Types of solar charger, elements should be considered when buying a solar charger and good recommendations are stated in this passage to help you buy a suitable solar panel.
Types of solar panel
Let’s start form the material used to make a solar panel cell. Most of photovoltaics are based on some variation of silicon, so does solar panel. There are mainly two types of solar panel cell, monocrystalline and polycrystalline, and the major difference lies in the purity of the silicon. The more perfectly aligned the silicon molecules are, the better the solar cell will be at converting solar energy to electricity.
Solar cells made of single-crystalline silicon called monocrystalline cells and you can easily recognize them from the black color and the shape of silicon ingots which are cylindrical. Monocrystalline solar panels have the highest efficiency rates (15-20%) since they are made out of the highest-grade silicon. By using a single cell, monocrystalline based silicon allows the electron greater freedom to move, so less energy is lost and higher efficiency is created. Due to this feature, they require the least amount of space compared to other types of solar panels and they tend to perform better than others in low-light conditions.
However, as the monocrystalline enjoys more advantages, it naturally is the most expensive type of cell, and it cannot provide high converting rate in any circumstances. Though it performs well in warm weather, the entire circuit can break down once the solar panel is partially covered with shade, dirt or snow. High warm weather performance goes together with low efficiency in bad environment.
Whereas monocrystalline panels appear more black, polycrystalline panels have a bluish blue. As the names suggest, a monocrystalline cell is made up of a single crystal ingot whereas a polycrystalline cell is made up of a gross of multiple crystal ingots. A good way to separate mono- and poly-crystalline solar panel is that the latter one looks perfectly rectangular with no rounded edges. Compared to monocrystalline cells, the process of making polycrystalline cells is simpler and cost less. So its price is a bit lower than monocrystalline cells as a result.
Because of the lower silicon purity, the efficiency of polycrystalline-based solar panel cells is typically 13%-16%, which is not as efficient as monocrystalline cells. And to output the same electricity with a monocrystalline panel, the polycrystalline panel will need larger sun-contact space.
Elements should be taken into consideration
There are numbers of elements we should consider when buying a solar panel since various data will lead to large differences in its performances. In this way, knowing the technical terms associated with solar panel will help a lot in choosing a solar panel that feed our needs best. Among those elements, watt, output, conversional rate and portability will deserve an explanation in detail.
To know the basics of watt, we will need to talk about amps, voltage and ohms first. Let’s compare electricity to a water pipe, then amps is like the water current, voltage is like the water pressure and ohms is like the pipe size. Watt is a measure of electrical power, which can be calculated as voltage multiplied by amps. To be professional, wattage is defined as joule per second and can be used to express the rate of energy conversion or transfer with respect to time. It is used to describe the speed of work an object can do.
For small handheld devices such as simple cell phone or mp3, a 4-5 watt solar panel is enough. However, with the heavy use of smart phones and tablets, you may need a panel of at least 7 watt to feed each of them and a more than 15 watt panel is needed to charge multiple devices if you want. Of course the lower the wattage is the cheaper a solar panels is, but one thing I would like to mention is that, don’t buy cheap solar panels because you may get a small panel and end up frustrated by the lengthy charging times.
The output of a solar panel has a marked impact on the performance of the panel. To be specific, it determines whether the panel can charge your devices or not. So when you buy a solar panel, be sure to match your needs to your amps and your use to your watts. For instance, a 2.1 amp USB port will be more efficient than a 1.3 amp one. Besides, read the specs clearly before you pay. When two panels claim the same output, they possibly mean different because some manufacturers report the total amperage of all ports while the others mark the max amperage of each port. For example, if a solar panel says it has 2.1 amps output, the 2 ports it has will split the power when 2 devices connected, but there is also a possibility that one of the ports can output 2.1 amps current while the rest can output 1 amp current simultaneously. So make sure you read and understand the specs of solar panels before you buy them.
Portability, conversion rate and others
Most of us use solar panel outside such as hiking, camping, or picnic, the portability of solar panels therefore is an important factor to consider. A good solar panel should be able to fold into small packs and be light so that it can be easy to carry and use. Some of the panels on market can be hang on backpacks and even have an integrated pocket to stash devices connected. That will free your had from holding those devices.
Conversion rate refers to the ability and efficiency of solar panels to transfer sunlight to electricity. In short, the higher conversion rate is, the better efficiency the solar panel has.
Besides, connections, integrated battery, ease of use, versatility are elements deserve your consideration.
After tested numbers of solar panels of different brands, we decide that the EasyAcc 2 ports 15W/28W High-efficiency Solar Panel are the best ones on current market. With a 21.5-23.5% conversion rate, this industry-leading solar charger largely shortens the charging time. The opened size (510 x 160mm / 20.1 x 6.3in) is big enough to absorb sunlight to power up 2 devices, while the closed size (282× 160mm / 11.1× 6.3 in) enables great portability. Plus the lightweight (370g / 13.1oz) design, minimum bulk will be added to an outdoor backpack. The Max output of one port in this EasyAcc solar panel is up to 2.1 amps and the 1 amp through the rest port. It also has the integrated pocket for devices storage.