The world has 12 years to limit greenhouse gas emissions or face severe impact from global warming.
That's according to the Intergovernmental Panel on Climate Change in a statement that set off alarm bells around the world.
In the face of escalating concerns about global warming, there is a growing sense of urgency among countries, local communities and businesses to do something about it.
Policy measures are stepping up. Many ‘green leaders’ are attempting to codify into law policies that will see the procurement of 100% renewable energy between 2040 and 2050. There are more ambitious targets, too: the US Green New Deal proposal aims to achive 100% rewnewables by 2030.
Alongside these policy measures, fundamental market changes in the past two to three years support the shift to renewables. Solar and wind energy projects are now cheaper to build and operate than their fossil fuel counterparts in many parts of the globe. Unsurprisingly, solar and wind already constitute the majority of new global investments in power.
Storage and transmision, as well as offshore wind technologies, are evolving. In advanced power grids like the US, renewables and emerging technologies already account for a staggering 90% of investment interest.
Against this backdrop, a 100% decarbonisation goal does not seem so far-fetched. Or does it?
What would it take to achieve 100% renewables?
Current evidence shows that large and complex power system (LCPS) tend to reach 25% wind and solar penetration with relative ease, provided that resources and infrastructure are in place.
At a market penetration of approximately 25%...
- The hourly contribution of wind and solar power ranges from as low as 0% to as high as 101%.
- The grid operator may curtail production if it exceeds agreed limits and puts downward pressure on prices.
- The costs of transition begins to accelerate as a result of the additional investment required in infrastructure and storage.
No single large and complex power system (LCPS) operates above 30% of intermittent renewable energy use today. What would it take for a LCPS to achieve 100% renewables penetration?
The US, because of the scale and complexity of its power network, is a useful market in which to explore the common challenges of RE100.
To achieve market penetration of 100%...
- In the US, another 1600 GW of wind and solar capacity would need to be in place by 2030. This could cost up to US$2 trillion.
- And 9000 GW of additional storage, more than doubling costs to US$4.5 trillion.
- The US would also need to double the size of its high-voltage transmission infrastructure to 400,000 miles, costing approximately $700 bn.
- Total estimated cost: US$5 trillion. That's an investment of US$250-500 billion per year, making it comparable to the total US defence budget.
What challenges must be overcome on the journey to 100% renewables?
RE100 policies carry significant unknowns. Challenges largely stem from the intermittent nature of renewable energy, specifically wind and solar, including:
- Can storage markets keep up?
- What happens when the sun doesn’t shine, or the wind doesn’t blow?
- On the flip side, what happens in very sunny climates, when excess energy is generated?
- How much backup power would 100% renewable systems need?
Our report concludes that 100% renewables goals are largely aspirational, with one major caveat. It is possible for highly aspirational policies to be realistic – if these policies address the complex operational and cost challenges. Fill in the form to access the report.