Solar power – the world’s largest source of electricity by 2050?

Solar photovoltaic and solar thermal electricity could generate 27% of the world’s power by 2050.

The sun could become the world’s largest source of electricity by 2050, ahead of fossil fuels, wind, hydro and nuclear, according to a pair of reports from the International Energy Agency (IEA).

Two IEA technology roadmaps show how solar photovoltaic (PV) power systems could generate up to 16% of the world’s electricity by 2050, while solar thermal electricity (STE) from concentrating solar power (CSP) plants could provide an additional 11%. According to the roadmaps, the technologies have the potential to prevent the emission of more than 6bn tonnes of carbon dioxide per year by 2050 – more than all current energy-related carbon dioxide emissions from the US, or, almost all the direct emissions from the transport sector worldwide today.

The IEA’s technology roadmaps detail expected technology improvement targets and the policy actions required to achieve that vision by 2050, highlighting priority actions and milestones for governments, research and industry stakeholders. They are not necessarily a forecast of the future.

If both solar PV and CSP are to flourish, both publications note the need for clear, credible and consistent signals from policy makers, to lower deployment risks to investors and inspire confidence.

In the recent past PV deployment has been much faster than that of STE – there is 137 GW of capacity currently installed worldwide and 100 MW is added each day. Cost reductions have played a big part in this. But the reports indicate that after 2030, where much growth could come from PV, CSP will have the potential to take off due to built-in thermal storage to complement PV generation. At somewhere between 5% and 15% of annual generation, PV will start to lose value in wholesale markets, says the IEA.

China will be by far the leading country for PV expansion according to the IEA, followed by the US. Over half the total PV capacity will be installed at the end-user’s location, whereas STE will be limited to very sunny areas with clear skies, becoming a major opportunity for Africa, India, the Middle East and the US. 

The future outlined in the roadmaps is consistent with the IEA’s ‘high-renewables’ climate-friendly scenario.

‘The rapid cost decrease of photovoltaic modules and systems in the last few years has opened new perspectives for using solar energy as a major source of electricity in the coming years and decades,’ said IEA Executive Director Maria van der Hoeven. ‘However, both technologies are very capital intensive: almost all expenditures are made upfront. Lowering the cost of capital is thus of primary importance for achieving the vision in these roadmaps.’

There is currently 137 GW of [PV] capacity installed worldwide and 100 MW is added each day.