Only the intensive electrification of high end-use sectors, such as transport, heating and cooling, and the energy industry, will make it possible to improve the quality of life of the planet's inhabitants. Provided that the use of electricity in place of more polluting fuels in sectors that are hard to decarbonise — transport being one — draws on massive production of energy from renewable sources, solar photovoltaic above all, and on a flexible and resilient grid dotted with energy storage systems and electrolysers for producing green hydrogen and synthetic fuels. In a nutshell, what the study Low-cost renewable electricity as the key driver of the global energy transition towards sustainability by the Finnish university Lappeenranta University of Technology (Lut) highlights is that we already have in our hands the knowledge and the tools to address the now incontrovertible effects of global warming and climate change.

The key role of solar photovoltaic in the Finnish scientists' model for the energy transition

The energy transition model drawn up by the researchers embraces the objective of the Paris Agreement on the progressive containment of global warming to 1.5 degrees Celsius above pre-industrial levels, and in some respects echoes the road map of the International Energy Agency.

The Energy system transition, Lut's model for the transition, collects data on energy, heat, transport and desalination from 145 sub-regions across the world — territorial units smaller than the regions that contain them. It analyses and combines them into nine macro-areas: Europe, Eurasia, the Middle East, North Africa (Mena), Sub-Saharan Africa (Ssa), South Asia (Saarc), North-East Asia, South-East Asia, North America and South America. The data are then aggregated and make it possible to understand how to meet the energy demand of very large areas while simultaneously ensuring the balance between energy supply and demand with resources already available.

Maximum electrification of the global energy system

The underlying assumption calls for a profound transformation of the global energy system, the planet's beating heart. And there are no excuses, so to speak, when it comes to the technical and economic feasibility of sectors powered exclusively by renewable energy. The researchers argue convincingly that abandoning fossil fuels and the parallel electrification are advantageous because they ensure an increase in the overall efficiency of the system. This comes with the trade-off of a global energy transition based on the technological, multisectoral, multiregional richness of the nine geographical areas.

"While the global energy system and the factors that influence it are far more complex than any scenario or narrative can capture, this research presents a possible energy system transition from the current structure towards a 100 per cent renewable and fully sustainable system in 2050." The model is "high in temporal resolution across the energy, heat, transport and seawater desalination sectors", the authors emphasise.

Change in the share of electricity production from large-scale solar photovoltaic (left) and from residential photovoltaic (right) worldwide in 2050 © Lappeenranta University of Technology

The leadership of solar photovoltaic

The electrification of the energy system must move forward immediately with a massive presence of solar photovoltaic. Solar photovoltaic alone would be sufficient to meet global climate targets, "as 70 terawatts (TW) of photovoltaic capacity can be installed by 2050, approximately 10 per cent more than the 63.38 TW found in this research", the authors write. With this technology alone, the researchers estimate, it will be possible to cover 76 per cent of electricity mix production by 2050.

At the same time, a flexible energy system must be guaranteed, capable of adapting to the intermittent production of renewable energy. An increasingly important role will therefore be played by storage devices, which will need to be scalable: "The net energy yield per unit of capital invested in renewable technologies far exceeds that of fossil fuels, which are neglected in most energy system analyses", the authors of the study write.

Production from solar photovoltaic "on rooftops for residential, commercial and industrial segments" can be supplemented, when needed, by that from "wind (onshore, offshore); hydroelectric power (run-of-river and reservoir); geothermal energy and bioenergy (solid biomass power plants and cogeneration, biogas and cogeneration from waste-to-energy)". To be rejected, in contrast to the position expressed by the IEA, is recourse to nuclear power and to carbon capture and utilisation technologies.

The role of politics in a just transition

A just transition will only come about by stimulating unprecedented economic and social changes. The equation will be a winning one in the face of massive capital investment that makes the energy system sustainable and promotes socio-economic wellbeing. Market dynamics, the authors point out, continue to shape energy choices around the world, but it will be political representatives who must be more decisive in their choices. It is precisely the variety of strategies, targets and policies that will drive the reduction in the cost of capital invested, with a view to establishing new business models and market arrangements. A springboard for smart grids to take shape and evolve in accordance with the individual needs of the countries in the areas identified in the study.

The findings of this research indicate that renewable energy, in addition to meeting the "growing global demand for energy" — mostly electrical — will help increase "access in developing countries, bridging the supply gap between developing and developed countries." The global South will benefit from "excellent sunshine conditions throughout the year." Desalination "will solve the problem of water scarcity and water stress, providing 3 billion cubic metres of clean water per day. Development will take shape among countries, equipping them with a sustainable energy infrastructure. Global conflicts caused by scarcity of resources and raw materials could be mitigated, and a path towards peace, sustained by widespread prosperity, could be achieved."

In short, it is now clear that the role of politics is to drive electricity production from renewable sources, rather than continuing to support an economic and productive model based on fossil fuels. Innovation is galloping ahead, there are many innovative technologies with a low environmental impact for producing energy, and all that remains is to deploy these solutions to reduce the environmental impact of human activities. The only side effect foreseen by the model developed by the Finnish scientists, they warn, could be the achievement of further sustainable development goals identified by the United Nations, thereby guaranteeing a better future for all.