Building-Mounted Photovoltaics

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From the invention of the first practical photovoltaic cell in 1954 until 2000, photovoltaics (PV) showed only a modest penetration of the electric power generation market. From 2000 to the present, however, the global PV market has shown astounding growth. According to the European Photovoltaic Industry Association, global annual production of PV in 2010 increased to 16,629 MW. Cumulative installed capacity increased from 1,459 MW in 2000 to 39,529 MW in 2010 -- nearly 27 percent growth. This eBook outlines how global political instability, terrorism, financial crises and natural disasters have caused many users to re-think their dependence on fossil fuels. Concerns about humanity's potential contribution to climate change also have driven the search for alternative energy technologies. How fast can a switch be made? Author John P. Thornton recounts two nautical examples of successful technology shifts in the last 160 years: the move from sail-driven to coal-powered ships; then from coal- to oil-fired vessels. There are additional and numerous modern examples of rapid technology upgrades, such as the growth of the mobile telephone industry. Thornton states that PV and other renewable technologies are poised to make this transition now. He catalogues the many characteristics that make PV a promising technology to reduce negative environmental impacts. This eBook also notes that significantly large global deployment of renewable technologies will have a major impact on society, and provides estimates on the significant contribution that building-mounted PV (BMPV) can make toward satisfying energy needs.

Introduction and Methodology

Objective
Scope
Methodology
Glossary

The Building-Mounted Photovoltaic (BMPV) Industry

Introduction
Background
Energy Efficiency and BMPV Deployment
LEED and its Effect on Building Design and
Performance
Industry Description
Market Trends
The BMPV Potential

Principles of Operation

Fundamentals of Insolation
PV Cell and Module Technologies
- Cell Technologies
- - Bulk Crystalline Silicon Cells
- - Thin-film Cells
- - Concentrator Cells
- Module Configurations
- - Crystalline and Polycrystalline Cell Modules
- - Thin-film Modules
- - Concentrator (CPV) Modules
- The Significance of PV Module Ratings
PV Systems
- Grid-connected and Grid-independent Systems
- - Grid-connected PV Systems
- - Grid-independent or Stand-alone Systems
- Net-metering
Balance-of-system Components
- Inverters
- Power Disconnects
- Wiring, Cabling and Electrical Interconnection

Building-mounted PV Systems

BMPV Systems
- Externally mounted PV Systems
- Building-integrated PV Systems
BMPV: Benefits and Issues
Optimizing PV Array Performance with Energy Efficiency
BMPV System Issues
- Rooftop PV Safety Issues
- Utility/interconnection Issues
- Maintenance and Operation
PV System Cost and Economics
- PV System Capital Cost
- PV System Cost-effectiveness
- PV System Maintenance Costs
Government Programs and Incentives
Designing and Procuring a BMPV System
- Design Resources
- - Guidebooks, Technical Literature and the Internet
- - Computer Modeling Tools
- - PV Sol
- - PVWatts
- - SAM (Solar Advisor Model)
- Codes and Standards
- Financing a BMPV Project
- Building vs. Buying a PV System
Designing BMPV Systems
- Externally mounted Systems
- - Minimizing the Effects of Wind Loading
- - Effects of Shading on System Performance
- - Effect of Tilt on System Performance
- - Calculating the Spacing between Rows
- - Flat vs. Tilted Arrays
- - Maintenance Considerations
- - Array Electrical Design Considerations
- - Array Structural Support
- - Equipment Placement
- BIPV Systems

Future Trends for BMPV

The Terawatt Challenge
Solar Cell Improvement
Component and System Improvements
Manufacturing Improvements
Material Availability
Cost Improvement

References

Tables & Figures

List of Tables
TABLE 2.1 The top ten PV manufacturers in the world
TABLE 2.2 Global PV production by country, 2010
TABLE 4.1 Example of PVWatts performance results for Boulder, Colorado
TABLE 4.2 A summary of the performance as a function of tilt angle for a PV array on a building in El Paso, Texas

List of Figures
FIGURE 2.1 PV diffusion model
FIGURE 2.2 Frank W. Reilly elementary school (Chicago)
FIGURE 2.3 The 4 Times Square building in New York City
FIGURE 2.4 The BIPV skylighted entryway on the Thoreau Center for Sustainability
FIGURE 2.5 Underside of Presidio skylight
FIGURE 3.1 Typical insolation and climatic data provided by the NSRDB
FIGURE 3.2 Crystalline modules mounted on a support structure that is anchored by rock ballast
FIGURE 3.3 T5 Solar Roof Tile showing its low profile
FIGURE 3.4 Prefabricated T10 Solar Roof Tile showing anchoring method
FIGURE 3.5 An exterior view of an early European building using transparent BIPV modules
FIGURE 3.6 Flexible membrane modules are specialty modules designed for standing-seam roofs
FIGURE 3.7 PowerTiltEM units use amorphous silicon thin-film modules
FIGURE 3.8 PowerMembrane units use amorphous silicon thin-film modules
FIGURE 3.9 Rooftop PV concentrator
FIGURE 3.10 A typical module nameplate showing rated capacity and performance
FIGURE 3.11 Schematic of a typical grid-connected PV system
FIGURE 3.12 Schematic of a typical grid-independent PV system
FIGURE 4.1 325 KW PV array on the Coca-Cola bottling plant in Los Angeles
FIGURE 4.2 PowerMembrane system on the Los Arcos Shopping Center in Seville, Spain
FIGURE 4.3 12 MW system on the roof of the General Motors assembly plant in Zaragoza, Spain
FIGURE 4.4 A vertically mounted PV facade on an apartment building in Santa Monica, CA
FIGURE 4.5 PV modules can be used to shade windows on commercial buildings
FIGURE 4.6 An example of a BIPV array distributed among different sections of a building rooftop in Santa Monica, California
FIGURE 4.7 An 8.6 MW segmented but interconnected PV array on the roof of a ProLogis distribution center in California
FIGURE 4.8 An exterior view of a 34.4 KW PV curtain wall on the Millennium Park Exelon Pavilion in Chicago, Illinois
FIGURE 4.9 An interior view showing the diffuse light pattern created by a PV curtain wall
FIGURE 4.10 The St. Mary Axe building in London is an attention grabber
FIGURE 4.11 A view from the lunchroom at the top of St. Mary Axe building
FIGURE 4.12 The result of an arc fault in a polycrystalline PV module
FIGURE 4.13 A comparison of the relative area and variation in the rated capacity of a BIPV array at tilt angles of 0º, 10º and 25º on a building in El Paso, Texas
FIGURE 4.14 A comparison of the average monthly energy production as a function of tilt angle for a PV array on a building in El Paso, Texas
FIGURE 4.15 Shading of a large inverter from direct sunlight is provided by a wooden fence