Home | Central Technical Supplies

This is a typical photovoltaic (PV) medium scale farm system found on many farms around Namibia. Over the past three years this system grew in PV size from 350Wpeak to ~1200Wpeak.

System specs are:

• PV modules with a total capacity of 1220Wpeak
• 1200VA, 24V Inverter charger
• 40A Solar Charge Regulator
• 360Ah battery bank@24V
• Battery Monitor showing: state of charge (%), charging/discharging current (A), Battery Voltage (V) and time to go (h)
• Switchgear for submersible pump control

The PV modules are mounted on frames facing true north for optimal energy harvesting. During times of limited sunshine, especially the rainy season, battery charging can be increased by starting the generator. Should the AC load increase behind the inverter rating, the generator can support the system to cater for the increased load. No automatic generator start function is included.

Furthermore a second PV system for the Farm workers has been installed to cater for lighting and a TV.

• 2x 90Wpeak PV modules
• 20A Solar Charge Regulator
• 2x 105Ah batteries
• 350VA, 12V inverter

CTS was awarded the first ever containerized off-grid solar electrification tender for the Ministry of Mines and Energy beginning of 2013. This project entailed:

• Upgrading of all government building wiring as per national standard for 9 sites in the Omusati region
• Manufacture, supply and install container power units for these sites.

The power containers consisted of ca 2.8kW of PV modules installed on the roof as well as 3,000 to 4,500 Ah of battery capacity depending on site requirements. Five KVA inverter charger and two 70A Blue Solar Charge regulator all from Victron Energy complete the system.

With a total of nine containers, school, hostels and other government buildings were electrified. Each container was subdivided into two rooms for batteries and inverter technology respectively.

With our 36T/m crane truck CTS was able to transport the container to site, navigating through thick sand with ease.

Central Technical Supplies was once again awarded the tender to electrify 4 remote localities in the Otjozondjupa Region of Namibia. Custom build containers where installed on site with SMA Sunny Island 8.0 inverter installed. In addition the offered lead acid battery technology has been replaced by state of the art lithium batteries reducing system maintenance. The use of AC coupled technology did allow for the SunnyBoy solar inverter to be in installed inside relevant buildings on which PV modules are mounted. All components are interlinked by means of wireless technology to allow for remote monitoring where GSM signal is of sufficient strength. System sizes vary form 3kW, 12kW, 15kW to 20kW of PV power while inverters are as much as 3 in a single phase cluster.

Sites that were electrified are:

• Nhoma
• Aasvoel Nes
• Kanovlei
• Grashoek

CTS was approached by a senior resident of Klein Windhoek to install a grid-tied photovoltaic system with the aim to cut back on the monthly electricity bill. The system included:

• 42x 130W photovoltaic modules and mounting structure
• 1x 6kW grid tied inverter

The system is designed such as to generate an estimated 900kWh per month.

The installed photovoltaic system at Elavi Clinic caters for the power supply to the clinic as well as the nurse houses. A 6.2kW PV module array generates enough power for the energy requirements. Should this not be sufficient the batteries can be charged by a backup generator.

The system consists of the following:

• 6.24 kW PV array
• 2x Victron BueSolar 150V/70A MPPT regulator
• 600Ah Battery capacity
• Inverter/Charger, Victron Multi, 48V/8000VA
• System Monitoring (BMV700, Color Control GX)

An off gird PV system with generator back up was installed at the Gcwatjinga clinic south east of Rundu. The system comprises of the following components:

• 6.24 kW PV array
• 2x Victron BueSolar 150V/70A MPPT regulator
• 600Ah Battery capacity
• Inverter/Charger, Victron Multi, 48V/8000VA
• System Monitoring (BMV700, Color Control GX)

The clinic was connected to the grid, which at time of system design and installation the grid connection plans were unknown to the engineer. As the clinic has PV installed, the existing system has been configured such as to allow for grid connection once the batteries reach a predefined SOC. This guarantees a continuous supply of power to the clinic and nurse houses.

In addition to the grid, a backup generator is incorporated in case PV as well as grid failure occur.