Our Pricing Advantage

Our Pricing Advantage

pricing

More Energy for Less Cost
  • By saving more energy for less investment, we are cheaper on any like for like comparison.
  • And we are cheaper than fossil fuel, by approx 85% per litre of water heated by electricity, taking a period over 10 years and taking into account the cost of the system.
  • Comparing any solar water heating system on price alone is completely meaningless and is the trap many people fall into.

Key Criteria for Comparisons
  • Any solar water heater that is SABS tested and passed or carries a SABS Mark has undergone rigorous tests which takes months. As well as meeting many compliance tests for quality, performance is measured in a laboratory environment, to calculate a deemed performance output on an average South African day of 20MJ per day m2.
  • Expressed as a ‘Q’ factor the performance figure can be converted back into kWh output by dividing by a factor of 3,6.
  • For example, to measure the amount of energy that is reaching every square meter of land in South Africa, divide the 20MJ by 3,6 and the result is 5,56 kWh. The levels of solar irradiation being received almost anywhere on earth are readily available on the Internet, which is generally calculated using satellite data.
  • So as another example, if a solar water heater has an output or ‘Q’ factor of 20, its deemed output is also 5,56kWh. The solar collector size however will be considerably larger than 1 square meter, so for example if it was 2 square meters the efficiency in converting the energy received into useable energy (in this case hot water), would be 50%.
  • Solar thermal collectors for heating water will typically be between 35%-60% efficient in converting energy received into energy output, while solar electric panels (PV) will typically be 16% to 24%.
  • Moving away from laboratory tests to real life, solar water heaters may have higher or lower performance depending on location, season, orientation and inclination to the sun as well as other factors such as shade.
  • For example, the same system in Uppington (an area of high solar irradiation), will have a much higher output than an area such as Richards Bay which is subect to coastal cloud.

Solar Water Heating Systems Performance Compared
  • With a deemed performance output in kWh’s for a solar water heating system, comparisons of one system against another is straightforward.

Calculating Rand Savings, Payback and Investment Returns
  • Taking the deemed kWh output and applying a cost per kWh charge from Eskom or municipal reseller provides a theroetical daily saving in Rands.
  • For example using the same example system above, the output at 5,56 kWh’s per day and an Eskom rate of R2,20 inc VAT per kWh unit, and the deemed daily saving would be R12,23.
  • With a deemed daily savings in Rands, the ‘payback period’ in days can be calculated by taking the installed cost of the system including VAT and dividing it by the daily rate.
  • For example, a system might cost R13,500 inc VAT. The theroetical payback would be (R13,500 ÷ R12,23 =) 1,103 days or 3 years. Adding in electricity inflation and the period would drop by a couple of months.
  • Investment returns can be calculated in the same way by calculating the savings on an annual basis, and adding inflationary increases.

Calculating Hot Water Performance Outputs
  • Hot water output can be measured in a couple of different ways using the specific heat of water formulae.
  • The more useful one is to take the kWh output and multiply by 36 to get the amount of litres at 40°C (the temprature one washes at). Using the same example (as above) 5,56kWh’s would provide 200 litres at 40°C at the shower head.
  • To calculate the deemed and expected temperature within the tank take the kWh’s output, multiply by 860 and divide by the tank volume, and add to cold water temperature.
  • For example 5,56 kWh x 860 ÷ 150litres =32°C (temperature increase)+16°C=48°C of 150 litres.

Solar Systems Designs and Performance
  • It is not a question of which is better or worse but one of choice.
  • Unless one has an interest of how things work ‘under the hood’ , the performance criteria is the area to concentrate on.
  • In the case of Ubersolar systems we are cheaper per kWh saved, or per litre of hot water produced, and have a faster payback on investment, and higher saving returns than other systems because all the systems on a ‘like for like’ comparsion basis are at a lower cost.

How do we achieve this?
  • When we use tanks, they are already in existence (retrofits) or we use tanks that are manufactured locally by the world’s largest domestic boiler maker and are solar ready. Their sheer volume and output enables economies of scale and as a result very competitive pricing.
  • On the solar front, our patented design uses high quality evacuated tubes which are very efficient. Rather than using EVT’s with heat pipe risers, which nearly trebles the cost of each tube, we use EVT’s filled with water (85% of the worlds solar thermal systems use EVT’s). Cheaper than flat plate types and with more power output, it again creates efficiency. Where other systems might use 30 EVT’s with heat pipe risers, we use 60 EVT’s using water, at a lower purchase cost and more energy savings.
  • Where other systems may be thermo-syphon, (the principle that heat rises), we use a pump and a solar panel to force the heat transfer. Although more expensive, the increase in the volumes of hot water and the temperature more than outweighs the less efficient thermo syphon system. In addition, the pump with a controller enables us to control the temperatures in both the tank and solar collector.

The End Result
  • A very simple design, using essentially stock of the shelf components, creates systems with any required power output, at a lower cost than other types of design.
  • In turn, this enables Ubersolar thermal systems to be 85% cheaper than using electricity for heating water.

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