Humankind has been trying to prevent land erosion for centuries. From the Incas’ terraced land in Machu Picchu to today’s farmers and their modern solutions, there has been no end to the search for the best way to stop soil erosion. However, as the world continues to develop and deforest land in the name of agriculture and building and powering new structures, erosion has become an even more pressing issue.
In the last 150 years, the Earth has lost half of its topsoil. As a result, both the environment and the animals and people that live within it have suffered. The energy and construction sectors must find better ways to prevent soil erosion and protect what little earth we have left.
Renewable energy professionals, in particular, have a unique role to play in finding and implementing different solutions. Already, they are charged with installing renewable energy infrastructure, which should, in turn, better conserve the planet and its resources. Yet, when they install wind turbines and solar panel fields, the soil often suffers. This cycle of taking one step forward and two steps back must end if the renewable energy sector wishes to accomplish its goal of improving the environment and public health.
How Does Renewable Energy Cause Erosion?
Solar panels and wind turbines may not be as big, heavy or destructive as a city skyscraper. However, they can cause just as much damage if renewable energy professionals don’t actively fight soil erosion. Much like any other kind of infrastructure, workers must first clear the land of trees and vegetation. This deforestation removes root systems that hold the soil together and prevent erosion. Rolling over the area with heavy machinery can also compact the earth and cause the dirt to wear away.
Additionally, once the panels are installed, rain dripping from their edges can pool around the foundations and further disrupt the soil. If the dirt is dense and compact or if the panels sit on a slope, rainwater can also carry dirt away, resulting in runoff and severe erosion.
Installing wind turbines also requires clearing vegetation and facilitates soil disruption, creating erosion problems in much the same way as solar panels. However, their rotating blades also blow up dirt and generate dust clouds. Naturally, this dust floats to other areas, removing soil from the original location and exacerbating erosion issues around the turbines.
The Consequences of Soil Erosion
Erosion is a natural occurrence. However, when outside forces speed up the process, consequences will inevitably follow. In addition to soil and land loss, erosion can cause an increase in sedimentation in streams and rivers. If there are contaminants like pesticides or other chemicals in the ground, these can leach into waterways, which reduces water quality, decimates fish and wildlife populations and disrupts marine ecosystems.
Additionally, erosion may damage renewable energy installations over time. As wind and water carry topsoil away, the dirt underneath can shift and create air pockets, channels, slopes and uneven ground. These formation changes can cause racking systems, cables and other electrical components to move, damaging them or severely inhibiting their power output. Ultimately, this may require workers to replace the systems completely, further damaging the soil and costing the renewable energy sector money.
Finding a Solution
Of course, finding and implementing an erosion solution will also cost renewable operations money. However, preventative measures are generally less expensive than paying to fix or completely replace solar and wind systems. Which solution energy pros use, though, depends on the land and climate, the budget and the renewable power setup.
Implement Erosion Control Blankets
If the climate is wet and rainy, a company may choose to use an erosion control blanket. These blankets keep soil from shifting or moving during heavy rains and winds, reducing runoff and preventing soil erosion. Keeping the dirt in place with an erosion control blanket also allows for new seeds to take root and enables vegetation to hold the soil together naturally over time.
These blankets are one of the most cost-effective erosion control options on the market today. Typically, they’re made of natural or synthetic fibers and are relatively easy to install. Plus, those containing natural materials usually break down over time, meaning there’s no need to retrieve them once vegetation begins growing.
Hydroseed the Land
Of course, after clearing the land in preparation for installing renewable energy systems, there won’t likely be much new plant growth without a little help from the energy professionals. However, instead of sowing dry seeds, some companies choose to hydroseed. This solution involves applying a mixture of seeds, mulch, fertilizer and water to the land with a pressure hose.
Often, professionals will hydroseed to plant grass but may also use this method to grow other types of vegetation like ground cover and wildflowers. While hydroseeding can be cost-effective, there’s always a chance the seeds won’t take root or will need additional irrigation before sprouting. Speaking with a consultant to decide which vegetation will grow best before hydroseeding will likely improve a company’s chances of cultivating this vegetation quickly.
Once the vegetation has taken root and is growing with little to no help from humans, renewable energy professionals must then focus on trimming and maintaining it. If the site doesn’t receive much rainfall or the chosen vegetation isn’t native, it may require an irrigation system. Otherwise, the plants may dry out and pose a fire hazard, especially around the electrical wiring of renewable solutions.
Energy professionals can also prevent fires by trimming vegetation, choosing short groundcover and clearing areas around fire hazards. Clearing a radius around mechanical components will minimize the chance of fire if a piece of equipment fails and sparks go flying.
Another way to prevent fires and soil erosion is to apply mulch to the site. Layering mulch over topsoil can reduce runoff as the wood chips will absorb excess water from rain and melting snow. Generally, professionals use this anti-erosion solution on flat, even ground, as opposed to slopes and hilly landscapes.
Even so, mulching will likely require some maintenance. Heavy rainfall and storms can displace mulch and leave topsoil exposed. When this happens, workers will have to return and replace the mulch in affected areas. Sometimes, they may even have to use heavier forms of mulch made of a mixture of rock and wood chips to better keep it in place.
Alternatively, professionals might apply geotextiles. These permeable fabrics sit right below the topsoil and trap floating sediment while allowing water to pass through. This system encourages proper drainage, mitigating runoff and helping the vegetation grow. Some are even designed to biodegrade after plants have taken root, allowing for more natural erosion prevention.
Of course, if the energy system sits on land with a relatively high grade, workers will have to pair geotextiles with diversion ditches to collect water and prevent off-site erosion. Moreover, in cases of sloped land, geotextile fencing may be more effective than ground cover textiles in catching sediment.
Solar panels angle toward the horizon and generally allow rainwater to drip directly onto the soil beneath them. While professionals typically install solar arrays on a grade of less than 5%, some renewable experts place them on land with a grade as high as 10%. Doing so often results in runoff and, subsequently, soil erosion. However, by introducing drainages, spillways and barriers to the site, renewable energy professionals can effectively mitigate runoff.
For instance, by strategically placing barriers on sloping land, professionals can break up the natural gradient, redirecting runoff and slowing its speed. In turn, this allows the renewable energy sector to build on landscapes it otherwise wouldn’t have due to grade concerns.
Maintain Construction Paths
Compact earth is notoriously bad at absorbing water. Therefore, it only makes sense that the more heavy machinery rolls over a site, the more topsoil erosion that will occur. As it rains, the dense earth won’t readily absorb water, which leads to runoff. Additionally, compact soil isn’t ideal for supporting most root systems, making planting vegetation nearly impossible.
Renewable energy professionals can avoid these issues by simply building and maintaining roadways and paths both during and after construction. Laying gravel and watering dirt paths can accomplish anti-erosion initiatives by mitigating dust and soil compaction.
Laying the Foundations
There are many options available for minimizing soil erosion and prolonging the life of a solar array or wind farm. In most cases, one solution will be more effective than others, so it’s important to survey and understand the soil and vegetation before choosing.
Once a company comes to a consensus regarding erosion control, it should implement the solution and continue maintaining it as long as the installment remains. In doing so, renewable energy professionals will lay the foundations for years of erosion prevention and increase the likelihood of more areas adopting renewable power. Moreover, they pave the way for future generations who may discover even more effective methods to conserve the Earth and the rich soil covering it.
Emily Folk is a freelance writer and blogger on conservation and sustainability. To see her latest posts, check out her blog, Conservation Folks, or follow her on Twitter, @emilysfolk!