Basic about Solar Energy, Solar Power and Solar Electricity.
In basic about solar energy, solar power and solar eletricity we will talk about the basic things behind this power. Formulas that will be used to find out which Solar Panel you should use and which battery you should select. And how much Solar Panels do you need to power up lights and other applications. Here are the main things you need to know and that will be used to calculate your needs.AC-DC system, Volt, Current(Ampere), Power(Watt), Resistance, Series and Parallel connecting.
AC-DC system
Ac stands for Alternative Current. Alternative current is almost that we found in wall outlet or electric outlet. Clever say'd that we found in wall. It is 230 Volt. DC stands for Direct Current. In solar panels it is used 12 volt dc system. DC is that current we can found in cells, batteries, and using adapters or regulators. See the picture of a dell charger. Dell charger also converts AC Current to DC 5.4 Volt and 2410mA. Solar Panels also uses DC voltage and Current.
Volt
Voltage is the electromotive force (pressure) applied to an electrical circuit measured in volts (E).
Example. P=200W, I=4.0A. If we have a value of watt and ampere and we want to find out how much volt does it use then we should use this from Power Circle. E=P/I. 200/4.0=50V. So we found voltage is 50V.
Current
Current is the flow of electrons in an electrical circuit measured in amperes (I).
Example. P=100W, E=12V. We want to find out how much ampere does it use. We take a look at circle. I=P/E. 100/12=8.33A. Current usage is 8.33A.
Power
Power is the product of the voltage times the current in an electrical circuit measured in watts (P).
Example. E=220V, I=0,4A. This example is taken from picture of Dell Charger. We have 400mA=0,4A. Take a look at circle P=E*I. 220V * 0,4A=88W. Answer is dell charger use 88Watt.
Resistance
Resistance is the opposition to the flow of electrons in an electrical circuit measured in ohms (R). Increased resistance gives higher voltage and higher power(watt).
Example. E=12V, I=3.0A. We want to find out resistance. We use formula R=E/I. 12V/3.0A = 4 Ohm.
Parallel Connecting - 12V System
Parallel Connecting solar panels gives higher current. And voltage will remain the same. Parallel Connecting is best for us. Because we do not need high voltage. Normal battery is 12v. And by selecting high voltage require higher voltage charge controller. To connect solar panels in parallel we have to connect plus + to plus and minus - to minus. See the picture for details.
Series Connecting - 24V System
By connecting Solar Panels in series connection. It will increase Voltage and current Amps. will remain the same. To connect solar panels in series we have to connect plus + to - minus on next panel. See the picture for details. In this example we have connected 2 solar panels in series which will give 24v output.
Series and Parallel Connecting - 24v System
If we are creating a 24v system. So then we have to connect two solar panels in series and connect two series connected panels in parallel as showed in figure under. Which increases voltage to 24v and when we have connected two other 24v connected solar panels in parallel so voltage remains same and increases current Amps. If we want to increase output current on 24v so we connect more solar panels in parallel same way under as shown in figure under.
Components used for solar energy system
- Solar Panel
- Charge controller
- Solar Tracker
- Batteries
- Inverters
Solar Panel
Multi-crystalline (Polycrystalline) Solar Panel
A polycrystalline cell contains many crystals. It has similar life span to the monocrystalline cell type, but it has lower efficiency and cost per watt.
Mono-crystalline Solar Panel
A monocrystalline cell is made of a single crystal. Monocrystalline solar panels are high efficiency solar panels.
How much watt solar panel we need?
Example we want to power up 5 lights of 20 Watt and we need to use these 5 lights for 3 hours every day. Here first we get a total watt usage. Ptotal = 20 * 5 = 100W. Than we multiply 100 with 3 hours. Pdaily = 100 * 3 = 300W. We are going to use 300 watt daily. Let us say we are going to have complete sunshine 6 hours each day. Now we divide 300W with 6 hours, so we will get hourly power charge that we need Phourly = 300 / 6 = 50W. So we need a 50 watt solar panel. But it is recommended to always choose a panel some bigger then we need. Because when solar panel charge the battery so it is wasting some power on charging too.
We recommend to buy solar panels of good qualtiy. If you is really looking for panels that can be used in 20-25 years without have massive loss so we recommend you to buy quality solar panels. Because normal quality solar panels have a about 1% or less yearly loss of energy each year. So it mean if you use them 20 years so they will have a loss percent of 20%. So a 100 Watt panel will produce 20% less then what it produced when it was new. 100 watt minus 20 it is equal 80 watt. After a 20 years usage in direct sunshine a solar panel will produce 80 watt.
Solar Tracker - Sun Tracker
Charge controller is used to charge batteries from Solar Panels. Solar panels normal give 15-17 volt, charge controller converts that to 12-14 volt and charges battery. Battery often need a higher voltage than it already have to charge the battery. Charge controller prevents batteries to be over charged. And stops to charge when battery is fully charged. And it will give longer life for battery. You can also use blocking diode instead of charge controller. But there are some negative effects of blocking diodes. If you do not use charge controller and just use a blocking diode, so battery can be over charged and damaged. If you is using big solar panel system so it is better to have an advanced charge controller. That gives you complete statistics of how much volt and ampere it have charged battery. Advanced charge controllers also show you how much ampere is on batteries. Charge controllers can automatic disconnect battery if it is going to be empty.
For bigger systems like tubewell or water pumping they are used high voltage charge controllers, called MPPT(Maximum Power Point Tracker) charge controllers. MPPT charge controller can convert dc-dc voltage. Example used in 24, 38, 48 volt systems. MPPT charge controllers are used with higher power panels like 135 watt and higher panels.
Solar Battery Storage
Normal Batteries
Batteries are very important resource in solar power system to store all the power. It is used normal car batteries. Normal batteries are cheap and good. Normal car batteries require some maintenance. The thing is you need to do is fill mineral free water or destilled water(Urd. Taizab) after a period. You have to check the battery after each 6 months or earlier for level of destilled water. Cable connection needs to be clean and tightened. Many battery problems are caused by dirty and loose connections.
Maintenance Free Batteries
Maintenance free batteries do not require any kind of filling of acids. These batteries have a liftime of 1000 charges or some years. So you have to change battery after this time.
How much watt a battery can store?
It depends on battery size and how much Ah(Ampere hour) is a battery. Example if a battery is 65Ah so it can store 780W. We know a battery is 12v and we have 65Ah. P = E * I = 12v * 65 = 780W.
How to increase battery capacity?
By connecting to batteries in parallel it will increase capacity. We are showing you how to connect batteries in parallel on the picture under. You have to connect positive wire from 1st battery over to second battery and connect negative wire over to negative wire on second battery.
Batteries connected in parallel gives more capacity
Batteries connected in series gives higher voltage
Inverters
Inverter is used to convert 12 volt system to 220 volt and 50Hz. There are two kind of inverters, modified sinewave and true sinewave inverters.
Modified sinewave
Modified sinewave inverters are cheap and is the most common type of inverter on the market. They can run most common tools and appliances, including microwaves, refrigerators, hand tools, televisions and computers. Devices that require true sine wave will not run on modified sinewave inverter. Remember if your product does not work with modified sinewave inverter so it mean you need to buy true sinewave inverter.
True Sinewave inverter
True sinewave inverters are expensive. These products require true sinewave inverter high-end audio video units, plasma displays, gaming systems, and certain scientific testing equipment.
