With the global trend of microgrid hybrid power solutions, solar solutions company Vert Energy was presented with a unique opportunity by property development company O’Nit Developments, whose strategic intent was to develop a power management solution that optimised the available energy sources at the Point Business Park project in Johannesburg, Gauteng. The interactive microgrid solution aims to manage the mains utility, photovoltaic inverters, and an emergency standby generator in one system.
Conscious of the rising utility costs and the need for reliable backup power solutions, the customer wanted a solution that it could easily manage from remote off-site locations. Vert Energy, in conjunction with renewable energy instrumentation collaborator Danish Electro & Instrumentation Factory (DEIF), embarked on the design and installation of generator controls for the total energy system. The end result has been a dependable, environment-friendly, safe and cost-efficient source of power at the business park, even during periods of load-shedding.
The Point Business Park comprises a variety of office units with various office warehouse configurations, business park amenities, and a diverse mix of services and fit-outs depending on business needs.
The solar power system at the park ensures that fuel-consumption and emissions from the backup generator have also been reduced, and maintenance requirements of the system remain minimal.
“This installation, with remote monitoring and remote access, offers our client full control over the system from anywhere in the world,” explains Vert Energy DEIF sales and support engineer Jacques Opperman.
He explains that the installation involved the integration of electric power generation products, including power from the national grid, a rooftop solar plant, a generator and load controls.
Opperman also points out a key element that he claims many people are unaware of when it comes to grid tied solar solutions. “In the event of a mains failure by the utility, the photovoltaic (PV) inverter has no voltage or frequency reference point, and so the entire PV system becomes redundant with no power or control.”
A standby generator is therefore used to provide this key reference point. However, many other controls need to be put in place to create optimal load management conditions on the generator, either preventing glazing of the cylinders or preventing the generator from using too much fuel with inadequate load sharing.
In addition, there is no control over the mains breaker and the exporting of power back into the grid. The power management system optimises these sources and creates the controls and protections over the various energy sources.
“As exclusive representatives of DEIF in Southern Africa, Vert Energy is privileged to represent a company that is at the forefront of innovative control systems for decentralised power generation solutions in Southern Africa,” adds Vert Energy sales and marketing director Ryan Robertson.
The DEIF brand encompasses generator set (genset) controllers, protection relays and interfaces, as well as switchboards and panels – offering advanced control technology features for high performance, high accuracy, improved safety, low maintenance requirements and reduced downtime.
To ensure the efficiency, protection and control of the Point Business Park installation, Vert Energy installed DEIF automatic genset controllers (AGCs) for applications such as back-up power, start/stop, synchronisation and load-sharing.
DEIF automatic sustainable controllers (ASCs) were used to maximise sustainable power penetration, depending on the total load demand to the hybrid system, without compromising constraints such as minimum genset load demand.
Opperman says this fully control-integrated system was the first sustainable control solution for renewable energy of its kind to be installed in South Africa, and the first to use DEIF’s power management solution with load control. The system provides a safe and reliable link between renewable-energy inverters and traditional diesel generators, he adds.
He explains that the system was designed to showcase its capabilities on a small-scale project for future implementation on much larger-scale projects.
“The system has a full power management solution and an integrated solution for managing loads when power sources are limited. This can be useful, for example, when then there is very low solar-power production while the system is on full production on the load side, and is running on generated power only,” Opperman explains.
In the Point Business Park installation, an AGC-4 controller manages and controls the incoming line from Eskom, an AGC-150 controller offers control and protection to the generator, while the ASC-Solar controls the photovoltaic solar plant, and automatic load controllers (ALC-4s) control the load feeder breakers.
Historically, system integrators have encountered challenges when integrating multiple control systems between the photovoltaic controller, or inverter, and that of the generator.
The benefit to the client in this instance was that the DEIF ASC-4 Solar seamlessly integrated with the generator’s controller, without any bespoke programmable logic controller programs and additional interfaces, consequently resulting in a total power management solution of the utility, photovoltaic system and generator.
The busines park owner also upgraded the supply transformer on site to accommodate heavy demand, and to ensure that the facility does not exceed the rated power during operations and can operate efficiently during load-shedding. Lightning protection devices were also fitted to prevent damage to equipment on site.
With the growing trend towards using photovoltaic technology to convert solar energy to electricity, Opperman emphasises the importance of incorporating quality branded electric power generation products into gensets. He also highlights the need for technically-competent support to ensure the dependable performance of every photovoltaic system.
“As solar integration becomes more feasible for larger companies, this solution will become more popular. For future projects, the project dates can be extended to suit the needs of the end-user. All such projects have slight variations, as few projects are exactly the same,” says Opperman.
Vert Energy is now working on larger-scale projects, with the company currently busy with the final stage commissioning of a multi-MW project combining wind turbines, diesel generators and utility sources.
Robertson firmly believes that these different scale projects have strategically positioned the company to deliver bespoke power management solutions to private companies and independent power producers alike.