Why bracing is essential for protecting solar frames

No investment can be completely risk free, however, all good investors will take steps to manage and reduce risk. The same can be said for utility solar farms, and with ever bigger sites being commissioned the level of exposure for developers is becoming greater and greater.

Extreme weather as well as other external forces can lead to costly damage, and the bigger the site the bigger the risk.

Taking the Mohammed bin Rashid Al Maktoum Solar Park in UAE as an example, an eyewatering investment of $13.6 billion has been made to develop the site. With investment on this scale, protecting your assets from external forces becomes vitally important.

One simple and effective way to reduce the risk posed by external forces is to ensure bracing is installed on solar frames. According to a report by renewable energy insurance specialist, GCube1, severe weather events are the cause of most solar insurance claims. But while severe weather is inevitable in some locations and increasingly common in others, catastrophic losses need not become the norm.

No site can be 100% risk free, but EPCs and developers can take action to minimise risk. Structural bracing is one key measure that can lead to huge cost savings by preventing or reducing structural damage.

Prevent stresses from external forces

Bracing is a well-established engineering technique, commonly used in the construction of steel frames to resist and prevent stresses from external forces such as wind and seismic activity. By applying bracing solutions which are engineered to improve the stability and strength of your solar applications, you can avoid the damage and losses that can commonly occur on solar developments.

What forces are you up against?

• Wind - from moderate winds through to tropical storms, all solar farms are exposed to wind forces which can have a potentially devastating effect on your photovoltaic frames and panels.

• Seismic - huge numbers of solar farms are situated in areas which are prone to seismic movement, and this can cause significant damage to your frames and panels.

• Rain - saturated ground caused by frequent, heavy rainfall can create serious foundation issues which can cause piles to move, drop or become misaligned.

• Heat – the extreme heat in many solar farm locations, including deserts, can cause frames to buckle and twist, impacting their structural integrity as well as damaging the expensive panels.

• Wildlife - over time, interference from wildlife can cause frames or racking to distort, twist, or misalign, which again will impact the frame as well as the panels.

• Snow - in colder climates, the weight from heavy snowfall can impact frame structures, while the extreme temperature can also cause distortion and damage. 

Cost implications

The damage caused by these external forces can cause significant problems for solar power plants, both in terms of repairs and replacements, as well as production outages. Even slight movements to the frame can cause micro-cracks in the panels which can lead to power losses of up to 33 per cent.

Although anecdotal studies show that the typical power loss is between 0% - 2.5%, even this is significant enough to eliminate profits or greatly increase the payback period for the solar farm.

Many sites use Tracker systems which tilt to follow the movement of the sun. These are also vulnerable to external forces, either through damage, or through power outages preventing the frame from following the sun’s path. In both instances, yield will be impacted, which will again reduce profits. In high-risk areas, insurance costs can also be significantly higher. With some providers this increase can be mitigated by taking preventative measures, such as bracing.

How bracing can help

Bracing is commonly used in the construction of steel frames to resist external forces. Tension-only bracing is efficient and effective as it utilises the high tensile capacity of slender steel sections or wire rope. By resolving the lateral forces into a tensile force, the bending moments within the frame members are reduced.

Bracing is also effective at reducing the lateral movement of the top chord by restraining it back to the foundation points. Excessive lateral movement can cause increased strain in the solar modules, resulting in the formation of micro-cracks which can negatively affect their performance and lead to failure.

With no bracing system in place, the frame will resist lateral forces through a combination of sway in the vertical members and diaphragm action through the modules. This creates internal stresses within the plane of the solar module, causing micro-cracks to form.

Figures 1 and 2 show how braced and unbraced frames respond to lateral forces.

Figure 1. Unbraced solar frame

Figure 2.Braced solar frame

Reduce the risk of damage

Clearly, the risks to solar power plants from external forces are incredibly high and can lead to devastating losses. To protect their assets, EPCs and developers should look to mitigate risk through bracing, which is a simple and inexpensive way to minimise damage from external forces.

At Gripple, we offer a range of lightweight solar frame bracing kits which offer the same high performance as heavy steel bracing, at a fraction of the cost.

Our PV Solar Bracing Kit is designed to reduce the moments in steel frames - reducing the deflection and stress placed on the steel by transferring forces applied to the top of structural legs into reduced moments at the bottom. The kit comes with protective tubing to reduce stress on the wire and PV racking system. A bracket can be supplied alongside the kits, so the kit can be seamlessly integrated into any system design. The kits are simple and quick to install on site using just hand tools, with minimal training and are easy to handle compared to heavy steel sections. 

As a business, we have been developing and manufacturing high quality bracing systems for over 30 years. Our innovative kits are tried and tested in critical infrastructure projects around the globe, including airports, highways, power plants and major construction developments.