Solar photovoltaic could account for 5% of global power demand by 2020, and up to 9% by 2030, according to this global solar photovoltaic outlook by the European Photovoltaic Industry Association (EPIA) and Greenpeace International.
The “Solar Generation 2010” report also projects investments in solar photovoltaic (PV) to double from €35 billion today to €70 billion in 2015. At the same time, costs for PV systems are expected to almost halve (-40%). As a result, PV systems can compete with current electricity costs for households in most industrialized countries. This so-called “grid parity” will change the PV market significantly.
You can download the report's executive summary here:
Solar Generation 2010