Even though there are a number of examples of BIPV, the concept of integration into the building and its design process have not yet been clearly defined. Lack of integration makes this new technology application expensive and very complex to implement. The challenge is how to make this new concept easily applicable and to spread this promising technology for users. In order for PV technology to be added effectively into the design process, full integration is essential. Full integration can be achieved when close interface develops between the PV System and the elements of the building design process. The design process is the spine that links the building from its inception all through its life cycle. The architects, along with the consultants and technical experts, are directly responsible for this process. PV has to be part of the building material and its building material properties have to be equivalent to other conventional building materials. PV has to fit into the building design process from the beginning. As a building component, it has to have certain standards and codes that will fit well within general building codes. This paper starts with the definition of the architectural building design process. It then continues with identifying the barriers that have direct effect on this process. These barriers are lack of interface (integration with typical building process), lack of common language, mismatched potential, unknown performance, and lack of economic analysis. The paper concludes by giving suggestions on how these barriers can be broken.

A 2 kW photovoltaic (PV) system with battery storage for emergency power supply was designed and installed as a test demonstration in a 112 square meter apartment. The system was installed to demonstrate the potential of a photovoltaic system (using thin-film solar modules) as an environmentally friendly and renewable source of energy compared to conventional electricity generation. Barriers to installation and preliminary estimations of system performance and costs are presented.

Commercially available photovoltaic (PV) modules and systems often fall short of meeting the performance ratings specified by the module manufacturers or system designers [1]. This has resulted in reduced performance and low system availability, some system failures, and generally, a lack of confidence by systems users. Hence, a need for an independent accredited laboratory to conduct the testing and certification of PV modules and systems has been indicated by the PV industry, electric utilities, and other system users and owners. To meet this industry and user need, the Florida Solar Energy Center (FSEC) has started a PV testing and certification program. The FSEC PV testing laboratory and certification program have been accredited by the American Association for Laboratory Accreditation (A2LA) and approved by the PowerMark Corporation (PMC, www.powermark.org ), which is the certification body of the PV industry in the United States. The FSEC program currently covers three areas: (i) PV module power rating certification, (ii) Stand-Alone PV system performance evaluation and certification, and (iii) Grid-Connected PV system design review and approval. The PV module power rating certification is central to these three areas of the FSEC program, as illustrated in Figure 1. The details of the FSEC PV testing laboratory accreditation and certification program are described in a previous paper [2].

The Florida Solar Energy Center has been accredited by both the American Association for Laboratory Accreditation and PowerMark Corporation to certify grid-tied photovoltaic systems. The certification process involves both the testing of photovoltaic modules for performance ratings and the review and approval of system designs to provide photovoltaic system design certification. This paper focuses on the design review and approval process, which consists of a documentation review and focuses on the completeness and accuracy of instructions, schematics, and accompanying materials. System designers have received substantive critiques and assistance through the third-party technical reviews used in this process. As a result, photovoltaic system manuals that accompany reviewed systems lead to a greater likelihood of code-compliant and high-performing installations.

This paper predicts relationship between array performance and surrounding ambient including installation conditions for PV array installed on building walls. A PV system assumed for calculation is a PV array installed on the north, south, east and west walls of a building which was constructed as a NEDO field-test project. In the case of performance simulation for the actual PV system, calculated performance generally agrees with real measured data. Based on them, produced electrical energy is simulated as a function of ground albedo, array tilt angle and space between the PV array and the wall for installation. In addition, shading effect on produced electrical energy is also estimated by assuming some neighboring buildings. Effect of sub-array installation on different walls on DC power output is also estimated.

Photovoltaic power systems of all types are being installed in the United States. Grid-connected installations have seen a tremendous jump in their numbers and sizes of installations but there is no complete photovoltaic product (component or system) or installer certification program in effect today in the United States. Standards for utility interconnect, listing for safety, and qualification of hardware are written and listing and qualification programs are available, but practitioner and hardware certifications are not yet in place. This paper addresses the timeliness, framework, and progress of hardware and practitioner certification efforts currently under way in the United States.

Amonix has designed, manufactured, installed, and tested over 500 kW of high concentrating PV systems based around a concentrating silicon cell that set a new world efficiency record in 1992. This paper describes the development of this product as well as the physical and operating characteristics of the system. The operating characteristics that make this system attractive for grid, distributed, and off-grid are discussed. Data is presented that demonstrates the high daily power generating capability and the energy performance of the concentrating PV system. Other attributes of the system are also discussed such as the automatic/unattended operation, the short installation time, etc. An array installed at Pomona, CA is described, it has operated unattended for over 3 years and is still producing power today.

One of the challenges associated with evaluating the reliability of a large number of grid-connected (GC) photovoltaic (PV) systems is the expense of the measurement and data logging equipment required to measure typical operating parameters for these system. In order to fully monitor a PV system, it is necessary to measure plane of array solar irradiance, solar spectrum, array temperature, DC voltage, and DC current as well as the AC voltage, AC current, and AC power produced by the inverter. This paper presents a technique for evaluating several aspects of the performance and reliability of a grid-connected PV system using just one AC power meter / data logger to record the minimum, maximum, and mean power produced by the system over small segments of time. The data can then be graphed to quickly identify a wide variety of inverter problems, several examples of which are presented.

A number of detailed studies on the energy requirements on the three types of photovoltaic (PV) materials, which make up the majority of the active solar market: single crystal, polycrystalline, and amorphous silicon were reviewed. It was found that modern PV cells based on these silicon technologies pay for themselves in terms of energy in a few years (1–5 years). They thus generate enough energy over their lifetimes to reproduce themselves many times (6–31 reproductions) depending on what type of material, balance of system, and the geographic location of the system. It was found that regardless of material, built-in PV systems are a superior ecological choice to centralized PV plants. Finally, the results indicate that efficiency plays a secondary role to embodied energy in the overall net energy production of modern solar cells.

The lack of consistently high performance from inverters has created numerous issues in the widespread application and confidence in grid-tied photovoltaic systems. Additionally, the lack of a metric by which inverter manufacturers can evaluate their products presents a challenge to manufacturers by not allowing them to distinguish their products from those of their competitor, and to users since there is no way of comparing seemingly-similar models. This problem is further compounded by the dearth of inverters that have high performance and reliability [1]. This document is the first draft of a test protocol under development at the Florida Solar Energy Center to assist in this area. A need for such a test protocol has been recognized nationally, and it is hoped that this document may provide a foundation for future test procedures while providing significant and reasonable findings in the interim.

This paper investigates adaptive optimal control of a grid-independent photovoltaic system consisting of a collector, storage, and a load. The algorithm is based on Q -Learning, a model-free reinforcement learning algorithm, which optimizes control performance through exploration. Q -Learning is used in a simulation study to find a policy which performs better than a conventional control strategy with respect to a cost function which places more weight on meeting a critical base load than on those non-critical loads exceeding the base load.

It has become increasingly apparent that the photovoltaics industry is in need of a resource for performance, reliability and economic information on fielded PV systems. This information would help manufacturers, distributors, utilities and other relevant parties in determining trends in operation, maintenance, and essential costs. By recognizing these recurring patterns, changes can be made in product design, manufacturing processes, installation procedures, or purchasing patterns to address, mitigate and/or correct these issues. Sandia National Laboratories has been developing a photovoltaics reliability database, with the Florida Solar Energy Center providing development and support for a database housing information on grid-tied systems. This paper contains a progress report on the status of the database and some preliminary results of analyses based on this data.

A new version of the ENERGY-10 computer program simulates the performance of photovoltaic systems, in addition to a wide range of opportunities to improve energy efficiency in buildings. This paper describes two test cases in which the beta release of ENERGY-10 version 1.4 was used to evaluate energy efficiency and building-integrated photovoltaics (BIPV) for two Federal building projects: a 16,000-ft 2 (1,487 m 2 ) office and laboratory building at the Smithsonian Astrophysical Laboratory in Hilo, Hawaii, and housing for visiting scientists [three 1400-ft 2 (130 m 2 ) and three 1564-ft 2 (145 m 2 ) houses] at the Smithsonian Environmental Research Center in Edgewater, Maryland. The paper describes the capabilities of the software, the method in which ENERGY-10 was used to assist in the design, and a synopsis of the results. The results indicate that ENERGY-10 is an effective tool for evaluating BIPV options very early in the building design process. By simulating both the building electrical load and simultaneous PV performance for each hour of the year, the ENERGY-10 program facilitates a highly accurate, integrated analysis.

In June 2001, Hawaii became the 35th state in the nation to adopt a net energy metering (NEM) law to promote the installation of small (10 kW and less) renewable energy (RE) grid-connected systems across the Hawaiian Islands. What effect has the availability of this law had on the diffusion of NEM photovoltaic (PV) systems in Hawaii? Given the typical abundant sunshine here coupled with consistently high electric utility rates, NEM should be taking off, yet consumer adoption has been slow. What have been the principal impediments to homeowners and businesses going solar electric? While the relatively small number of NEM PV systems installed to date does not allow for definitive conclusions on the ability of the NEM law to achieve its purpose, this initial evaluation will identify what challenges and obstacles exist and make recommendations to overcome them.

Amonix has manufactured and installed over 350 kW of their 5 th generation high concentration PV systems for Arizona Public Service (APS). This paper describes the power and energy performance of the system since the start of installation in May 2000 and describes the operating characteristics that make this system attractive for both on-grid and off-grid use. The performance of a unit with the latest design revisions is compared to the performance of one of the first manufactured units, and the reasons for the improvements are discussed. Data are also presented that show the Amonix system will produce more annual energy per installed kW than will a conventional fixed-flat plate system. The current construction status of the largest concentrating PV plant in the world is also discussed.

In this paper, it is attempted in the present study to estimate the factors to reduce power generating efficiency using the results of measurements and to calculate the optimal tilt angle in Kyushu area. Also, the study was made as to how the annual power generation amount is influenced by the deviation of the optimal tilt angle from actual installation angle. We have obtained the results that modeling was performed on the factors to reduce the efficiency obtained from measurements, and PV power generation amount in Kyushu area was estimated. Also, from the results of calculation of the optimal installation angle of the fixed system at installation site, it was demonstrated that the installation of PV systems on roof surface as generally practiced at present did not lead to a greater loss.

This paper presents the results of survey on 333 grid connected residential PV generation systems in western part of Japan. The average equipment capacity is 3.4kWp. This research yielded the following results. • The electricity generated for a year was in average 938 kWh/kWp/year. • The generated electricity is equivalent to about 45% of the electricity consumption in a residence. • The cause of variation in system performance was analyzed. • The simple prediction method of PV system output was developed. (The prediction accuracy of simulated hourly electricity generation is r 2 = 0.87.)

A 35 kW roof top photovoltaic (PV) system has been installed at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland. The system, located on the flat roof that connects NIST’s Administration Building to its adjoining conference and cafeteria facilities, produced NIST’s first site-generated renewable energy on September 14, 2001. In addition to providing electrical energy and reducing monthly peak electrical loads, the rear surface of each module is laminated to 51 mm of extruded polystyrene enhancing the thermal performance of the roof. A unique ballast system secures the photovoltaic system, eliminating the need for roof penetrations. An instrumentation and data acquisition package was installed to record the ambient temperature, wind speed, solar radiation, and the electrical energy delivered to the grid. Additional solar radiation instruments were installed after determining that the original solar radiation sensor was influenced by reflections from the south-facing wall of the Administration Building’s tower. NIST’s electric utility billing schedule includes energy and peak demand charges. The generation charges vary significantly depending upon the time interval — off-peak, intermediate, and on-peak — during which the energy is consumed. The schedule is divided into summer billing months (June-October) and winter billing months (November-May). During the winter billing months, the distribution, transmission, and generation peak demand charges are based on the greatest power demand imposed by the site on the grid. During the summer billing months an additional demand charge is imposed to capture electrical demand during the onpeak time interval. This paper summarizes the monthly and annual measured performance of the photovoltaic system. The monthly energy produced by the system is tabulated. Conversion efficiencies — computed using solar radiation measurements from a single photovoltaic cell radiation sensor, four thermopile-based radiation sensors located around the perimeter of the photovoltaic array, and a remotely located thermopile-based radiation sensor, are presented. Using the electric utility’s rate schedule, the monetary savings credited to the photovoltaic system is determined by combining the cost of the displaced energy with the reduction in peak demand charges attributable to the photovoltaic system. Finally, using utility provided data and the Environmental Protection Agency’s (EPA) Environmental Benefits Calculator, estimates are made of the avoided emissions of the photovoltaic system over its projected life span.

Even though PV technology is new and expensive for the building industry today, and regardless of market development and technology advancement, a BIPV system cost can actually be reduced and its application can spread further into the building industry as this paper will manage to show. However, PV systems still have not been accepted by the building industry and consumers yet. According to the results of a survey by the workshop of Building Integrated Photovoltaic for Design Professionals which was sponsored by the National Energy Laboratory (NREL) and the American Institute of Architects (AIA), “a major barrier to analyzing renewable energy systems is assembling and presenting the technical and financial data to persuade a client that a BIPV would make economic sense.” [Wenger and Eiffert, 1996] This paper uses Life Cycle Cost Analysis (LCCA) for identifying BIPV system cost components and makes the connection between the findings of LCCA and the design process. It identifies specific quantifiable measures/variables that will be compared with a non-PV integrated building or different PV system applications by using the LCCA method that confirms cost related issues. Calculations of payback period as a result of LCCA gauge the sensitivity of these variables and show how some of them are significantly more important than others in reducing the pay back period. Offering an efficient approach for integration of PV into curtain wall also meets the long-term objective of the satisfaction of the building user.

A zero net energy building (ZNEB) is grid-tied, net metered and produces as much energy on-site as it uses in a typical year. In this paper, we describe methods to cost optimize designs for ZNEB’s. The goal is to find a constrained optimum, i.e., the minimum-cost design that achieves ZNE. Increased first costs for improved efficiency are balanced against the size of the PV system required to achieve ZNE (where the net-metered PV system is the energy source of last resort, because it is expensive but can meet the remaining load “using the grid for storage”). Discrete building component options are considered within various categories (e.g., walls, ceilings, foundations, glass types, air conditioners, furnaces, etc.). Each category is optimized by balancing the marginal cost of saved energy for efficiency options against the cost of energy from the PV system. Categories are optimized sequentially with iteration to adjust for possible interactions between categories. The process is automated with software that manipulates input files, launches DOE2 simulations, reads the results, and executes the optimization methodology.