“Historical policy to stimulate solar PV has brought down costs. We’re now at the point that a virtuous cycle between cost declines and additional deployment doesn’t require more ambitious policies targeting solar anymore,” says study team member Femke Nijsse, a climate and energy systems researcher at the University of Exeter in the UK. “More ambitious policies for other renewables [are] still needed.”
In the last fifteen years, solar and wind power costs have drastically decreased. Scholars have started discussing the possibility of a "tipping point" at which the cost-only viability of renewable energy sources would surpass that of fossil fuel sources, but there was little consensus when or how this might happen.
Therefore, it has been widely assumed in models of the global energy system that the dominance of fossil fuels will persist. Previous models have routinely underestimated the rate at which solar power will increase in practice.
Rather, Nijsse and her colleagues used a set of three models that reflect that positive feedback loop between declining costs and growing use of green technologies to examine the global energy system. The models project the adoption of several energy technologies until 2060, based on current economic and technological data.
The researchers predict that by 2030, solar power will surpass wind power and take the lead in energy technology globally by 2050. Their findings are published in the journal Nature Communications.
The results parallel a research study conducted last year, which found that switching to renewable energy sources quickly will be far less expensive than sticking with fossil fuels. According to the latest analysis, it is no longer reasonable to regard fossil fuels' prolonged dominance as "business as usual."
The result was unexpected, Nijsse says: “We were seeking to find which policy was required to ‘tip’ this tipping point. We found it had already tipped, assuming a set of four barriers can be overcome or avoided.”
The four barriers to solar’s takeover are unstable power grids, lack of financing for solar in developing countries, supply chain capacity, and political resistance from regions that lose jobs. The researchers suggest policies aimed at removing these obstacles could have a greater impact on the clean energy transition than initiatives to lower solar prices, like carbon taxes:
- The addition of additional renewable energy sources, power transmission links between regions, batteries and other energy storage devices, and demand management policies can all help policymakers create resilient electric grids that can withstand daily, seasonal, and weather-related variations in the amount of solar energy available. If not, the globe might become ensnared in an energy system that uses fossil fuels to cover energy demand peaks.
- To extend financing for solar installations to underdeveloped nations, new regulations are also required. Most solar financing now exists in high-income nations, whereas most international development funding allocated to this sector resides in middle-income nations. Low-income nations are excluded, particularly those in Africa. Therefore, it's uncertain that the developing world will decarbonize based on declining costs alone.
- Large quantities of specific minerals and metals, such as copper, nickel, cobalt, lithium, and rare earth elements, are needed for electrification and batteries, but the supply chains for these can occasionally be unstable. Policies to maximize material recycling and reuse will also be crucial, as will research into alternatives.
- Last, political resistance from those who profit from fossil fuels and from populations that rely on such industries for jobs could hinder the implementation of solar technology. Some of this opposition may be avoided by ensuring that communities dependent on fossil fuels are taken care of during the green transition.