Earlier this year, the International Energy Agency published an alarming report predicting catastrophic global warming. Based on current trends, it said, we’re set for a 6 degree Celsius temperature increase this century–a level scientists agree would make life untenable for much of the planet. International agreements have set a target of just 2 degrees C, because that’s what scientists say would be a relatively safe outcome.
The IEA did offer positive news, though. It said that an aggressive move to energy efficiency and renewables could keep the world’s temperature under 2 degrees, and that such a move need not cost much. In fact, $44 trillion in investment by 2050 would net $115 trillion in fuel savings, such is the wonder of energy efficiency and potential for energy storage.
Now, the IEA has more good news. Two solar technology “roadmaps”–one for photovoltaics (the panels on your roof) and another for solar thermal (systems that capture solar energy as heat)–show how solar can meet an ever-increasing share of energy demand. It says PV systems could generate 16 percent of all electricity by 2050, with solar thermal adding another 11%. That would make solar energy the single largest source of power by mid-century.
Decreasing costs have led the IEA to double its solar forecasts in the last few years. In 2010, it saw PV supplying only 11 percent of electricity by 2050. It now sees the price of utility-level PV falling from $177 per megawatt hour currently (including capital costs) to $54 by 2050, and rooftop solar falling from $201 to $78.
The IEA’s numbers aren’t forecasts exactly: They’re more like projections based on an assessment of what’s achievable given the right conditions. The agency calls on governments to set long-term solar generation targets, to create rules that account for distributed solar’s role in securing grid supply, and to put in place policies to bring down finance costs and reduce risks for investors.
It’s very possible the IEA is in fact underestimating solar’s potential (this is the view of many smart people). Given its falling costs and the way it has spread very quickly in the last few years, it’s possible it will make more of an exponential jump, rather than track a neat curve.
If so, cleaning up energy’s contribution to climate change may not be as difficult as first feared, though as the IEA says, nothing will happen without better, more consistent policy-making. If there’s one thing that could stop the solar boom, it’s policy that stands in the way.