What a PV hot water system is?
A PV hot water system or a PV water heating system is a more modern and convenient variant of a solar collector system of hot water supply for domestic applications. To heat water, such system uses electricity generated by PV panels and sent to a tubular heating element by means of a special Solar Kerberos device. The device can operate autonomously providing hot water on a sunny day, while on an overcast day or at night, water is heated using power from the utility grid. Any excess electricity produced by PV panels can be sent to an additional tubular heating element or used to charge a battery.
A water heating system based on the Solar Kerberos requires much less space compared to a solar collector system with its additional pump equipment. What is more, you can use an existing boiler with a tubular heating element, which reduces the cost of a system.
Electricity produced by PV panels is passed through a surge protection to the Solar Kerberos inverter where it is converted into alternating current and sent to a tubular heating element that heats water to a certain temperature set by a user. A PV hot water system is resistant to overheating characteristic of solar collector systems. Once the temperature set by a user has been reached, the Solar Kerberos stops applying the voltage to the tubular heating element. There are several versions of the Solar Kerberos that provide additional options depending on a user’s needs.
- 315.B, 320.B – ordinary version meant exclusively to heat water in a single boiler;
- 315.C – when the temperature set by a user is reached, surplus power is used to charge the backup battery;
- 315.H, 320H – when the temperature set by a user is reached, surplus power is sent to another tubular heating element and used to heat water in an additional boiler.
PV panels are an important component of the water heating system. It is exactly PV panels that generate electricity which is sent to the Solar Kerberos and used to heat water. At the moment, the most common types of PV panels are monocrystalline and polycrystalline panels. Apart from manufacturing techniques, solar panels can be different in output, efficiency, size and so on. If space is limited, it is better to choose more efficient PV panels.
The engineering and installation center “Teplocel” advises choosing only trusted manufacturers of photovoltaic panels, such as Longi Solar, Jinko Solar, Ja Solar, Panasonic, Sunpower, Hanwha and so on.
- Solar panel mounts and racking
PV panels for a water heating system can be mounted both on a building’s roof or front and on the ground (static or tracking type PV arrays). PV array can also be part of an adding to the structure – for instance, a weatherproof solar canopy. We recommend installing quality mounts and racking made of aluminum and stainless steel, because not only this affects the operation of the system, but also the durability of the roof as well. Mounts and racking must be rustproof and weatherproof (resistant to strong wind, rain, hail and so on).
- Internal lightning protection
To ensure safe and lasting operation of a PV water heating system, it is necessarily to install protection equipment for the Solar Kerberos inverter. Such equipment consists of AC/DC protection and ensures stable operation of the system in the event of overload, short circuits, voltage swing and suchlike. Mandatory components of internal lightning protection are circuit breakers, fuses and residual current devices. A specific set of equipment depends on a version of the Solar Kerberos and characteristics of a system. It is worth mentioning that according to manufacturers’ requirements, with overvoltage protection equipment installed improperly or missing any of mandatory components, the device is not subject to warranty repair in case of malfunction.
- Grounding and external lightning protection
To protect cable lines and PV panels from a direct lightning strike, we install external lightning protection: busbars, lightning rods, equipotential bonding busbars, surge arresters and so on. In the case of ground-mounted PV arrays, their grounding is mandatory. For external lightning protection, as well as for grounding systems, only corrosion-resistant metals, such as zinc plated and stainless steel or aluminum are used.
Installation of a PV water heating system is carried out by our specialists in compliance with all the electrical regulations and standards, State Construction Norms (DBN), safety rules and so forth. Approximate cost of installation is 10% of the cost of equipment, and the final cost is defined after a site visit has been conducted and the system has been designed.
Installation of a PV water heating system includes the following tasks: *
- Mount installation
- PV panels installation
- Doing electrical wiring
- Installation of the Solar Kerberos device
- Internal lightning protection installation
- External lightning protection installation and grounding
- Commissioning and start-up
Advantages of a PV water heating system
No overheating characteristic of a solar collector system
EASY TO MODIFY
Depending on a version, it is possible to use an additional tubular heating element or charge a battery
The system makes it possible to use an existing boiler
Requires much less space than a heliosystem
- 2700 $
- 3150 $