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After close to 20 years of operation, the existing electrically heated hot water boilers were replaced. A modern, energy efficient system supplied by Stiebel Eltron was installed. The system comprises of the following:

2x heat pumps
5x 1000L hot water tanks (with electrical backup)
1x Control panel with remote monitoring and SMS alarm functionality.
2x booster pumps to feed the hotel with water during times when municipal supply is shut off

The installation has been achieved in a 3 week period. All works have been carried out with minimal interruptions to the hot water supply to the hotel. Remote monitoring of the plant in included to assist the client with possible troubleshooting, thus avoiding unnecessary trips to Lüderitz. SMS communication allows the quick reaction times of hotel maintenance personnel to act in cases of municipal water loss.

Central Technical Supplies was approached by the University of Stellenbosch to take part in a tender to supply a solar resource measurement station to the Namibia University of Science and Technology in Windhoek.

We were successful in winning the tender. The station is based on the Kipp and Zonen Solys 2 sun tracker with CMP 10 Pyranometer and CHP1 Pyrheliometer.

The station is based on the CR1000 logger from Campbell Scientific and measures wind speed and direction as well as ambient temperature, humidity and rain in addition to the solar resource data.

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

Ministry of Agriculture through, through SASSCAL funding, did acquire 3 automatic weather stations in 2018 which where finally installed in 2019 after sites have been determined. These stations from part of the existing SASSCAL weather station network that has been established over the past years. All stations conform to SASSCAL requirements and are inline with WMO standards.

The stations are installed at :

• Dudukabe (Zambezi)
• Okalongo (Ohangwena)
• Omafo (Ohangwena)

Station info can be obtained from www.sasscalweathernet.org

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 

CTS was awarded the tender to install a water heating system for the Hilton Hotel Windhoek.

The system was installed according to the following specifications:

•    2x 250kW gas fired hot water boiler

•    2x 6800 liter hot water storage tank (also known as calorifier)

•    1x Danfoss Aqua drive 11kW for glycol circulation pump control

•    2x Automatic bypass valves to control water temperature inside tank

•    4x Hot water circulation pumps

The boilers as well as glycol circulation pumps and one hot water storage tank were installed in the boiler room located in the upper basement of the hotel. The second hot water storage tank is installed on the 9th floor of the Hilton Hotel. A glycol circulation system connects the two calorifier with the two gas fired hot water boilers. The glycol circulation pumps are controlled from one Danfoss Aqua drive with cascading functionality to control the pumping speed depending on the temperature in the glycol line.

Each hot water boiler is cycled on a 24 hour basis, should the glycol temperature fall below a predetermined threshold for certain period of time the second boiler will start automatically.

Automatic bypass valves guarantee that the water temperature of each calorifier is kept at a constant 60 – 65 degrees Celsius.