The single largest energy consuming device in our homes are geysers. So it makes sense to look at ways on how to safe more energy on water heating.
Electricity prices are rising faster than inflation, with yearly increases in double figures to become a norm which should become more concerning as time pass.
Solar PV Heating vs Traditional Heating
Traditional thermosiphon is considered the most efficient means to heat water in theory. But consider this, the price per m2 for PV panels are becoming cheaper vs
Drawbacks of Thermosiphon and Pump close loop systems
Thermosiphon systems must be mounted such that vapor rises up and liquid flows down to the boiler, with no bends in the tubing for liquid to pool. The system also has to be completely airtight; if not, the process of thermosiphon will not take effect and cause the water to only evaporate over a small period of time. So plumbing need to be checked regularly to minimize system problems, thus incurring a high operating cost compared to PV heating system. On pump systems cavitation can occur without anny means to monitor it realistically, so you may experience losses without knowing its happening and this will add up after a a few years, thus dropping efficiency considerably. Thermoheating panels mostly use no proper temperature control. Thus the water will heat up to high temperatures or boiling point when its not really needed and if the safety valves dont work( which happens very often) the boiler may burst, thus adding more cost to running costs.
PV panel Prices have dropped !
The cost of PV panels have dropped significantly over the last couple of years, bring doen the price per watt of power to level below R7-00 per watt on Poly panels and below R8.00 per watt on some mono panels. Home owners can use the benefits of low PV costs as a long term investment strategy. The savings of the water heating system will accumulate over the years to real value that can be used somewhere where its really needed, instead of giving it all to the Energy providers.
The other factor to consider is the advantages of a PV system.
PV heating system makes use of photovoltaic technology and a unique PTC AC/DC element to heat the water in the geyser by means of sun energy converted to electrical energy. This differs from the traditional thermal hot water systems where water is cycled from a collector through pipes to the hot water cylinder by either making use of a 220V pump, 12V pump or thermosiphon .
Other Advantages over thermal hot water systems are as follows:
- Any existing geyser can be converted
- No Additional plumbing is required
- No pumps necessary to circulate water
- No risk of damaged panels in frost prone areas
- The water temperature can be controlled on very hot summer days – reduced risk of overheating problems
- Suitable in all water conditions
- Suitable in areas where the geyser is not situated near the panels
- Modular system – can be expanded to build off-grid power system for the home
- PV Heating don’t use inverters to convert energy. Thus saving cost
PV panels lifetime of power supply and efficiency have improved dramatically!
Another big advantage that PV Heating with PTC has over traditional units is longevity. PV will outlast the traditional heating panel system for many years. This will contribute to more savings over the lifetime of the system.
The new modern PV heating system from Orbic uses the latest Dual power DC/AC Titanium element by means of sun power converted smartly to DC power for the element. But the element also has an AC connection to use so that in the event that the sun supply of energy is not enough and hot water is required, the excess power can be taken from Eskom or another power source.
PV solar geysers also are much easier to install and no plumbing will be required as only the old element and thermostat will be replaced on the current geyser boiler. Once installed the system will control the temperature automatically and smartly with a temperature controller. You will always have hot water, without wasting any energy!
The other benefit is that by controlling the water temperature you lower the risk of a geyser boiler bursting considerably.
PV solar geyser systems may repay the cost of the system more than 10 times over the lifetime of the panels.
No need to replace your old geyser!
Our PV solar geyser will work with most geyser models. So you don’t have to change the geyser, only the element and thermostat are replaced.
Standard PV panels can be used to power the element efficiently for 25 years with DC Power. We will assist you with the right panel selection for your need.
Our PV solar geyser uses the strongest Titanium dual power PTC element, the element is designed to last the full lifetime of the system and are covered with a 10-year guarantee. The Titanium dual power element is also much more efficient compared to traditional wire elements.
Sun power is used as high priority to power the DC side of the geyser element. Only when the weather is very bad or in the evenings if the temperature goes down past a threshold setting, will the controller use Eskom grid power to assists.
Thus, Eskom is only required in severe weather conditions or only if the water temp needs to be hot at an unplanned time and if you already have a solar system to power the loads our PV Heating system can easily be integrated.
So in most conditions, more than 85% of the time the power used will be sun power!
PV Solar geysers are also designed to use PV panels from different manufacturers some PV panels will last 25 Years or longer compare to heat exchange panels that might last 10 years.
Operation Of a Photovoltaic Heating system with Temperature control
The system operates by converting sunlight into energy. The energy is converted to DC power and uses to power the Ti element. The system then use a temperature control to monitor the temperature and use this info as well as the time of day to control the power required to get the temperature to set-points. The client can have multiple set-point for different times of the day. So its possible to have warm water in the Morning and the evening at different times for each day of the week. SO if you shower later in the day on a weekend, the system will adjust to give you warm water when you need it. The system also have a override feature, say you have many guests and need the water warm all day, all you do is to press the override button and the system will start heating the water immediately. When the guests leave, you just press the button again and the override is off and you back to green power.
Diagram of PV ( Photovoltaic) Heating System
Want to go Off grid ?
The Solar PV geyser system also works very well when integrated with a Solar Inverter system. By using a smaller size element 1.5 kw instead of 2.2 the amount of current drawn is a bit less , so your inverter might be adjusted to assist heating the water when the batteries as full.
Orbic Solar uses smart relays for integrating the PV geyser into off-grid and grid tied systems.
This can make a huge difference in saving energy and using it at the right times so the overall system can be more reliable and increasing savings even more, thus no PV energy not used can be minimized.
If you need installers , we are available in the Western Cape, else we can send you a complete kit as required and you can do a DIY or use your electrician for installation, the Kit comes with a comprehensive installation manual.
Our Solar PV geyser are therefore a much safer investment and will provide longevity and better return on your investment while providing nice hot water when you need it.
One of the other big advantages is that we don’t use any pumps!
Start Saving money for your retirement,
To learn more about PV solar Geysers please contact us, so we can make an assessment of your requirements
Comments by Orbic Solar
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