Baseload to be marginalised as solar takes pole position

The International Energy Agency says solar energy – a combination of solar PV and concentrated solar thermal with storage – is likely to become the dominant source of energy across the world, accounting for more than 27 per cent of all electricity produced by 2050.

The IEA says its core scenarios for reaching climate targets by 2050 call for 68 per cent of generation to be sourced from renewable energy, but in the (increasingly likely) event that carbon capture and storage and nuclear cannot take up their imagined shares, then the IEA has painted a “high renewables” scenario where solar takes an even greater role.

This might sound like some mighty radical thinking from what is one of the world’s most conservative energy organisations (it was established in the 1970s to devise policies to ensure a continuation of oil supplies), but in reality it is not.

Solar PV, for instance, is likely to expand way behind even the IEA’s most bullish scenarios, as a result of widespread deployment and continuing cost cuts. The IEA suggests that solar PV could account for 16 per cent of global generation by 2050, although this would require an average of more than 116GW of solar PV to be deployed over that time.

Its estimates, however, seem conservative given that most private forecasters suggest that the solar industry will reach 100GW installation a year anyway by 2017 or 2018, and capacity is likely to grow further beyond that. Its “vanilla” scenario for reaching its climate goals require just an average of 67GW of solar PV to be installed a year. The solar market is likely to reach that figure in 2015.

In any case, the IEA says that solar thermal with storage, the kind of facility that has been deployed in Spain, and is now being constructed in the US, and in South Africa and Chile, will also play a critical role, accounting for 11 per cent of global electricity supply in 2050 because of its ability to switch on production, and switch off, at any time of day.

This, as many independent analysts have told us before, is going to create a radical change in the way that electricity markets operate. What is interesting is that the IEA is now buying into these scenarios, albeit more tentatively than others.

For that reason, it is interesting to note how the IEA sees twhat a high solar scenario could look like (see graph below). Solar PV (in yellow) becomes the dominant energy source during the day, while CSP with storage (orange) is used to supplement production during the day and into the evening. In practice, the CSP with storage can be switched on and off whenever it is needed.

Purple represents other dispatchable energy, which could include fast-response gas-fired generation, but is also likely to include most storage. The green line represents base load power, which plays just a limited role in overall generation. Of course, such scenarios would change dramatically according to location, and the individual solar resource.