Solar panels are still a mystery to most people. Some still think that all PV modules can only be blue, almost nobody really knows the answer to “How do solar panels work?”. This is why we decided to write a short text on various types of PV modules and the technology behind all of them. Let's get into it.
Short History of Solar Panels
The photovoltaic effect or the ability of some elements to produce current when exposed to the light was discovered back in the XIX century. In 1873 Willoughby Smith found out that selenium produces charge when the light hits it. The first commercial solar panel appeared in 1881 and was made by Charles Fritts. Those early models were very inefficient, especially when compared to coal plants. The breakthrough in solar panel development was made by Russell Ohl in 1939 who designed a solar cell, which became a prototype for cells in modern panels. A decade later Bell Labs improved Ohl's cell and made the first silicon solar cell for commercial purposes.
How Do Solar Panels Work?
Solar panels make use of what is called photovoltaic effect. Certain materials, like silicon, can produce current when they are exposed to the sunlight. This is why cells of panels are made of silicon, which is a component of beach sand, for example. When sunlight hits a module, current is produced in each cell and flows from a panel through the wires to your inverter. An inverter converts direct current from panels to alternating and either sends it to your appliances or pumps it into the commercial grid so that someone else can use it.
Three Types of Solar Panels
Currently, there are three most widespread types of panels on the solar market. Let's take a look at each one of them.
Polycrystalline
Poly-panels were the most popular type back in the day — 15-20 years ago. You can easily recognise them by the blue hue of solar cells and their rectangular shape. The blue color comes from using a special anti-reflective coating. Several silicon crystals are used to make cells for poly-panels. This manufacturing process is relatively cheap, but the final product is not as efficient as monocrystalline panels. Overall, poly-panels show 15%-17% efficiency. They last for more than 25 years. Poly-panels are also more vulnerable to high temperatures than mono-panels. Overall, we could say that the time of polycrystalline panels has passed: other types almost completely replaced them on the market and have much more potential in the future.
Monocrystalline
Monocrystalline solar panels are the most popular type of photovoltaics today. They offer great efficiency, but they are slightly more expensive than poly-panels. What makes two types different is that cells for mono-panels are made of one silicon crystal. Back in the day it was quite expensive to make cells this way, but now there isn't a huge difference between the two methods, which is why today mono- and poly-panels are close in terms of cost. Cells of mono-panels are usually black in color and have rounded edges. Efficiency of mono-panels usually ranges from 17% to 22%. Mono-panels also last for more than 25 years and handle high temperatures much better.
Thin-film
Thin-film panels are the third most widespread type of solar panels that shows a lot of promise. Some experts claim that this type has the most potential out of three and is going to replace others in the next decades. Thin-film panels are flexible and very light. Their efficiency is the lowest among three: 10%-15%, but they are the cheapest to produce. They also have a shorter lifespan: usually it ranges from 10 to 15 years. However, thin-film modules are being constantly improved and some models already show an efficiency and lifespan that is comparable to poly- or even mono-panels. Currently, these flexible panels are very popular in mobile installations, like RV and boat systems, where you don't need a lot of power.
Benefits of Solar Panels
These are the three main types of panels: the principle behind their work is the same. Some other types may rise to popularity in the future: for example, building-integrated photovoltaics (BIPV) show a lot of growth recently. With BIPVs solar elements are built into walls, windows and roof of a building which saves space and doesn't affect the appearance of a building. There are also Concentrated PV cells that take advantage of a system of mirrors and lenses and some other types. For different reasons, the primary being high cost, these types aren't yet all that popular among the general public.
Let's now finish this article by listing the main benefits of solar panels:
- Renewable energy saves the planet. Using solar panels contributes to the fight against climate change. The pollution that is produced by the solar industry is comparatively tiny. Review the top solar panel companies before making a decision to ensure you are getting a good deal.
- Almost no maintenance needed. Unlike gas generators, solar panels don't need any fuel and they certainly don't smell and don't make any sound. You will need to wash them maybe once a year and regular checkups by a certified electrician are going to prolong their lifespan.
- Great long-term investment. On average a PV system brings in over $100 monthly by reducing your energy bills and pays for itself in 6-8 years in the USA. Since the lifespan of a PV module is over 25 years, you can expect your solar system to pay for itself a couple of times.
- Independence from your utility. While most solar users choose a grid-tie system, you can also disconnect yourself from the commercial grid and live solely off solar energy by getting batteries. Hybrid inverters provide you with uninterrupted power supply: when there is power outage in the grid, your home is still supported by your own energy storage.
