Plan de Análisis o trayectoria metodológica

The estimated value of open space as explained in this section is used to assess the potential land use benefits associated with replacing central power facilities with distributed generation resources. Three case studies presented here – a condominium project in Philadelphia, a wastewater treatment plant in Portland, and a national park project on Santa Rosa Island – provide a context and focus for estimating land use benefits of DG.

The Philadelphian Condominium

Columbia Boulevard Wastewater Treatment Plant

The Philadelphian is a 1.4-million sq ft, upscale condominium building in downtown Philadelphia, Pennsylvania, adjacent to the Philadelphia Museum of Art. In 1989, the Philadelphian Owners’ Association opted to install an on-site combined heat and power (CHP) plant for the 22-story, 776-unit building. The Philadelphian Owners’ Association financed the project

The Columbia Boulevard Wastewater Treatment Plant is the largest water treatment facility in Oregon. Operated by the City of Portland, the plant treats an average of 80 to 90 million gallons of sewage per day. Byproducts of the water treatment process are bio-solids that are also treated. In the bio-solids processing, anaerobic digesters use the action of bacteria to break down solids and thus

46 _{Dollar figures adjusted to 2006 dollars using the average U.S. Gross Domestic Product Implicit Price Deflator over the previous 24 years,} 1981 to 2005.

The Philadelphian Condominium

Columbia Boulevard Wastewater Treatment Plant

using a 15-year guaranteed energy savings contract with Cogeneration Partners of America. The association contracted with Eastern Power Corporation to operate the plant. The CHP system, which generates all the heating, cooling, water heating and most of the electrical power for the building, has resulted in about $300,000 yearly energy costs savings, a 25% reduction from previous years.

The building must be conditioned 24 hours a day and have a constant supply of outside air for ventilation. The building’s cooling load is about 1,500 tons, and its heating load is about 38,163 million British thermal units (Btu). Annual electricity consumption is about 10 million kWh, or 7.14 kWh per sq ft, coming primarily from resident plug load, the central plant pumping system, the cooling towers and the electric chillers. Load reaches a high of 1.1 million kWh in July and August. Summer peak demand is about 1,900 kW and winter peak demand is 1,200 kW.

produce a combustible gas composed primarily of methane and carbon dioxide. Following the adoption of a city climate change strategy, the plant was tasked with considering options for environmentally friendly uses of the produced anaerobic gas.

While options were under consideration in 1995 and 1996, the plant experienced extended power outages. These outages forced shutdown of the control center, which provides communication to more than 100 pump stations throughout the community. During this time, the city consolidated billing among several facilities with its electricity provider, Portland General Electric. Because of the city’s environmental commitment, it opted to return part of the resultant cost savings from the consolidation to the utility as a green power premium through which the utility would build 500 kW of wind energy capacity. In turn the utility returned the premium to the city to install a 200 kW fuel cell at the plant that would run on the anaerobic gas, helping to solve both the environmental problem associated with the gas and the need for backup power at the control center.

The fuel cell system, which began operating in 1998, provides continuous power for the plant and waste heat for process heating requirements. The fuel cell plant consists of the ONSI PC 25C fuel cell with integrated fuel reforming. The raw digester gas is treated by the gas processing unit, which consists of a dual set of tanks containing activated carbon that absorbs hydrogen sulfide and halogens. An air-metering pump provides a small amount of air for proper operation of the carbon beds. The system is clean, producing virtually no NO2. The

total price of the fuel cell installation was $1.3 million.

Channel Islands National Park Photovoltaic Installation

Santa Rosa Island is part of the Channel Islands National Park. The 52,794 acre island is located off the Santa Barbara coast, 44 miles west of the park headquarters in Ventura, California. The park’s employee housing facility is located in a remote island location, requiring an independent power system. As diesel was considered expensive and risky to transport to the island, the park selected two off-grid 6.4 kW photovoltaic systems to power the housing facility. These systems, installed in 1998, complemented four solar hot water systems previously installed in 1988.

Sources: U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. The Power to Choose, and Save: Residents of the Philadelphian High-Rise Condominium Cut Energy Costs by 25% with CHP; Columbia Boulevard Wastewater Treatment Plant – CHP Case Studies in the Pacific Northwest; and Channel Islands National Park PV installation: Million Solar Roofs Success Stories. The monetary benefit values presented in these three case studies are based on two variables: (1) land-use required by central power sources as well as by DG; and (2) dollar amounts representing the value of

open space and ROW cost savings. Data available on preserved farmland is utilized for the per-acre monetary value estimates. The quantity of open-space estimates is generated from the difference between the land-use required for the average central power source (492.86 ha or 1,217.86 acres) and the land use required for DG. Information on the land estimates is provided in Table 6.11.

Table 6.11. Quantity of Land Resources Required by DG Case Study Projects

DG Technology

Electricity Generation

Minimum Open- Space Estimates: Land Required for

Case Study47

Maximum Open-Space

Estimates Case Study

Philadelphian Condominium CHP 1.55 MW 503 sq ft 1217.85 Acres Portland Oregon Wastewater

Treatment Plant Fuel Cell 200 kW 200 sq ft 1217.83 Acres Santa Rosa Island Photovoltaic 12.8 kW 2,304 sq ft 1217.85 Acres

The open-space estimates in Table 6.11 can be described as the minimum and maximum quantity of land acreage that is not used by a central power source. The minimum open-space estimate is the land required for the DG project. The maximum open space estimate assumes that a single central power source would be constructed for each specific project.

The range of land use benefits for each DG facility is presented in Table 6.12. Table 6.12. Land-Use Benefits for Three DG Facilities

Case Study

Lower-Limit Benefits

Upper-Limit Benefits

Land Use Benefits Per kW48

Philadelphian Condominium $1.99 $6,374,718.03 $22,169.64 Portland Oregon Wastewater Treatment Plant $0.71 $6,374,756.93 $2,853.54 Santa Rosa Island $9.08 $6,374,501.70 $41.81

The lower-limit value in Table 6.12 is derived from the per-acre estimates observed by previous USDA CRP research (equivalent to $171 in 2006 dollars) and assumes minimum land required for the DG facilities. The upper-limit benefit is the maximum benefit to society of the DG project based on the price of land per acre, presented by Irwin (2002) (equivalent to $5,234 in 2006 dollars) and the maximum available acreage data presented in Table 6.11. Irwin (2002) has presented the greatest per-acre value of preserved agricultural lands. Land-Use Benefits per kW represent the dollar value comparisons between central power and DG land use requirements for each project. Each project creates land use savings, compared to the land required by central station projects, based on per-kW land use estimates.49 _The

47 _{Information in this table is developed using data on sq ft/kWh presented in Table 6.8, Land Use for Typical Distributed Energy Resource} Facilities. Specifically for the Philadelphian Condominium, the parameter sq ft/kWh in Table 6.7 entitled Natural Gas Engine is used, which is equal to 0.325. On the other hand, for the Portland Oregon Wastewater Treatment Plant and Santa Rosa Island case studies, the

parameters located in the columns entitled Fuel Cell and Building Integrated Photovoltaic Array are used, 0.9 and 0.

48 _{The land use estimates for this column utilizes information from Table 6.11, specifically for the Philadelphian Condominium and Portland} Oregon Wastewater Treatment Plant. The sq ft/kWh for a central power facility is assumed to be 233.18 which is derived from Spitzley and Keoleian (2004). The sq ft/kWh for the Santa Rosa Island example is 180 which is calculated from data presented in Spitzley and Keoleian (2004)

49

amount of land saved at each site is equal to the difference between the land required by the DG project on a kW basis and the land required by a central power source on a kW basis.

The range of these savings can be significant and depends upon the area selected for construction of the central power source. When a central power source is developed in close proximity to an urban area, where open space is limited, the benefit of implementing DG resources may be more advantageous due to the higher value placed on open space in these regions. Alternatively, when a central power source is sited in a rural area, where open space is abundant, land use benefits from DG might not be as positive.

Rights-of-way costs may still be significant for electricity transmission firms. Data on per-acre ROW costs and total ROW costs are presented Table 6.13.

Table 6.13. Range of Saved Rights-of-Way Acquisition Costs for a Single Distributed Generation Facility

Low-Limit Benefits Upper-Limit Benefit Median Benefit

Per-Acre ROW Costs $1,780 $60,000 $30,890 Total ROW Costs (assuming 9.21 acres) $16,394 $552,600 $284,497

Rights-of-way electricity transmission costs are shown to be between $1,780 and $60,000 per acre. The low-end figure of $1,780 per acre is based on Energy Information Administration data on the construction of transmission lines from a single central power source in 2003 (Energy Information Administration 2003). The upper range is representative of the per-acre costs observed in the natural gas, vehicular transportation, and electric power industries.

In summary, then, estimated rights-of-way savings could result from the three DG case studies, ranging from $16,394 to $552,600, depending on the location of the rights-of-way and the amount of assets located on the land. If multiplied throughout the economy, such savings could be significant, providing positive impacts to state and local governments as well as the utilities themselves.