Residential photovoltaic worth : an assessment of retrofit vs. new construction

Abstract

This paper characterizes the basic differences between photovoltaic retrofit and new construction applications. It quantifies the tradeoffs forced by rooftop area constraints, special array mounting costs, maintenance costs, energy loads of older homes, and available terms of finance.

While the larger average energy loads of older homes tend to enhance the value of retrofit applications, other conditions serve to enhance the relative financial attractiveness of PV on newly constructed homes. New construction applications benefit from more attractive financing terms, lower installed system costs, enhanced efficiency with architectural integration (appropriate orientation), and generally lower costs of operation, maintenance and insurance. Many of the differences characterizing these two applications may be reduced or eliminated when retrofit PV systems are simply packaged, vis-a-vis both long-term financing and easily installed hardware.