Discussion Of Strategies For Mounting Photovoltaic Arrays On Rooftops

The mechanical attachment of photovoltaic (PV) arrays to rooftops presents a number of unique and challenging issues for system designers and installers. With a resurgence of roof-mounted PV installations due to increasing duel costs and decreasing PV system prices, the Florida Solar Energy Center (FSEC) has accelerated its investigations of array mounting strategies, with the objectives of identifying key performance and cost parameters from a systems engineering perspective. Two principal classifications can be defined for rooftop PV array mounting systems: building-integrated (BIPV) and building-attached (BAPV) or standoff designs. The various attachment methods within these categories each have pros and cons that affect the labor and cost associated with the install and the system performance. An overview and assessment of some existing rooftop PV array attachment methods or mounting approaches, and their advantages and disadvantages with respect to key design criteria are presented to assist designers and installers in the selection of the appropriate method for a given project

Roof solar reflectance and cooling energy use: Field research results from Florida

Traditionally, architects have recognized that reflective building colors can reduce building thermal loads. Experiments in Florida have examined the impact of reflective roof coatings on air conditioning energy use in a series of tests on occupied homes. The experiments were conducted on nine residential buildings from 1991 to 1994 using a before and after test protocol where the roofs were whitened at mid-summer. Measured air conditioner electrical savings in the buildings during similar pre-and post-weather periods averaged 19%, ranging from a low of 2% to a high of 43%. Utility peak coincident peak savings averaged 22% with a similar range of values. Cooling energy reductions appear to depend also on initial ceiling insulation level and roof solar reflectance, air duct system location and air conditioner sizing

Towards Zero Energy Demand: Evaluation Of Super Efficient Building Technology With Photovoltaic Power For New Residential Housing

The performance of a project designed to test the feasibility of designing and testing efficient residential buildings with integrated photovoltaic (PV) generation systems was reported. The objective of project was to demonstrate the ability to reduce space cooling loads and to bring the house utility coincident peak demand close to zero. When the PV electric generation was included during the peak period, the PVRES home net demand was found to be 199 W