Solar has become the world’s favourite new type of electricity generation, according to global data showing that more solar photovoltaic (PV) capacity is being installed than any other generation technology. Worldwide, some 73 gigawatts of net new solar PV capacity was installed in 2016.
Wind energy came in second place (55GW), with coal relegated to third (52GW), followed by gas (37GW) and hydro (28GW).
Together, PV and wind represent 5.5% of current energy generation (as at the end of 2016), but crucially they constituted almost half of all net new generation capacity installed worldwide during last year.
It is probable that construction of new coal power stations will decline, possibly quite rapidly, because PV and wind are now cost-competitive almost everywhere.
Hydro is still important in developing countries that still have rivers to dam. Meanwhile, other low-emission technologies such as nuclear, bio-energy, solar thermal and geothermal have small market shares.
PV and wind now have such large advantages in terms of cost, production scale and supply chains that it is difficult to see any other low-emissions technology challenging them within the next decade or so.
That is certainly the case in Australia, where PV and wind comprise virtually all new generation capacity, and where solar PV capacity is set to reach 12GW by 2020. Wind and solar PV are being installed at a combined rate of about 3GW per year, driven largely by the federal government’s Renewable Energy Target (RET).
This is double to triple the rate of recent years, and a welcome return to growth after several years of subdued activity due to political uncertainty over the RET.
If this rate is maintained, then by 2030 more than half of Australian electricity will come from renewable energy and Australia will have met its pledge under the Paris climate agreement purely through emissions savings within the electricity industry.
To take the idea further, if Australia were to double the current combined PV and wind installation rate to 6GW per year, it would reach 100% renewable electricity in about 2033. Modelling by my research group suggests that this would not be difficult, given that these technologies are now cheaper than electricity from new-build coal and gas.
Renewable future in reach
The prescription for an affordable, stable and achievable 100% renewable electricity grid is relatively straightforward:
Use mainly PV and wind. These technologies are cheaper than other low-emission technologies, and Australia has plenty of sunshine and wind, which is why these technologies have already been widely deployed. This means that, compared with other renewables, they have more reliable price projections, and avoid the need for heroic assumptions about the success of more speculative clean energy options.
Distribute generation over a very large area. Spreading wind and PV facilities over wide areas – say a million square kilometres from north Queensland to Tasmania – allows access to a wide range of different weather, and also helps to smooth out peaks in users’ demand.
Build interconnectors. Link up the wide-ranging network of PV and wind with high-voltage power lines of the type already used to move electricity between states.
Add storage. Storage can help match up energy generation with demand patterns. The cheapest option is pumped hydro energy storage (PHES), with support from batteries and demand management.