Steel Tanks vs. Concrete Tanks: a comparison

The differences between steel tanks and concrete tanks remain a crucial question as industries and businesses increasingly prioritize energy efficiency and sustainability. In a context such as this, the choice of materials for storage tanks becomes paramount. 

This is particularly true in the case of critical structures such as Thermal Energy Storage (TES) tanks. In a rapidly evolving world marked by an increasing demand for sustainable energy solutions the role of Thermal Energy Storage (TES) tanks has never been more pivotal. 

TES tanks represent a storage medium that allows for the efficient storage of thermal energy, typically in the form of heat or cold. Designed to store and release energy on demand (making them useful for heating and cooling), the choice of materials for TES tanks is fundamental to their efficiency.

This is precisely where the comparison between steel tanks vs. concrete tanks remains crucial, as these are reshaping the landscape of energy production and consumption.

While both steel tanks and concrete tanks have long been at the forefront of tank construction, let’s take a look at which one holds the key to optimal thermal performance.

5 differences between steel tanks and concrete tanks

Lifespan

The lifespan of steel and concrete tanks can represent a deciding issue when considering how to successfully implement an energy storage system.

On the one hand, it’s worth noting steel tanks are susceptible to corrosion, but proper coatings and maintenance are able to extend their lifespan way past the use of concrete tanks.

On the other hand, concrete is generally more resistant to corrosion and presents an extended working life. While it can deteriorate over time due to chemical exposure and freeze-thaw cycles (and potentially lead to leak issues), regular maintenance can avoid related issues.

Considering long-term performance of steel tanks, maintaining insulation and addressing potential thermal bridging is crucial to avoid degradation of thermal insulation materials over time, affecting their thermal efficiency.

CAPEX

Stainless steel can be more expensive than other alternatives, and its maintenance costs can also be higher. However, this higher initial cost is often offset by its longevity and resistance, which can lead to lower long-term expenses. 

The option of pre-fabricated stainless steel tanks is often a choice for a lower initial cost, one that can efficiently serve a small-scale project. 

On the other hand, bigger projects searching for a low initial cost might look into the option of a reinforced concrete tank.

Construction times

The differences in construction times often depend on the material properties, construction techniques and the size and complexity of the tank. 

Typically,  steel tanks can be quicker to fabricate off-site compared to concrete tanks. This means steel tanks are often assembled on-site from pre-fabricated components, which can lead to faster construction times, particularly for standardized designs. 

As opposed to this, concrete tanks typically involve more on-site construction, including formwork, pouring, and curing, which can extend the construction timeline.

However, there are options that see the concrete being precast/prestressed, meaning less occupied area and lower installation times.

It must also be noted that steel tanks represent a more mobile option: while concrete tanks, steel tanks can be relocated.

Available shapes 

The choice of material for thermally-efficient tanks, whether steel or concrete, can influence the available shapes for the tanks. 

On the one hand, steel tanks offer greater flexibility in terms of shaping and customization. As such, they can be easily fabricated into various shapes and sizes (cylindrical, rectangular, spherical, irregular…) to meet specific project requirements. This makes steel tanks particularly well-suited for complex and non-standard designs, making them ideal for accommodating unique site constraints or specialized functions.

On the other hand, concrete tanks, while versatile in terms of size, tend to be more limited when it comes to shapes. They are typically constructed in traditional shapes such as cylindrical, rectangular or square.

This means that customizing the shape of concrete tanks can be more challenging and may require specialized formwork and construction techniques, which can increase costs and construction times.

Sustainability

The choice between steel and concrete as materials for thermally-efficient tanks can have significant implications for sustainability. Both materials have unique environmental impacts. 

Steel is highly recyclable, and the use of recycled steel in tank construction can significantly reduce the environmental impact. On the other hand, concrete is difficult to be recycled, but presents a long lifespan, resulting in lower long-term environmental impact.

The production of steel typically consumes less water compared to concrete production, which often requires significant water resources for mixing and curing.

However, it’s possible to address all these issues from an integral design perspective, so that sustainable tank design and construction practices are implemented, including insulation and site selection, to further reduce the environmental impact of these vital infrastructure components.

Steel tanks vs. concrete tanks: a summary

As we’ve seen, the choice between steel and concrete for thermally-efficient tanks is influenced by factors such as project size, customization requirements, environmental conditions, maintenance considerations and budget constraints.

It's important to conduct a thorough analysis of the specific project needs and consult with engineers and experts to determine which material is the most appropriate for the given application.

Additionally, here are some closing thoughts on the comparison between steel tanks vs. concrete tanks in the shape of the recommended cases of use for both steel tanks and concrete tanks: 

Steel tanks are usually a better option in several scenarios: 

• Projects with high customization requirements, as they can be easily fabricated to meet specific design needs.
• When project timelines are a critical factor, steel tanks are a good choice due to their quicker construction times, especially for standardized designs.
• In applications where tanks may be exposed to corrosive chemicals or harsh environments, steel tanks can be designed with appropriate coatings and materials to resist corrosion effectively.
• Steel tanks will also be a preferred choice when tanks may need to be moved or relocated, as they can be disassembled and reassembled more easily than concrete tanks.

On the other hand, the recommended cases for concrete tanks are:

• Projects that do not require custom shapes or sizes, and present traditional cylindrical or rectangular tanks 
• Larger capacities
• Areas with specific limitations, such as those with high water table or regions prone to seismic activity
• Projects that require an underground site location
• Projects that require an integration with an existing building

At Araner, we’re committed to offer extraordinary thermal engineering for our clients. As part of our  services, we are in charge of designing, fabricating and implementing efficient thermal storage tanks, including cutting-edge technologies such as stratified thermal energy storage systems. 

Looking for the right material for your TES project? Get in touch with our team and learn more about our work and how we can help you achieve an efficient, sustainable structure.