Vegetation control is one of the most persistent operational challenges on solar sites. Poor vegetation planning also creates hidden operational and financial risks over time, which we cover in more detail in our article on the hidden costs of poor vegetation planning on solar projects. Left unmanaged, plant growth can reduce output, increase risk, and drive up maintenance costs. Most solar operators rely on either mechanical mowing or livestock grazing to manage vegetation, or some combination of both.
Each approach has advantages and limitations. The right choice depends on site conditions, regional climate, regulatory requirements, and long term operational goals.
Here is how mowing and grazing compare and what solar owners and operators should consider when choosing a vegetation strategy.
Mechanical Mowing
Mechanical mowing is the most common vegetation management method on solar sites. It offers predictable results and can be scheduled as part of routine O&M.
Benefits of mowing
- Provides immediate and visible vegetation control
- Easy to schedule and scale across large portfolios
- Works in almost all site conditions
- Allows precise control over vegetation height
Limitations of mowing
- Repeated passes increase labor and equipment costs
- Heavy machinery can compact soil and increase erosion
- Risk of damage to panels, wiring, and racking
- Does not prevent regrowth, only controls it temporarily
Mowing works well for sites that require consistent visual control or where grazing is not feasible, but it tends to be more resource intensive over time.
Livestock Grazing
Grazing, most commonly using sheep, is becoming more popular as a low impact vegetation strategy on solar sites. It combines vegetation control with environmental benefits, but it requires careful planning.
Benefits of grazing
- Reduces the need for mechanical equipment
- Lowers long term labor and fuel costs
- Improves soil health and reduces erosion
- Supports pollinator habitats and biodiversity goalsLimitations of grazing
Limitations of Grazing
- Requires fencing, water access, and animal management
- Not suitable for all site layouts or climates
- Seasonal availability may vary
- Requires coordination with grazing operators
Grazing is most effective on sites that are designed or adapted to support animals safely and where long term sustainability is a priority.
Performance and Risk Considerations
From a performance standpoint, both strategies can control shading and soiling if executed correctly. The difference lies in consistency and risk management.
Mowing offers control and predictability but increases the risk of accidental damage and site disruption.
Grazing reduces mechanical risk and environmental impact but introduces operational dependencies on animal care, scheduling, and site suitability.
The wrong strategy can increase downtime, raise costs, and create compliance or safety issues, regardless of whether it is mowing or grazing.
Cost Comparison
Mowing typically has lower upfront barriers but higher recurring costs. Grazing often requires more setup but can reduce long term operational expenses.
Costs vary by region, site size, and frequency of maintenance. Over the life of a project, a poorly matched strategy can significantly increase total O&M spend.
What Works Best
There is no universal answer. The best vegetation strategy is site specific and often involves a hybrid approach.
For example:
- Grazing may be ideal for large, rural sites with low public interaction
- Mowing may be better for urban, constrained, or high visibility locations
- Some sites benefit from grazing most of the year with limited mechanical mowing during peak growth seasons
The key is not choosing a method but designing a strategy that aligns with the site’s physical, environmental, and operational realities.
Choosing the Right Strategy for Your Solar Sites
Effective vegetation management is not about choosing mowing or grazing. It is about understanding your site and implementing a plan that reduces risk, stabilizes costs, and protects long term performance.
A strategic approach considers:
- Site layout and accessibility
- Climate and seasonal growth patterns
- Environmental and regulatory requirements
- Safety and operational constraints
- Long term asset protection goals
This is where specialized solar vegetation planning makes the difference between reactive maintenance and optimized operations.
Plan Smarter Vegetation Management for Your Solar Sites
If you are evaluating mowing, grazing, or a hybrid approach for your solar sites, KerTec can help you assess what works best for your specific conditions.
Go to the Contact page to talk with our team about developing a vegetation strategy that supports performance, safety, and long term asset value.