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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

A 71kW grid tied (Nampower ) PV system was installed at the Klein-Aus Vista Lodge just outside Aus. Remote Monitoring and Energy meter is included to obtain precise information about own consumption as well as exported power. This aids in future electrical reticulation upgrades and designs.

System Specifications are:

• 240 x 295W Canadian Solar PV modules
•  3 x Fronius Symo 20.0 – 3 Grid Inverter
• Shed roof mounting with structure for IBR roof sheeting
• AC & DC surge and Lightning protection
• Configured for remote monitoring

When A La Mer Hotel in Swakopmund decided to expand, they approached CTS with a unique challenge: to create a functional laundry that was both energy and water efficient, and would also fit into a small space, while being whisper quiet, so as not to disturb any guests. In addition, the laundry has to perform excellently, producing quality wash, tumbling and ironing results. Only one brand came to mind: Miele.

Miele recently launched new bench mark machines, which have short program cycles, excellent spin performance, a redesigned patented honeycomb drum and have low consumption values. A La Mer Hotel was the first in Namibia to purchase these new machines.

CTS installed washer extractors with water recovery units, as well as automatic dosing systems, to ensure the best quality wash, every time. The tumble drier has an air recycling system, saving up to 60% of energy. And with a matching drying ironer, optimum finishing results are achieved. Small accessories made this laundry a complete turn key solution.

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.

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 (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.