The Solar Response to Climate Change
By: Gary Palar and Alice Fan
Global warming and the rise of renewable energy
Over the past decade, the issue of climate change has leapt to make headlines on newspapers around the globe. The causes of which, are the ever-increasing numbers of Greenhouse gases (GHG) in the atmosphere. These are well documented to contribute to the heating of the earth, and on a wide scale could fundamentally change the way we live.
In response to increasing public concern regarding the potentially disastrous future impact of this, which is arguably beginning to be seen today, governments have begun playing a greater role since the turn of the millennium to reduce GHG emissions.
Since most GHG emissions arise from the burning of fossil fuels, government support in the form of tax credits, renewables targets and publicly funded R&D for renewables has provided for increased expansion of renewable energy (RE) technology. Of consideration, solar RE tech is solidifying it’s position as the most important.
Renewables mix, now and 2050
To illustrate the potential for growth in RE, looking at the U.S. at present, the share of renewables within the U.S. energy mix is 19% according to the U.S. Energy Information Administration (EIA). In their 2020 Outlook report, EIA modelling expects this share to increase to 38% at the midpoint of the century.
Within the RE industry itself, the largest fields are currently wind and solar. Wind offers a 38% share of RE generation in the U.S., while solar stands at 15%.
But in recent times, the case for solar energy above wind and other forms of RE has increased. Within the next 30 years, projections by the U.S. show a significant reversal in the mix of RE generation. By 2050, it was estimated the share of wind in the RE mix will decrease to 33%, while solar breaks new ground to 46%. EIA report outlooks have changed substantially since 2012, with each yearly report showing solar energy seizing more of the RE energy mix by 2050.
Why the drastic change in outlook?
Primarily, this is due to downwards projected costs of solar photovoltaics (solar PV). Solar PV is a RE technology which converts light directly into electrical energy. This is in comparison to Concentrating solar power (CSP), which uses light to heat water, create steam and drive a turbine.
As mentioned previously, the supposed reduction in costs of solar PV to 2050 was the backbone of RE mix estimates in the report. This was also due to some of the presumptions made during EIA modelling. For example, from 2022, a reduction in U.S. government investment tax credits, from 30% for corporate and residential utilities to 10% for only corporate utilities will be minor according to this modelling.
Some of this is questionable.
However, as shown, historical data released by the International Renewable Energy Agency (IRENA) shows there is a large scope for a decline in the cost of solar PV.
Since 2017, total costs associated with solar PV crossed below that of onshore wind. Additionally, cost estimates of solar and onshore wind have been detailed by IRENA (IRENA 2019), forecast from 2019 to 2030 and 2050, shown below:
This highlights the expected significant reductions in the cost of solar PV energy, compared to the other major RE competitor, wind. As a result, it is expected this will lead to an increased presence of solar energy in general electricity generation.
The edge of solar, above alternatives
Some features that differentiate solar and other renewable energy assets from fossil fuel and nuclear include the relatively low operational costs. The clearest reason for which, the absence of fuel costs. Earth’s surface receives 20,000 times more power in the form of solar radiation than what is needed to supply the whole world, thus insinuating unlimited fuel, gratis. Moreover, current solar PV tech produces solar panels with a life span of 25-30 years. Due to the nature of solar PV, this implies most investment costs will be incurred upfront.
Solar beyond other renewables
It is notable solar radiation is more predictable than rainfall or wind which is conducive to accurate output forecast, and that the installation process for solar panels is easier with shorter construction lead times in comparison to wind turbines.
The 2020 EIA Outlook report makes note of the distinction between residential and utility solar PV growth. A key benefit of solar PV can be attributed to the scalability of solar assets. Solar panels can be positioned on rooftops or the ground and can flexibly be installed on a wide-ranging scale. In part, this understated ability, alongside reducing costs of solar PV for households, is likely to increase uptake by residentials. This was one of the other main assumptions of drivers of growth in the EIA report.
But the drawbacks are well-known across the major renewables
One of the main barriers to adopting solar assets is its inherent variability in power output. The amount of power generated per unit volume, or power density, should be of concern when estimating the amount of energy that can be derived from an area of land. This is especially the case in places where land is relatively scarce, such as Japan.
Globally, the power density for solar radiation is 170W/m2. However, this pales in comparison when assessed against other traditional sources of energy like nuclear, oil, and gas. A mitigant to the intermittent nature of solar power output, and perhaps should be one of the main focuses in the future, is the use of battery-based energy storage systems to decouple energy supply and demand.
Although such storage technologies are expensive, IRENA, the U.S. EIA and the International Energy Agency (IEA), have a consensus that these will fall rapidly over the next five years. Meanwhile, the increase in scalability of both generation and storage is expected to proliferate demand for solar assets.
However, some issues may arise, which become more apparent in the future with larger-scale projects. Some of these include the inability of batteries to store energy efficiently, without a diminishing charge, upon being disconnected to the energy source. It is too optimistic to say future technological advancement are solution to issues such as these. Instead, by pairing this with headway on projects like smart infrastructure to enhance grid resilience, the effects of these issues could be mitigated.
In 2011, the IPCC released a special report titled ‘Renewable Energy Sources and Climate Change’. This report underscored the potential of solar energy over other forms of renewables and re-affirmed this viability to governments.
In a world of increasing R&D and scale of production, and decreasing solar PV costs, on top of the technical potential of solar energy – the place of solar by the end of the century is becoming ever more certain.
- Solar is expected to emerge as the main renewable energy.
- This is due to the expected decrease in the cost of solar PV.
- These causes are due to further innovation in solar PV, scaling production and ease of installation, which will drive solar uptake to 2050.
Aside, on technical potential
The technical potential estimates a RE’s potential energy output after accounting for topographic, land use and system constraints, in the context of system performance. From various sources, below:
Arvizu, D., Balaya, P., Cabeza, L., Hollands, K. G. T., Jäger-Waldau, A., & Kondo, M. (2011). Special Report on Renewable Energy Sources and Climate Change Mitigation SRREN. Cambridge and New York: IPCC.
Creutzig, F., Agoston, P., Goldschmidt, J. et al. The underestimated potential of solar energy to mitigate climate change. Nat Energy 2, 17140 (2017). >https://doi.org/10.1038/nenergy.2017.140
Creutzig, F., Ravindranath, N. H., Berndes, G., Bolwig, S., Bright, R., Cherubini, F., … & Fargione, J. (2015). Bioenergy and climate change mitigation: an assessment. Gcb Bioenergy, 7(5), 916-944.
Edenhofer, O., Pichs-Madruga, R., Sokona, Y., Seyboth, K., Matschoss, P., Kadner, S., … & von Stechow, C. (2011). Summary for policy makers. IPCC special report on renewable energy sources and climate change mitigation.
IEA (2019) World Energy Outlook, https://www.iea.org/reports/world-energy-outlook-2019. All rights reserved.
IRENA (2019), Future of Solar Photovoltaic: Deployment, investment, technology, grid integration and socio-economic aspects (A Global Energy Transformation: paper), International Renewable Energy Agency, Abu Dhabi.
IRENA (2019), Future of wind: Deployment, investment, technology, grid integration and socio-economic aspects (A Global Energy Transformation paper), International Renewable Energy Agency, Abu Dhabi.
IRENA (2019), Renewable Power Generation Costs in 2018, International Renewable Energy Agency, Abu Dhabi.
Motyka, M. (2020). 2020 Renewable Energy Industry Outlook. Deloitte United States. https://www2.deloitte.com/us/en/pages/energy-and-resources/articles/renewable-energy-outlook.html.
S. Energy Information Administration (2020), Annual Energy Outlook 2020. https://www.eia.gov/outlooks/aeo/
S. Energy Information Administration (2020). Electricity Data Browser, https://www.eia.gov/electricity/data/browser/
Umweltveränderungen, W. B. D. B. G. (2003). Welt im Wandel: Energiewende zur Nachhaltigkeit. Springer Berlin Heidelberg.
Other Further Reading:
Zhou, Y.; Gu, A. Learning Curve Analysis of Wind Power and Photovoltaics Technology in US: Cost Reduction and the Importance of Research, Development and Demonstration. Sustainability 2019, 11, 2310.
Other Related UNIT Articles:
For 2020, in the context of COVID-19, see “COVID-19 and Climate Change”
Disclaimer: The views expressed in this article are solely that of the author’s, and do not necessarily reflect the position of UNIT nor the University of Melbourne. Transacting off this information is done so at one’s own risk, and individuals are encouraged to consult a finance professional before making investment decisions based off of this article.