A decade ago, no one believed that electricity from renewable energy resources alone could power the entire world. Experts in the energy sector and related industries now believe it is possible.
Currently, countries such as Costa Rica and Iceland already generate near 100% of their electricity using green energy sources like wind, solar, hydro or geothermal. At the same time, around the world, 12 countries have passed laws to reach 100% renewable electricity by 2030.
To achieve this, governments will need to evaluate their energy resource mix and identify which available technologies to invest in; but how much power will be needed from individual plants?
The megawatt capacity of plants are available for everyone to examine, but megawatts don’t indicate the scale nor challenges that lie ahead. To get a more accurate impression of large-scale power plants, you need to visualise how big a 130MW solar PV power plant is and what it can produce.
Looking at an example outside of Africa, in northern Mexico, the 130MW Akin Solar plant consists of 390,000 multi-crystalline solar modules installed on single-axis trackers. It is connected to the grid through an electrical substation via a 7km powerline.
This shiny new plant started operation in 2020, supplying electricity to industrial clients. This particular plant can produce electricity for the equivalent of 340,000 average households.
However, to physically accommodate that many modules, the plant expands over 266 hectares. That is a sizable piece of land that could be more valuable for agriculture or housing.
Another issue is where the water will be sourced to clean that many modules. Further down the line, as solar PV power plants age, what will happen to the modules that are no longer performing to standard?
Professor Izael da Silva, deputy vice-chancellor for research and innovation at Strathmore University and an incredibly passionate energy expert I have had the pleasure of engaging with, points out that the land footprint raises eyebrows.
Therefore, land-use concerns have to be seen in the context of alternative use of that specific area. “If nothing has to be done with it for the last say 50 years or nothing is expected to be done in the next 50 years, then ‘use of land’ is not a relevant item to consider,” he said in a LinkedIn comment.
What can agriculture do with 266 hectares? GrainSA notes that normal planting populations used for new cultivars in dryland production vary from 15 to 20,000 plants per hectare and 18 to 36,000 plants per hectare in higher potential soils. While the benchmark for a solar plant is 2 hectares per megawatt.
When considering the footprint of power plants, do not be tempted to compare land in Mexico’s desert to prime land on the outskirts of a city.
The scope of restoring the land beneath and around all power plants should be given thought at the time of financing the projects. While older plants’ operators now have the burden of putting plans in place.
In the EU, applications into restoring the land are captured in biodiversity enhancing and maximisation. The recycling and handling of waste from the solar panels will become another ‘plastic’ problem in the future if not planned for ahead of operations.
Research and development must continue in order to be able to solve these problems and the challenges that we’ve not even considered. As impressive as the expanse of a 130MW solar PV plant is to see, innovation into reducing its land footprint and waste implications are a priority.
What innovations in solar modules, land policies and future waste management have come to your attention?
Until next week.