# Size & Cost of PV panels you need to cover your electricity consumption.

###
**Economical view:**

A solar Photovoltaic power system is a technology that converts the energy from
sunlight into electrical energy. Residential solar Photovoltaic systems can
offset much of your household's power needs, depending on the size of
the system ,your household's needs and your location.Before deciding to spend thousands of dollars on a Photovoltaic system, It’s wise to evaluate how energy-efficient your home is, and how much your family’s lifestyle affects your energy usage. Without knowing this information, you really can’t determine the size of the Photovoltaic system that’s right for your home.

So the fist thing you need to know is your average monthly consumption of Electrical energy and we mentioned how to get it in a previous topic of "photovoltaic systems".

**But let's talk about me for example: my average monthly consumption is about 200kWh and this cost me about ( 200 * 0.2$ = 40$ per month).**

Ok- Let's see if it is economical for me to setup a PV solar system? and what area I need to install it?

###
**Solar radiation data:**

As we know the amount of solar radiation that you can collect varies depending on your location, the season and all over the day. It's complicated to make a full report about this and you can find these details in previous topics "Solar radiation and The seasons", but we are talking now about average as we are looking at the matter with economical view.**But is there any other way to know nearly the solar power per square meter amount without owning a solar power meter?**Of course yes. But you can't get an exact number with it. You can get a range.

Look at the annual world solar energy map below. - See more at: http://www.solar-city.net/2013/08/solar-radiation-data-necessary-to-go.html#sthash.NbtpHpLP.dpuf

Look at the annual world solar energy map below.

Solar Radiation

**But is there any other way to know nearly the solar power per square meter amount without owning a solar power meter?**Of course yes. But you can't get an exact number with it. You can get a range.

Look at the annual world solar energy map below. - See more at: http://www.solar-city.net/2013/08/solar-radiation-data-necessary-to-go.html#sthash.NbtpHpLP.dpuf

**But is there any other way to know nearly the solar power per square meter amount without owning a solar power meter?**Of course yes. But you can't get an exact number with it. You can get a range.

Look at the annual world solar energy map below. - See more at: http://www.solar-city.net/2013/08/solar-radiation-data-necessary-to-go.html#sthash.NbtpHpLP.dpuf

You can see that each color represents a range of energy that the place collects all over the year with the unit

and to get more accurate number I recommend you to use

You can see that each color represents a range of energy that the place collects all over the year with the unit (KWh/m2) per year.**(KWh/****m**) per year.^{2}and to get more accurate number I recommend you to use

*this online tool.***If you have a problem with understanding any thing feel free to let your comment.**- See more at: http://www.solar-city.net/2013/08/solar-radiation-data-necessary-to-go.html#sthash.NbtpHpLP.dpufTo get more accurate number I recommend you to use this online tool.

**If you have a problem with getting your annual solar radiation feel free to let your comment with your exact location.**

Again about me: in my location my annual solar radiation is about

**2200kWh/m^2**.

So monthly solar radiation energy could be about: 2200 / 12 = 183.3 let's say

**180kWh/m^2**

###
**Efficiency of Photovoltaic cells will reduce power:**

Unfortunately we can't convert all of this amount of energy into electrical power as Photovoltaic cells have an efficiency range from 10% to 20% according to type. Let's say the efficiency is 15% so power that I can get will be: 180 * 0.15 = 27 let's say it's **25 kWh/m^2 monthly**.

###
**Size and cost:**

Now about me again to get 200kWh monthly I'll need: 200 / 25 =**8 m^2**of PV panels.

about cost to evaluate cost I need to get daily energy consumption first: 200/30(days per month) = about

**7kwh/day**.

a general rule of thumb for calculating the cost of a PV system is $3.50 per installed watt.

so this could cost me 7000 * 3.5 =

**24,500$**

**Notice that my consumption is considered very high.**

Now I'll need 8 meter square of area on my roof (out of shade) and 24,500$ to cover my electrical consumption which is 200kWh every month.

so I'll save about 50$ per month (remember that electricity cost increases with time)

so I'll need 24,500 / 50 = 490 month =

**41 years to cover It's cost.**

Now follow the steps above and try to fill the table below for you:

**If you faced any trouble feel free to ask in a comment.**

In the coming topic of "photovoltaic systems" we are going to tell you more about PV solar panels types.

We never forget to recommend you that having a clean world and powerful energy sources is the responsibility of all of us. So as you are here you must play your role by sharing this topic with your friends. We know that your dream is to see our world as a large solar city.

## 0 التعليقات: