pump base cost. Again, as in all the other equipment module spreadsheets, the associated equipment table factors—including piping, electrical, steel, concrete, and instrumentation—are multipliers to derive the full pump module cost. Of course labor and indirect costs are factored as well in Table 8.25. 

The advantages of nuclear power plants include the fact that they operate at a 90% capacity factor (loading). Also, 1 kg of natural uranium generates about as much electricity as 20,000 kg of coal. In contrast to fossil fuels, nuclear power does not contribute to global warming. In the past, the cost of... 

This combination makes them the least costly generating option for low and intermediate capacity factor power generation as shown in Table IV. (2) NERC projections indicate that the only major shifts anticipated in unit capacity factors will be an increase from 15% to 50% in liquid fueled combined cycle units and a decrease from 52% to 23% for gas fired boilers. 

Electricity Cost Capital charges 20% ann. capacity factor 14% of capital per yr MM/yr 0.669 /kWh Sunny location like CA 0.081 ... 

The use of PV electricity for electrolytic H2 production is a means of storing solar energy and overcoming its limitations as an intermittent power source. However, the intermittency of solar energy reduces the utilization capacity factor of electrolysis plants, which increases H2 production cost. The relevant question is whether the... 

The large effect of electricity price on H2 production costs is readily apparent in Fig. 3, which breaks down H2 production cost by electrolysis plant cost factors. The cost of electricity accounts for greater than 80% of H2 production costs across the range of electrolyser capacity factors. One of the criticisms to the application of PV electricity to electrolytic H2 production is its intermittent supply, which lowers the utilization capacity factor of electrolysers and increases H2 production cost. The low electrolyser capacity factor cost penalty is evaluated in Fig. 3. Over the 25-95% range in electrolyser capacity factors presented in Fig. 3, the H2 production cost of an electrolysis plant with a 25% capacity factor is approximately 11% higher than the H2 production cost of an electrolysis plant with a 95% capacity factor. In other... 

From Fig. 3, it is obvious that the relationship between electrolyser cost and H2 production cost across a 25-95% capacity factor range is non linear. In this case, the appropriate method to evaluate the effect of electrolyser cost on H2 production cost... 

The critical element affecting the production cost of electrolytic H2, over the range of electrolyser capacity factors, is electricity cost. While the 11% H2 cost pe nalty for the low electrolyser capacity factor from the use of PV electricity is signifi cant, it is hardly prohibitive. In conclusion, based on the assumed progress in PV cost reduction, PV electricity can be an economically viable source of electricity for electrolytic H2 production. 

Sensitivity analyses are performed to evaluate the effect of changes in cost factor values on H2 production and PV electricity prices. The cost factors for H2 production are PV electricity electrolysers electrolyser operating capacity factor electrolyser efficiency (in terms of converting electricity energy input into H2 energy output) electrolyser O M expense and the discount rate. The cost factors for PV electricity... 

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