Categories: Green Buildings, Green Roofs
Feasibility analysis of renewable energy supply options for a grid-connected large hotel
Link: http://dx.doi.org/10.1016/j.renene.2008.08.012
Abstract: This study presents an analysis of the technical and financial viability of grid-only, Renewable Energy Supply (RES)-only and grid/RES hybrid power supply configurations for a large-scale grid-connected hotel (over 100 beds). Assessment criteria comprised net present cost (NPC), renewable fraction (RF) and payback time. The RES software HOMER (National Renewable Energy Laboratory, US) was utilised as the assessment tool with modeling performed with hourly load data input from a hotel located in a subtropical coastal area of Queensland, Australia. The results demonstrate that RES, in principle, has the potential to supply significant power for a large-scale tourist accommodation, in conjunction with the grid-electricity supply. Optimisation modeling demonstrated that, at 2004 prices, the NPC of the grid/RES hybrid configuration is comparable with the grid-only supply and resulted in a RF of 73%, a payback time of 14 years and a reduction in greenhouse gas emissions of 65%. Optimisation modeling also showed that whilst a RES-only configuration can potentially supply 100% of power demand, such a configuration is presently uneconomical given current electricity costs. Results indicate that wind energy conversion systems (WECS), rather than photovoltaics, are the most economically viable RES technology for large-scale grid-connected operations. Specifically, large-scale WECS (over 1000 kW) are more efficient and more economical than multiple small-scale WECS (0.1–100 kW). Hydrogen fuel cells and storage are presently uneconomical in grid-connected configurations. Sensitivity analysis demonstrated that operations that rely on grid-only supply are more economically susceptible to escalations in electricity costs and the imposition of carbon taxes, in comparison to grid/RES hybrids. Indeed, at present electricity prices, which have nearly quadrupled since 2004, the grid/RES hybrid is more economical over a 20-year span than the grid-only system, with a NPC which is 50% lower, and a payback time of 4.5 years. The analysis demonstrates that RES is both technically feasible and economically viable as an addition to grid-connected supply for large-scale tourist operations, and should become more attractive as costs of conventional supplies increase.
Keywords: Renewable energy systems; Wind, PV, micro-generation; Grid-connected supply; Large-scale tourist hotel accommodation; Optimisation software; Net present cost
Renewable Energy via Elsevier Science Direct www.ScienceDirect.com
Volume 34, Issue 4; April, 2009; Pages 955-964
Green Noise or Green Value? Measuring the Price Effects of Environmental Certification in Commercial Buildings
Link: http://mpra.ub.uni-muenchen.de/11446/
Abstract: Evaluating the environmental performance of a building is rapidly gaining importance as a metric in real estate investments . Since interpretation of the technical measurements is difficult and requires high expertise, investors tend to rely on markers as provided by environmental certification standards instead of evaluating environmental performance directly. It is argued that there are likely to be three main drivers of price differences between certified and non-certified buildings. Drawing upon the CoStar database of US commercial real estate assets, hedonic regression analysis is used to measure the effect of certification on both rent and price. Franz Fuerst and Patrick McAllister first estimate the rental regression for a sample of 110 LEED and 433 Energy Star as well as several thousand benchmark buildings to compare the sample to. The results suggest that certified buildings have a rental premium. Furthermore, based on a sample of transaction prices for 292 Energy Star and 30 LEED-certified buildings, Fuerst and McAllister find a price premium of 10% and 31% respectively.
Keywords: Green buildings, LEED, Energy Star certification, commercial real estate, appraisal, partial equilibrium, price premium, innovation diffusion
by Franz Fuerst 1 and Patrick McAllister 2
1. University of Reading
2. Henley Business School
Munich Personal REPEC Archive (MPRA) http://mpra.ub.uni-muenchen.de
April, 2008; Deposited On: November 8 2008
The New York Times Company's New Headquarters Makes Headlines with 70% Energy Savings using Lutron's Advanced Lighting Controls
Link: http://www.lutron.com/cms/assets/ecosystem/nytimes/nytimes.html
From the Lutron "Case Study":
It takes a lot to impress The New York Times, so when a Times exec analyzed the performance of the company’s state-of-the-art lighting system in their new Manhattan headquarters, and then called the results “groundbreaking,” it was as if the architectural community itself was being told to “Stop the presses!”
The New York Times Building was making headlines within the company with a total light management system that allows it to use 70 percent less energy for lighting than the building’s design called for– and, as we know from the U.S. Energy Information Administration, a typical office building’s lighting system is the largest source of electricity consumption (44 percent).
The 70 percent lighting energy reduction represents a savings of $315,100 per year at New York City electric rates. It also means the prevention of 1,250 metric tons of CO2 emissions each year.
“The energy usage savings is stunning,” said Glenn Hughes, the Director of Construction for The New York Times Company during the design, installation and commissioning of The New York Times Building. “Lutron’s lighting control system has delivered an absolutely over-the-top performance. When I talk with other construction an
lighting consultants, they’re astonished at the results.”
“We designed our building to use 1.28 watts per square foot of lighting power. With Quantum, The New York Times Company is using only 0.38 – that’s 70% less.” according to Hughes.
The company resolved to exercise control at every stage of the project’s design and construction processes, ensuring that the new building accurately represented its corporate culture and values, and reaped real business benefits for the company. “We desired an interior environment that allowed our employees to be as comfortable as possible and that would reinforce our company’s emphasis on open communication, collaboration and transparency,” said David Thurm, Vice President and Chief Information Officer of the Times Company. “In addition, we insisted that the building be as environmentally friendly as possible.”
To accomplish these objectives, the Times Company hired the world-renowned architect Renzo Piano, along with two major architectural firms, FXFOWLE of New York, and Gensler, headquartered in San Francisco. The Times Company also employed the lighting design services of SBLD Studio of New York.
The result is a dazzling 52-story tower with 1.5 million gross square feet jointly owned with Forest City Ratner Companies of New York. The building is a mix of office and retail. Its chief attributes are open spaces and floor-to-ceiling glass walls that provide building occupants wide views of the neighboring skyscrapers and, conversely, allow outsiders to look in. “The whole building structure is designed for maximum light,” said Thurm, whose company owns 28 floors or about 625,000 square feet—the interior space designed by Gensler. “The number one priority was to allow natural light to make our employees feel more comfortable and to produce an energizing work environment.”
... Executives extensively researched the state-of-the-art lighting control options to satisfy their twin desires for daylight harvesting and for the flexibility to reconfigure spaces easily and simply. The word extensively is not used loosely. As Thurm himself described in an article published in the Harvard Business Review, virtually every decision fell under tight scrutiny to drive innovation and to avoid what he called, “well- ntentioned guesses by others as to what you want.”
After the building had been occupied for a year, Glenn Hughes, now president of Glenn D. Hughes Consulting Associates, utilized Quantum’s 30-day energy usage report to see for himself how much energy savings was achieved by the Quantum solution. “We designed our building to use 1.28 watts per square foot of lighting power,” Hughes said. “With Quantum, The New York Times Company is using only 0.38 — that’s 70 percent less.” Hughes said the figure of 1.28 watts per square foot of lighting power was within the local code in effect when the building was constructed. It has since tightened to about 1.1 watts.
He said the Lutron lighting control system has established an excellent baseline for the building is poised to achieve even better energy savings as the system parameters are tweaked.
The research eventually gravitated to the Building Technologies Department at the Lawrence Berkeley National Laboratory at the University of California. With guidance from the Berkeley Lab, the project design team and manufacturers, the Times Company built a replica of the southwest corner of its new building at one of its printing facilities in Queens, New York. For six months, from winter solstice to summer solstice, the mock-up tested an array of different lighting technologies and products from a variety of manufacturers including a new technology just emerging from Lutron Electronics Co. Inc. The testing, plus Lutron’s response to a competitive bid, convinced the Times Company to select Lutron’s Quantum light management solution for its office space.
The energy-saving lighting control strategies employed in the building include the following:
-- light level tuning (setting the appropriate target light level for each space);
-- daylight harvesting (automatically dimming electric lights when enough daylight is present); and
-- occupancy sensing (turning lights off when space is vacant).
Lutron's Quantum prevents wasted lighting energy by maximizing the efficient use of light in a building. The system automatically dims or switches all electric lighting, and controls daylight using automated window shades. Quantum also manages, monitors, and reports on all the lighting usage in a building for optimal energy performance and productivity while minimizing maintenance and operating costs.
For more information about Quantum total light management and The New York Times Building project, visit: www.lutron.com/nyt
Lutron www.lutron.com
Louisville Kentucky Metro Center Green Roof
Link: http://www.louisvilleky.gov/GoGreen/metro_go_green.htm
http://www.louisvilleky.gov/GoGreen/metro_go_green.htm>
Green Roof Concept: Louisville
Louisville Metro’s first green roof is being constructed atop the Metro Development Center (MDC), 444 South 5th Street, which serves as a one-stop shop for Louisville’s developers, builders and contractors. The six-story building was originally built in the early 1900's as a parking garage, and it was converted it to an office building in the 1980's.
In addition to its central downtown location, MDC was chosen to receive the first green roof for a very basic reason – the roof needed repairs! It was also determined to have a suitable load-bearing structure. About 11,000 square feet will be available for planting, excluding a 1,200-square-foot “penthouse”, which houses various mechanical systems. Although the penthouse roof will not be planted, it will receive a special Energy Star-certified coating.
The firm of Luckett & Farley was chosen to design and oversee the green roof project.
An “extensive” style roof was dictated by the roof structure analysis, which established limits for the weight of the green roof materials.
To keep the roof as maintenance-free as possible, native plants will be widely used, including a variety of drought-resistant sedums. Planters with small trees will be located over structural support columns. Metro Landscape personnel will provide periodic seasonal maintenance. An irrigation system is being installed as part of the roof.
The new green roof will provide many environmental benefits. It will provide insulation value, and the energy value will be tracked through Portfolio Manager monitoring software. Storm water run-off is expected to be reduced by up to 50%. The roof will contribute to urban heat island mitigation, improved air quality, and added habitat for insects and birds.
On September 21, 2008 the Courier-Journal reported that The Zero Co. of Cincinnati won the contract to install the roof. The project is expected to cost more than $425,000. The Journal also reported that the roof will be planted mostly with sedum, which is a hardy, drought-resistant succulent. Four planters will include green hawthorn trees surrounded by prairie dropseed grass.
also see: http://www.courier-journal.com/apps/pbcs.dll/article?AID=/20080921/NEWS01/809210523/1008/NEWS01
Louisville Kentucky Government Website http://www.louisvilleky.gov/GoGreen/metro_go_green.htm
