If you are eligible for the “Recycle – Replace Water Heater” program, then learn everything about the solar water heater subsidy and how to submit your application.

Size

The most basic question: How many liters of solar water heater do I need?

To choose the right water heater for your needs, of course you should take into account how many people are in the household. In general, the ratio is about 40 liters per person.

Energy source

As is logical, solar water heaters use solar energy as their main energy source; however, they all also have additional sources for functional reasons. They are divided into 2 types: dual-energy and triple-energy solar water heaters. But how does such a water heater work?

• Dual-energy: Their main characteristic is that while they operate by collecting solar energy to heat the water, they also have a built-in heating element so that on cloudy days they can operate on demand with electricity as well, like a classic boiler. 
• Triple-energy: They have all the benefits of dual-energy solar water heaters, but they also have an additional inlet to use the hot water from the heating circuit produced by the home’s central heating system (boiler or heat pump) as a heating medium.

Parts (Types of Solar Water Heater)

A solar water heater consists of 2 main parts, the collector and the boiler. This is also how we usually distinguish them as a type.

Collector 

The collector is the panel located in front of the boiler, where solar energy is collected. There are two types of collectors, selective and vacuum. 

• Selective collectors: These are the collectors we are used to seeing. The collector surface has a coating of copper or titanium oxides and collects solar energy to operate the circuit and heat the water. Titanium collectors are much more efficient, as they can absorb up to 95% of solar radiation.
• Vacuum collectors: Vacuum collectors have cylindrical tubes that are placed vertically on the collector surface. Their operation is quite simple: the tubes are filled with water and the sun heats the water inside them, which is transferred to the boiler ready for use.

In Greece, due to the high temperatures during the summer months, selective collectors are preferred, as they are much more resistant to high temperatures.

Tip: In vacuum collectors, European U-pipe technology is much more reliable than Chinese heat-pipe technology.

Boiler

The boiler is the tank in which the water is stored and heated. It consists of the inner tank, which comes into direct contact with the water we consume, the magnesium anode that collects limescale, the heating element, and various layers of insulation. Boilers are categorized based on the material of the inner tank.

• Glass: This is a very reliable choice and the most common on the market. It has a glass enamel coating so there are no problems with microorganisms and germs in the domestic water. This type always needs to have a magnesium anode, which should be replaced about every 2 years. 
• Copper: This is perhaps the best quality you can choose, but it is also considerably more expensive. It is a material that does not corrode and contributes to more efficient heat transfer. Its lifespan is from 40 years to a lifetime. 
• Stainless Steel-INOX: It is made of stainless steel, is very resistant to corrosion, and also has an anode. 

Circuit 

Solar water heaters are divided into two types depending on the circuit they have:

1. Open circuit: Open-circuit solar heaters use the water we consume itself as the heating medium, passing it through the solar collector. Due to the way they operate, the water collects salts and is not drinkable. For this reason, this type has almost been phased out of the market.

2. Closed circuit: These systems heat domestic water indirectly. The heating medium circulates in a separate circuit without mixing with the water we consume.

Installation

The installation of the solar heater is always carried out by a specialist; however, depending on the place where you will install it, you will need to choose a different water heater. On a rooftop, prefer to install the classic solar heater with a 45° or 60° tilt. If, however, you have a tiled roof, you will need a horizontal collector and special support so that the tiles are not damaged and leaks are not created.

In special cases, if there are restrictions in the area, you may need to get a compact or low-height water heater, so that it is more discreet. The above is especially applicable on islands and in areas that must comply with specific architectural features.

A common question you may have is how much it costs to install a solar water heater. In general, the installation of the solar system costs around €200-250, but there may be a small difference in the final price depending on the floor of the house and how many meters of piping will be needed. In addition, if you need to uninstall your old water heater, the cost usually ranges around €70. Both installation and uninstallation are supported by Skroutz in collaboration with experienced partners, and you can select them in your cart during checkout. More information can be found here.

Maintenance

Like all appliances, a solar water heater also needs some maintenance. More specifically, you should do the following:

• Check and replace the magnesium anode approximately every 2 years.

• Annual check of the circuit fluid level and topping it up if necessary.

• Check and repair the insulation.

• Check the non-return valve and the safety valve once a year.

Now that you know everything about solar water heaters, you can choose the one that best suits your needs.

If you are eligible for the “Recycle – Replace Water Heater” program and the average annual income per family member, according to the income tax return (E1) for the year 2021, does not exceed €30,000, you can apply and claim a subsidy voucher for the value of the water heater, before VAT, of up to €900. The subsidy amount depends on the income category you belong to and the size of the solar water heater you choose.