Here’s an interesting graph used by Suntech’s Stuart Wenham (sourced from Applied Materials) during a presentation at the Solar 2013 conference in Melbourne on Thursday. It highlights the extent of “grid parity” for solar PV across the world – it is now in 102 countries.

This definition of “grid parity” is the cost of rooftop solar versus the cost of electricity sourced from the grid – this is sometimes known as “socket parity”. Most of the countries – though not all – are those with good solar resources and relatively high electricity pricesAustralia reached “socket parity” several years ago.

Wenham says that solar PV will fall a further 50 per cent in costs up to 2020 – see our story today. He says that solar PV at a utility level will also challenge fossil fuels – as it already does in those with high gas and diesel costs, and will offer the cheapest avenue to countries which have little electricity infrastructure.