HOW MANY SOLAR PANELS I NEED FOR A HOUSE

13 7 minutos de lectura

To calculate the amount of photovoltaic solar panels that we need for a house, we must take into account three fundamental aspects to achieve the correct number.

The amount of energy we need, the watts we currently consume and the light hours in our area, are 3 essential steps to know exactly how many solar panels we need in our home.

HOW MANY SOLAR PANELS I NEED FOR A HOUSE

Next we will go into detail in each of these points so that in this way we can decipher the number of solar panels we need for a house, so that we can fully meet our goal of self-generation.

Determining how many solar panels I need for a house means first defining what its objective is.

Do you want to minimize your carbon emission? Maximize the return on your investment? Save as much money as possible?

To calculate how many solar panels you need, you need to know the following: how much energy your home consumes; useful surface of your roof; the weather and the peak of sunlight in your area; the wattage and relative efficiency of the photovoltaic (PV) panels you are considering; and if net measurement is available.

An easy way to answer the question “How many solar panels do I need?” Is to consult a professional solar power installer, who can provide you with a free solar evaluation at home.

If your idea is to put solar panels, the obligatory question arises how many solar panels do I need for a house ?

This question is not so simple to answer because the calculation depends on many variables that I will try to explain below.

Calculation of the number of panels required for the energy needs of your home, that is, I must know how many kW are needed for a house.

The conversion to solar energy is an alternative ecological energy option that has received more attention in recent years.
Consumption depends on the type of appliances you have and how often they are used.

- So, when it comes to “going out of the network” I should know how many solar panels I need for an average house , and should determine a realistic energy consumption sufficient to meet their energy and lifestyle needs.

What is a solar array?

A solar array is an interconnected system of smaller photovoltaic (PV) modules called photovoltaic cells or solar cells.

These cells, when connected in series (one after another), can charge a battery bank that stores energy until necessary.

A device called an inverter is placed between the batteries and the final charge, converting this energy into electricity that can be used to turn on your lights and appliances.

Each solar set has a specific rating. Some are 50 W, 80 W or 120 W, which means the amount of energy that can be emitted under ideal sun conditions.
As you can see, the power of the panels is measured in watts, but the energy needs of most devices are measured in kilowatts.

Therefore, several of these solar panels are required to meet typical daily energy needs.

HOW MANY SOLAR PLATES I NEED FOR A HOUSE

How many solar panels do I need for a house and what should its power be?

To know how many solar panels do I need for a house ? First we must know some technical data such as the output power of solar panels

Electric power is measured in watts and energy consumption is measured in kilowatt hours (kWh). A kilowatt hour is simply:

The amount of electricity used (1000 watts = 1 kilowatts), in kilowatts kw
multiplied by
The number of hours energy is used.

Generally, the calculation indicates the period of time, such as a day, a month or a year.

For example: if a 100 W bulb is on for 10 hours a day, then:

100/1000 (kilowatts) x 10 (hours) = 1 kWh per day.

In a month, that same 100 W bulb, lit for 10 hours a day, will consume:

100/1000 (kiloWatt) x 10 (hours) x 30 days = 30 kWh hours per month.

Your electricity bill will generally show how many kWh all your electrical devices used during the last billing period (usually around 30 days).

Determine your energy demand

To determine how many photovoltaic panels a house needs, we must know the monthly and annual consumption of your house Before converting to solar energy, look at your electricity bills for the last year and determine your energy consumption.

To know the annual consumption observe the kWh spent each month and add them to all those values and thus you will get the annual expenditure in kWh.

Some of us will use more energy in the summer when the air conditioner is running.

Others, who live in colder climates, can use more electricity in the winter, when the nights are cold and long.

Make a good estimate of the amount of energy you will need per day to know well how many solar panels does a house need ?

If you don’t have your utility bills, here are some average numbers to start with (important note: these can vary widely, depending on the type and brand of light or appliance you buy. The numbers are shown for illustrative purposes only):

16 W spotlight (on for 10 hours) – 4.8 kWh / month (57.6 kWh / year)
100 W focus (on for 10 hours) – 30 kWh / month (360 kWh / year)
Refrigerator – 36.7 kWh / month (440 kWh / year)
Dishwasher – 41 kWh / month (492 kWh / year)
Clothes washer: 24.9 kWh / month (299 kWh / year)
Electric clothes dryer: 74.7 kWh / month (896 kWh / year)
Stove and oven (self-cleaning) – 61.25 kWh / month (735 kWh / year)

Will solar panels work in my area?

It is a determining point for us to define the amount of energy we can expect from our solar panels. Depending on the light hours, we will also determine the number of modules we need.

For example, if we live in an area with many light hours, we will not use the same amount of solar panels as in one with few hours of sun. That is, the smaller the number of light hours, the greater the number of solar panels to be used, so that we can match our energy demand.

Once we have obtained the result of wh / day we consume and the peak hours of light, we divide the need for energy (in wh / day) by the number of daily peak hours of sunlight in our area.

The number that will throw us will be the average of the amount of Wp of solar panels that are required to cover our consumption. We have to take into account that depending on the type of solar system we want to use, or self-consumption system with network connection or isolated system, we will have some energy losses in the system since the transformation of energy produced by the different equipment (including the panels), it is not 100% since all the equipment loses some energy in the form of heat.

Normally, total energy losses of a self-consumption installation of around 20-25% are estimated. In an isolated system the losses that have to be considered can be much greater.

How many panels do I need? To answer this question, we must analyze whether in all areas where people live, solar panels work in the same way.

The solar panels will work wherever there is sunshine. That said, however, some places are better than others.

These are some of the most important factors to consider:

Location. The southern locations receive more direct sunlight than the northern locations.
Season. In the northern hemisphere, daylight hours are longer in summer and, once the batteries are fully charged, excess electricity will be wasted. In winter, the days are shorter and there may not be enough sunlight to recharge the batteries for nighttime requirements.
Weather. Solar panels are more efficient in direct and bright sunlight. Efficiency can be drastically and significantly reduced if the sky is cloudy. If snow accumulates on the panel, the assembly will stop producing electricity until the snow is melted or removed manually.
Obstacles Anything that blocks the incidence of sunlight on the panels will reduce the efficiency of the matrices. This includes shadows, leaves, dust and other debris. The panels can become inefficient quickly when they are prevented from receiving direct and complete sunlight.

How many solar panels are needed for a house?

The answer to this question depends on your lifestyle and energy consumption. As an estimate, if you need 3.85 kWh per day, you will need the following number of solar panels:

3.85 kWh (per day) divided by 7 hours of sunlight (per day)
= 0.55 kW from the solar array

If you have a 120 W panel, one of the largest units available today, you will need:

0.55 (kW) divided by 120/1000 (kW)
= 4.6 panels

This is an approximate calculation but shows that under ideal conditions , you will need more than one solar panel to meet a typical lifestyle. This is assuming the following:

Its roof is large enough to accommodate 5 panels (since it cannot have “4.6” panels).
The panels receive direct sunlight for at least 7 hours a day.
There are no obstacles in front of the matrices.
The panels are kept clean.