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A new version of the ENERGY-10 computer program simulates the performance of photovoltaic (PV) systems and evaluates 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: an office and laboratory building at the Smithsonian Astrophysical Laboratory (SAO) in Hilo, Hawaii, and housing for visiting scientists at the Smithsonian Environmental Research Center in Edgewater, Maryland. The capabilities of the software, the design assistance provided by ENERGY-10, and a synopsis of results are given. Estimates of annual energy delivery by the five PV arrays of the SAO are compared to F-Chart to help inform a validation of ENERGY-10. Results indicate that, by simulating both the building electrical load and simultaneous PV performance for each hour of the year, ENERGY-10 facilitates a highly accurate, integrated analysis useful early in the design process. The simulation is especially useful in calculating the effect of PV on the building peak load, and associated demand cost savings.

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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-ft2 (1,487 m2) office and laboratory building at the Smithsonian Astrophysical Laboratory in Hilo, Hawaii, and housing for visiting scientists [three 1400-ft2 (130 m2) and three 1564-ft2 (145 m2) 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.

The report documents a Colorado State University Solar Energy Applications Laboratory study investigating cost-effective ways of improving fabrication and installation of residential solar energy heating systems. The study entailed on-site observation of twelve installations focusing on the phase of mounting and manifolding of solar collectors. Time lapse photography and work measurement techniques were employed to record these installations. Generic collector types studied included air and liquid panels both internally and externally manifolded. Principal findings of the study synthesized from field observations, analysis of photographic data, time studies, and discussion with installation personnel and manufacturers' representatives are presented in the technical report. iii Conclusion/Inference: Manufacturers and installers should recognize the potential for damage to pipe fittings from over-torquing. Recommendation: Manufacturers should specify the tools required for installation and recommend using wrenches of a particular length, since over-torquing tends to occur when long wrenches are used. Observation 11 Rigid connections between internally manifolded liquid collectors do not allow for much alignment error. Unevenness of the mounting surface (e.g., the roof) may contribute further to the problem. Conclusion/Inference: System leaks may occur due to misalignment of collectors beyond the capacity to accept misalignment. Recommendation: Use flexible connections between the rows (columns) of collectors or use a gauge to ensure uniform dimensions of installed pipe fittings. Collector manifolds should be designed to tolerate reasonable misalignments. Observation 12 Collectors are typically 36 in. (91cm) wide, making it difficult to install, anchor, and capstrip by reaching across the panel. Conclusion/Inference: A "narrow" panel may allow the installation of between panel fittings without requiring several ladders and/or walking across the panels. Workers could then systematically install an array while working in one direction with a minimum of workers and movement. Recommendations: Manufacturers should consider high aspect ratio panel designs. Observation 13 Most collector arrays are at least 15 ft in height, whereas most collectors are approximately eight ft in height. Conclusion/Inference: Cost per square foot of collector installed could be reduced if collectors were shipped and installed in modules longer than eight feet. Leakage problems would also be reduced due to the need for fewer connections. Recommendation: The use of a light weight crane (see Observation 5) would make it possible to build and ship collectors in a more cost-effective size. Observation 14 During installation on sunny days, exposed panels reach high internal temperatures at the absorber. Hot panels in such cases can be handled only with gloves which are cumbersome to wear during other steps of 9 the installation. Heat escaping from panels makes working around the array uncomfortable. Glare from exposed glazing also reduces worker eff...