John Lisle | Updated September 6, 2023 | Renewable Energy Foundations

Over the past 20 years renewable energy generation has grown by a staggering 90% in the United States. In 2020 alone, wind and solar power were responsible for nearly 12% of all the utility-scale power here in the U.S. Clearly, renewable energy is the undisputed future of power.
However, there’s more to wind and solar energy than wind turbines or solar panels. One of the caveats is they don't generate power 24/7. Wind turbines need, well, wind in order to work. Solar panels need sunlight. So if it's a calm day or the sun isn't shining, there's less (or no) energy being generated. 
To overcome this, large banks of industrial-sized batteries called a battery energy storage system (BESS) are used to store generated energy, which is then released on-demand to maintain stable power. 
Because they're filled with dense batteries, energy storage systems are extremely heavy. For example, a single Tesla ‘Megapack’ BESS unit can weighs-in at 51,000lbs. As demand grows, so too will the size and weight of these energy storage systems.
The enormous weight of an energy storage system, and because they're often put in tough locations like this one in Alaska, means choosing the right foundation is vital for safety and reliability. You can't afford any foundation issues under mission-critical infrastructure like hydro. 
While the usual foundation for energy storage systems has been driven steel h-beam piers, a massive shift is happening. Helical pier foundations, a nearly two-century old solution, is quickly becoming the preferred foundation for supporting energy storage systems in the United States. 
See how helical piers are expediting timelines, slashing carbon emissions, and boosting efficiency, for battery energy storage systems across America.   

Are Helical Piers a Good Foundation for Energy Storage Systems?

Helical piers are a foundation technology that's been getting more attention in the last couple years, as multiple industries have adopted them as a preferred alternative to poured or driven solutions.
You might even be familiar with helical piers or have heard about them before. Just in case you haven't heard of them or aren't quite familiar, let's catch you up on the technology.

A foundation technology that's existed for nearly 200 years, helical piers are experiencing a huge revival in their use across the world

Helical piers were originally invented by a remarkable Irish engineer named Alexander Mitchell. Despite being blind due to childhood illness, Mitchell had become a sharply skilled engineer and entrepreneur by the early 1800's.
He was deeply disturbed by the mariners who died as their ships were smashed to pieces or sank in treacherous conditions or at night. At the time, lighthouses could only be built in areas where the ground could support them. That meant areas like soft sandbanks or shoals were out of the question as lighthouse sites. 
Mitchell reasoned that if a foundation could be designed to provide support in sandy coastal areas and offshore locations, countless ships and lives could be saved.
His reasoning was right, and soon after their invention and installation under two lighthouses in the 1830's, helical piers quickly became the preferred foundation for lighthouses, bridges, piers, and more. The technology caught-on in the United States in the 1840's and would be used for hundreds of structures. In fact, some lighthouses like the Thomas Point Shoal Lighthouse are still standing on their original wrought-iron helical piers 148 years later.

Helical piers are an end-bearing deep foundation capable of completely replacing technologies like poured concrete or driven steel beams. Instead of requiring excavation or pile-driving, helical piers are turned into the ground similar to a very large screw. In fact, that's why helical piers were originally called "screw piles".
Helical piers work on a simple and elegant concept:● Take a round or square steel shaft and weld helix plates to it● Ensure the helix plates have a defined pitch so the pier advances into the ground at a constant rate without displacing soil● Add extensions to the helical pier until the helix plate anchors in firm stratum (measured by the torque required to advanced the pier)● Because the helix plates are wider than the pier shaft, the bearing of those plates (along with shaft friction) in the soil provides resistance to compression and tension loads● The (comparably) narrow shaft helps the pier resist immense upheaval forces from expansive soils, frost, moisture, etc

The unique design of a helical pier can be seen here - these are the first sections of the helical pier to be installed. Additional sections will be attached to reach correct depth.

The unique properties and benefit of helical piers made them an extremely popular foundation through the 19th and early 20th century. However, advances in steam hammers made it cheaper and easier to install driven piles compares to helical piers. As a result, helical foundations became less common under large structures. 
Throughout the late 1800's to the mid 1980's, helical pier technology continued to be developed and used primarily in agricultural and utility applications. 
In the mid 1980's, hydraulic drives had evolved to the point where they could apply enormous torque in a relatively compact package. This made installing high-capacity end-bearing helical piers dramatically faster and easier, and would signal a revival of the helical foundation.
Today, almost 200 years later, the ingenious invention of an Irish engineer is being recognised as the ideal foundation solution for battery energy storage systems.

The Truth About Expansive Soil, BESS Installations, and Helical Piers

Across much of the United States you’ll be dealing, in some capacity at least, with expansive soils. 
Expansive soils are among the most challenging and destructive for foundations, causing billions in damages in the U.S. each year. 
These expansive soils swell with moisture and shrink as it dries out. As the soil undergoes this shrink/swell, it can exert thousands of pounds of pressure on the foundation.

An extreme example of the relentless power of expansive soils. The shrinking and swelling of the soil has led to the complete failure of this house

Owing to their design, helical piers are great at resisting this movement even in the most challenging expansive soils. But, high performance in tough soil is just one reason more renewable energy companies are switching to helical pier foundations.
Some of the other stand-out benefits that make helical piers a worthy foundation for your battery energy storage systems (BESS) are...

Quick to mobilize

Unlike bulky and awkward pile driving rigs or concrete pumps, a helical pier installation only needs basic equipment like excavators or skidsteers. That means less equipment to move and house on your job site which greatly reduces the mobilization cost and timeline of a helical pier foundation.

Minimal site disturbance

When it comes to installing renewable energy infrastructure, the last thing you want is to tear up the local environment. Helical piers don’t require excavation, drilling, or pouring concrete. They simply “screw in” to the ground with a hydraulic drive.

It causes minimal disturbance to the soil and leaves zero evidence on your job site.

More environmentally friendly

Helical piers are made from steel, a material that can be infinitely recycled. Many pier manufacturers use recycled steel in their piles, as it’s just as strong as “new” steel.
More importantly, you can easily uninstall a helical pier by simply reversing it out of the ground with a hydraulic drive. You may even be able to reuse the pier after inspection and testing.

Increased confidence

It takes energy to turn a helical pile through the soil and into the ground. We measure that energy as torque. Decades ago, researchers found that a helical pier’s weight capacity was directly related to how much torque was applied during installation. This research resulted in a powerful equation we still use today when designing helical piers.

It helps us figure out how much torque we need to apply to the helical pier in order to reach our desired capacity. We don’t use torque to confirm capacity, however. That’s best left to load-testing.

We use torque readings to confirm geotech reports, speed up installation, identify “problem soil” in real-time, and increase confidence in the foundation’s performance.

Long life

All things being equal (and in good soil conditions), an average helical pier could easily last well over 75 years under an energy storage system in the United States. While the exact lifespan of a helical pier foundation depends on a number of factors, they'll have no problem meeting the design life of your project.
Curious how long a helical pile could hypothetically last in U.S. soil? We wrote a blog post about it right here.

Helical Piers Vs. H-Beams for Battery Energy Storage System (BESS) Foundations

One of the most common foundations for battery energy storage systems (BESS) in the United States are h-beams.

Steel h-beam piles are a common foundation for battery energy storage systems (BESS)

Let me say first that I’ve got no problem with h-beam piers. There’s nothing inherently wrong with them. This isn’t a question of whether h-beams are good or bad. It’s a question of whether h-beam foundations are the best foundation for an energy storage system.

While the specific benefits can vary from project-to-project, on the whole a helical pier foundation could be more:● Safe● Efficient● Durable● Economical● Convenient● Eco-Friendly● Easy
Will a helical pier foundation always be better than a driven h-beam? I won’t say that because every project is unique – there’s too many variables to consider. In fact if you do run into someone that claims helical piers are always a better option, don’t trust them. They’re just trying to sell you something.

What I will say is, in the majority of energy storage system projects we've assessed, helical piers often offer a distinct advantage over other foundation solutions.

Conclusion

As renewable energy continues to grow we’re going to see demand for battery energy storage systems explode across the United States. 
The question you need to answer is what will you build your future on?

 Easier to transport, easier to store, easier to install. Helical piers have big benefits for BESS installations across the United States

I’ll never claim that helical piers are a “miracle foundation” or the “one answer” to all your foundation needs. That’s marketing hype.
What I am confident in claiming is that helical piles are often a faster, more economical, more efficient foundation for battery energy storage system (BESS) projects. And when you’re dealing with the environmental and construction challenges that come with renewable energy projects, you need every advantage you can get.
If you’re planning a battery energy storage system (BESS) installation or other renewable energy infrastructure, why not scroll down and have a friendly chat with one of our foundation experts? 
We skip the sales pitches and cut straight to the truth – which includes being honest if helical piers aren’t the right fit.