Photovoltaics — a path to sustainable futures

International audienceAs both population and energy use per capita increase, modern society is approaching physical limits to its continued fossil fuel consumption. The immediate limits are set by the planet's ability to adapt to a changing atmospheric chemical composition, not the availability of resources. In order for a future society to be sustainable while operating at or above our current standard of living a shift away from carbon based energy sources must occur. An overview of the current state of active solar (photovoltaic) energy technology is provided here to outline a partial solution for the environmental problems caused by accelerating global energy expenditure. The technical, social, and economic benefits and limitations of photovoltaic technologies to provide electricity in both off-grid and on-grid applications is critically analyzed in the context of this shift in energy sources. It is shown that photovoltaic electrical production is a technologically feasible, economically viable, environmentally benign, sustainable, and socially equitable solution to society's future energy requirements. Introduction Although global fossil fuel resources have not yet been exhausted, the negative social, health, and environmental impacts of our current unsustainable patterns of energy use are apparent [1,2,3,4,5]. In the future, large-scale alternative methods of producing the vast quantities of energy needed to sustain and enhance our standard of living are necessary [6,7,8]. As Peter Harper proposed, the problem of contemporary society can be stated succinctly: "We need to get (probably) 11 billion people through the transition complex to 'Sustainia', the sustainable state, before irreversible damage is done" [9]. If current trends continue, future society will require increased electrical energy. This energy must be produced using sustainable technologies in order for society to continue to prosper indefinitely. Fortunately, advances in science and technology have provided us with several alternative means of producing energy on a sustainable level, such as wind, geothermal, biomass, and solar [10]. Of these means, solar (photovoltaic technology) provides the most widely adaptable applications and converts sunlight directly into electrical energy with the highest efficiencies [11,12]. This paper will demonstrat