The Power Group’s Impofu Wind Farm in Oyster Bay, Eastern Cape, needed an off-grid solution for its site office to reduce its reliance on a diesel generator for power supply. Rubicon supplied a battery energy storage system (BESS) container which includes the first 50kW Solis inverters to be installed in parallel worldwide. The solution was installed by Rubicon’s client, NH Solar.  

The client’s challenge 

The operations at the Impofu Wind Farm site office have relied on a diesel generator for power supply. This approach was costly and environmentally unfriendly. Challenges of diesel dependency include:  

• High costs: Diesel prices can be volatile, leading to unpredictable operational costs.  

• Environmental impact: Diesel combustion emits greenhouse gases and pollutants associated with environmental degradation.  

• Complex logistics: Depending on diesel requires frequent refuelling and related transport logistics. This can become impractical and costly.  

• Noise and maintenance: Diesel generators are noisy and require regular maintenance, impacting the work environment and operational uptime.  

The client’s requirements 

The client needed a solution that allowed them to move away from relying on their diesel generator for power. The solution needed to be scalable from 50kW to 100kW to cater for a potential increase in their power consumption needs. In addition, the client wanted a spare inverter for redundancy.  

The solution 

Rubicon supplied a BESS solution consisting of:  

• A customised 20ft container to house the BESS solution.  

• 190kWh of WeCo battery storage consisting of 36 x 5k3 batteries.  

• Three 50kW Solis hybrid inverters with a 10-year extended warranty. 

• The container is insulated and contains two Wi-Fi enabled air conditioning units to regulate battery temperature.  

• Stat-X Aerosol Fire Suppression was installed for enhanced safety.  

The three 50kW Solis inverters used for this project were the first in the world to be installed in parallel. The Solis inverters are smaller and more compact than the large battery inverters traditionally used in our BESS containers.  

The BESS solution was integrated with existing infrastructure, namely: 

• The existing generator to provide backup power during periods of low renewable energy due to unfavourable weather.  

• A 110kW PV system which was already installed on site.  

The results 

The client was impressed by Solis’ user-friendly interface which allows for complete monitoring of the system. Since the solution was installed, the Power Group have significantly reduced their diesel usage and only intend using the generators during severe weather conditions. 

By implementing the BESS solution, the Power Group's Impofu Wind Farm site office transitions towards a more sustainable and cost-effective energy model. This initiative not only addresses immediate operational challenges but also contributes positively to environmental stewardship and long-term financial viability. 

 Find out more about our Solar & BESS solutions.