Introduction

Did you know the New Brunswick government intends to increase our solar power capacity by 200 MW? It's a similar story across Canada, with companies and contractors racing to build the solar arrays needed to support an energy transition.

The government isn't the only one interested in solar power, either. More homeowners, businesses, and farmers, are looking at solar energy as a solution to reduce their power bills and reliance on the "traditional" grid.

This rapid increase of interest in solar power has led to a significant rise in demand for these systems, leaving installers scrambling to keep up with demand.

That's why more people are looking at helical pile foundations as the solution to support their large and small solar arrays.

Helical piles are enabling solar energy projects to be built faster, stronger, and with less impact on the land. Delivering serious performance that can withstand the worst weather conditions our region has to offer, they're helping both homeowners and companies significantly expedite construction timelines.

But, what exactly are helical pile foundations and how do they transforming the way we build clean energy here in New Brunswick? Find out as we explain why helical piles could be a perfect match for your solar energy project.

Helical Pile 101: A Foundation For The Future?

Before we fully dive into helical piles, there's a quick (but important) distinction we have to make when talking about foundations. And that is the difference between a deep foundation and a shallow foundation.

Shallow foundations are installed on, or very near to, the ground surface. Typically comprised of a concrete block or slab, these foundations rely on their weight to defend against shifting or movement. Loads are transferred from the solar panels down into the foundation and dispersed over a wider area.

Deep foundations are installed at a greater depth, extending below our frost-line to anchor in firm soil layers less prone to shifting. Common options are pre-cast piers, steel piles, and poured caissons. Structural loads are transferred down into supportive strata, providing greater protection against ground movement.

If you compare the two, you'll find that deep foundations offer stronger and more dependable support than shallow foundations. Because they transfer structural loads down into firm and stable layers of soil, the solar panels on-top will enjoy significantly stronger support.

Helical piles fall under the "deep foundation" category, as they're installed below the frost-line to find bearing in reliable soils. But, unlike other deep foundations like driven piles or poured concrete piers, helical piles "screw" into the ground. Here's how they work...

How a Helical Pile Works

A helical pile is kind of like a massive wood screw, except they don't have threads extending all the way up. Instead, there is one (or more) helix plates (pl. helices) located along the pile shaft. 
These helices have a comparatively larger diameter than the pile shaft, and are manufactured with a specific "pitch" that ensures they advance the pile smoothly into the ground.

Speaking of smoothly advancing, a helical pile is installed by rotating it into the ground with a powerful hydraulic drive. Since we're using a wood screw analogy, think of the hydraulic drive like a massive drill.

When a helical pile is installed, the soil exerts pressure on the top and bottom of the helix plate as it advances through the soil. The helix plate creates a large surface area that, once anchored in a firm layer, prevents the pile from moving.

Due to this unique method of installation, no excavation or pile driving is required for a helical foundation (unless the pile tops need to sit below grade). Additionally, virtually no soil is displaced by the pile itself which greatly reduces impacts on the land.

If soil conditions are particularly challenging, extensions can be used to install a helical pile deeper into the ground until suitable layers are found. 
Attaching an extension is a quick process usually achieved by bolting an additional section of pile shaft to the already-installed pile. In some situations, these extensions may have additional helices to provide even more support.

By the way, helical piles can be removed from the ground by simply reversing them out of the soil. Once uninstalled, the piles can be reused after inspection and approval, or 100% recycled. This makes future remediation and restoration of the site dramatically easier and cheaper.

How Solar Panels Connect to Helical Piles

Putting helical piles in the ground is only part of the equation. For it to become a functional foundation, you need a way to connect the piles to your solar panels.
This is achieved through the use of a pile adapter, also known as a pile cap. 
These are available in off-the-shelf and custom designs to suit any project. For solar arrays, an adjustable bolt-on pile adapter is a common solution that securely fastens to a wide range of panels.
In situations where off-the-shelf adapters aren't suitable, then a quality helical pile contractor will be able to produce a custom design that will fit any project.
Regardless of the specific pile adapter used, they make the mounting and removal of solar panels a painless prospect.

Why Helical Pile Foundations for Solar Panels in New Brunswick?

Now that you know how a helical pile foundation works for solar energy, you're probably already imagining some of the benefits they could bring to your project. Because here in New Brunswick, we have two major problems to deal with...

1: Difficult soil conditions
2: Challenging climate

New Brunswick is no stranger to challenging soil conditions, facing everything from poorly-draining clay to loose sands. To make things more difficult, we also experience high amounts of rainfall in the warmer months and plunging cold temperatures in winter.

When you combine our typical soil conditions with high moisture and deep freezes, the result can wreak havoc on both shallow and deep foundations.

The biggest problem comes from our "freeze-thaw" cycle. As the ground melts in spring and receives rain throughout the warm season, it becomes saturated with water. This saturation causes the soil to expand as individual particles swell with moisture. When groundwater freezes in winter, it expands even further.

Next spring, as the ground thaws, the soil particles shrink which causes significant movement and pressure. This can result in a shallow or deep foundation sinking, heaving, or moving side-to-side.

It's not just the freeze-thaw cycle that can create this soil movement, either.

If the soil dries out, for example in the hot summer months, it will also shrink and exert pressure on a foundation. When the rains return, you guessed it, the particles swell back up and the cycle repeats.

Over time, this constant shrink/swell action can damage and ultimately destroy a foundation.

So, what makes helical piles so good at resisting the harsh effects of soil movement?

The secret can be found in the combination of a relatively narrow diameter pile shaft and comparatively large diameter helix plate. This design minimizes the surface area for soil to exert pressure on, while still providing tens of thousands of pounds of load capacity. Though the soil around the helical pile may shift and move, it will hold firmly in place.

Now, this is a simplified explanation of how a helical pile interacts with the soil and why they perform so well in New Brunswick. There is a lot more we could get into, like the performance of helical piles in specific soil conditions. But, that would make this a very long article!

What's most important to understand about helical piles and their performance in New Brunswick is this:

Across most of our province we have challenging soils that often cause problems for "traditional" foundations. Helical piles, owing to their unique design, effectively overcome these tricky conditions and provide stable support that will not move.

How Are Helical Piles Installed?

1: Design The Foundation

Every successful foundation install begins with an engineer-approved design. Our helical piles at Postech Moncton, for example, are approved by the CCMC and well-understood by our engineering partners. This ensures we deliver a foundation that's not only safe, but efficient and economical as well.

2: Prepare the Site

In most cases your helical foundation will require minimal site preparation (especially when compared to other options). In fact, if your site is already free of obstructions and relatively level, odds are you won't need any site preparation at all. No excavation is required to install a helical foundation, unless you're looking to have your pile tops sit below grade. This shortens overall installation time, disruption, and mess.

3: Transport Material & Equipment to Site

Many contractors, engineers, and solar companies appreciate helical piles for their ease of transport and minimal equipment requirements. The piles themselves are compact and readily stack for efficient delivery to site. As for equipment, a simple excavator is typically all that's required to install the piles.

4: Install Helical Piles

One-by-one, the piles are attached to the hydraulic drive on our excavator and maneuvered into place over pre-determined locations. We then smoothly rotate the pile into the ground, being sure it advances at a steady and consistent rate. 
During installation, we monitor the torque required to continue advancing the helical pile. Using equations established by researchers over the decades, we can translate installation torque to load capacity for each pile. That means you can be confident that each pile has been installed correctly and to specification.

5: Mount Pile Adapters

Once installed, each pile is checked for accuracy and quality. The pile adapters can then be attached, and the foundation is ready to use! No waiting for concrete to cure, a helical pile can be loaded immediately after installation. As covered earlier, off-the-shelf or custom pile adapters make it a snap to mount your solar panels to the foundation.

Benefits of Helical Piles for Solar Power

Speed of Installation

Time is money, as they say, so if you can save time you'll be saving money. This is particularly true in construction, where every day spent building can easily cost hundreds or thousands of dollars. The sooner you can start generating power with your solar panels, the more money you'll keep in your pocket.

Thanks to their minimal site prep, rapid installation, and real-time quality control, helical piles are significantly faster to install than other solutions. When compared to poured concrete for instance, a helical foundation can reduce installation time by over 180%. 

Reduces Land Impact

Deep foundations are often associated with large impacts on the land, primarily in the form of extensive excavation and site preparation. However, helical piles offer the strength and durability of a deep foundation without disturbing the landscape.

Because a helical pile rotates into the ground, advancing like a screw, it doesn't cause the displacement of large amounts of material. This helps preserve soil integrity and greatly reduces the affects of foundation installation on the local ecosystem. Additionally, helical piles require much less raw material compared to something like concrete.

Future site remediation and restoration is also made more economical, as removing helical piles simply requires rotating them out of the ground. As there are no large holes or mess left behind, it's easy to bring the site back to its original condition.

Versatile Support in Various Soils

From loose coastal soils with a high sand content to thick mucky clay, helical piles readily adapt to a broad range of ground conditions and compositions. The unique design of the helix plate allows them to find firm footing even in extremely difficult conditions, making helical piles an ideal solution for less-than-ideal dirt.

Another versatile aspect of helical piles is their ability to be installed at an angle to increase the lateral (side-to-side) support for your solar panels. These are called "battered piles", and while not required in every project they can help you overcome particularly difficult soils or high lateral loads.

Oh, and what if you have great soil conditions? You're in luck, as it means your helical foundation design and install will be even easier than usual.

Long Service Life

Pictured is the Thomas Point Shoal Light, which has stood for nearly 150 years in the Chesapeake Bay on a helical pile foundation

Building a solar energy system, whether small or large, represents a big time and financial commitment. The last thing you'd want to do is go back in a few years to replace your foundation because it's failing.

Helical piles are made from steel, which is by nature an incredibly strong and durable material. Once installed into the ground, most of a helical pile will not actually be prone to corrosion as the oxygen content diminishes the deeper you go. On top of this, our piles are given a galvanized coating for further protection.

The result is a foundation that can last well beyond 50 years if installed correctly, far outliving even the solar panels they're supporting. 

Overall Economy

We'll be completely honest, if you assess the price of a helical foundation on a per-pile basis you might find they are more expensive than other solutions. This can surprise people, as they assume helical piles are a "cheap" option.

Here's the thing: looking only at the "per-pile" price is not how you should be thinking about your solar energy foundation.

First, you need to consider performance.

Yes, you could go for an inexpensive shallow foundation for your solar panels. But if you end up battling on-going problems because your foundation isn't stable, you'll waste more money and time dealing with it in the long-run.

Or, what if your soil conditions are saturated and muddy? You could try poured concrete piers, but it's going to take a lot more effort to dig and install them in tough conditions. Not to mention they can be prone to pushing upwards when placed under relatively light structures like solar panels.

Remember that sometimes the "cheap" option doesn't truly end up being so affordable in the end.

Second, consider the time and effort each foundation option demands.

A helical foundation is efficient to install and doesn't ask for large amounts of site prep. This drastically reduces your project timeline, allowing your solar panels to start producing power sooner. If you're a solar company or contractor, finishing projects faster frees your team for more jobs.

When you look at the overall economy of a helical foundation, not just the per-pile price, you'll almost always find they exceed other solutions all things considered.

Frequently Asked Questions About Helical Piles for Solar Energy

Summary & Conclusion

As we said earlier in this article, it doesn't matter whether you're building a small or large solar energy project. They all represent an investment of your time, money, and energy.

If you're a homeowner, you want to sleep easy knowing you'll enjoy countless years of worry-free power performance from your solar panels.

If you're an engineer, you want to be confident in the long-term stability and safety of the foundations you put your name on.

If you're a contractor or solar energy company, you want to finish projects faster so you can get more done in less time.

No matter who you are or the scale of your project, helical piles deliver the performance you need in a fraction of the time. They'll last for decades in the ground, won't shift or move, are easy to use, and can someday be removed without a trace.

While we won't say that helical piles are the absolute best option for every solar project, they are an excellent solution for many. If you want to find out if they're the best option for your solar panel installation...

...get in touch with our experienced helical foundation team at Postech Moncton!

We'll help you determine how helical piles can improve your solar energy installation. And if a helical foundation is not the right solution, we will be the first to tell you.

The process couldn't be easier, so give us a call or send an email to tell our team about your solar energy project and get started today.