While solar energy generated by photovoltaic (PV) power plants has many advantages, there are also challenges and limitations that need to be considered when discussing its ability to power our world. Below is a comprehensive list of reasons why solar energy from PV power plants face obstacles in becoming the sole energy source for our planet:
Intermittent Production: solar PV energy is producing electricity roughly 15% of the hours in a year. The other 85% of the time (typically 8760 hours/year) cannot be produced by solar PV power plants. That is roughly 1.275 hours/years. Off course, PV arrays in northern Chile or high solar radiation countries produce more, reaching up to 2.700 hours of production per year.
An alternative is to build solar PV arrays that supply electricity into storage options (batteries). The stored energy could then be used the other 85% of the time. This, of course means – in a scenario where the same demand holds true 24-hours a day – that every solar array would be 6.6 times larger (100/15) than today.
Of course, this is hypothetical, and each country will have different consumption levels and a combination of import-export electricity which may need to be considered in a serious analysis.
Storage: On the other hand, the assumption here is that the hours of energy stored will exhaust or allow the supply of energy from the storage source (batteries) the same number of hours that it required to charge them. This off course is a poor assumption. Most battery systems are currently efficient enough to charge in less time than the time they can supply power. Of course, it is also expected that, if batteries are supported and demanded, technological developments will make them more efficient. This, off course is also hypothetical. If other technologies are embraced, batteries may stagnate and not improve their absorption and supply rates.
What matters from the previous two paragraphs is that the low number of hours of production of solar PV energy per year, do not allow, the world to be powered by solar PV energy alone.
Variability: the latter information of course is considering an ideal scenario where there are no clouds, rain, snow or dust that decrease the efficiency of the production or more importantly vary the production volumes of a array. In reality, this is not the case. With weather changing drastically as a consequence of global warming, the worlds weather will change and predictions of production may be more variable then today.
Land Use and Environmental Impact: It’s clear that countries with limited non-agricultural land, low solar radiation, and or significant protected areas, will encounter political, communal, municipal, and other opposition.
In effect, the amount of land required to build a solar farm is roughly 20.000 m2 of land per 1 MWp. As an extreme example, a nuclear power plant which will not emit CO2 emissions during its more than 8.000 hours of production per year, over a lifetime of 30 year, will require 100.000 m2 of land to construct 1.000 MWp, whilst a solar PV plant could only build a maximum of 5MW on this same peace of land.
This high level of land occupancy may lead to land use conflicts, habitat disruption, and loss of agricultural or natural areas.
Countries with limited none-agricultural land, or excessive mountains, or a combination of this and low solar production rates should prefer other energy production sources or importing electricity (when possible) to cover their needs.
Material Availability and Resource Constraints: The production of solar panels relies on raw materials such as silicon, silver, and rare earth elements. While these materials are still abundant, there may be supply chain constraints or geopolitical risks associated with their extraction and availability. Furthermore, the demand for these materials could increase significantly as solar energy deployment scales up, leading to potential price volatility and market disruptions.
Thus, a scenario where all the energy in the world is produced from solar PV is not really realistic.
Transmission and Distribution Infrastructure: some people may mention this as a constraint, and some others as the advantage of solar PV energy production because it can be installed basically anywhere.
The truth is that connecting any large-scale energy source to the electricity grid requires extensive transmission and distribution infrastructure. Building new transmission lines and upgrading existing infrastructure to accommodate renewable energy sources, alike that for any large scale or Utility scale project, is expensive, time-consuming, and risky.
If we get picky, one can also say that an additional hurdle may come from long-distance transmission of electricity from solar-rich regions to populated centres, when and if, the areas the transmission goes through are in conflicted war zones or politically unstable areas. In the latter, transmission lines may be moved from private to public owners without major notice leaving power plants isolated and incapable of delivering energy to the consumptions points. This of course is an extreme case and should not be considered part of the norm. If they do happen, they will occur for any form of power generation.
Grid Integration and Stability: Integrating large amounts of variable renewable energy into the grid requires grid upgrades, advanced forecasting tools, and grid management strategies to ensure stability and reliability. In effect, as it happens with solar energy, most of it is generated at mid-day. If all solar power plants generate at the same time, the grid reaches its maximum capacity, just as a high would in jam hours. This overheats the cables, risking the grids performance and ability to distribute power. Its also very dangerous and must therefore be carefully monitored, managed and controlled. This in turn, can introduce challenges such as voltage fluctuations, frequency regulation, and as mentioned grid congestion. These risks must must be addressed to maintain grid stability and resilience.
Economic Considerations: While the cost of solar photovoltaic technology has declined significantly in recent years, there are still economic challenges associated with large-scale deployment. Initial costs are often exceeded by wrong building, excessive errors during construction, delays in commercial operation date, and even earlier, during the development phase, or later, during the operation and maintenance of the power plant.
If financial costs rapidly rise as a consequence of inflation, in the market of deployment of the assets, the excessive costs, not contemplated in the development stage may lower profitability and risk the adoption of other comparable energy sources in a specific market.
Additionally, the levelized cost of electricity (LCOE) from solar PV must be competitive with other forms of energy generation to be economically viable without subsidies or incentives.
Social and Political Factors: given the amount of land solar farms require, the transition to solar energy may face opposition from vested interests, regulatory barriers, and public resistance. Political factors, including energy policies, government incentives, and international cooperation, can influence the pace and scale of solar energy deployment. Social acceptance and community engagement are also critical for the successful implementation of solar projects.
Technological Limitations and Innovation: curious as it may sound, solar PV technologies developments are not as fast as people think. In effect, there are multiple technological limitations that need to be addressed. Improvements in solar cell efficiency, energy storage systems, grid integration technologies, and manufacturing processes are necessary to further reduce costs, increase reliability, and enhance performance. Continued research and innovation are essential for overcoming these challenges and unlocking the full potential of solar energy. Low efficiencies have never seemed to be a barrier to deploy solar since the sustainable image of solar seams stronger than its impact.
Global Impact and Equity Considerations: Transitioning to solar energy on a global scale requires coordinated action and collaboration among countries, regions, and stakeholders. The distribution of solar resources and energy infrastructure may vary geographically, leading to disparities in access to clean energy and energy services. Addressing issues of energy equity, social justice, and environmental sustainability is essential for achieving a fair and equitable energy transition.
In summary, while solar energy from photovoltaic power plants offers significant potential as a renewable energy source, there are challenges and limitations that need to be addressed to realize its full benefits. More importantly, as demonstrated, powering our world with solar PV alone is not possible. Powering our world with solar and a backup (battery or water pump storage) solution, could be possible yet it will require additional infrastructure that would eventually make the solution unviable to solve with solar PV alone.
Overcoming these challenges will require a holistic approach that considers technological innovation, policy support, economic incentives, and social acceptance to enable the widespread adoption of solar energy and accelerate the transition to a sustainable energy future.
