Equipment

Natural Gas Power Generation
Creating energy right where it will be used is highly efficient. Distributed generation saves money on power bills, supplements electricity from the electric grid and helps meet your need for power reliability.

There is more information about each of these technologies below. If you’re interested in talking to Chattanooga Gas about distributed generation options, email us at gasadvantage@aglresources.com. Or just call us at 866.643.4168 and choose option 5.

Industrial Gas Turbines
The use of natural gas-fueled turbines is growing among industrial plant operators as well as large commercial energy users and institutions, such as hospitals and universities. Gas turbines are also the heart of Combined Heat-and-Power (CHP) systems.

Major process industries—primarily chemicals, paper, and oil and gas—have been using large turbine CHP systems (over 25 MW) for some time. Now the economics of smaller turbine systems (1 to 10 MW) have recently become more attractive.

Natural gas turbines include higher power ratings and efficiencies, advanced controls, lower emissions of nitrogen oxides (NOx) and lower lifecycle costs.

Natural gas turbines can be operated in three ways:

• Simple cycle turbines use an air-compression section, a burner and a power turbine driving a load, such as a generator for producing electricity. The turbine's high temperature exhaust heat can be used to produce process steam.
• Recuperated turbines incorporate a heat exchanger, which recovers heat from the turbine exhaust to preheat the compressed air before it enters the burner.
• Combined-cycle turbine systems use exhaust heat to produce steam to drive a second turbine, which produces additional electricity. Most combined-cycle systems are larger than industrial-scale plants.

Today's turbines reach efficiencies of 30 to 40 percent or greater. In CHP systems with heat recovery, overall thermal efficiencies of 70 to 80 percent are common, and 90 percent is achievable.

Air emissions from gas turbines have decreased substantially. Early systems used water or steam injection to reduce flame temperature and control NOx emissions. Manufacturers now offer "dry" low-NOx combustors without water or steam, which reduce NOx emissions to 25 parts per million or lower.

Energy Solutions Center: Industrial Turbines

Gas Technology Magazine: Gas Turbines Spell Opportunity for Industry

Reciprocating Engines
Reciprocating engines are the fastest-selling, lowest-cost form of DG. They can be used in a variety of applications due to their small size, low unit cost and useful thermal output.

Reciprocating engines are available commercially in sizes from .5 kW to 6.5 MW, suitable for a wide range of commercial, industrial and institutional applications. These applications include continuous power generation, peak shaving, back-up power, standby power and mechanical drive use.

Reciprocating engines also offer heat recovery potential. They make up a large portion of the cogeneration market in the United States.

Learn more from the Energy Solutions Center.

Microturbines
Microturbines are essentially miniature jet engines connected to small generators to produce electricity. They have very sophisticated electronic systems, which allow them to provide safe and efficient operation by consistently monitoring themselves. Easy to install, they have low emissions.

Microturbines most frequently are used during peak electricity time periods so companies can avoid high demand charges. They are particularly cost effective when used in CHP systems that capture waste heat from the exhaust. The exhaust heat, which is about 600 degrees Fahrenheit, can be used for heating, cooling, water heating or preheat boiler applications.

Learn more from the Energy Solutions Center.

Boilers convert water to steam, which can be used for central heating, water heating and manufacturing processes. Many businesses in the Chattanooga Gas service area use boilers – but many don’t know how powering their boilers with natural gas can help them move more money to the bottom line.

For information about installing a new natural gas boiler, or converting an oil- or propane-fired boiler to natural gas, contact us at gasadvantage@aglresources.com or at 866.643.4168 choose option 5.

Natural gas cooling is ideal for commercial facilities such as supermarkets, hotels, warehouses, office buildings and institutions like hospitals, nursing homes, churches and schools. High efficiency, gas-fired cooling equipment is also an excellent choice for factories and other industrial facilities.

Three basic types of gas cooling systems are available: absorption, engine-driven and desiccant. To learn more, contact us at gasadvantage@aglresources.com or 800.242.5830 and choose option 5.

Absorption Systems
Absorption cooling systems rely on a cycle of condensation and evaporation to produce cooling. The absorption process is driven by a heat source rather than a mechanical compressor, like those used in electric chillers. Absorption systems are available as chillers or chiller/heaters, and may be direct-fired by a gas burner or indirectly powered by another heat source (like waste heat from a cogeneration system or industrial process). These systems greatly reduce electric consumption and peak demand. In addition, absorption systems have few moving parts and need very little maintenance.

The advantages of gas absorption systems over conventional electric cooler systems include: 

• Lower operating and maintenance costs
• Reduced carbon footprint
• Safer, quieter operation
• Smaller space requirements

Learn more from the Energy Solutions Center.

Engine-Driven Systems
Gas engine-driven cooling systems use a mechanical process much like electric cooling systems. However, a high-efficiency gas engine instead of an electric motor drives their compressors. Also, the engine and exhaust heat from a gas cooling system can be recovered to efficiently produce hot water or process steam. These systems are available in the 250- to 2,100-ton range, and are popular with universities, hospitals and office complexes, businesses where natural gas engines can power centrifugal or screw chillers in central plants. Customers with smaller cooling needs can install neatly packaged compact units in sizes ranging from 15 to 800 tons. 

Desiccant Systems
Desiccant systems help control humidity levels by taking moisture out of the air. These systems are well suited for supermarkets, health spas, hotels, restaurants and other facilities that require low humidity levels. It takes more energy to cool humid air than drier air. By removing moisture, the desiccant system works in tandem with the cooling system and reduces the customer's overall cooling costs. This process also allows for the separate control of temperature and humidity.

Natural gas forklifts are an especially good choice for companies concerned about air quality in their warehouses:

• Costs 
  Fuel costs for a natural gas forklift typically are less than for electric-powered lifts, which also require greater downtime for refueling. Natural gas lifts need less maintenance than electric ones.

• Safety 
  Natural gas forklift operation can help to make your facility a safer workplace. In the event of a leak, natural gas dissipates harmlessly into the air as water vapor and carbon dioxide, unlike other fuels that are flammable.

• Indoor Air Quality 
  Natural gas forklifts produce much less carbon monoxide than those powered by gasoline or diesel, meaning better indoor air quality. Natural gas also produces lower emissions of other hazardous materials, such as nitrous oxides, and can help companies meet OSHA requirements for indoor air quality standards. In addition, natural gas does not produce the noxious odor sometimes associated with gasoline and diesel vehicles.

• Refueling 
  Natural gas refueling is safer, more convenient and less of an environmental liability for your company. Natural gas is dispensed through a sealed system with no leakage. Operators easily can be trained to dispense natural gas, and protective clothing is not required. There is no need to change out tanks; therefore, it reduces the risk of back injuries. Natural gas forklifts also can be refueled safely indoors, unlike propane, diesel and gasoline vehicles.

• Reduced Maintenance 
  Natural gas burns cleaner than gasoline or diesel, which means less wear and tear on engine parts, according to the American Gas Association. Natural gas forklifts do not require the battery maintenance of electric lifts, which can lead to extensive downtime and increased space for charging and storage.

Conversion to Natural Gas

Converting your forklifts to natural gas is an investment, but it’s not as expensive or time-consuming as you might think. It just means installing a natural gas refueling station and converting the vehicles by installing new fuel tanks, carburetors, fuel lines and fittings.

Case Study: Warehouse Associates
Warehouse Associates is an Ohio company that provides warehousing services at two locations with more than 500,000 square feet of space. Management became concerned when employees began to complain about headaches, especially during the winter months when facility doors were kept closed for heating purposes. A study revealed excessive carbon monoxide from the company’s 21 forklifts was the problem.

The company considered switching to electric vehicles but abandoned those plans because of the high costs. Warehouse Associates instead converted its lifts to run on natural gas—starting with 13 forklifts. After tests revealed that CO levels had dropped and employee complaints about headaches had dissipated, the company converted its entire fleet.

In addition to the improvement in indoor air quality, the company achieved an estimated $30,000 dollar reduction in annual fuel savings and annual savings of more than $13,000 in maintenance costs because reduced wear and tear on engines from cleaner burning natural gas.Source: American Gas Association

Case Study: Duckwall-Pooley Fruit Company
The Duckwall-Pooley Fruit Company is an 80-year-old packing business in Odell, Oregon. To improve air quality and reduce energy costs in its warehouses, the company converted 10 of its 24 forklifts to natural gas. The company found that the natural gas forklifts not only cost less to operate but also reduced carbon monoxide emissions by 80 percent. Fuel costs for the natural gas forklifts amounted to about $600 to $700 per year, approximately $900 less than the fuel costs for their other 14 units. In addition, the on-site compressor and fueling station allowed for convenient refueling, without requiring changing the fuel tanks.
Read the entire case study.

Equipment Suppliers
The following companies provide equipment and services for natural gas forklift conversions:

• P.C. McKenzie Company
      877.244.4883

• NESC Williams (Thompson & Johnson Equipment, Inc.)
      315.437.2881

Combined Heat-and-Power (CHP) systems are intelligent energy efficiency. For example, a basic CHP system generates electricity through a large gas-fired turbine, producing a great amount of waste heat. The heat that would otherwise be allowed to escape is then applied for heating an industrial boiler or producing heat for a building.

This highly efficient system produces a given amount of electricity and usable heat with 10 to 30 percent less fuel than if the two functions were separate. A typical electric generation system may achieve up to 45 percent efficiency, but with the addition of a waste heat recovery unit, it can gain energy efficiencies in excess of 80 percent, producing big savings.

CHP systems can produce as little as 20 kilowatts (kW) to as much as 300 megawatts (MW) of electricity, depending on your electrical and usable heat needs. In many cases, the excess electricity can be sold to your local electric utility.

Industrial uses are ideal for CHP, but commercial establishments also can benefit. Universities, hospitals, office buildings and condominiums/apartments all require electricity and have large space and water heating needs, making cogeneration a sound choice.

Clarion Hotel Saves With CHP – Energy Solutions Center Case Study

Food Processing Industrial Turbine CHP Project Fact Sheet – Energy Solutions Center

For more information on how cogeneration can help your business, please contact Mark Clay at 678.278.5276.

Gas booster heaters are a high-efficiency, environmentally clean and cost-effective solution to providing the final rinse for sanitizing dishes for restaurants; hotels and motels; schools and universities; and hospitals and nursing homes. Gas booster heaters take hot water at temperatures of 120°F–140°F and "boost" it to 180°F.

The gas booster heater’s high-temperature rinse eliminates the need to use chemicals for sanitizing, minimizes drying time and lowers dish inventory requirements while increasing the dishwashing production rate. In addition, a gas booster can replace existing high-maintenance electric booster heaters that contribute to high demand charges.

Gas booster heaters are available from a number of manufacturers and come in an assortment of sizes. They generally range from 50,000 to 200,000 Btu, and are for use with both smaller, door-type dishwashers and larger conveyor systems.

Gas booster heaters can be installed near the dishwasher or at a remote location. Innovative new space saving designs can be installed underneath the dish table or mounted on the wall.

Heat transfer for gas booster heaters is 80 percent or greater, making them among the most efficient and cost-effective of all gas equipment. Most gas booster conversions have achieved a simple payback in two years or less.

Calculate your savings with the Energy Solutions Center's gas-fired booster heater savings analysis tools.