John Lisle | January 18, 2023 | Helical Pier Environmental Impact

If you're building projects in renewable energy, oil & gas, or transmission and distribution, you have a lot to think about. Timelines, budgets, materials, equipment, permits, inspections, and on it goes. There's plenty to keep busy with when planning a new project or expansion to existing infrastructure.
There's another aspect you have to closely consider as well: the environmental impact of your project. 
Politicians, investors, the media, and the public, are all looking to the construction industry to make an even greater effort to reduce the carbon emissions of our projects. Here's the tough reality people outside the industry don't realize... reducing CO2 emissions isn't easy. 
Balancing cost, speed, and carbon emissions, is a tall order when we're talking about industrial construction.
Much of the emissions a construction project creates are caused by the raw materials being used. The production of steel, concrete, and plastics, releases CO2 into the atmosphere. So, it stands to reason that one of the easiest ways to reduce the carbon footprint of your construction project is to use less raw material.
This is why companies and contractors are looking to helical pier foundations to reduce their CO2 emissions. But, how do helical piers actually reduce your project's CO2 emissions? 
After all, helical piers are manufactured from steel, which is responsible for up to 9% of global CO2 emissions. Concrete is responsible for 8% of global CO2 emissions, a close second to the steel industry.
What gives? How can I claim that helical piers have a lower CO2 impact than concrete when both raw materials have similar overall carbon emissions?
Like pretty much everything when we're talking emissions, there's no "cut and dry" answer. In fact through writing this article I gained a greater appreciation for how complex answering this question really is. 
Time to tackle the big question: What the TRUE carbon cost of a helical pier foundation versus a concrete foundation?

Why You Should Care About Your Project's CO2 Emissions

There's a lot of opinions (and arguments) regarding the CO2 emissions our construction process produces.

At S&B Helical we're a team of foundation experts, not climate experts. This article isn't debating whether or not climate change is happening. Regardless if it's happening or not, it's clear the politicians, media, and public, expect you to reduce emissions in your construction projects.

Whether this intense scrutiny is warranted or fair can be argued. But, it's the reality for construction in the U.S.A and none of us can change it by complaining. 

The construction industry is expected to do more to curb our CO2 emissions - could helical pile foundations be one of the answers?

It's important to get that out of the way, because there's always "those people" who lose sight of the true issue and argue about whether climate change is a conspiracy or not. Even if climate change was a conspiracy that wouldn't change the issue you're facing right now:

How can you reduce the CO2 emissions of your construction project?

That's what we're focusing on today.

Why Carbon Emissions of Helical Piers vs. Concrete Foundation Are Complicated

Calculating the CO2 emissions related to a construction project is a complex question to tackle. 
Everything from the raw materials you use to how many personnel and equipment are on-site will affect your environmental impact.  
This makes calculating the "carbon cost" of a helical pier foundation versus a concrete foundation a little tricky. There's countless variables that will affect your total CO2 emissions. I don't want to get stuck in details like emissions from excavators or concrete trucks. I'll touch on that topic shortly, but it's not our focus. 
To keep things straightforward, we're just interested in the overall carbon cost of the raw materials of a helical pier foundation versus a concrete foundation. We won't factor the CO2 emissions from equipment, transportation, personnel, or other sources.
That in mind, here are some variables that affect the CO2 emissions of your foundation.

Where was the raw material produced? 

Different countries have different environmental laws surrounding the production of steel and concrete. China, for example, has much looser regulations on pollution so steel produced there tends to have higher carbon emissions than domestic steel. 
One study found that Hot Dip Galvanized (HDG) steel produced in China emitted 50% more greenhouse gas compared to North American HDG steel.

American-produced steel, on the other hand, tends to be comprised of recycled steel which produces lower CO2 emissions. 
According to the American Institute of Steel Construction, American steel mills recycle over 70 million tonnes of scrap each year.

How was the raw material produced? 

Steel can be produced in a blast furnace-basic oxygen furnace (BF-BOF) or in an electric arc furnace (EAF).

A BF-BOF melts down iron ore to create steel material, a process that produces huge amounts of CO2 emissions. 

An EAF, on the other hand, takes recycled scrap and transforms it back into useful steel, which requires fewer emissions. EAF's can also be run using renewable energy which cuts their emissions even further.

How far did the raw material travel?

Some helical pier manufacturers in the U.S.A. use steel from China to build their piers, while others source materials from North America. If you put hundreds of tonnes of steel on a boat and transport it thousands of miles, it increases the final carbon emissions of that material. 
Cement is no different. 
The Mineral Commodity Summary for Cement for 2022 published by the National Minerals Information Center at the USGS stated that domestic U.S. cement production was slowed by inexpensive cement imports - and at least 43% of cement imports were from overseas.

It goes without saying, but sourcing raw materials closer to home will reduce the CO2 impact of your foundation.

What type of machines/equipment are needed to install the foundation? 

Cast-in-place concrete foundations need quite a few machines for installation. Cranes, loaders, skid steers, excavators, pump trucks, and mixers, to name a few.

Each machine or piece of equipment on your project adds to your overall carbon emissions. Not only that, but each new machine also adds to your construction costs. 

Helical piers have fewer equipment requirements compared to concrete foundations, which lowers your overall CO2 emissions

High-capacity helical pier foundations tend to require much less equipment overall. For example we installed a helical pier foundation for a one-million pound slug catcher using just one excavator, one skidsteer, one arm-loader, a tractor-trailer, and a 1-ton support truck.

The less fuel-guzzling machines you need on site, the fewer emissions your project will produce.

Are recycled raw materials being used to manufacture the foundation?

Virgin steel could emit up to 350% more CO2 compared to recycled steel. That means the type of steel that's used in your foundation will impact your final emissions figures.

According to Materials Palette, recycled steel typically contains as much as 97% recycled content overall. Steel can also be recycled infinitely without losing any of its integrity or structural properties.

Concrete can be reused or down-cycled, but it's not a true recyclable material. You can't crush concrete and turn it back into a functional mix. It can be reused as aggregate but still needs cement and other materials mixed back in. 
It's still a good idea to re-purpose concrete waste, but it shouldn't be considered "recyclable". 

How much raw material is required for the foundation?

This is one of the biggest contributing factors to the overall carbon emissions of your foundation. How much raw material do you need to manufacture and install your foundation? 
It's where things start to get a little more complicated. In fact, we'll need a whole other section just to dive into it. 
Keep reading.

Carbon Emissions Per-Tonne for Helical Piers Vs. Concrete Foundations

Which is heavier - 1000lbs of steel or 1000lbs of concrete?

I know I know, it's an age-old dad joke (I'm a dad, what can I say).

It also illustrates an important point about steel helical pier foundations versus concrete foundations:

1000lbs of steel helical pier does not equal 1000lbs of concrete foundation.

Helical piers are, by nature, vastly more efficient in their design than a concrete foundation. That's not to say a concrete foundation can't be well-engineered or that it can't be efficient, it certainly can be.

Overall, though, helical piers require less raw material, equipment, and time, to manufacture and install. 
Because of the unique design of a helical pier, we can replace hundreds of tonnes of concrete and get the same (even better) support. 

Like I mentioned above, the amount of raw material you need for your foundation will have the biggest impact on your CO2 footprint. 
I think the best way to demonstrate that is by comparing the CO2 emissions of a helical pier foundation and the comparable poured concrete alternative.

Helical Pier Foundation Specifications

Total Piers Required: 408Weight of Steel: 152tFinal Weight: 152t

Like we saw earlier, there's several factors that affect the carbon footprint of steel. How it's produced, where it's produced, and how much recycled material is used are a few.

The Steel Manufacturers Association published an independent report that calculated CO2 emissions for the manufacture of steel in the United States. I'll be using their numbers to calculate the CO2 emissions of steel to keep things simple.

Their report indicated that "virgin steel", new steel that's created using a Blast Oxygen Furnace (BOF), releases an average of 1.67t/CO2 per 1t of steel produced. 
Recycled steel that's produced in an Electric Arc Furnace is much more efficient and only produces 0.37t/CO2 per 1t of steel produced.

Here in the U.S. almost 70% of all our domestically produced steel is recycled steel. That makes it a little tricky to know whether to use a figure of 1.67t/CO2, 0.37t/CO2, or something in-between, when calculating the carbon emissions of the raw steel material.

To keep things simple, I'll calculate the CO2 emissions of steel using a "worst case scenario" of 1.67t/CO2. 
Just know that your actual CO2 numbers will vary depending on how your structural steel is produced. In North America the odds are it will be recycled steel produced in an Electric Arc Furnace, which will lower your CO2 emissions.

One more thing to keep in mind. These calculations only hold true for steel produced here in North America.

Steel sourced from China tends to have a higher carbon impact overall due to how it's produced and the overseas shipping. That's one reason we only source materials produced here in North America. It reduces the carbon footprint of our foundations while also ensuring better raw material availability and service for our customers. 

Calculating CO2 Emissions for a Helical Pier Foundation

The CO2 emissions of your foundation can vary depending on where your helical contractor sources raw materials and how their helical piers are manufactured.

Remember that our helical pier foundation required 152 tonnes of raw steel material to manufacture the piers. All we need to do is multiply the tonnage of steel we need by the CO2 emissions per-tonne of steel (1.67t/CO2). This gives us:

152t steel * 1.67t/CO2 = 254t/CO2 emissions

In order to produce the raw materials needed to manufacture the helical pier foundation to this project, it's going to output 254 tonnes of CO2 into the atmosphere.

How does that compare to concrete? Let's find out.

Concrete Foundation Specifications

Total Piers Required: 336
Weight of Steel Rebar: 88t
Weight of Concrete: 1427t
Final Weight: 1515t

CO2 Emissions For a Concrete Foundation

Let's calculate the CO2 emissions of the rebar first, using the same 1.67t/CO2 per 1t of steel as above. Recycled steel has a lower carbon impact, but I'm using the "worst case" emissions figure for the sake of simplicity.

We need 87t of rebar to reinforce the concrete, which makes our equation for the steel look like this:

87t steel * 1.67t/CO2 = 147t/CO2 emissions for steel rebar

Now we know the carbon cost of the steel, but what about the concrete? This is where it gets tricky. 
One of the key ingredients of concrete is cement, and it's cement that's responsible for the majority of emissions when it comes to concrete production. Other materials, like quarried or recycled aggregate, contribute very little to emissions compared to cement.
The IEA calculates that 0.5t/CO2 to 0.6t/CO2 are produced per 1t of concrete. Other companies report up to 0.7t/CO2. 
Since we're calculating a "worst-case scenario" with our steel emissions, we'll continue the trend with concrete and calculate the emissions using the figure of 0.7t/CO2 per 1t of concrete. 
Remember, these figures are to help paint a picture of the emissions cost of helical pile foundations compared to concrete. If you want a more accurate picture of what the CO2 emissions for your foundation would look like, get in touch with our team and we'll calculate it for you.
This foundation needs 1427t of concrete, which produces a CO2 cost of...
1427t concrete * 0.7t/CO2 = 999t/CO2 emissions for concrete

Now, we add the CO2 cost of the rebar and concrete together:

147t + 999t = 1146t/CO2 emissions total for concrete foundation

In order to produce the raw materials needed for this concrete foundation, it will output 1146t/CO2 into the atmosphere.
Let's talk about what these (shocking) results mean. 

Summary: The True Carbon Cost of Helical Pier & Concrete Foundations

Our final CO2 emissions figures for our helical pier foundation came out to 254t/CO2. 
This might have seemed like a lot of emissions, until we compared it to the 1146t/CO2 emissions a comparable concrete foundation solution would create. 

In our example, a concrete foundation solution would output 351% more CO2 emissions compared to helical piers. But, CO2 emissions aren't the only consideration when it comes to assessing the environmental impact of your foundation.

The helical pile foundation in our example would use 163% less raw material than a comparable concrete solution. That means there's less raw material removed from the earth, less processing required for that materials, and less weight to transport.

Here's one more way to think of it...

By using helical piles instead of concrete for our example foundation, it would save the CO2-equivalent of taking 194 passenger vehicles off the road for an entire year.

And remember, these calculations were all done using the "worst case scenario". It's very likely that, depending on where you source your foundation, your CO2 emissions will be even less.
Of course, this isn't a scientific paper and I'm not an expert on the complexities of global CO2 emissions. In the real-world, the precise CO2 emissions of your foundation will depend on things like:● Where was the raw material produced? ● How was the raw material produced? ● How far did the raw material travel?● What type of machines/equipment are needed to install the foundation? ● Are recycled raw materials being used to manufacture the foundation?● How much raw material is required for the foundation?
What I hope this article did was give you a better appreciation of how much more efficient a helical pier foundation can be when compared to concrete. In this example, we could replace 1515t of concrete and steel rebar with a mere 152t of steel helical piers. 

Conclusion

The scrutiny we face in the construction industry about our CO2 emissions isn't going away. In fact, it's only going to become more intense in the coming years. 
There's no better time than right now to get ahead and reduce the environmental impact of your projects, keep regulators and investors happy, and enjoy a faster and safer foundation installation. Not only does it make better sense for your project, it makes better sense for our communities and the future of our planet.
If you'd like to learn more about helical piers and how they can slash the carbon emissions impact of your project, scroll down to talk to one of our foundation experts.