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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.

Central Technical Supplies (Pty) Ltd. – Geiger Engineering (CTS) was approached by Farmers Meat Market Mariental to design, supply and install a solar water heating system with the aim to reduce the monthly diesel consumption as two diesel boilers are operated to heat water up to 82 deg. C for production purposes.

The water requirements of the abattoir are as follows:

1. 2,000 liter/hour @ 45 C°
2. 3,000 liter/hour @ 60 C°
3. 500 liter/hour @ 82 C°

This adds up to a total daily water requirement at 60 deg. C of roughly 25,000 liter.

The system is design such as to preheat water from 18 deg. C to between 50 deg. C and 60 deg. C before supplying the diesel boiler system, thus reducing runtime and diesel consumption of the diesel boilers. A 20,000L stainless steel tank (non pressure tank) manufactured locally according to CTS design, acts as the buffer tank for the daily water requirement. A total of 120 flat plate collectors supplied by Solsquare Namibia with a total surface area of 300 m2 are connected by means of a 450kW Alfa Laval flat plate heat exchanger to the water tank.

A set of two Calpeda circulation pumps connected to Danfoss variable speed drives and a timer circuit guarantees at all times that the heat from the collectors is effectively transported to the water tank. Flow as well as temperature monitoring on all four ports of the heat exchanger make it possible to determine the instantaneous as well as accumulated kWh produced from the collector field.

Furthermore additional heating energy is obtained from the ammonia refrigeration plant. A heat exchanger is installed on the ammonia discharge side before the existing cooling towers to be able to heat the water during night time as well, as this is the time when the refrigeration plant runs at full capacity to cool down the newly slaughtered meat in the cold rooms. Again flow control and temperature monitoring on the hot water side of the heat exchanger accurately indicate heating energy obtained from the refrigeration plant.
A total of four pump sets have been installed and pumps are cycled on a 24 hour basis in automatic mode. Should at any given time a pump fail, the system can be switched to manual mode to be able to repair the pump without system down time and a resulting increase in diesel consumption.

All systems components are sized such as to allow for future heating capacity upgrades should it be required.

After a year of operation, the plant is performing better than expected and the client is able to safe nearly N$ 60,000 per month on diesel costs, bringing the payback period of the entire system down to below two years. This clearly shows that solar energy, be it for heating or for electricity production, surely is the way forward for a cleaner and greener future for generations to come. CTS is proud to be part of making Namibia and the world a better place for our grandchildren to live in.

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 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.

CTS was instructed to supply, deliver, install, test and commission laundry equipment for Lady Pohamba Private Hospital in 2015. Situated in Windhoek’s Kleine Kuppe area, this new and stunning 134-bed hospital caters for a wide variety of patients.

When it comes to Hospital textiles, cleanliness and perfect hygiene is of the essence. The challenge is to safely wash large quantities of used and soiled fabrics, while ensuring consistent, hygienic cleaning, maximum longevity and shortened wash times. As Namibia is facing a water crisis, special attention needs to be given to using as little water as possible. Our solution was Miele.

Miele offers a wide range of machines with cutting edge technology and specialized wash programs. With their patented stainless steel Honeycomb Drum, the specially designed drum ribs allow the water to saturate the laundry very quickly, reducing washing times. The high spin speeds with a G-factor of up to 500 make for optimum water extraction. There are also connections for detergent dispensers, ensuring that the same amount of detergent is used for each wash. A water recovery unit saves up to 30% of the water consumption. The tumble dryers are equipped with a heat-pump system, with results in a reduction of 60% of energy consumption.

Thanks to the residual moisture level of approximately 50% achieved by Miele’s washer-extractors, bed linen does not need to be dried any further before it is fed into a rotary ironer with a high heat output. Miele’s technology guarantees economy and quality, and actively contribute towards protecting our health and environment.

CTS removed old and obsolete laundry equipment and installed new machines.

The installed equipment sonsisted of:

• 3 x new Primus RS35 washer extractors
• 3 x Maytag energy saving tumble dryers
• 2 x Miele through-feed drying ironers
• including laundry trolleys, ironing trolleys, hand-irons and ironing tables