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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

A 200kW PV peak grid tied PV system was installed at Quality Tyres Lafrenz Industrial Area. Remote monitoring of all 10 inverter allows for early fault detection and system degradation as well as maintenance planing.

System Specifications are:

• 680x 295W Canadian Solar modules
• 10x Fronius Symo 20.0-3 Grid Inverter
• Roof mounting structure for IBR roof sheeting
• AC surge protection
• configured for remote monitoring

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.

After successful completion of the Omusati off grid electrification project, CTS was successful in winning the bid for the second phase of containerized PV solutions for the Kunene region. With the experience gained from phase 1, the containers were optimized in many ways. The final design consisted custom build 20ft container by Namspace in Swakopmund.

Sites that were electrified in the Kunene region are:

• Otjitjekua School
• Otjiu School
• Otjiu Hostel
• Epupa School

The project included the following:

• Upgrading of all government building wiring as per national standard for 4 sites in the Kunene 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 4,500 Ah of battery capacity. Five kVA inverter charger and two 70A BlueSolar Charge regulator all from Victron Energy complete the system. Remote monitoring of all sites is achieved by using the Victron Color Control GX unit.

A 1.5t boiler was installed at the Hartlief factory to cater for the growing needs of steam. The project included:

• Installation of new steam boiler next to the existing boiler
• Modifications to HFO line to cater for new boiler
• Commissioning

Over the past year's minor refurbishment, maintenance and upgrading projects where completed as well such as:

• Installation of condensate pumps to reduce back pressure of equipment inside the factory
• Raising current condensate storage tanks to increase head pressure for feed water pumps
• Three monthly service of both steam boiler and yearly inspection with Ministry of Labor inspectors
  

Based on our excellent service and knowledge we have rendered to the Botswana Meteorological Department as well as University of Hamburg, CTS was able to secure the 2nd Phase of the manufacture, supply and installation of automatic weather stations in Botswana.

The stations supplied to make use of satellite communication due to the extreme remoteness of the sites, these were:

• Mababe (Savuti Marsh)
• Tubu (Okavango)
• Baines Drift (Eastern Botswana)
• Xade (Central Kalahari Game Park)
• Ngwaltle (Western Botswana)

These stations are not located at any Meteorological Department property, thus fences had to be erected for protection against animals.

Station design is based on our well proven tripod mast with all relevant sensors and a CR1000 logger as the processing unit. Data is transmitted at fixed timeslots allocated by EUMETSAT (Germany) on an hourly basis. Satellite transmission is based on a fire and forget principle, thus no remote maintenance can be done.

Weather data can be found at: http://www.sasscalweathernet.org .