Steam Turbines can reduce overall operating costs,

 by utilizing the energy in fuel more efficiently through either a turbine generator,

 or a mechanical driver when replacing a Pressure Reducing Valve (PRV).

• Large facilities such as medical centers, universities, and office buildings that generate heat can use the waste heat to generate electricity. These thermal users burn more fuel to make the heat that was just thrown away, in doing so they throw away the potential to make electricity, which is much more valuable than heat. Thermal users typically generate their steam at relatively high pressures so that they can feed their campus or large building with small steam pipes that carry a lot of energy, due to the high pressure. When the steam reaches the building where it will be used, and a pressure-reducing valve (PRV) is installed to lower the pressure, making it suitable for producing hot water or steam that goes to radiators or processes. The potential to make electricity is wasted. This raises the cost of energy and pollution. A steam turbine can take that same energy available, reduce the pressure, and turn it into valuable electricity or power to drive equipment. A steam turbine does not consume steam; it only reduces its pressure.

• Steam cogeneration is the simultaneous production of electricity and useful thermal energy.  This means that you can generate electricity with the same steam you are now using for heating or a process. Cogeneration has also come to mean using waste fuel for in-plant electricity generation. Steam turbine generators make electricity or drive equipment by converting a steam pressure drop into mechanical power to spin a generator. High-pressure steam enters the turbine, drives the generator or other equipment and exhausts at a lower pressure for use in plant heating or process. Steam turbines save money by allowing you to produce your own electricity for a fraction of the cost of utility power, or avoiding the electricity cost in driving equipment.

• When you produce steam at pressures above 50 psig, and then use it only for heat or a process, you have wasted an opportunity to reduce energy costs by either generating electricity or driving plant equipment. The steam pressure passed through a NESTCO turbine-generator package or mechanical driver reducing the pressure is worth three to four times the value of the heat removed from the steam. As an example of potential savings, say you have a situation where you reduce 10,000 pounds of steam per hour from 150 psig to 15 psig today, using a pressure-reducing valve. Our turbine will produce 175-kilowatt hours of electricity every hour for 1.27 cents per kWh, if your fuel cost is as above. If you are paying 4.0 cents per kWh from the electric company, this will save $4.78 per hour, or $40,000 per year. Such an installation will typically cost about $100,000, so it pays back the capital in less than 3 years. After that, you simply have $40,000 less to pay for energy every year.

• There are options to consider, and it starts with a NESTCO turbine generator or mechanical driver. Our engineers can help you select a machine that will operate in parallel with your present pressure reducing valves, and capture the potential of your steam to make or save electricity. The turbine removes the pressure portion of the energy in the steam you made, leaving just the heat that you need. This is an efficient way to make electricity. 90% of the energy removed from the steam by our turbine becomes electricity. If your boiler converts fuel energy to steam with 85% efficiency, the overall efficiency of our turbine generators will exceed 80%. Compare this to the 33% average utility industry. It all happens because you will be using both the heat and electric potential always present whenever fuel is converted to steam.

• The value of electricity is typically much higher than your cost of making the extra steam. If you are paying $3.00 per million British thermal units for your fuel, (typical natural gas price) adding a million British thermal units of steam will cost you an extra $3.53. Our turbine generator set will convert that million Btu's into 278-kilowatt hours of electricity. At the average commercial price for delivered electricity throughout the U.S. of 6.5 cents per kWh, you will have produced electricity worth $19.64 with $3.53 worth of fuel. Most companies continue to buy some power from the utility and use the utility as a supplement to their cogeneration system.  Since the typical cogeneration system is often connected in parallel with the utility, you can buy as much electricity as you need from the utility, just as you do now.  Except with a cogeneration system installed, you need to buy much less from the utility.

• Cogenerated power is cheaper because cogeneration systems can achieve fuel efficiencies of up to 80%, whereas the best utilities can do is about 40%.  Any company with a significant process steam use or surplus waste fuel.  Many companies are unaware of their great cogeneration potential.  Cogeneration systems can be designed into new boiler plants or can be easily added to existing boilers. 

• In most cases, your existing boiler can be used to make the steam for cogeneration if it is operated at 100 psig or greater. The amount of fuel used depends upon the system design.  The turbine generator sets from NESTCO, for example, are ideal for use with oil or gas boilers and increase fuel use by only a few percent. There is a cost in steam used to power a turbine, but when the steam is already being generated for use in the plant for a process, the overall costs for the facility barely change. If you have a waste fuel such as wood, waste elimination of waste disposal costs can be a very important benefit to also consider. 

• When oil was inexpensive the need to generate power in discrete locations was not financially sound.  Beginning with the 1973-74 Arab Oil embargo electricity prices and fuel prices have risen. Many companies are utilizing cogeneration. As utility rates increase, and they will, more and more companies are adding cogeneration systems to their power plants or replacing large electric motors. A small system generating of 50 kW may cost $30,000. Normally the payback on a cogeneration project, is often between one and a half to three years.  Payback is a function of power, system price, and electric savings.  The higher your current electric rates, the shorter the payback. Also, since equipment price per kW declines as power increases, the higher the power, and the more cost effective the system.

• Steam turbines have a service life of 20-years minimum; and the single stage turbines are designed for 3 or more years of continuous duty at full load without shutting down for maintenance.  Generators feature a service life of 20-years.