The solar power system works on the principle of photovoltaics. However, there are some components that are essential for magic. Also, it is better to understand why solar energy is good and why not.
If you have solar panels in the right direction without shade they will work well for more than twenty-five years. Connection of panels to each other or to the inverter to transform DC to AC and further transmittance to the load should be apt. That is in brief how the solar power system works and what is the core of production in terms of all components of the system. Well, if the solar panels stay clean most of the time or if you keep solar panels clean they’ll work flawlessly with sunshine.
A major advantage of solar energy, on the whole, is that “any solar power system generates energy for its lifetime at the same cost, however, energy prices around you keep rising all the time”. This is a fact. Let us look at the process of how solar panels generate electricity and how it is available for use in an energy flow diagram.
Let us look at the flow of energy in an on-grid system, to understand all the components.
We know a lot about the Sun itself as it is up there mostly or partly. Let us look at the Sun from the perspective of using electromagnetic radiation (EMR) in form of sunlight. The path of the Sun and the seasons on Earth are the main aspects of making a solar power system work. Or in other words, the sunlight from the sun and the position of the Earth to the Sun are essential to install solar panels. By the way, the energy we get from the sun (173000 terawatts) is more than 10 thousand times of world’s energy use. How does this energy as photons of light strike the solar panels and what happens ahead?
Solar panels or array of panels
From our solar photovoltaic article, we already know what solar panels are made of. Also how photons of light become current. The panels generate DC or direct current when sunlight strikes. A single panel is usually enough for some basic electrical loads like LED lights, small fans, chargers, etc. For larger loads, for instance, a house several solar panels do the work.
So solar array comes into the picture which comprises several solar panels. The required voltage and current output from the solar array define the connections between the panels. The rule is the voltage of panels added when they connect in series. Whereas, the current remains of a single panel. On the other hand current of panels add when they connect in parallel. The voltage remains that of a single panel in a parallel connection. To better understand series and parallel connections, read this.
Now as the panels or array of panels generate current they transmit it to the inverter. However, with batteries charge controller transmits current from solar panels to batteries.
Solar power system inverter
The purpose of the inverter is to convert direct current from panels to alternating current. The electricity we get in the wall sockets is in form of alternating current. Also known as power conditioning unit or PCU where technologies like MPPT (maximum power point tracking) increase and refine the generation and transmission of solar current. There are two types of inverters or solar inverters which convert DC to AC or vice versa.
For an array of solar panels, one inverter is termed a string inverter. Electricity in form of direct current (DC) from the array transmits to one string inverter through a DC junction box. This inverter converts DC to alternating current (AC). The same AC is the product of a solar power system. This transmits to connected loads or the grid. To prolong its life and for efficient working, the installation of string inverters is in shade mostly.
Unlike string inverter, each panel has its inverter. At the rear of the solar panel, the DC converts to AC. Many small inverters instead of a single-string inverter. These are costly but are more efficient and long-lasting. In this case, AC from an array of solar panels connects to the grid or connected load via a junction box and meter.
Meter and the grid
A junction box or PCC (point of common coupling) is the point where current from solar panels meets the load and the grid. From where it goes to the connected load of the house or the building and also to the grid. A grid-interactive solar power system generates and supplies current at the same voltage and current levels of the grid. The frequency of electricity from the solar power plant is also kept at the same level as that of the electrical grid. Like when there is zero or less consumption of electricity where solar panels are installed, extra electricity generated is supplied to the grid.
A common term used hers is “net metering”. The input and output of electricity are measured by a single bi-directional meter or two meters are installed. In this way at night electricity from the grid is used and at the time of extra generation, the electricity is fed to the grid from solar panels.
Why batteries in solar power systems?
We already discussed the grid-connected solar power system above. Two other types are stand-alone or off-grid and hybrid solar power systems. In a stand-alone system, solar panels charge the batteries with help of a charge controller. One or many batteries behave as energy storage. Batteries are connected to a DC electrical load or an inverter is used to convert DC to AC and power the electrical loads. There is no grid connection in these types of systems.
Another advanced system is the hybrid solar power system. In this, batteries are used as the power back up, and also grid connection is available. A mix of stand-alone and grid-connected systems is a hybrid solar power system. So batteries give you a choice of going totally off the grid and producing and using your energy. Also, batteries assure you of backup when grid electricity is not available in form of a hybrid system.
A solar power system works with a combination of panels, wiring, inverter, battery, grid and other ancillary equipment. Good design, connections, and efficiency of all the components make the solar power system work for many years.
Did you know?
Solar Edition publishes the top 10 best solar panels monthly since 2019. In addition to this, we also publish a top 10 72 cells solar panels for industrial scale every quarterly (Q1,2,3,4).