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Energy Efficiency
Energy is a requirement for hotels to operate. Typically, twenty-five percent of overall building operating costs is energy use. Fifty percent of that energy use is used to create an artificial indoor environment through heating, cooling, and lighting (Worldwatch paper #124). Conventional energy sources consume raw materials and produce pollution. Thus, the type and amount of energy used to operate buildings deserves a lot of attention with respect to environmental impacts. Because of the initial investment costs whenever a changeover to new energy sources is done, it is critical to first exhaust all opportunities to conserve energy and make the operation as efficient as possible. This will result in immediate savings and a reduction in the future capital investment. It is estimated that buildings that incorporate climate-sensitive design can save sixty percent on heating and cooling costs and fifty percent or more on lighting costs as compared to conventional buildings (Worldwatch#124. P.39). Any reductions in conventional energy usage lessen air pollution, lessen contributions to global warming, and reduce our global dependency on fossil fuels. ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT Transition to a Carbohydrate Economy ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT Transition to a Carbohydrate Economy ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT Identify and implement all available energy conservation strategies. Conservation is less expensive than any energy retrofits. Reduce energy usage by targeting the largest component of energy use first. Space conditioning (heating or cooling) is often the largest component of energy usage in a hotel and should be addressed by preventing heat transfer within the building. Improving windows, decreasing infiltration, insulating exterior partitions and ductwork, and retrofitting lighting fixtures are effective strategies. This can be identified at the design stage or during operation with the aid of electricity meters. Shifting electricity usage to off peak times may also reduce costs. ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT Every effort should be made to reduce energy use. ENVIROMENTAL DESIGN ELEMENT ENVIROMENTAL DESIGN ELEMENT ENVIROMENTAL DESIGN ELEMENT ENVIROMENTAL DESIGN ELEMENT ENVIROMENTAL DESIGN ELEMENT ENVIROMENTAL DESIGN ELEMENT Install greywater heat-recovery equipment in residential projects, commercial or institutional buildings with multiple showers, and industrial applications with large, continuous flows of hot water, such as clothes washers. Manufactured products are available and well proven. ENVIROMENTAL DESIGN ISSUE issue content ENVIROMENTAL DESIGN ELEMENT Diversify energy sources by changing to a portfolio that includes renewable energy sources such as photovoltaics (PV), mini-hydro, wind, biofuels, fuel cells, geothermal, and less polluting fossil fuels such as propane. ENVIROMENTAL DESIGN ELEMENT Solar photovoltaic panels were originally developed for spacecraft. Arrays of photovoltaic cells arranged into panels (or windows, roofing tiles, wall panels) convert solar light rays into electricity. Thin-film technology and economies of scale are reducing the relatively high cost of manufacturing solar arrays. ENVIROMENTAL DESIGN ELEMENT Rack-mount PV systems or mount them directly on roof and wall surfaces. Optimize the panel’s tilt to take full advantage of solar energy. Incorporate panels into building envelope or roof design. ENVIROMENTAL DESIGN ELEMENT Wind energy is the fastest growing energy source on the planet. Technological advances have made wind power competitive with fossil-fuel generation – if you have the right site for your turbine farm. Wind generates about 1 percent of America’s electricity, 15 percent of Denmark’s. ENVIROMENTAL DESIGN ELEMENT Water power has been harnessed since the earliest civilizations for agricultural processing and latterly for the production of electricity. If you live in an old mill or have an upland stream flowing through your property, you probably have a site suitable to generate all or a significant proportion of your domestic power requirements. ENVIROMENTAL DESIGN ELEMENT A fuel cell operates like a battery. Unlike a battery, a fuel cell does not run down or require recharging. It will produce energy in the form of electricity and heat as long as fuel is supplied. ENVIROMENTAL DESIGN ELEMENT Bioenergy technologies help protect the environment by making use of renewable plant material such as sawdust, tree trimmings, rice straw, alfalfa and switchgrass; poultry litter and other animal wastes; industrial waste; and the paper component of municipal solid waste. They are used today in a wide variety of processes, including the production of clean transportation fuels, electricity and chemicals. ENVIROMENTAL DESIGN ELEMENT The term "green power" generally refers to electricity supplied in whole or in part from renewable energy sources, such as wind and solar power, geothermal, hydropower, and various forms of biomass. Increasingly, electricity customers are being given electricity supply options, either as retail power markets open to competition or when their regulated utilities develop green pricing programs. More than one-third of retail customers in the United States now have an option of purchasing a green power product directly from their electricity supplier. In addition, consumers can support renewable energy development through the purchase of green energy certificates. ENVIROMENTAL DESIGN ISSUE The ozone layer, which spans most of the stratosphere, about 50km above the Earth, exists because of oxygen filtering up from the lower parts of the atmosphere reacting with sunlight to form ozone. This dependence on sunlight means that ozone forms in the tropics where the light is strongest before being dispersed to the poles by the wind. ENVIROMENTAL DESIGN ELEMENT Do not select appliances or mechanical equipment that uses chlorofluorocarbons (CFCs) as refrigerants or cooling chemicals. Avoid composite materials and components that contain products that use or release CFCs in their manufacturing. Specify fire suppression equipment that does contain CFCs or Halons. Dispose of old equipment properly using professionals to reclaim the refrigerants. ENVIROMENTAL DESIGN ELEMENT In retrofit projects with existing air-conditioning and refrigerating equipment, conduct a life-cycle cost analysis to assess replacement with equipment using chlorine-free refrigerants. The analysis should consider rising CFC/HCFC costs, maintenance and energy operating costs. It is often cheaper to replace older chillers with new HFC 134a equipment, both on a life-cycle and a first-cost basis. CFC air conditioners and heat pumps more than eight years old (midway through typical service lives) are often cost-effectively replaced by new equipment using HCFC or non-chlorinated refrigerants.
Overview
Efficiency, Pollution, Role of Fossil Fuels
Overview
Efficiency, Pollution, Role of Fossil Fuels
Energy Conservation
Energy Conservation
Make it a priority to save energy wherever possible. Conservation measures involve little investment and are the most cost-effective means of reducing operating costs.
Energy Systems
Energy Systems
Electrical Power Systems
Specify energy efficient office equipment. Select office equipment with automatic shut off systems.
Specify energy efficient appliances. Select energy efficient models in all appliance categories. Replace older appliances with newer energy efficient models. Select CFC-free refrigerators. Dispose of old refrigerators properly.
Consider higher system voltages. Higher voltages installed at the design stage will provide a lifetime’s worth of energy savings.
Improve power factor. Select proper motor sizes and corrective equipment to minimize losses from poor distribution and motor losses.
Use K-rated transformers. They handle harmonics introduced to the system from appliances such as personal computers more efficiently.
Size conductors correctly. Proper selection of conductors reduces voltage drops and the resulting losses of power.
Electrical Power Systems - Renovation Issues
Optimise energy use of current equipment. Optimize existing appliances and systems. Specify that any new appliances are efficient models.
Retrofit computers with shut off devices.
Plumbing Systems - Hot Water Heating
Consider hot-water heating options. Specify efficient equipment including heat pumps, heat recovery systems, tankless water heaters, and combination space heating-water systems.
Reduce hot-water system standby losses. Apply insulation to hot water distribution lines and storage tanks. Install tank insulation, anti-convection valves, and heat traps. Select the smallest heater and most efficient heat recovery systems for the task.
Evaluate system configuration. Compare the costs of localized versus central hot water heating systems.
Reduce hot water service temperatures. Determine the minimum temperature required to cut energy use and losses.
Install hot water system controls. Consider a time-of-day control system that lowers operating temperatures during off peak times.
Consider solar hot water heating. Either as supplemental heat or as a full system, solar hot water systems can be extremely effective and efficient in warm and hot climates.
Plumbing Systems - Water Pumping
Use low flow plumbing fixtures. Saves both water and energy used for pumping and heating hot water.
Use water booster pumps. Consider systems with a pressurized tank to reduce pump cycling and increased efficiency.
Prepare an efficient plumbing system layout. Design simple, short piping layouts. Stack water services in multi-storey buildings. Employ gravity rather than mechanical systems for effluent flows. Calculate minimum pressures required for distribution and booster pumps.
Outdoor Lighting and Electrical Systems
Light the minimum area for the minimum time. Avoid lighting areas that do not require it. Identify lighting needs and direct light through shades or other means to only light required area. Utilize timers, motion sensors to avoid constant excessive lighting and energy use.
Clearly identify the actual purpose of lighting to determine minimum acceptable levels.
Use energy-efficient lamps and ballasts. Only specify energy efficient fixtures and lamps with the exception in the case of indoor environmental quality.
Use low-voltage lighting. They decrease energy use and cost of 120 Volt installation.
Use renewable energy sources for lighting and other outdoor power. Utilize PV systems when lighting is more than 150 metres from the grid.
Heat Recovery Systems
Greywater heat-recovery equipment can save up to 60% of water-heating energy where hot water drain flow occurs at the same time as hot water supply flow - such as multiple showers or industrial process water systems. Systems serving fixtures on upper floors, where 60 in. of vertical drain pipe is replaced by proprietary greywater heat-recovery devices, need no pump and little or no maintenance. For below-grade applications, systems with demand-operated pumps are available; these need occasional service, and are best installed in a mechanical room for regular maintenance access.
Where there is less simultaneous hot water drain and supply flow (i.e., predominantly baths, sinks, laundries, etc.), greywater heat-recovery systems with heat storage add heat to the water supply to the hot water tank. These require more space, and regular inspection and cleaning.
Renewable Energy Systems
Renewable Energy Systems
Geothermal (Heat Pumps)
Power generation is feasible only in certain areas, and environmental concerns limit its application. However, more local building size heat pumps are used for heating and cooling and are extremely efficient. Often energy efficiencies in the range of 300 percent can be achieved due mainly to the free source of heat - the Earth.
What it costs: 4 to 6 cents ($US) per kWh
Solar Electric Photovoltaics
Typically, commercial photovoltaic panels convert 10-25% (efficiency) of the light that reaches the panel. Electricity generated by photovoltaic panels is direct current (DC)electricity although panels are available with inverters built into the system that provice alternating current (AC).
Photovoltaic systems can be optimized by orienting the panels to an optimum angle perpendicular to the sun. This optimum angle can be determined by knowing your latitude.
Optimum Panel Angle Calculation:
(Note this is for northern hemisphere, reverse sign for southern hemisphere)
Summer Solstice (June 21) Angle
(Latitude - 23 degrees) = Angle from horizontal
Winter Solstice (December 21) Angle
(Latitude + 23 degrees) = Angle from horizontal
For example:
In Rockhampton, Australia the optimum December 21st panel angle would be perfectly parallel to the ground (latitude = -23 degrees + 23 degrees = 0) or 0 degrees.
Further efficiency is possible by mounting the panels on a tracking system. In this way, the panel is in the optimum perpendicular position for the majority of daylight hours. Of course, a clear view path is necessary for the optimum energy gains to be achieved.
What it costs: 12 to 40 cents ($US) per kWh
Building Integrated Photovoltaics
Watch for the commercial availability in the near future of partially transparent PV panels for use as window-shading devices.
Consider the use of large PV arrays to generate electricity while shading parking lots or other outdoor areas.
On a smaller scale, PVs can be used to economically power nighttime walkway and landscape lighting. This system saves the cost of installing an underground electrical system.
Wind Energy
In Denmark, a country that has embraced wind energy through manufacturing and installation, the growth rate of the domestic industry is so dramatic that the entire country would be employed by 2020 if the growth continued.
The unit cost of wind energy is already comparable to other energy sources even though it receives only minimal subsidization as compared with other non-renewable energy sources.
Wind currents turn turbines that generate electricity. The downside with wind energy is that it requires some space to erect a wind turbine. Fortunately, many can still take advantage of wind energy either through the use of smaller turbines (for example 400 Watt) roof mounting units or through utility companies that provide green power.
By using renewable energy you prevent the release of:
CO2 = 2.2 tonnes/yr
*based on a 1000 Watt Generator
What it costs: 3 to 9 cents per kWh
Small or Micro Hydro
The main power requirements are in the winter months, so there should be little or no conflict with other river demands. Adequate provisions may have to be made for migratory fish, and if new works are to be constructed, care must be taken with regard to the effect on land drainage upstream of your intake. If there is insufficient power to provide your needs electrically, then there is the additional possibility of using water power to drive a water source heat pump which will increase the power output by three times in the form of heat.
The power available from a stream is determined by the head and flow of water on the particular site. This power is harnessed by constructing a dam or diverting the flow in such a way that all the fall occurs in one place. Where it is not practical to construct a channel, the water may be piped and the head of water is exploited as a high velocity jet driving an ‘Impulse Turbine’. The power available is a function of the fall (head) and flow so building a large waterwheel on a low fall will only increase the cost and reduce the shaft speed but not increase the power.
HEAD
Metres (Feet)
FLOW Litres/Min (Gallons/Min)
40 (10)
80 (20)
150 (40)
300 (75)
400 (100)
3 (10)
20
50
90
120
6 (20)
15
40
100
180
230
15(50)
45
110
230
450
600
30 (100)
80
200
500
940
1100
60(200)
150
400
900
1600
Water wheels are limited to sites with a head of less than 10 meters. They are aesthetically pleasing and have good performance under low water conditions. Unfortunately, due to their size, they are both costly to build and install, largely because of the gearing required to increase the shaft speed, typically from 10 to 1500 rpm. The use of low speed generators does not help since it is the low speed end of the drive which is the expensive part.
Water turbines, on the other hand, are able to make use of a very wide range of head, from less than a metre to many hundreds of metres. To cover the full range of sites, it is necessary to make use of several different types of turbine. It is not that you cannot use one type of turbine for all sites but that each design has it economic and hydraulic area.
What it costs: 5 to 12 cents ($US) per kWh
Fuel Cells
A fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water and heat.
FIGURE 1: A Fuel Cell
Excerpt from http://www.fuelcells.org/whatis.htm
Hydrogen fuel is fed into the "anode" of the fuel cell. Oxygen (or air) enters the fuel cell through the cathode. Encouraged by a catalyst, the hydrogen atom splits into a proton and an electron, which take different paths to the cathode. The proton passes through the electrolyte. The electrons create a separate current that can be utilized before they return to the cathode, to be reunited with the hydrogen and oxygen in a molecule of water.
A fuel cell system which includes a "fuel reformer" can utilize the hydrogen from any hydrocarbon fuel - from natural gas to methanol, and even gasoline. Since the fuel cell relies on chemistry and not combustion, emissions from this type of a system would still be much smaller than emissions from the cleanest fuel combustion processes.
What it costs: 8 to 15 cents ($US) per kWh
Biomass
By displacing more polluting forms of energy generation, bioenergy resources help the developed world reduce its dependence on oil and cut emissions of harmful greenhouse gases. Bioenergy technologies are also creating jobs and fueling economic growth across the world.
What it costs: 8 to 15 cents ($US) per kWh
Green Power
Why Buy Green Power?
By choosing to purchase a green power product, you can support increased development of renewable energy sources, which can reduce the burning of fossil fuels, such as coal, oil, and natural gas.
CFCs and Ozone Layer
The first hole in the ozone layer was spotted over the Antarctic. The air in the Antarctic is so cold, about -90 degrees Celsius, that clouds of icy particles form. These particles act as chemical catalysts - they allow chemical reactions to take place on their surfaces. These reactions involve the chlorine compounds released into the atmosphere by us, such as chloroflurocarbons or CFCs. These reactions release chlorine atoms which, in combination with energy from the sun, take part in a series of reactions which destroy ozone. In fact, the series of reactions can begin without sunlight, in winter, and so the ozone destroying potential of these reactions builds up until the arrival of the sun in spring completes the job. The solar ultraviolet radiation releases chlorine to scavenge more ozone molecules, turning ozone into oxygen, and the chlorine can repeat this cycle thousands of times. So even small amounts of chlorine can have a devastating effect upon the ozone levels. As spring turns to summer the clouds of ice particles which allow these reactions to take place evaporate and so the ozone hole begins to close once again.
CFCs/HCFCs/Halons
Elimination of CFCs/HCFCs/Halons
For new equipment, the choice of air conditioners and heat pumps using non-chlorinated refrigerants is currently limited. Non-HCFC equipment is preferable, if it meets capacity, efficiency and other criteria, since HCFC equipment is likely to be replaced or retrofitted in future as R-22 (the principal HCFC refrigerant) production ends.