NO MATTER THE SEASON
THIS BUILDING IS GREEN
NO MATTER THE SEASON
THIS BUILDING IS GREEN
One of the greatest revolutions of the 20th Century was neither political nor technological-it was a revolution in attitudes.
In the last 100 years, society has slowly begun to view the environment asan asset to be protected, instead of a frontier to be conquered.This environmental revolution is growing, led mostly by individuals andsmall communities who choose to live off the grid-either to satisfy theirenvironmental beliefs, or to fulfill a desire or need to live apart from thegrid-connected population. Moreover, these enlightened minds have long wondered when the world's established institutions would join them in their quest to save the Earth.
Corporate Green
If the concept of environmentally-friendly urban office buildings is anyi ndicator, we may be getting closer to winning the support of establishedinterests in our environmental revolution. Kyocera Corporation provided an indication of this with the August 1998 opening of its new worldheadquarters in Kyoto, Japan. This facility is a 20-story showcase of green technologies designed to be "the world's most environmentally friendly corporate headquarters building."
Kyocera, one of the world's leading producer and supplier of solar energy products, has a history of developing business opportunities by address ingenvironmental needs. In reflection of this, the company's new headquartersbuilding features the largest vertical solar energy system installed on anyurban skyscraper; a co-generation system; perimeter zone ventilation; airconditioners regenerated by ice which the facility freezes at night todiminish afternoon peak electricity consumption; and systems to utilizenon-potable rain water runoff and underground water to promote conservation.In an unusual twist for a multi-billion-dollar corporation, this building is designed to place the highest priority on environmental issues. Then again,"unusual" has become a recurring theme at Kyocera, where the official corporate motto is "Respect the Divine and Love People."
Building Concept
The city of Kyoto is full of urban amenities and rich cultural heritage.Kisho Kurokawa Architects & Associates designed the Kyocera headquarters toharmonize with the local environment and even improve upon it by adding a3,300 square meter (35,000 square foot) park on the site for the localcommunity to enjoy.
The building is at once aesthetically pleasing and environmentally friendly.No sacrifice was made in space, comfort, or functionality to incorporate the facility's many environmental systems. In fact, the building houses two world-class museums on its lower floors. The Kyocera Museum of Art features Quianlong glassware, modern Japanese paintings, bronze sculptures,Kiwa-yohen pottery, and works by Picasso. The Kyocera Museum of Fine Ceramics History displays the development of advanced ceramic technology(the name "Kyocera" is actually a contraction of "Kyoto" and "ceramics").
Solar Power Generation System
The building features 1,392 solar panels on the south wall, and 504 panelson the rooftop. This creates a total output of 214 KW, or 12.5 percent ofthe building's electrical requirement. The annual power generation fromthese solar panels can total up to 182,000 KWH, equivalent to what 45,000liters (12,000 gallons) of oil would produce at a conventional ther malpowerplant. This conservation of petroleum eliminates a significant amountof air pollution-approximately 97.2 metric tons (107 US tons) of carbondioxide, 133 kg (293 pounds) of sulfur dioxide and 92 kg (203 pounds) of nitrogen oxide per year.
The solar-electric panels have been installed in a unique array, which hasbeen adopted as a joint research theme between Kyocera and Japan's New Energy Development Organization (NEDO). This research project will be usedto gather data on various solar energy systems operating long-term to help increase public understanding of solar electricity.
The installation of the solar panels at a 15 degree angle against the vertical south wall optimizes their efficiency and provides space between the wall and the panels for air intake and exhaust vents. The frames of the solar panels and their surface glass were reinforced in consideration of thewind resistance at each installation level. Inconspicuous detailing wasadded to the lengthwise joint to help it blend in with the other surfaces onthe building facade.
The rooftop photovoltaic array (504 panels) faces south at an angle of 5degrees, and gives a maximum output of 57 KW. The 5 degree tilt optimizessun exposure to the south without letting the panels shade each other, andwithout compromising panel space on the roof. Many other systems have been installed on the roof, such as cooling towers for air conditioning facilities, various fans and pumps, and a heliport. The photovoltaic installation has been carefully designed to maximize photovoltaic surface area while allowing for the specific building requirements of an urban office tower.
The photovoltaic array is believed to be the first in any large-scale solarg enerating system in Japan to use a modular design. This modular designcombines many small-scale photovoltaic systems into one large system.There are two different methods for installing large photovoltaic systems.The standard is to have all the modules connect to a single inverter. This causes problems when the inverter needs repair, since the entire system must be shut down to repair a problem with just one of the major components.Instead, Kyocera chose the modular approach. They have twenty-two separate systems of 10 KW each. Each 10 KW system is complete in itself, which minimizes output loss by enabling each sub-system to be optimally controlled. In a non-modular system, for example, overall efficiency drops whenever any of the solar panels are in the shade, or if a panel or electrical component needs to be repaired. A modular system eliminates these problems by allowing individual sections of the overall photovoltaicinstallation to act as independent systems.
There is one potential pitfall to this design: when multiple PV system sexist throughout a building, control and monitoring of the system as a wholecan become difficult. Kyocera solved this problem by developing a "local operating network" which provides high-quality monitoring, data collection,and control, with minimal wiring.
The building's local operating network includes 22 separate photovoltaic subarrays. Each PV module is rated at 113 watts at 16.9 volts, measures 1 meter(3.3 feet) square and 36 mm (1.4 inches) thick, and weighs 21.8 kg (48pounds). The input voltage of each series string is 300 VDC, feeding into a10 KW transformer less inverter rated at 200 VAC. Kyocera developed this 10KW transformerless inverter specifically for the local operating network. Ithas no fan, so it operates quietly, and boasts a conversion efficiency of 95percent.
This building is fully grid-connected, since maximum power loads exceed the capacity of the photovoltaic system. Also, any excess electricity generated during weekends or holidays by the photovoltaic system can be sold back to the power company.
Co-Generation System
The building's co-generation system uses reciprocating engines to turn two520 KW electrical generators. These engines run constantly, and can be usedas an emergency backup generation system to supply approximately 60 percentof the building's power capacity needs in the case of a grid power outage.The engines are powered by natural gas to reduce carbon dioxide and sulfurdioxide emissions.
An absorption chiller makes effective use of the engines' waste heat bychilling water for the building's climate control systems. As a result, theenergy efficiency of the co-generation system is estimated to be more thantwice that of commercially generated electrical power from the local grid.Kyocera is the first company in Japan to combine a natural-gas-poweredco-generation system, a photovoltaic system, and standard grid-connected electric power in an urban office tower.
AC Regenerated by Ice
The building's air conditioning system takes advantage of the utilitycompany's relatively abundant off-peak energy to produce ice at night(between 10 PM and 8 AM). The ice provides refrigeration during the day toreduce energy consumption during peak energy usage hours. In addition toreducing costs, this type of system can help diminish the large gap between daytime and night time energy loads. This can help reduce the likelihood of brownouts on the utility grid.
Perimeter Zone Ventilation System
In non-winter months, sunlight hitting an office building creates a "hotzone" indoors near the windows, where indoor temperatures can be much higher than the air outside. In conventional buildings, this area is cooled by additional air conditioning, which consumes a significant amount of energy.In the new Kyocera headquarters, a perimeter zone ventilation system senses indoor/outdoor temperature differentials. During the spring and fall, it automatically brings cooler outdoor air in to help cool the air conditioning fan coils in this hot zone. This provides a natural,environmentally-friendly boost to the building's air conditioning system.
Air Conditioner Airflow Controls
Two airflow control systems use sophisticated temperature sensing to givethe building's air conditioning another efficiency boost. One system incorporates blowers with variable-speed motors to automatically adjust airflow to each floor of the building, which reduces unnecessary airflow. Inconcert with this, a second system provides local airflow control within individual offices by adjusting airflow as needed from each ceiling duct automatically. These systems create significant energy savings in comparison with conventional office buildings by reducing loads on the AC system.
Use of Underground Water and Rainwater
This system helps make efficient use of natural resources by usingnon-potable underground water and collected rainwater as an agent for theair conditioners, to flush toilets, and to irrigate the landscaping.
Other Environmental Systems
Kyocera's new headquarters building includes energy measuring systems foreach floor, high-efficiency zoned lighting, heat reflecting glass, and even"smart" escalators, which run only when they sense the approach of a passenger.
From any angle, this building's basic concept of combining ecological systems with world-class comfort and style is a milestone in urban design.We believe it represents a new model for the modern office tower, which could serve as an example of environmental awareness in many regions of theworld.
In the words of architect Noriaki Kurokawa: "I regard this building as morethan just a new corporate headquarters. I believe it embodies a true spiritof challenge-a spirit which initiates new ventures and opens new doors."
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