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How does it work?

 

The SolarMate is a South African designed, patented and manufactured product. It utilises a patented* collector array (see figure 2) to transfer solar energy to a storage tank by direct energy transfer and all the components which transfer the energy and store it are plastic or rubber, excluding the collector array which is made from copper and is known to have anti-bacterial properties. The tubing  connecting the array and the storage tank as well as that connecting the SolarMate to the inlet and outlet water supply is made from food-grade material and the storage tank is suitable for potable water storage. There are fewer parts to assemble and the manufacture of the system is simplified as a result; in addition corrosion of any parts in contact with water cannot occur. The SolarMate housing consists of treated and painted galvanised steel and a  toughened glass cover lets solar energy through to heat the collector array. It can withstand hail which occurs on the Highveld.

*Patent No. ZAP/2004/02832

Figure 1: Standard fin and tube collector

Figure 2: SolarMate’s collector array

 FREQUENTLY ASKED QUESTIONS

  1. How is the Solarmate water heater installed? It is installed on the roof of the dwelling, 2 m away from the electrical geyser and heats up the inlet water to the electrical geyser.
  2. Why is the Solarmate water heater installed in line with an electrical geyser and not just used on its own? All dwellings are built with electrical or other types of geyser. Because the sun does not always shine brightly in the daytime or at night, the conventional geyser provides a constant supply of hot water irrespective of weather or hot water consumption rate. The Solarmate water heater simply reduces the cost of heating water significantly by providing hot water to the conventional geyser. In the initial 3½ year period the unit pays itself off and thereafter you gain free solar energy to heat the water in your geyser. It’s like someone dropping off a litre of fuel on your doorstep every morning for free.
  3. Does the Solarmate require maintenance? Once the Solarmate is installed, the only maintenance required (and it is optional) is to wash down the glass collector face with water using a hosepipe from the ground floor once a month in the dry season. This must be done in the late afternoon or early morning before the glass has heated up or after it has cooled down.
  4. I have a gas geyser can I install a Solarmate to save gas costs? Yes, the Solarmate will preheat the water for your gas geyser. You can turn down the heating flame because heated water will be feeding into the gas geyser. You may have to change the setting on cloudy days or during winter, compared to summer.
  5. I have a new development and want to install solar water heating. The Solarmate will require a conventional geyser to be installed as well, is that worth it? It depends on the cost, compare a solar water heater with an element to the combination of a Solarmate and a conventional geyser. An advantage of having 2 geysers is increased hot water capacity/availability in case of a water shortage. 
  6. I use borehole water with high total dissolved solids (TDS) like lime, potassium, will the Solarmate handle it? You will have to install a water softener to feed the Solarmate otherwise it will block up over time. But your whole water supply system is prone to blocking so it is a good idea to prevent these problems by installing a water softener. They are relatively low cost (about R8000 for a domestic application)  and Solarmate can refer you to suppliers or install it for you. Some maintenance is required on a monthly basis to operate the softener efficiently.
  7. I want to go off-grid and install PV panels including water heating. Do I need to install a separate solar water heater like the Solarmate? Yes, PV works efficiently when there is sunlight. In cloudy or dark conditions, a PV system draws power which is stored in batteries. For heating water a large amount of power is required so pre-heated water from a Solarmate will reduce the load on the batteries and allow maximum heating of water to be achieved; also PV may not have sufficient power for all the other requirements like lights, pumps etc.
  8. If I have a 100l, 200l or 300l electrical geyser how many 100l Solarmate units should I install? 1, 2 and 3 units respectively
  9. If I have a 150l geyser how many 100l Solarmate units should I install? It depends on the amount of hot water used daily. If you are using less than 100l, the payback on 1 unit will be proportionally longer; if you use 100l the payback will be 3½ years; if you use more than 100l then the payback will be 3½ years but you will not reduce the electricity bill as much as for the 100l consumption case. In this case it is better to install 2 Solarmates but the payback will be longer than 3½ years on the 2nd unit. The advantage is you will have more hot water capacity for cloudy or electrical outage days and 2 units will ensure that 200l of hot water is always supplied to the geyser. 1 unit is cooled down by the cold inlet water as soon as it starts being used.
  10. Does the price per unit include installation? Yes, provided it can be installed up to 2m from the current electrical geyser and on a single storey structure. Any other arrangement will incur installation costs depending on the individual requirement.
  11. Does it pay to install a solar water heater? Yes, if you use the full capacity of the heater every day. If you use less than its capacity, it will take longer than 3½ years to pay back; if you use more than its capacity then you will pay it back in 3½ years but the extra hot water used will have to be heated and this will cost because it is more than the capacity of the solar heater
  12. How long does the Solarmate water heater last? It is guaranteed for 5 years but should last 10 years at least. After the 3½ year payback, it will provide free heating energy to your electric geyser.
  13. How does the Solarmate water heater compare to the tube type solar water heaters? The tubes of the tube type heaters are imported (not 100% locally manufactured like the Solarmate water heater), they are not resistant to heavy hail (>36mm in diameter) and they are less environmentally effective than the Solarmate because they are designed for northern hemisphere climates with less solar exposure than South Africa. This means they discharge overheated water in summer, thus wasting precious water resources.
  14. I switch my electrical geyser off every day to conserve electricity and costs. Is it better to switch it off during the day or the night? It depends on when you use most of the hot water in the geyser. If that is in the day time, then it’s best to switch it off at night after it has heated all the water up and vice versa.
  15. I don't want to pay for a solar water heater but I still want to save money and the environment with my electric geyser. Is there something I can do quickly? The easiest thing to check is the temperature of the water the geyser heats up. This should be no more than 55ºC measured at the hot water tap. If it is higher adjust the geyser's thermostat to a lower temperature until the outlet water gets to 55ºC measured at the hot water tap. Ask a plumber or electrician to do this for you. You can also insulate the geyser with a thermal blanket.

The following graphs show how the costs of a 100l SolarMate unit are recovered:

                                                                                                                                    Based on: R2.09c/kWh electricity cost and annual increase of 5%
                                                                                                                                                    48ºC average maximum daily water temperature
                                                                                                                                                    100l of heated water are used each day

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    

                                                                                                                                                               Based on: R2.09c/kWh electricity cost, annual cost increase of 5% and finance interest rate of 10.25% over 42 months
                                                                                                                                                    48ºC average maximum daily water temperature
                                                                                                                                                    100l of heated water are used each day

 

For enquiries call/Whatsapp 082 808 1483 or e-mail solarmate@mweb.co.za