Photovoltaics towards terawatts – progress in photovoltaic cells and modules

After 30 years of development, photovoltaic (PV) technology has been recognised to be capable of contributing significantly to future energy supply. The global cumulative installed PV power now exceeds 180 GW_p, and the annually installed power exceeds 40 GW_p. The cost of electrical energy produced by PV systems is now close to that from conventional sources. This study discusses the physics, construction and manufacture of PV cells and modules, taking into account current trends in technology. All parts of PV systems that influence the cost of the electrical energy produced are considered. Three generations of PV module are described. Crystalline silicon (c-Si) is and will remain the dominant PV material at least until 2020 because of its high efficiency, long service time and relatively low cost. It represents nearly 90% of total module production. There are no material supply constraints to limit production and a decrease in c-Si PV module cost to below 0.4 €/W_p before 2017 can be expected. PV power generation will reach industrial grid parity before 2020 and a cumulative installed power of 1 TW_p is expected before 2025.