How Aqunion abalone farm threads the cost-effective solar needle

Aqunion CEO Rowan Yearsley would like to expand the solar project, but is mindful of the overinvestment risks.

For Aqunion, solar energy has brought both benefits and challenges.

Yearsley explained that the company's initial solar installation was driven by the need to quickly integrate renewable energy into their operations.

"To implement these solar panels relatively quickly, we decided to instal them on our existing footprint above the abalone tanks,” he said.

“But in this installation, about 30% of the investment cost is actually the structures to place the solar panels above the tanks.”

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While this setup has worked well, particularly since the shading benefits the abalone, Aqunion is now exploring more cost-effective options.

"Our next solar investment would likely be ground-mounted," Yearsley noted, saying that this approach could reduce structural costs and better utilise the available space on their farm.

Balancing energy production and usage

One of the significant challenges Aqunion faces is aligning solar energy production with their energy needs, especially given the seasonal variations in energy demand.

"The size of the current solar system is sufficient for our needs in summer, but it's less than what we require in winter," Yearsley explained.

This creates a scenario where excess energy is produced in the summer, leading to potential wastage without an agreement to sell the surplus.

To mitigate the risk of overproduction, Aqunion is looking to enter into agreements with local municipalities to offload excess energy during peak production periods.

This step is crucial in avoiding the financial pitfalls of overinvestment, where the cost of generating unused power can outweigh the benefits.

Partnering for solar success

Aqunion is walking this journey toward solar energy in partnership SPS, a finance and engineering services company specialising in turnkey renewable energy solutions across sub-Saharan Africa.

"We started meeting with Aqunion in 2023 to discuss the possibility and feasibility of solar and battery solutions at their various facilities," Anja Visagie, head of project development at SPS, shared at the ribbon cutting.

Following these discussions, Aqunion issued a competitive tender, which SPS won, marking a significant milestone for both companies.

SPS brought its extensive experience in renewable energy to the table, including its pioneering work in the industry.

Power purchasing model

"In 2015, SPS joined forces with Metal Solar Investments, which enabled us to not only offer quality engineering solutions but also provide funding and PPAs," Visagie said.

Power purchase agreements (PPAs) allow SPS to own the solar plant and sell electricity to clients like Aqunion, eliminating the need for upfront capital investment and providing immediate savings.

This model has helpful for companies looking to transition to renewable energy without the financial burden of large-scale infrastructure investments.

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While Aqunion is eager to increase its renewable energy usage, the company is proceeding with caution.

"We've taken it in what we thought were manageable increments. Currently, we saw the right way to get to 30% renewable energy, and we can see a way to get to 50% next," Yearsley said.

However, achieving a higher percentage remains a complex challenge due to the technical limitations associated with seasonal overproduction.

Microgrid masterpiece

Johan Wolmarans, SPS's senior energy storage specialist

Aqunion's journey into renewable energy began with a clear mandate: achieve energy security while realising cost savings.

Johan Wolmarans, SPS's senior energy storage specialist, described the project as a "juicy problem for engineers to sink their teeth into," given the need to seamlessly integrate cost-saving solar power with reliable backup energy to prevent any disruptions to critical systems, such as the abalone farm’s pumps.

It's important to note that the system itself does not just consist of solar panels and batteries. It's so much more.

"There was absolutely no break in energy delivery allowed," Wolmarans explained, highlighting the importance of maintaining uninterrupted power to safeguard the farm's operations.

According to Wolmarans, "It's important to note that the system itself does not just consist of solar panels and batteries. It's so much more."

Robust system

At the heart of this system is a microgrid controller, which Wolmarans likened to a "musical conductor" orchestrating the various components to work in harmony.

This microgrid controller integrates not only the new solar and battery systems but also existing infrastructure, such as the hydro plant and backup power systems.

The result is a robust and resilient energy network that can seamlessly switch between on-grid and off-grid operations without any interruption in power delivery, a critical feature for maintaining the farm's operational continuity.

The SPS philosophy is to procure all these components individually and to find the best in class for every technology, for every subsystem.

"The batteries themselves have integrated fire detection and suppression systems inside," Wolmarans noted.

Additionally, the batteries are equipped with a liquid cooling system, which, despite its seemingly contradictory nature of both heating and cooling, ensures that the battery cells maintain an optimal temperature.

This not only enhances performance but also extends the lifespan of the batteries, making them a sustainable choice for long-term energy storage.

Stability

The battery inverters, which are also liquid-cooled, play a crucial role in maintaining the stability of the microgrid.

Abalone thrives under the shade of the solar panels

These inverters are capable of switching between on-grid and off-grid modes without any power interruption, a feature that ensures operations remain unaffected by external power fluctuations.

"The SPS philosophy was, and still is, to procure all these components individually and to find the best in class for every technology, for every subsystem," Wolmarans explained.

This helps ensure that each part of the system, from the solar panels to the battery inverters, contributing to the overall efficiency and reliability of the energy solution.

Visagie highlighted the company's ability to learn and adapt from previous projects, such as the installation of the largest rooftop PV system in Namibia and off-grid systems in Kenya.

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Managing risks

As Aqunion continues its solar energy expansion, the company remains focused on managing the risks associated with overinvestment.

The partnership with SPS ensures that Aqunion benefits from cutting-edge technology and innovative financing models, making their renewable energy goals more attainable.

As they prepare to export to the European Union, Aqunion's commitment to sustainability is expected to resonate well with international markets, further solidifying their position as a leader in the aquaculture industry.