The first grid-connected, building-integrated, thin-film photovoltaic installation in Brazil has completed four years of continuous operation in September 2001. The fully monitored 2kWp double-junction amorphous silicon PV system logs irradiation, temperature and electrical performance data every four minutes, and has been operating non-stop since start up in 1997. The installation is comprised of four 500Wp sub-systems, each connected to a separate 650W inverter, with each of the four inverters single-phase connected to the public utility grid. Over this four-year period a seasonal variation in performance ratio can be clearly seen, together with the initial light-induced degradation inherent to amorphous silicon, with relative performance better in summer than in winter months. Overall performance ratios were 84.3% AC and 91.7% DC averaged over a 49 months period, and annual system AC energy yield averaged ～1300kWh/kWp/year. Florianopolis (27°S, 48°W) can be regarded as one of the worst possible sites in the country in terms of solar resource; much better PV system energy yields should thus be expected for other sites in Brazil. Based on our system's performance records and the Brazilian solar atlas developed at LABSOLAR, a preliminary version of a Brazilian PV performance atlas was derived and is presented. In a country with an electrical energy mix relying heavily on water constrained hydropower plants, our results and the complementary nature of hydro and solar electricity generation indicate that large-scale grid-connected PV could contribute significantly to Brazil's present and future energy needs, and that amorphous silicon is a good choice of technology for operation in warm climates.
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