solar power calculator

solar power calculator

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Choosing your 12v Solar Panel

If you are looking into Solar panels to keep a battery topped up I have put together a few points to help with your decisions.

Solar Panels take the energy from the sun and change it into 12v dc electricity that is suitable to charge your battery. You may have noticed that there are a few different appearances of panels available.

The 3 main modern competitive cell types are Monocrystalline, Polycrystalline and Amorphous. They all have their advantages and disadvantages. Listed below are the basics to help you choose.

Monocrystalline (single flat dark blue colour) has a typical efficiency rating of about 15-17%. Costs are usually slightly higher than other types due to complicated manufacturing techniques.

Polycrystalline (lighter blue broken glass appearance) is similar to monocrystalline except the slices are made from multiple crystals grown together. Costs are slightly lower and efficiency is around 12%. These panels suffer from efficiency loss at high temperature.

Amorphous (brown gloss as seen on calculators) operates at around 6% but has the advantage of being flexible. Larger panels tend to be more expensive than crystalline versions as they are less popular.

The next problem you may be facing is which size to buy. There are many panel size calculators out there on the internet and these are based great scientific data. That's wonderful but in reality it is quite different and using these calculators alone may get you into trouble if you are going to rely on the power.

Through talking to various people and doing my research I found a simple way to do my calculations on the 12v solar panel sizing. There are 2 options to making the calculation and this is based purely on whether you will be using it in only the summer or both summer and winter. The reason for this is that the sun is far less powerful in the winter and the calculation is different.

Using your battery as normal. How long does it last before it dies? (I'm a caravan user and my battery usually last me 4 days)

How large is you battery or battery bank? This is rated in AH on the battery label. (the battery I use is a 100AH)

So now you divide the capacity (ie 100ah) by the time it takes to deplete (ie 4days) = 25AH per day. This is my consumption so I then need a panel that will generate this amount of power each day to keep the battery full. I was then able to look on the website and see that the 40w 12v Panel was the ideal partner for me. I only use the caravan in the summer so I was easily able to see from the information given to me on the site.

I hope others may find this informative and help overcome the same problems I had.

Customized Credit Card Size Solar Power Calculator.mp4