Everything You Need to Know About Solar Panels

The world is swiftly moving towards clean energy, and we must adapt.  China stands first in investing in renewable and alternate sources of energy, followed by India and USA.  Many countries have started moving towards sustainable energy sources. Germany, Canada, New Zealand, Brazil, Norway, Iceland and Denmark, are some of the nations leading in renewable energy. Scotland is now completely run by wind turbines. Chile has so much electricity, that it is frequently given away for free!

So, is there a way we can get electricity for free?

Sure there is…..just install a solar panel above your house!Sounds simple, but there are many factors we must take into account and many other aspects to be considered. Let’s have a look at them:

There are basically two types of Solar Cells, also known as Photovoltaic Cells (PV Cells):

  1. Polycrystalline
  2. Monocrystalline
  • A polycrystalline cell, as the name suggests, has multiple crystal structure arrangements that have a random pattern. The Silicon Wafer, which is considered to be the heart of the cell, is made up of polycrystalline silicon.
  • Conversely, a monocrystalline arrangement will have its crystal structures arranged in a unidirectional pattern.
  • Monocrystalline structures need an additional manufacturing stage to align the crystal structures, and therefore are a bit expensive as compared to polycrystalline cells. However, if you are considering a small system, maybe for domestic use, the difference in the cost may be overlooked.
  • The working principle of a Solar Cell or a Photovoltaic (PV) Cell is based on the separation of P-type and N-type semiconductors by the depletion region. When the depletion region is exposed to sunlight, it makes the valence electrons to move freely as a result of the solar-thermal energy, reaching the “fingers” of the solar cells in the form of photons.
  • Pretty cool right? But the free electrons still need to move in one direction. That is taken care by the busbars. These busbars are metal strips generally made of silver paste, copper or any other highly conductive material, that conduct the direct current, from the panels to the inverter batteries.
  • A standard panel consists of a silicon layer which is covered in silicon monoxide, followed by titanium dioxide. Surface treatment also includes texturing the titanium dioxide layer, so as to increase the probability of light being absorbed by the PV cell. To top it off, the whole cell is then covered with an EVA sheet (Ethylene Vinyl Acetate sheet), that protect the cell from dust, rain and oxygen and other gasses that can oxidise the metal components

Now let’s talk about the types of Solar Energy Systems:

  1. Off-Grid: Disconnected from the electric grid
  2. On-Grid: Connected to the electric grid

The Off-Grid System

In an off grid system, the whole system is isolated and self-sufficient. Naturally, batteries and inverters come into the picture. The number of batteries depends on the number of panels you have, and the Wattage they produce. Now, we can use Lithium Ion batteries that are a tad expensive, but need minimum maintenance, or we can go for the conventional Lead Acid Batteries, that cost less, but need timely maintenance. Also, we must make sure that we do not overcharge the batteries.

The Lead Acid batteries are easily available, but need a top-up of distilled water after every 2-3 months. These batteries will start giving you an ROI after 2 year, but have a life of around 5 years.

The On-Grid System

The On-Grid System is connected to the grid and doesn’t involve batteries. However, there is an electric panel that consists of an inverter, and a metering device sometimes called a Net-Meter, which is basically a Power Conditioning Unit.

One advantage of the On-Grid system is that it seldom needs any maintenance and, it can borrow power from the grid as and when necessary. If you are producing more than you are consuming, the Net-Meter will send the excess energy to the grid.

The whole system is a one-time investment that starts to pay for itself after around 5-6 years depending on the usage.

Here are a few Pros and Cons of the Solar  Energy System:

Cons:

  1. Solar Panels can be expensive, especially if they have to be shipped.
  2. They can take up a lot of space.
  3. They are totally dependent on the weather.
  4. Finding installers in you locality can be a bit of a challenge.
  5. Not every roof is suitable for solar panels. The direction and angle are to be ideal for optimised results.
  6. An Off-Grid system will completely shut down if there is no sunlight, and the batteries run out of charge.

Pros:

  1. Lowers Carbon Footprint, no emissions, no noise, environmental friendly.
  2. Comparatively low maintenance cost compared to other renewable resources.
  3. Diverse applications. Can be customised to fit requirement.
  4. Energy savings. Starts giving an ROI, starts paying for itself in a short span of time.
  5. Recent technology has made it easier and cheaper.
  6. Manufacturing does not produce Green-House Gases.
  7. Financial support from the Government in the form of loans or subsidiaries.
  8. The life of a solar cell is around 25 years. Even after that, they may work, just not that efficiently.
  9. Independent and abundant source of energy.
  10. Installation of Solar Panels will increase the market value of your house. In the US, the average increase in the value of houses was around 4.1%.

Pro Tip:

  1. Make sure to install the panels at the right direction and inclination that are provided by the manufacturer, which might vary depending on your area.
  2. It is advisable to use double-Insulated Zinc-coated Copper Wires, for the batteries. Special sets of wires are also available for both, AC and DC, for Solar Panels. Make sure you use the right wire for the right application.
  3. The Lead-Acid Batteries need a top-up every 2.5-3 months. Make sure you use Distilled Water, which is available in markets for the very purpose of refilling Lead-Acid batteries.
  4. Along with Solar Energy Systems, make sure to use LED or CFL lights, which reduce your overall consumption and make the solar panel even more worthy.
  5. Make sure to add a lightning rod, a AC Distribution Box, a DC Distribution Box, and any other safety equipment provided by the manufacturer.
  6. Make sure the Solar Panels are situated in a No-Shade zone. Any obstacles must be avoided, and the panels must be cleaned regularly.

FAQs:

  1. Can I walk on the solar panels?

NO. Residential panels are not made to be walked on.  Nothing heavy is to be kept on the panels. Although the panels can survive moderately heavy rain, nothing that might cause damage is to be in contact with the panels.

  1. How much panels do I need?

Depending upon your monthly consumption, you can easily calculate your requirement. Note the number of units (kWh- kilo Watt hours) you use per month.

For example:

Wattage No. of Panels Operating in sunlight ( hours) Units (kWh) Daily Units Monthly (x30)
100 3 5 1.5 45
250 3 5 3.75 112.5
350 3 5 5.25 157.5

 

The average monthly consumption of an American household is 1000 kWh. The cost of installation is to be discussed with the installer. The process takes 1-3 days.

  1. What is the size, weight of a solar panel?

The standard size of a solar panel is 3.5 ft. x 6 ft., consisting of around 60 cells.It is approximately 1 inch thick.A solar panel weighs 15-25 kg. and as a thumb rule you could say the weight per sq. ft. is 2 kg.These numbers may vary as per the manufacturer/required customisation.

  1. Do solar panels work in moonlight?

Not yet. However, scientists are now developing solar panels that capture energy from moonlight and also from rain, although these are still in the testing phase.

  1. Why do Solar Systems need an inverter?

The inverter acts as a moderator for both, On-Grid and Off-Grid systems.

  1. Is a Solar panel completely useless in cloudy weather?

No. The efficiency might be lesser, but it will still convert solar energy into electricity.

  1. Can I heat my Pool using Solar Cells?

Yes you can, in fact it is the cheapest way. Depending on how big the pool is and how much panels you have, the time taken may vary.