With the rise of solar power in recent years, many are interested in how long solar panels can store energy. The short answer is quite a while. According to Global Market Insights, Inc., traditional solar cells can store approximately 0.6 to 1.0 volts. Moreover, thin-film solar cells can store approximately 1.8 to 2.0 volts.
Many factors determine the storage capacity of solar cells, including the quality and type of the materials used. However, the most important factor is how the solar cells are designed and manufactured. If you want to maximise the energy storage capacity of your solar panels, follow the tips below.
Choose The Right Cell Type
The first step to increasing the energy storage capacity of your solar panels is to choose the right cell type. As already mentioned, traditional solar cells can store only a small amount of energy. For best results, use solar cell technologies that were developed in the 1970s and that are still considered state-of-the-art. In particular, the copper indium gallium selenide (CIGS) solar cell has a higher energy conversion rate than the traditional silicon solar cell. More information about CIGS can be found at http://en.wikipedia.org/wiki/CIGS._Solar_cells.
Thin-film solar cells are used in small gadgets and can be found in most cell phone stores. These cells are a combination of materials that are very thin and light, such as gallium, indium, and zinc sulfide. The most important feature of thin-film solar cells is that they can store more energy than traditional solar cells because the materials are less dense. However, these cells are more expensive to manufacture and they have a shorter lifespan. The maximum capacity of thin-film solar cells is approximately 2.0 volts.
The abovementioned cell types have a different design and structure, which determines how much energy they can store. For example, the CIGS cell has a thicker portion that is known as the active layer. This active layer is sandwiched between two electrodes that are made of transparent metal contacts. In contrast, the materials in thin-film solar cells do not have a distinct structure. Instead, they are arranged in a parallel and uniform fashion, creating a crystal-like appearance.
The lifespan of solar cells is also different. While traditional solar cells have a lifespan of approximately 15 years, thin-film solar cells are estimated to last only five to seven years. Nevertheless, the price of these cells is not as high as that of traditional solar cells, so the lifetime cost is comparable. Moreover, due to their design and construction, thin-film solar cells require less maintenance. The above statistics indicate that traditional solar cells are not suitable for long-term energy storage, whereas thin-film solar cells can be used for this purpose because of their higher capacity and longer lifespan.
Make Use Of Multi-Junction Cells
Multi-junction solar cells are used in space-related applications because they can handle higher radiation levels. These cells are a combination of two or more materials that are able to convert light into electricity with greater efficiency. Moreover, they are durable because they are constructed with multiple layers, each with a different bandgap. The most famous multi-junction solar cell is the triple dot solar cell, which is made of a combination of aluminum, gallium, and indium. This material is more durable than single layers of aluminum or gallium, which are prone to corrosion. When exposed to radiation, the aluminum in the triple-dot solar cell will transform into an aluminum oxide that is more resistant than the original metal. This oxide layer prevents further oxidation and subsequent leakage of the electricity produced by the cell. In addition to enhancing the lifespan of the solar cell, the aluminum oxide also improves the energy conversion rate of the cell. This material is commonly found in satellites because it is more resistant to radiation than the metals used before it (e.g. aluminum and gallium). The abovementioned metals, if not protected, will eventually corrode and release dangerous free radicals that could cause damage to the orbiting satellite.
This section is dedicated to discussing a different type of solar cell, called the p-type silicon solar cell. This type of cell has a positive charge and is made of a single crystal of silicon, which is a form of carbon. The abovementioned cell can store approximately 0.8 to 1.2 volts. This is not very high compared to other types of solar cells, but it is still enough to run most electronics.
Choose A Passive Material For The Backside Of The Solar Cell
The backside of a solar cell, also called the n-side, does not convert light into electricity. This is because the backside is opposite to the light-receiving side, which is called the front side. The backside of a solar cell is made of a material called the passive layer, which is used to diffuse the incoming light. If you are looking for a long-term energy storage solution, then an ideal passive layer material for the backside of the solar cell is silicon dioxide. This material has the advantage of being both transparent and thin. Incoming light can travel through the thin silicon dioxide layer and be absorbed by the active layer without being reflected by it. This minimises the losses of light caused by reflection and absorption, which would reduce the overall efficiency of the cell.
Avoid Expensive Metallurgy Processes
The manufacturing processes of a solar cell are highly complex and can be both expensive and time-consuming. The most important steps in the manufacturing process of a solar cell are the diffusion process and the metalization process. The above processes are used to make the front side of the cell, which is where the actual conversion of light into electricity takes place. The metals in the abovementioned processes are used to create electrical connections and conductivity in the cell. These metals, which are typically made of gold, silver, or copper, add to the overall production costs of the cell. In addition, the metals in the above processes are also prone to corrosion because of the high radiation levels in space. This makes the cell weaker and more likely to break down.
Maximise The Energy Conversion Efficiency Of The Cell
One of the factors that determine the energy conversion efficiency of a solar cell is the material used for the electrodes. To achieve the best possible efficiency with the p-type silicon solar cell, use metal contacts that are highly reflective and conductive. One of the most widely used metals for the formation of these contacts is silver because it is both reflective and conductive. Moreover, if the electric field created by the electrode is strong enough, then electrons from the photoexcited layer will be collected by the electrode and will subsequently flow through a wire connecting the two.
The energy conversion efficiency of a solar cell can also be increased by using specific electrical contact blockers. These materials are used to prevent electric currents from flowing into certain areas of a cell. For example, a p-type silicon solar cell with multi-junction active layers can be used to prevent electric currents from flowing into the aluminum oxide layer. This is because the aluminum oxide layer has a significantly higher resistance than the p-type silicon layer. In this way, the efficiency of the cell will not be degraded even if high levels of radiation damage the material.
Consider The Environmental Cost Of Recycling
While there is no precise data available, it is estimated that the amount of energy consumed by the electronics industry each year is approximately 2.5 exabytes. If this energy is sourced completely from solar power, then it would only be necessary to consider the environmental cost of manufacturing and recycling the panels. The lifecycle of a solar cell begins with the extraction of its raw materials, which can be either recycled or replaced directly. In the case of conventional solar cells, approximately 70% of the materials are recycled while 30% are replaced directly. Nevertheless, with a long-term energy storage solution such as a CIGS solar cell, the materials will be recycled more than 95% of the time because the CIGS material is far more difficult and expensive to extract than the raw materials of a regular silicon solar cell.
For best results, only use environmentally-sound and recyclable materials to manufacture your products. In addition, proper recycling procedures should be followed to avoid any negative environmental impacts. Lastly, purchase energy-efficient electronics and appliances wherever you can to reduce your energy consumption and the environmental footprint of electronic production.