Home | Central Technical Supplies

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.

Pionieerspark Medical Centre can call themselves a proud owner of a 38kW photovoltaic grid feed system. Considerable savings on the monthly electricity bill are achieved as most of the electricity requirements are produced directly at the customer. Excess energy is fed back into the grid and credited on the monthly electricity bill by City of Windhoek.

The system consists of 144 265W PV modules mounted flat on the roof of the building with 2 Fronius three phase grid feed inverters and remote monitoring via the Fronius App on the cell phone. Remote monitoring allows CTS to advise the client on possible faults and recommended actions to be taken.

A modern hot water plant was installed based on heat pump technology. Stiebel Eltron storage tanks as well as heat pumps are supplied that are extremely energy efficient and long life expectancy while at the same time low on maintenance. Further energy savings are achieved as the system is connected to heat recovery units as part of the refrigeration plant.

The challenge of such a system is to guarantee even loading and unloading of the tanks with water to guarantee a uniform temperature distribution in all tanks. This has been achieved by careful piping planing based on the Tichelmann principal.

The system comprises of the following:

• 6x 1000 L buffer tanks
• 2x 23kW heat pump units.
• various pumps and control unit

CTS has supplied 21 weather stations for the Biota research project. These weather stations are designed according to world meteorological standard.

Each station consists of:

• Wind Speed and Direction Sensor
• Irradiance Sensor
• Humidity/Ambient Temperature Sensor
• Barometric Pressure Sensor
• Ground Temperature Sensor
• Leaf Wetness Sensor
• Rain Bucket

The weather stations are equipment with the CR1000 logger from Campbell Scientific. Special software has been developed to allow automatic transmission of the weather data to a server based in Germany via GPRS using the local GSM network. Software updates can be done remotely minimizing travel.

Weather data can be viewed at: www.sasscalweathernet.org 

Three localities in the Otjozondjupa region where successfully electrified by means of Off-Grid PV containers. The system sizes varied from 6kW, 12kW to 25kW of PV power. PV modules where installed on roofs of nearby houses, batteries, inverter/charger and switchgear are located in our proven design of prefabricated containers to keep the components cool, even in the hottest of climates.

The system is an AC coupled PV system with SMA Sunny Island (SI 8.0) inverter and SunnyBoys of various sizes. Communication between all components is based on a wireless RS485 solution from Phoenix Contact with a distance covered of 1.5km.

Sites that were electrified in the Otjozondjupa region are:

• Rooidag Hek 
• M’Kata
• Kukurushe

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)