CONSERVATION WHITEPAPER

Although 67% of all gas utilized in the residential sector is utilized for space and water heating. Also, energy is expended from laundry, cooking, dishwashers, and pool/hot tub heaters in the residential sector. Energy is expended in a similar manner in the commercial sector as well. Energy is consumed due to space and water heating, process heating and cooling, and food preparation in office buildings, retail and grocery stores, schools, hotels, motels, hospitals, and restaurants.

Thus, most of the energy conservation potential in the residential/commercial sector lies in sound insulation to prevent unnecessary heating, in increasing equipment efficiency, and in decreasing thermal loads. Old buildings and equipment can be modified or replaced and new measures can be implemented in new buildings during the construction phase.

Space heating loads in California can be decreased by 10 to 20% by making improvements to pre-1979 building shells, according to SCAQMD. This can be accomplished by standard envelope weatherization measures, advanced window glazing, and insulation of solid concrete walls with both interior and exterior products. In commercial buildings, ventilation is necessary to remove odors and pollutants from rooms but the amount of air exchange is usually more than necessary. When outside, air ventilation is reduced, a 5 to 10% savings in heating or cooling can be gained. Studies on solar energy can benefit commercial buildings by providing heat during the winter and subduing solar radiation in the summer. Furthermore, research should be performed to study the basic building structures, such as the effect of wall thickness and insulation, solar radiation absorbing or reflecting materials, building orientation, roof overhangs, and partial undergrounds on energy conservation.

These heating, ventilation, and air conditioning (HVAC) systems and lighting consume two thirds of the building energy consumption. There are tremendous opportunities for energy savings with the use of sensors and controls which optimizes the temperature that will not require a large investment. Appliances in residential and commercial applications are also improving in efficiencies. Savings of 80 to 90% in energy consumption can be achieved by highly efficient refrigerators and freezers, 50% in commercial refrigeration systems, 75% in T.V.s, 90% in photocopiers, and 95% in computers. New compact fluorescent light bulbs are now available that screw into standard light bulb sockets that last 10 times longer than incandescent light bulbs. According to the Rocky Mountain Institute, replacing incandescent bulbs with compact fluorescent bulbs will earn 60 to 85% savings in energy costs. Furthermore, by replacing just one incandescent bulb with a new compact fluorescent bulb, three quarters of a ton of CO₂ emissions and 15 pounds of SO₂ emissions will indirectly be reduced at the powerplant level.

Technology advancement in improving the efficiency of equipment such as boilers and furnaces will tremendously save energy. For example, conventional water heaters in California have an average energy factor (EF) of 54% and already, models with higher efficiencies with an EF of up to 72% are available commercially. Some are available with an EF as high as 82% with improvements in insulation, burners, and vents. Cooking equipment can be improved to cut energy consumption by 20 or even 30 percent.

Decreasing thermal loads will be a sure way to conserve energy. The California Energy Commission already mandates a replacement of shower and faucet heads with low flow models to reduce the water usage by 20%, which will in turn reduce the amount o energy needed to heat the water. In addition, smaller water heaters can be used, which will reduce standby heat losses. Development of heat pump water heaters that can recover heat from cooling condensers, wastewater, and exhaust air is also beneficial.

The newly opened Energy Resource Center of the Southern California Gas Company located in Downey, California, is standing proof as to how energy efficient and cost effective buildings can be built. The ERC has succeeded in exceeding California Energy Commission's Title 24 standards by 45%, which makes it one of the most energy efficient buildings in the world. This was accomplished by installing sound non-CFC rigid foam insulation, low emissivity glass windows, skylights to maximize daylight usage, a combination of gas fired and electric heating and cooling systm3es, and other energy efficient technologies and materials. The ERC also maximized natural resource usage by recycling much of the materials used to build the center. The old Gas company building built in 1957 was dismantled in parts and 60% of the building reused. Other components of the building made use of recycled parts, like the wood flooring of the lobby, which was taken from a Banana Republic warehouse built in the 1880's in San Francisco that was condemned after the Loma Prieta earthquake, and the aluminum accented wall, which is made from surplus military aircraft aluminum.

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Industrial Sector (Section 7.2)

Many areas can be targeted to increase energy conservation in the industrial sector as well. In the industrial sector, energy is utilized for manufacturing in processes like steam generation, curing/drying processes, metal melting, and heat treatment. Like the residential/commercial sector, increasing the efficiencies of furnaces and boilers will reduce energy demand. Other measures that can be taken are to increase insulation of heat transfer pipes, to recover waste heat an utilize it for space heating, to increase the efficiency of cooling towers, and to lower the operating pressure of process equipment. All of these measures will decrease the amount of fuel that will need to be burned, in turn reducing the amount of pollutants as well.

A technology that has been around for 30 years but still remains relatively unknown is the catalytic infrared heating system. This system uses natural gas to cause a chemical reaction with oxygen in the air in the presence of a platinum catalyst to generate long-wave infrared radiation to provide heat of up to 600^oC. The advantages of catalytic infrared systems are impressive. Energy and time savings of up to 80% can be obtained over conventional convection or electric infrared heating systems. Also, the chemical process of the natural gas reacting with oxygen produces water and CO2 only, as opposed to a combustion process which will produce unwanted NOx and other emissions. The catalytic infrared heating system has a multitude of applications in the industrial sector such as:

• drying and curing of finishes and adhesives

• softening of plastics for forming

• welding, preheating, degreasing, mold heating, expansion part-fitting of metals

• cooking and dehydration of food products.

In paint curing, the catalytic infrared heating system can slash time by two thirds, eliminate the use of solvents, slash the number of blowers required in convection ovens, cut gas consumption by 30% and electricity consumption by 60%.

Increasing energy conservation in the transportation sector is a very complex ordeal since technological. political, and social aspects must all work together to reduce energy consumption. California must especially tackle the problem of its transportation sector seriously since it is the sector consuming the largest amount of energy and is responsible for a large part of the air emissions problem.

Conventional internal combustion engine powered automobiles can be fine tuned to increase efficiency. Mechanical efficiencies can be increased with aggressive transmission management to reduce average engine speeds and with variable valve control (VVC) to reduce throttling and to increase specific power. Reducing the engine size and displacement while maintaining constant maximum power will reduce engine friction and increase mechanical efficiency. Higher efficiency engine accessories and reduced rubbing friction is another method as well.⁴²

Thermal or indicated efficiencies of internal combustion engines are on the average around 38%, relative to LHV of the fuel. Improvements can raise this efficiency up to 45 or 50% by:

• increased compression ratio

• lean burning

• recovery of work from exhaust

• faster combustion

• effective control of air fuel ratio for each cylinder and each cycle

• and effective control of valve timing and enhanced breathing so that intake and exhaust timing is optimized for each engine speed.⁴³

Lean burn technology is very effective and current production models like the Geo Metro and Honda Civic VX can successfully achieve 50 miles per gallon. By raising the air-fuel ratio by a factor of 1.67 above the stoichiometric value, a 10% increase in efficiency is gained. New developments in lean burn 2-stroke engines with advanced fuel injection is showing impressive results. the problems associated with lean burn though, is the fact that the engine can misfire due to lean condition resulting in incomplete combustion and excessive hydrocarbon emissions. also, current three-way catalysts are only able to operate in a very narrow stoichiometry range and will be unable to reduce NO_x emissions.

Reducing the load also results in higher efficiencies. A 5% decrease in fuel consumption in highway conditions and a 4% decrease in urban conditions can be gained from a 10% reduction in load. The use of new materials such as aluminum and fiber-reinforced composites can reduce the weight tremendously. GM has been successful in developing a prototype called Ultralite, which has a curb weight half that of a comparatively sized car with the use of fiber-reinforced composites. Reduction of aerodynamic drag will also decrease fuel consumption . Drag coefficients (C_D) of the mid 1970's were around 0.45, which has been reduced to around 0.35 by 1990. A production model called the Opel Calibra has brought down the drag coefficient to around 0.26 and prototypes shown promises of realizing C_D's of 0.19.

More drastic measures to improve the energy consumption situation in the transportation sector include the development of zero emission vehicles. Zero emission/electric vehicle technology is currently the focus of automobile manufacturers worldwide. With the California Air Resources Board requiring 2% of all cars sold in the state to be zero emission vehicles by 1998, manufacturers are fine tuning their prototypes to make the cars practical and acceptable to consumers as well as to various air quality regulations.

The main technological bottleneck to the success of electric vehicles is the energy storage system or the battery. Current lead batteries are bulky, taking up conventional storage space, and are heavy. Limited range and long recharge period are also very negative factors that must be overcome technologically. furthermore, the lack of recharging stations will hamper long range travel.

Auto manufacturers are beginning to show promising results, however, through advanced research and development. One such manufacturer is Ford Motors Co., who has developed Ecostar, an advanced zero emission delivery truck with a 100 mile range. Ecostar does not compromise the luxuries such as power disc brakes, air conditioning, heat, mobile phone, and stereo which are all too familiar in current conventional automobiles, but is a key to ameliorating the environmental and energy problems. Its high-tech features include low rolling-resistance tires, light-weight materials, regenerative brakes, and an advanced sodium sulfur battery, which contain three times the energy that conventional lead-acid batteries. With electric vehicles, however, the load impact on electricity generation plants and power plant emissions must be considered as well. However, in California for example, the California Energy Commission has determined that little additional capacity would be needed for the Southern California Edison service area, in which case fewer internal combustion engine powered automobiles on the streets would tremendously help the environment and reduce the amount of petroleum consumption.

Ratepayers' funds of over $30 million have been contributed by San Diego Gas and Electric, Southern California Edison, and Pacific Gas for electric vehicle R&D up to date. Over the course of 5 years, $100 million more will be spent starting in 1995.

Alternative fuel vehicle (AFV) technology, especially natural gas vehicles (NGV), is also another area of opportunity. In an area like California where 17 million passenger vehicles guzzles 13 billion gallons of gasoline each year, turning to natural gas, which is cleaner burning and has the potential of being very efficient, is very sensible.

natural gas vehicles store natural gas in the form of CNG or LNG which is directly burned in the engine. Tanks are necessary to store CNG at pressures of up to 3000 psi and LNG at temperatures of -253 F. These bulky, heavy storage tanks take up much car space and leaves room for little else. Efforts are being made to minimize s6torage tank space by institutions like DOE, Gas Research Center, and Southern California Gas. they have successful in salvaging 75% of the trunk space, making the NGV practical for normal use. Safety has been assured through dynamite explosion and armor piercing bullet testing of the storage tanks.

the environmental benefits from a switch to NGVs may be enough to convince governments and people as well to abandon conventional gasoline powered vehicles. A Technical Guidance Document was released by the Environmental Protection Agency on January 28, 1988 which announced that a 50% reduction in tailpipe emissions of CO, 40% reduction in tailpipe emissions of HC, and 100% reduction of HC emissions from filling stations and evaporation could be achieved by a switch to NGVs. Old gasoline automobiles can be retrofitted to run on natural gas with a 99% reduction of CO, 92% reduction of HC and 65% reduction of NO_x emissions.

Fine tuning engines to run on natural gas is very important to obtain optimal performance. A high compression ratio is needed to gain performance from natural gas which has an octane rating of 140. Normal gasoline engines running of octane 90 gasoline have a compression rate of 8:1, whereas NGV engine will typically run at a compression ratio of 12:1. The higher compression ratio consequently give rise to higher thermal efficiency, resulting in reduced fuel consumption.

Lack of refilling stations is the problem that is currently impeding the wide acceptance of NGVs. Until more refilling stations are built, NGVs will not be practical for most consumers except for use by large fleet owners. Southern California Gas, for example, is planning to build on natural gas station for every ten stations by the end of the century.

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There are also opportunities to increase the efficiencies of power generation systems. Cogeneration of electricity and heating for commercial or residential use can be more efficient than having separate facilities for each function. There are also opportunities to achieve both energy conservation and environmental improvements when new generation is installed.

Currently, about 25% of all existing power generation systems in California are over 30 years old. Simply by replacing these outdated systems, which have diminished in efficiency and reliability, significant gains in energy conservation can be gained. Typically these 30 year old systems consume 6 to 8% more fuel per year to produce the same output when it was first commissioned at a cost of millions of dollars per year.

Cogeneration is also a very effective way to conserve energy. The major industrial cities in Korea offer good opportunities for supplying regional heating systems from waste industrial heat. Also Korea's practice of building planned satellite cities offers opportunities to combine regional heat supply, cogeneration and waste incinerator in central energy facilities to conserve energy. A study by the U.S. Office of Technology Assessment shows that 25% less energy is required in a natural gas cogeneration system when compared to a combination of anew coal-fired electric powerplant and an oil-fired boiler producing steam with comparable output, while at the same time emitting less than 1% of SO_x and 10-57% of NO_x emissions as compared to a coal-fired system and no ash and sludge as compared to 60,000 tons of ask and 168,000 tons of sludge per year for coal fired systems.

Aeroderivative gas turbines are displaying great versatility and efficiency improvements in electric utility applications. In the steam injected gas turbine (STIG), with average efficiencies of about 44%, steam is directly injected with air and fuel to increase power and efficiency, a concept transplanted from aircraft technology. NO_x levels as low as 25 ppm can be obtained from STIG systems, about 70% lower than simple-cycle gas turbine systems.

Modifications such as intercooling and reheat can push the efficiencies even higher in STIG systems. An intercooled STIG (ISTIG) system has an approximate efficiency of 52.5% and an intercooled STIG with reheat (IR-STIG) has an efficiency as high as 55%, both with NO_x emissions of 25 ppm.

The latest development in aeroderivative gas turbine systems is the intercooled chemically recuperated gas turbine with reheat (IR-CRGT), which can obtain efficiencies of 55% while maintaining NO_x emissions as low as 1 to 3 ppm. In CRGT systems (See Figure 4), the steam is blended with natural gas to pass through the superheater tubes of the turbine's heat recovery steam reformer (HRSR), where the blend reacts chemically with a nickel-based catalyst to produce a hydrogen rich, low Btu gas reformulate that is injected into the combustor.

Research and development of fuel cells, another form of power generation, are surging ahead at full speed. The fuel cell is one of the most promising methods to produce electricity and heat efficiently with minimum emissions, all without the combustion of fuel. Hydrogen which can be chemically reformed from natural gas, is the fuel to power the fuel cells. Electricity and heat is derived from a chemical process when hydrogen is combined with oxygen to form water. continually supplying hydrogen and oxygen will provide non-interrupted power unlike conventional storage batteries.

Fuel cells are ideal for cogeneration applications. Three main types are currently being developed. Phosphoric acid fuel cells (PAFC) are nearing commercialization. It operates at 200 C and has an 80% efficiency (40% electricity, 40% usable thermal energy). More attractive are molten carbonate fuel cells (MOFC), which operate at 650 C with an electricity producing efficiency of 45%, and the solid oxide fuel cells (SOFC), which operate at 1,000 C with an electricity producing efficiency of 50%. These higher temperatures allows the direct use of natural gas as a fuel without a reformer and allows more efficient use of rejected cell heat resulting in higher overall efficiencies. Along with high efficiencies, the fuel cells have excellent emissions characteristics. The byproduct of chemical process produces only water and NOx emissions as a result of the reformer burner is as low as 5 ppm. Also, another favorable characteristic include no noise and vibration unlike turbine and compressor systems. They are especially attractive in urban or residential areas where construction/installation of additional power lines are too difficult or economically unfeasible.

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