A new report has suggested the world will need to install solar PV at an average rate of 53GW a year from 2013-2020 as it transforms its energy mix to prevent dangerous climate change.

As reported here, global investment bank Citigroup has become the latest authoritative source to warn of the high cost – economic and environmental – of inaction on climate change action, and to tally the economic benefits of shifting to low-carbon energy, transport and industrial systems.

Energy markets – as the single biggest emitter of greenhouse gases – are, of course, a big focus. And according to Citi’s ‘action’ scenario, we will need to add a lot of renewable energy to the global power mix if we are to avoid dangerous climate change – and a great deal of that will need to be solar PV.

“In comparison with our Citi ‘Inaction’ scenario, the carbon intensity of the electricity mix drops in our Citi ‘Action’ scenario from 0.54t (CO2

e)/MWh to 0.25t (CO2e)/MWh due to the shift in electricity mix (Figure 69),” the Citi report, published on Tuesday, says.

“In 2040 we estimate that 15.4GTCO2e per year is being saved between both our scenarios. Two-thirds of these savings relate to investments into solar PV and onshore wind while the remaining third is due to energy efficiency investments.”

Citi says that a key difference between its forecasts for renewables growth and those from the International Energy Agency (IEA) is the assumed penetration in the electricity mix. In the particular it says, in its Citi “Action” scenario, its forecasts for solar PV deviate significantly from the IEA’s.

“Our granular country by country solar PV forecasts show an average installation rate of 53GW per annum 2013-2020,” the report says. “This compares to 33-34GW installations by the IEA (lower bound New Policy scenario, upper bound 450 scenario).”

Citi says that with the rapid fall in the cost of electricity from renewables it expects solar PV to be competitive with conventional fossil fuels by

2030; “and hence there is theoretically no need for further incentives via a carbon price in the power market alone.”

This is what Citi calls Energy Darwinism – as you can see in the charts below. It means that solar PV is going to get cheaper and cheaper – and with battery technology, more reliable – and beat out traditional energy sources, with or without policy help (although the latter is important out to 2030 if we want to get on top of that thing called climate).