The photovoltaic systems are the devices that generate electricity using sunlight. In this process, different components intervene, such as the inverter, the controller of the battery, the batteries ect.
Below we will mention the most important information about photovoltaic systems .
What is a photovoltaic system?
A photovoltaic system, in simple terms, is the grouping and joint work of certain electrical components to achieve the transformation of solar energy into electrical energy usable for any device or conventional electrical device of a house, a business or even an industry.
To achieve the generation of this type of renewable energy, the basic electrical components of a photovoltaic system are: solar panels, inverter, load center and bidirectional meter.
How does a photovoltaic system work?
What are the components of a photovoltaic system?
A solar energy system are more than solar panels
Inside the components of a solar energy system the solar module or also known as solar panel. The solar panel is the main component of all types of photovoltaic systems.
In addition to this there are different parts that add to the system that vary according to the application. In the following illustration you can see the components in a more didactic way.
Solar module (solar panel) photovoltaic
Component responsible for transforming solar radiation into electrical energy through the photoelectric effect. They are mainly made by mono-crystalline or poly-crystalline semiconductors (silicon).
The best price and highest availability in the international and Colombian market is polycrystalline. These are characterized by their nominal power or maximum power that this panel can generate in ideal conditions (radiation of 1kW / m2 and temperature of 25ºC).
This component of the system efficiently manages the energy towards the batteries, prolonging their useful life, protecting the system from overload and over-discharges. This component is marketed based on its maximum current capacity to be controlled (amps).
The electrical energy of the panels, once regulated, goes to the batteries. These stores the electricity to be used at another time, its marketing is based on the capacity to store energy and is measured in Ampere hours (Ah).
This component converts the direct current and low voltage (12v or 24v typically) coming from the batteries or controller into alternating current, in the case of Colombia 120 V, in a simplified way it can be said that it transforms the direct current into a conventional outlet. It is usually marketed based on its power in Watts, which is calculated as the current voltage (P = VI).
Corresponds to the maximum demand of (power) of the equipment to be connected. This component can be dispensed with when the equipment to be connected can be powered by direct current.
As it is the case of some types of lighting, motors and equipment designed to work with solar energy.
This is a passive component of solar energy systems. Responsible for maintaining the photovoltaic modules in place and must be designed to withstand the weather constantly, thermal expansions for at least 25 years.
Each of the above components of a solar energy system uses different technologies. Which make the systems more or less robust and provide other types of properties.
The use of each of these components and the technology to be used depends very much on the need. What is sought to cover and technical limitations.
In other words, if you want a portable system, you should reduce the weight of the batteries. Lithium-ion batteries should be more convenient. In cases of very high humidity, encapsulated controllers with a high degree of water protection should be used.
What are the types of photovoltaic systems?
Types of Solar Photovoltaic Systems
Photovoltaic systems convert solar energy into electricity.
There are three types of systems; connected to the utility without batteries, connected to the utility with backup of batteries or “backup”, and remote system without connection to the utility.
- ” GRID TIE ” or Connected to the network.
The PV solar system is connected to the electrical system of the ESA and is designed to provide part or all of the energy you need. This photovoltaic system allows you to use ESA to supplement your energy and also allows you to exchange the excess energy of your system with ESA at no cost. In Puerto Rico, it is regulated by law 114 of 2007.
Advantage: It is the most efficient and least expensive in energy savings.
Disadvantage: It does not provide backup of energy or backup, it is disconnected if the utility (AEE) fails.
• The solar panels feed an inverter that maximizes the available energy capacity and exports to the electric distribution system of their property.
• The excess energy is stored in the distribution of the EEA and can be used at night.
• It is known as a net measurement (Law 114 of 2008).
• Your monthly invoice is the difference between what you consume from AEE and what you export to PREPA.
• Does not use batteries and disconnects when there is no electricity.
• It is the most efficient since the energy is directly transferred to the electrical distribution network.
” GRID TIE WITH BACKUP ” or Connected to the network with batteries.
They interact with the electrical network and use batteries in UPS mode to supply energy during power interruptions.
It is efficient in energy conversion and energy saving and provides power during blackouts.
Installation is complicated and slightly more expensive
• The system connected to the network with batteries is similar to the direct PV solar system without batteries, except that they can provide electricity to the critical loads in case of the EEE fails.
• Solar panels generate power that reduces their electricity from the electricity distribution network and reduces their electricity bill. If the power is not enough, the balance is replaced by the AEE, if the solar panels generate more electricity than it is consuming, then the meter counts that surplus energy in its favor.
• In the case of systems connected to the network with solar batteries, the sales process occurs when the batteries are charged. The primary advantage of a solar system connected to the grid with batteries is to provide continuity to critical loads during blackouts.
• It can be converted to a remote system with the addition of more batteries for daily loading and unloading.
- REMOTE .
It is a system that includes some reserve mechanism, usually deep cycle batteries. Solar panels accumulate energy in batteries to 24 hours a day.
It is independent of the utility distribution network. It is the least efficient for the losses of chemical conversion to electrical energy and vice versa.
Provides total energy independence. It is efficient in energy conversion and energy saving and provides power during blackouts.
It requires more batteries, more expensive.
It is necessary to consider several factors such as the days of the reserve, the capacity of the batteries, the capacity of discharge or deep cycle, the useful life of these, environmental conditions, maintenance, price and guarantee.
The amount of batteries is significantly higher because it usually takes 3 to 5 days of reserve to handle the variations of solar production and night energy needs.
Sometimes you need a second source of energy such as a generator or windmill to supplement the energy on cloudy days.
You may be interested in reading about how to store solar energy.