Plan de responsabilidad social empresarial empresa Harinera del Valle

300 MW PC Coal Plant 750 MW PC Coal Plant (SC)

Plant Rating Net MWe 100 300 750

Plant Capacity Factor

(typical) % 60-80% 65-75% 70-80%

Fuel Type Coal/lignite Coal/lignite Coal/lignite

Plant Heat Rate (rounded) kJ/kWh 9,700 9,550 9,400

CO2 Emissions Mt/MWh 0.88 0.87 0.87

Planned Maintenance Rate % 10% 10% 10%

Forced Maintenance Rate % 5% 5% 5%

Plant Life yr 30 30 30

Cost Estimates

Year of Estimate yr 2009 2009 2009

Capital Cost $/kW 2,200 2,000 1,800

Fixed O&M Cost (range) $/kW-yr 25-35 20-30 20-30

Fixed O&M Cost (point) $/kW-yr 27 25 24

Variable O&M Cost

(range) $/MWh 1.5-2.5 1.5-2.5 1.5-2.5

Variable O&M Cost

(point) $/MWh 2 1.9 1.8

8.2.2 Circulating Fluidized Bed Boiler

Circulating fluidized bed (CFB) combustion is a combustion technology where the solid fuel is suspended on upward-blowing jets of air during the combustion process. The result is a turbulent mixing of gas and solids. The tumbling action, much like a bubbling fluid, provides more

effective fuel combustion reactions and heat transfer. CFB plants are more flexible than

conventional PC plants in that they can be fired using a variety of solid fuel types and sizes and also have the flexibility of using fuels which are difficult to burn using conventional PC

technology. Another advantage of CFB plants is the possibility of achieving a low emission of nitrogen oxides (NOx) during combustion and the possibility of removing sulfur in the fuel in a simple manner, before it can convert to sulfur dioxide (SOx), by using limestone as bed material. The steam produced in a CFB boiler is subcritical and the steam cycle is similar to a subcritical PC boiler plant. The efficiency of CFB plant is similar to PC plant, about 33%. Table 8-2 lists typical cost and performance data for three CFB plant capacities.

Table 8-2 Typical Performance And Cost Estimates for CFB Plants Plant Type >> Coal fired CFB Plant Parameters Units 10 MW

CFB

25 MW CFB

50 MW CFB

Plant Rating Net MWe 10 25 50

Plant Capacity Factor (typical) % 60-80% 60-80% 60-80%

Fuel Type Coal/ Waste Coal/ Coke

Plant Heat Rate (rounded) kJ/kWh 10,500 10,300 10,000

CO2 Emissions Mt/MWh 0.95 0.93 0.91

Planned Maintenance Rate % 10% 10% 10%

Forced Maintenance Rate % 10% 10% 10%

Plant Life yrs 30 30 30

Cost Estimates

Year of Estimate yr 2009 2009 2009

Capital Cost $/kW 2550 2000 1800

Fixed O&M Cost (range) $/kW-yr 30-45 30-40 25-30

Fixed O&M Cost (point) $/kW-yr 35 35 27

Variable O&M Cost (range) $/MWh 3-5 2-4 2-4

Variable O&M Cost (point) $/MWh 4 3 3

8.2.3 Simple Cycle Combustion Turbine

A gas turbine, also called a combustion turbine, is a rotary engine that extracts energy from a flow of combustion gas. It has an air compressor coupled to a turbine, and a combustion chamber in-between. Energy is added to the gas stream in the combustor, where air is mixed with fuel and ignited. Combustion increases the temperature, velocity and volume of the gas flow. This is directed through a nozzle over the turbine blades, spinning the turbine and powering the compressor and delivering excess energy to the generator. Energy is extracted in the form of shaft power, compressed air and thrust, in any combination, and used to power aircraft, trains, ships, generators, and even tanks.

Gas turbines are described thermodynamically by the Brayton cycle, in which air is compressed isentropically (constant entropy), combustion occurs at constant pressure, and expansion over the turbine occurs isentropically back to the starting pressure.

Caribbean Regional Electricity Generation, Interconnection, and Fuels Supply Strategy – Final Report 8-7 As with all cyclic heat engines, higher combustion temperature means greater efficiency. The limiting factor is the ability of the steel, nickel, ceramic, or other materials that make up the engine to withstand heat and pressure. Most turbines also try to recover exhaust heat, which otherwise is wasted energy. Recuperators are heat exchangers that pass exhaust heat to the compressed air, prior to combustion.

Mechanically, gas turbines are considerably less complex than internal combustion piston engines due to fewer moving part: the shaft/compressor/turbine/alternative-rotor assembly. However, the required precision manufacturing for components and temperature resistant alloys necessary for high efficiency often makes the construction of a combustion turbine more

complicated.

The principal environmental concerns associated with gas-fired combustion turbines are

emissions of nitrogen oxides (NOx) and carbon monoxide (CO). Fuel oil operation may produce sulfur dioxide. Nitrogen oxide abatement is accomplished by use of “dry low-NOx” combustors and a selective catalytic reduction system. CO emissions are typically controlled by use of an oxidation catalyst. No special controls for particulates and sulfur oxides are used since only trace amounts are produced when operating on natural gas.

The efficiency of combustion turbine depends on compressor pressure ratio, gas firing

temperature, and if any of the exhaust heat is recovered. Typical efficiencies of the simple cycle gas turbines range from 28-35%. The LMS100™ system combines frame and aeroderivative gas turbine technology for gas fired power generation. This new gas turbine provides cyclic

capability without maintenance impact, high simple cycle efficiency, fast starts, high availability and reliability, but at higher capital cost. The unique feature of LMS100 is the use of inter- cooling within the compression section of the gas turbine, leveraging technology that has been used extensively in the gas and air compressor industry. Table 8-3 list typical performance and cost estimates for simple cycle gas turbines, including the new LMS100.

Table 8-3 Typical Performance and Cost Estimates for Simple Cycle Combustion Turbines Plant Type >> Simple Cycle Combustion Gas Turbine Plant Parameters Units 20 MW GT 50 MW GT LMS 100

Plant Rating Net MWe 20 50 100

Plant Capacity Factor (typical) % 10% 10% 20-40%

Fuel Type NG / Distillate/Diesel

Plant Heat Rate (rounded)

(HHV) kJ/kWh 11,900 11,100 8,900

CO2 Emissions Mt/MWh 0.54 0.51 0.41

Planned Maintenance Rate % 4% 4% 4%

Forced Maintenance Rate % 4% 4% 4%

Plant Life yrs 30 30 30

Cost Estimates

Plant Type >> Simple Cycle Combustion Gas Turbine Plant Parameters Units 20 MW GT 50 MW GT LMS 100

Capital Cost $/kW 500-700 450-650 700-800

Fixed O&M Cost (range) $/kW-yr 15-20 15-20 10-20

Fixed O&M Cost (point) $/kW-yr 17 17 15

Variable O&M Cost (range) $/MWh 5 4 2-4

Variable O&M Cost (point) $/MWh 5 4 3

8.2.4 Combined Cycle Combustion Gas Turbine

In a combined cycle gas turbine (CCGT) plant, a gas turbine generator generates electricity and the waste heat in the exhaust gas is used to make steam to generate additional electricity via a steam turbine; this last step enhances the efficiency of electricity generation.

A combined-cycle gas turbine power plant consists of one or more gas turbine generators equipped with heat recovery steam generators to capture heat from the gas turbine exhaust. Steam produced in the heat recovery steam generators ((HSRGs) powers a steam turbine generator to produce additional electric power. Use of the otherwise wasted heat in the turbine exhaust gas results in high thermal efficiency compared to other combustion based technologies. Combined-cycle plants currently entering service can achieve 48 -50% efficiency (on HHV basis) in converting the chemical energy in the natural gas into electricity. Additional efficiency can be gained in combined heat and power (CHP) applications or cogeneration by bleeding steam from the heat recovery steam generator, steam turbine, or turbine exhaust to serve direct thermal loads.

A single-train combined-cycle plant consists of one gas turbine generator, a heat recovery steam generator, and a steam turbine generator (“1 x 1” configuration). Using “FA-class” combustion turbines - the most common technology in use for large combined-cycle plants - this

configuration can produce about 270 megawatts at reference standard (International Organization for Standardization, or ISO) conditions. Increasingly common are plants with two or even three gas turbine generators and heat recovery steam generators feeding a single, proportionally larger steam turbine generator. Larger plant sizes result in economies of scale for construction and operation, and designs using multiple combustion turbines provide improved part-load

efficiency. A 2 x 1 configuration using FA-class technology will produce up to 540 megawatts at ISO conditions.

Advantage of combined cycle plant is that additional peaking capacity can be obtained by use of various power augmentation features at nominal additional cost, such as inlet air chilling and duct firing (direct combustion of natural gas in the heat recovery steam generator). For example, an additional 20 to 50 megawatts can be gained from a single-train plant by use of duct firing. Though the incremental thermal efficiency of duct firing is lower than that of the base combined- cycle plant, the incremental cost is low and the additional electrical output can be valuable during peak load periods.

Caribbean Regional Electricity Generation, Interconnection, and Fuels Supply Strategy – Final Report 8-9 Gas turbines can operate on either gaseous or liquid fuels. Pipeline natural gas is the fuel of

choice because of historically low and relatively stable prices, deliverability and low air

emissions. Distillate fuel oil can be used as a backup fuel, however, its use for this purpose has become less common in recent years because of additional emissions of sulfur oxides,

deleterious effects on catalysts for the control of nitrogen oxides and carbon monoxide, the periodic testing required to ensure proper operation on fuel oil, and increased turbine maintenance associated with fuel oil operation. It is now more common to ensure fuel availability by securing firm gas transportation.

As with combustion turbines, the principal environmental concerns associated with gas-fired combined-cycle gas turbines are emissions of nitrogen oxides (NOx) and carbon monoxide (CO); and emission abetment is achieved through SCR for the NOx and an oxidation catalyst for the CO.

Fairly significant quantities of water are required for cooling the steam condenser and may be an issue in arid areas. Water consumption can be reduced by use of dry (closed-cycle) cooling, though with cost and efficiency penalties. Gas-fired combined-cycle plants produce less carbon dioxide per unit energy output than other fossil fuel technologies because of the relatively high thermal efficiency of the technology and the high hydrogen-carbon ratio of methane (the primary constituent of natural gas).

Because of high thermal efficiency, low initial cost, high reliability, relatively low gas prices, and low air emissions, combined-cycle gas turbines have been the new resource of choice for bulk power generation. Other attractive features include significant operational flexibility, the availability of relatively inexpensive power augmentation for peak period operation and relatively low carbon dioxide production.

Table 8-4 lists typical performance and cost data for combined cycle plant.

Table 8-4 Typical Performance And Cost Estimates for Combined Cycle Plants Plant Type >> Combined Cycle GT

Plant Parameters Units 100 MW