Frequently Asked Questions

General

1. What kind of solar systems you offer?

Provitaz offers Solar water heating systems and Solar electric systems.

2. What is solar water heating system?

Solar water heating system utilizes sun’s rays to heat water in solar collectors. The heated water is stored in a tank and used for variety of applications such as domestic hot water, pool water and pre-heating for floor heating.

3. What is solar electric system?

Solar electric system utilizes sunlight to generate electricity by solar PV panels. The electricity can be used to power building’s electrical systems, including lights, cooling systems, and appliances.

4. Which system is better for me?
This depends on your personal needs. Is your main need for hot water or electricity? If you want to cut your energy bill (gas or electricity), the solar water heating system gives you more savings in most cases.

Solar Water Heating Systems

5. How does a solar water heating system work?

Solar water heating system harvests solar energy through a solar collector which absorbs light and heat from the sun and heats the water that flows through the solar collector. The heated water is transferred to an insulated tank which feeds the building’s water heating system. A solar controller is an electronic device that is used to control the system. It controls a pump to enable the water circulation from the tank to the solar collectors and then back to the tank. The solar controller also controls valves which are used to direct water flow in advanced water heating systems.

6. How can solar water heating system benefit my home or business?
Solar water heating system reduces your energy bill (gas or electricity) by providing you with free solar energy for water heating.
7. What type of businesses can benefit from solar water heating system?
Any business or facility that needs hot water can benefit from the system, especially if there’s need for large quantities of hot water.
8. Can I heat my home with solar collectors?

Yes and no. The solar collectors are not suitable for providing heat to the regular heating system with radiators. However, if you have underfloor heating system, you can use the solar water heating system to preheat the water that is fed into the gas heater (kombi) and thus reduce the gas consumption.

9. How much of my yearly hot water need will a solar water heating system provide?
Appropriately sized systems can provide 60-70% of the annual hot water need.
10. How much money will a solar water heating system save me?
Savings vary widely depending on hot water usage, system size and cost of conventional fuels (gas or electricity). A site analysis is the first step toward reaching customer specific figure on system savings. As mentioned above, Appropriately sized systems can provide 60-70% of the annual hot water need.
11. How much does a solar water heating system cost?
As with any investment, there is an initial cost to installing a solar water heating system. Over time, the savings on utility bill (gas or electricity) will pay back the system cost and provide profit. A site analysis is the first step toward reaching customer specific figure on system cost.
12. What size solar water heating system should I get?
For home, you need approximately one solar collector (area 2 m2) for each two persons. So, we typically recommend system with 3-4 collectors for a villa. For businesses, a site analysis will provide customer specific system size that may vary anywhere between a few collectors and hundreds of collectors.
13. Does solar water heating system work on a cloudy day?
On cloudy days, the solar collector has little effect, so an alternative heating system (gas or electric) will provide the needed hot water. However, a larger solar water tank helps to store the solar-heated hot water for days with no sun.
14. Does solar water heating system work in winter?

Yes, it does. On a winter day, a solar water heating system can heat the water up to 35-45 degrees, depending on the system size. However, the system is a lot less efficient than it is over the summer. For this reason you need to rely more on your backup water heating system (gas or electric) in winter. Although the heat produced by your solar water heating system is reduced over the winter months, throughout the year it can dramatically reduce your heating bills.

15. Can a solar water heating system work with an on-demand water heater?
Yes. The solar water heating system can be used to preheat the water that is fed to an on-demand water heater, thus reducing the water heating need and gas consumption.
16. If I install a solar water heating system, can I still keep my regular water heater?

Yes, you need your regular water heater as a backup to provide part of the water heating during cloudy days and colder seasons.

17. Can I monitor the solar water heating system performance?

You can monitor the water temperatures in the system with most of our solar controllers, excluding the most affordable models. Our higher-end solar controllers together with additional equipment offer advanced functions such as energy measurements and an online system monitoring.

18. Do you provide installation work?

Yes, the installation work is done by our trained mechanics.

19. Does the solar water heating system need maintenance?

The solar collectors must be regularly cleaned from dust to ensure the best performance. The system overall (collectors, piping, insulation, etc) should be checked from time to time to ensure good operation.

20. How long will a solar water heating system last?

A Lifetime of the solar collectors may be as long as 20 years. This includes changing the polycarbonate (transparent window) in case needed, which is rather inexpensive operation. The lifetime of the solar tank and controller may also reach 20 years.

21. Do you give warranty?

Yes, we give one year warranty for the solar water heating system, if the system is installed by our mechanics. It is also possible to agree on longer warranty period or sign a maintenance contract for additional cost.

Solar Electric Systems

22. How does a solar electric system work?

Solar panels comprise many small units called photovoltaic cells. Each photovoltaic cell is made up of two slices of semi-conducting material, usually silicon — the same stuff used in microelectronics. The two slices have been treated so that the other has positive and the other has negative electrical charge. When a photon of sunlight hits the cell, it knocks electrons free, creating an electric current.

An inverter converts the electricity in suitable form to be used by any electric appliance. Some systems utilize solar batteries to store the energy to be used at night or during cloudy days. Charge controller controls the charging of the batteries and protects them from overcharging.

23. What are the different kinds of solar electric systems?

There are two kinds of solar electric systems: On-grid system and Off-grid system.

24. What is an On-grid system?

An On-grid system is a system for houses and facilities that are connected to electrical grid. On-grid system delivers electricity during daylight, thus creating savings on electricity bill. On-grid system will not provide electricity outside daylight hours or during power cut, however, because it does not include solar batteries for storing the electricity.

25. What is an Off-grid system?

Off-grid system is a system for houses and facilities that are not connected to electrical grid. Off-grid system comprises of solar panels and inverter, just like On-grid system, but in addition, it utilizes solar batteries for storing the energy to be used at night or during cloudy days. The higher the battery capacity, the longer the system can deliver electricity outside of daylight hours. For extended operation time, there needs to be sufficient amount of solar panels as well.

Off-grid system can be used for various applications where energy independence is needed. Off-grid system provides freedom from the electrical grid. Some of the Off-grid systems can be connected to generator to obtain continuous electricity output even during longer periods without sunshine.

26. Should I buy On-grid or Off-grid system?

From financial perspective, we recommend On-grid systems for houses and facilities that are connected to electrical grid.

Off-grid system is the only choice for houses and facilities that are not connected to electrical grid, because it includes batteries to provide electricity outside of daylight hours.

27. How can solar electric system benefit my home or business?

Solar electric system reduces your electricity bill by providing you with free solar energy.

28. Can I heat my home with solar electric system?

Yes. You can use solar PV panels to generate electricity, and then power your heat pump (air conditioner) with this energy. Please also note that if you have underfloor heating system, you can use the solar water heating system to preheat the water that is fed into the gas heater (kombi) and thus reduce the gas consumption.

29. Can I heat domestic hot water with solar electric system?

Technically you could use solar PV panels to generate electricity, and then power your water boiler with this energy. However, using solar water heating system is much more cost efficient. You can use the solar water heating system to preheat the water that is fed into the water boiler or gas heater (kombi) and thus reduce the energy consumption.

30. How much money will a solar electric system save me?

The amount of savings depend on the type and size of the solar electric system. Larger systems give more savings. A small 1 kW system (with four 250 Watt panels) delivers around 1400 kilowatt hours of energy per year.

31. How much does a solar electric system cost?

The cost of solar electric system varies a lot depending on the system type and size. Off-grid system is more expensive compared to On-grid system, since it includes batteries, battery charging system, and possibly control for backup generator.

32. What size solar electric system should I get?

The system size depends on your specific needs. As for On-grid system, you can choose any system size that fits your budget. Larger system covers bigger part of your monthly electricity need. But even a small system will save you money. Off-grid system size needs to be calculated carefully taking account your electrical loads (the devices you want to power with solar energy) and the time of operation of each device during a day. The size of the electrical load and the time of operation greatly affect the system size (amount of solar panels, size of the inverter and amount of batteries) and thus, the price of the system.

33. Does solar electric system work on a cloudy day?

On cloudy days, the solar panel has little effect, so an alternative electricity source (electrical grid or generator) is needed. However, the solar electric system is financially feasible, even when all the cloudy days are taken into consideration.

34. Does solar electric system work in winter?

Yes solar panels work in winter weather, but for obvious reasons, their output is lower than during the height of summer — days are shorter and more cloudy. That said, solar panels are actually more efficient in the cold weather. This helps to compensate for the drop in production during winter. However, the solar electric system is financially feasible, even when all the winter days are taken into consideration.

35. Do solar electric panels work during power cut?

On-grid system does not work during power cut. If the electrical grid goes down for any reason, the solar electric system shuts down automatically to protect any utility workers working on fixing the electrical grid.

Off-grid system is not connected to electrical grid and therefore works independently and is not affected by power cuts.

36. Do I need to install batteries with my solar electric system?

If your house or facility is not connected to electrical grid and you need electricity outside daylight hours, then yes, you need to have Off-grid system with batteries. However, we recommend system with batteries for grid-connected houses or facilities only in special cases. See above for questions concerning the differences between On-grid and Off-grid systems.

37. Do you provide installation work?

Yes, the installation work is done by our trained mechanics.

38. Does the solar electric system need maintenance?

The solar panels must be regularly cleaned from dust to ensure the best performance.

39. How long will a solar electric system last?

The solar electric panels will provide at least 80% of their original output power for 25 years. Normally, they will continue to work even longer with reduced power output. Solar inverters typically last at least 10 years and solar batteries at least 5 years.

40. Do you give warranty?

Yes, we give warranty for each system. The length of warranty period varies depending on the product.

Still Have More Questions?

We’d be happy to chat. Call or email us to learn more about Provitaz.