High Performance Design -- The Next Generation
The New York Chapter of USGBC sponsored a panel discussion on January 20, that gave an update on the status of high performance buildings.
Fiona Cousins, Principal, ARUP, described five buildings, several of which are located in New York City, that have achieved near zero energy and other goals. In her first project, a Smithsonian facility, located in a tropical (Caribbean) location, the efforts got very close to zero energy, but was not able to make it totally to net zero. In this project, as with many of the projects mentioned by others on the panel, solar voltaic panels (PV) were the one of the major components employed. In this application, a large 40 KW solar roof-mounted array produced a major amount of energy, but also cut heat gain, as it served as an R-15 insulation factor to the roof. The installation also featured rainwater collection, as well a solar thermal application for what heat was needed at this location during cooler parts of the year. Heat Pumps, utilizing the adjacent ocean water, were studied, but rejected, as it was feared that they would contribute too much ocean warming, and hence, cause undo environmental damage that would far outweigh the benefits. Daylighting was incorporated into the facility by integrating openings into the solar panel array at strategic points.
In her second building, the Bronx River Alliance features a solar array that generates almost all the needed energy. Green walls were also used to further reduce energy needs, and control storm water. In addition, an open design allows for passive solar heat harvesting. Her third project, in Bushwick (Brooklyn) also used a large 11 KwH per square foot per year, which again, not quite net zero energy, provides almost all the needed energy for that facility, which is a city park building. Also in Brooklyn, (Coney Island) is the newly renovated Stillwell Avenue Terminal of the New York City Transit Subway. This project utilizes a 210 KW solar array incorporated into a roof canopy design that totally overhauled and modernized a nearly one hundred year old transit hub that once belonged to the BMT Subway System.
Fiona Cousins also described goals for the 2020 Green Building Plans. Once again, these include net zero energy, water, and waste, and will emphasize solar panels, more efficient use of energy by computers and other appliances, along with the Living Machine for waste-water treatment on-site (where applicable) and rainwater collection. In addition, in the post 9/11 era, the use of thin skin high efficiency building skins will allow for safety features, such as day lit multiple stairwells within a building, that, while providing for energy savings, will allow for faster evacuation. The thin wall construction is also double skinned with provisions for food production via trays that can be incorporated into it, that will hold vegetable plants. This also deals with the storm water runoff and quality treatment at the same time.
Cousins also described a building on East 23 Street that in the planning stages. It will have its walls covered in vines for energy, water and aesthetic value. Large roof-mounted solar PV panels, along with a small building footprint, (compact volume) that is East - West oriented will contribute to the effort. Ground source heat pumps are to be supplemented with natural ventilation. The issue of waste water treatment is still under study; an option being considered would be a Living Machine type system. She says that they may be better off sending the waste to an off-site municipal system.
The next panelist, Matthew Herman, (CoSA, Buro Happold) emphasized the need for infrastructure analysis as a part the building design effort. Passive methods often will need additional active ventilation to meet air quality needs. The use of comparative fluid analysis aids greatly in seeing how prevailing winds effect energy transfer through the building. In addition, he emphasized the need to define the boundary - state of system to be able to measure the flow of energy in and out of the building. This will involve the calculation of nodes (mathematical formulas) to measure and predict heat transfer, waste and carbon production. Understanding margins and controls is key here. Herman told us that buildings are dynamic and change over time, and thus continual monitoring and tweaking of systems is often needed. He also mentioned the value of variable speed motors to enable a "sweet spot" in order to get a 50 percent reduction in energy use. Computerized models often run up against the ability of the system to produce the expected efficiency, as well as the laws of thermodynamics. Solar shading can help achieve a "negative energy" during cooling applications. Herman feels that code changes as well as primary fuel source pricing are major issues that need to be addressed in this area in order for PV and wind systems to more profitable in terms of the life cost analysis.
Anthony Pereira, President of Alternative Power, discussed solar voltaic applications for New York City. 350 million KwH per year of power is possible, and for all of New York State, we would only need to use .75 percent of the land space to meet ISO power needs. PV systems would eliminate peak power plant needs, and very likely eliminate brown-outs during heat waves. PV Watts Density Tools, which are simple to use, enable one to evaluate solar PV efficiency. These are: 10 watts peer per square foot, the angle of the array, orientation of the array, and the cost of energy. This will show, with one or two percent, the amount of energy that will be produced. Pereira feels that the major issues here involve lack of funded incentives on the part of New York State, as well as interconnectivity rules and power export. However, NYSERDA does offer a 30 percent tax credit, and a three dollar per watt for the first 40 KW and two dollars for the next 40 KW, but only 80 KW total will be offered credit; any larger amount receives no further incentive. This is small, when compared to Germany and even elsewhere in the United States. There is, however, a 35 percent property tax credit in NYC.
The panels can be flat panel horizontal arrays, or integrated into building facades. This has value in NYC where building spacing permits. In NYC, especially with the combined NYSERDA grants, NYS tax and NYC property tax credits, the payback can be as little as two years. In some tall buildings, the bulkheads can be fitted with transcending arrays of PV panels, that can be angled from side to side (and even up and down from summer to winter) to further optimize the solar efficiency.
The panel discussion concluded with several major points of agreement among the panelists. Solar PV systems make the most economic and energy efficiency sense in NYC. The issue of human behavior is a major factor, as is our defined levels of thermal comfort. It was felt that micro-turbines are not of value in NYC at this time, due to the Con Edison rates and problems with interconnectivity, as well as first cost basis. Wind power is also felt to be of lessor value in NYC when compared with solar. While increasing the efficiency of systems is of utmost importance, the need to limit our use of energy wherever possible will be needed to reach the zero energy goal. As mentioned earlier, large solar PV roof arrays are an integral part here, but vertical arrays are also of great value, too.
Fiona Cousins, Principal, ARUP, described five buildings, several of which are located in New York City, that have achieved near zero energy and other goals. In her first project, a Smithsonian facility, located in a tropical (Caribbean) location, the efforts got very close to zero energy, but was not able to make it totally to net zero. In this project, as with many of the projects mentioned by others on the panel, solar voltaic panels (PV) were the one of the major components employed. In this application, a large 40 KW solar roof-mounted array produced a major amount of energy, but also cut heat gain, as it served as an R-15 insulation factor to the roof. The installation also featured rainwater collection, as well a solar thermal application for what heat was needed at this location during cooler parts of the year. Heat Pumps, utilizing the adjacent ocean water, were studied, but rejected, as it was feared that they would contribute too much ocean warming, and hence, cause undo environmental damage that would far outweigh the benefits. Daylighting was incorporated into the facility by integrating openings into the solar panel array at strategic points.
In her second building, the Bronx River Alliance features a solar array that generates almost all the needed energy. Green walls were also used to further reduce energy needs, and control storm water. In addition, an open design allows for passive solar heat harvesting. Her third project, in Bushwick (Brooklyn) also used a large 11 KwH per square foot per year, which again, not quite net zero energy, provides almost all the needed energy for that facility, which is a city park building. Also in Brooklyn, (Coney Island) is the newly renovated Stillwell Avenue Terminal of the New York City Transit Subway. This project utilizes a 210 KW solar array incorporated into a roof canopy design that totally overhauled and modernized a nearly one hundred year old transit hub that once belonged to the BMT Subway System.
Fiona Cousins also described goals for the 2020 Green Building Plans. Once again, these include net zero energy, water, and waste, and will emphasize solar panels, more efficient use of energy by computers and other appliances, along with the Living Machine for waste-water treatment on-site (where applicable) and rainwater collection. In addition, in the post 9/11 era, the use of thin skin high efficiency building skins will allow for safety features, such as day lit multiple stairwells within a building, that, while providing for energy savings, will allow for faster evacuation. The thin wall construction is also double skinned with provisions for food production via trays that can be incorporated into it, that will hold vegetable plants. This also deals with the storm water runoff and quality treatment at the same time.
Cousins also described a building on East 23 Street that in the planning stages. It will have its walls covered in vines for energy, water and aesthetic value. Large roof-mounted solar PV panels, along with a small building footprint, (compact volume) that is East - West oriented will contribute to the effort. Ground source heat pumps are to be supplemented with natural ventilation. The issue of waste water treatment is still under study; an option being considered would be a Living Machine type system. She says that they may be better off sending the waste to an off-site municipal system.
The next panelist, Matthew Herman, (CoSA, Buro Happold) emphasized the need for infrastructure analysis as a part the building design effort. Passive methods often will need additional active ventilation to meet air quality needs. The use of comparative fluid analysis aids greatly in seeing how prevailing winds effect energy transfer through the building. In addition, he emphasized the need to define the boundary - state of system to be able to measure the flow of energy in and out of the building. This will involve the calculation of nodes (mathematical formulas) to measure and predict heat transfer, waste and carbon production. Understanding margins and controls is key here. Herman told us that buildings are dynamic and change over time, and thus continual monitoring and tweaking of systems is often needed. He also mentioned the value of variable speed motors to enable a "sweet spot" in order to get a 50 percent reduction in energy use. Computerized models often run up against the ability of the system to produce the expected efficiency, as well as the laws of thermodynamics. Solar shading can help achieve a "negative energy" during cooling applications. Herman feels that code changes as well as primary fuel source pricing are major issues that need to be addressed in this area in order for PV and wind systems to more profitable in terms of the life cost analysis.
Anthony Pereira, President of Alternative Power, discussed solar voltaic applications for New York City. 350 million KwH per year of power is possible, and for all of New York State, we would only need to use .75 percent of the land space to meet ISO power needs. PV systems would eliminate peak power plant needs, and very likely eliminate brown-outs during heat waves. PV Watts Density Tools, which are simple to use, enable one to evaluate solar PV efficiency. These are: 10 watts peer per square foot, the angle of the array, orientation of the array, and the cost of energy. This will show, with one or two percent, the amount of energy that will be produced. Pereira feels that the major issues here involve lack of funded incentives on the part of New York State, as well as interconnectivity rules and power export. However, NYSERDA does offer a 30 percent tax credit, and a three dollar per watt for the first 40 KW and two dollars for the next 40 KW, but only 80 KW total will be offered credit; any larger amount receives no further incentive. This is small, when compared to Germany and even elsewhere in the United States. There is, however, a 35 percent property tax credit in NYC.
The panels can be flat panel horizontal arrays, or integrated into building facades. This has value in NYC where building spacing permits. In NYC, especially with the combined NYSERDA grants, NYS tax and NYC property tax credits, the payback can be as little as two years. In some tall buildings, the bulkheads can be fitted with transcending arrays of PV panels, that can be angled from side to side (and even up and down from summer to winter) to further optimize the solar efficiency.
The panel discussion concluded with several major points of agreement among the panelists. Solar PV systems make the most economic and energy efficiency sense in NYC. The issue of human behavior is a major factor, as is our defined levels of thermal comfort. It was felt that micro-turbines are not of value in NYC at this time, due to the Con Edison rates and problems with interconnectivity, as well as first cost basis. Wind power is also felt to be of lessor value in NYC when compared with solar. While increasing the efficiency of systems is of utmost importance, the need to limit our use of energy wherever possible will be needed to reach the zero energy goal. As mentioned earlier, large solar PV roof arrays are an integral part here, but vertical arrays are also of great value, too.
Posted by Alan L. Englander at 1/22/2009 11:21 PM 
Categories: Net Zero Energy and Water,USGBC New York Chapter,Zero Waste,Infrastructure analysis,High Performance Buildings,Energy Flow,Solar PV
Categories: Net Zero Energy and Water,USGBC New York Chapter,Zero Waste,Infrastructure analysis,High Performance Buildings,Energy Flow,Solar PV
Comments