In all ages, humankind decided to spend considerable amounts of the available productivity on special monumental projects. Managing climate change and rebalancing within the planetary boundaries is such an activity. The enormous energetic productivity of solar PV may evolve as the central pillar to create a sustainable civilization.
Since civilizations have existed, monumental projects have been undertaken, such as the Pyramids of Giza, the Great Wall of China, the Gothic cathedrals, or the Apollo programme. Substantial labour and resources were invested in such projects, ranging from 0.5% up to 10% of the available productivity in the respective society, and lasting between a few years and more than a century. Such monumental projects can be grouped into five categories: culture, infrastructure, technology, war and conflict, and disaster response. A recent study from Forschungszentrum Jülich, Helmholtz Institute Erlangen Nürnberg for Renewable Energies and LUT University entitled Marshalling our productivity to create a sustainable global civilization investigated monumental projects and their link to excess productivity.
Since the industrial revolution, unprecedented wealth around the world, along with an enormous increase in life expectancy, reduction of infant mortality, reduction of starvation, freeing people from poverty, and creating unparalleled standards of living for many. These benefits were made possible by an ever-increasing use of fuel. At the same time, excessive fossil fuel consumption has led to various repercussions, in particular environmental destruction and climate change.
Reaching a global net-zero emission energy system can be considered a monumental project. Depending on different sources, such as McKinsey, BNEF, the International Energy Agency, or the United Nations, the required annual expenditures to achieve this goal may lie between 0.7 and 1.3% of the global gross domestic product (GDP) to be allocated for a few decades. Such expenditures are in the range of accepted societal choices in the past, for instance the military spending during the Cold War (3% of GDP of the United States for decades, for example) or the Belt and Road Initiative (an estimated 0.75% of GDP of China).
Solar PV gaining ground in the energy system driven by sustainability
The ongoing global energy transition has various facets, with solar PV at its core reaching over 70% of all newly installed power capacity in the world in the recent past as the fastest ramping energy source since the industrial revolution, and positioning solar PV as a prime energy supply solution around the world. Plummeting costs of solar PV and additional renewable energy technologies, complemented by growing battery storage, form the basis of a comprehensive electrification. Since the mid-1990s, global energy transition studies regularly find the contribution of solar PV to the global energy supply by mid-century to be in the order of about 70%.
The energetic sustainability of solar PV has been improved since the invention of the silicon solar cell. The rate at which solar panels have improved over time has been consistent and high for decades. For example, the energy required to make a solar panel has been reduced by 14% every time installations doubled between the 1970s and the 2010s. This learning has been enabled by continuously rising efficiencies, an increase in technology lifetimes, and a reduction in the use of materials per rated power output, as summarized in a recent publication by international PV experts. The energy payback time for PV systems ranges globally between 0.44 – 1.42 years and in Europe between 0.89 – 1.24 years depending on location. The low payback time also results in a large value for the energy returned on investment – a PV system that is operated for 30 years generates between twenty and seventy times the energy that was needed for its production. The lifetime of PV systems may be further increased up to 50 years in the longer term. System-level studies have shown that the energetic sustainability of solar PV remains robust even when accounting for additional energy investments required for batteries, complementary renewable energy technologies, and curtailment, both at global and regional scales.
Rebalancing withing safe and just planetary boundaries enabled by solar PV
Solar PV may emerge as the key driver for a sustainable civilization. This would mean supplying all humans with all needed energy for the highest standards of living, which is estimated to require 150-200 TWp of solar PV installations by the end of this century. A comprehensive Solar-to-X Economy across energy sectors will become a major characteristic in many regions around the world. The upper limit of the range of solar PV installations would even include the energy demand for massive carbon dioxide removal activities to rebalance civilization within safe und just planetary boundaries, which equals to about 10 – 12% of global primary energy supply and may cost about 0.4 – 0.7% of the global GDP to return to 1.0℃ with about 350 ppm of atmospheric CO2 concentration. In this way, PV installations could help in powering carbon dioxide removal to avoid global GDP loss of about 8% if the unintended consequences of our productivity are not addressed. Reaching permanent climate safety and its respective investments can be regarded as a highly profitable venture of civilization in the row of monumental projects in history. The high energetic productivity of solar PV is a major driver to reach a sustainable civilization.
Authors: Christian Breyer, Ian Marius Peters, and Dominik Keiner
This article is part of a monthly column by LUT University.
Research at LUT University encompasses various analyses related to power, heat, transport, desalination, industry, and negative CO2 emission options. Power-to-X research is a core topic at the university, integrated into the focus areas of Planetary Resources, Business and Society, Digital Revolution, and Energy Transition. Solar energy plays a key role in all research aspects.