Many people are turning away from the traditional power sources in Ireland to an eco-friendly, cheaper, and more flexible solar power system. However, installing a solar power system capable of powering your whole appliances throughout the year requires a good piece of knowledge. 

You need to understand some basic requirements and necessities before installation, such as the type of panel and how many you need based on your energy consumption. You can calculate the number of solar panels needed with a not-so-complex formula. Or you could make a rough estimate of how many solar panels you need as per some factors.

This article will cover all you need to know concerning these factors; how to calculate your required solar panels; and the cost of making these solar investments.


Major Factors That Determine The Number Of Solar Panels You Need In Ireland

The more precise way to estimate this is through the formula. Still, these solar panel elements also play a major role. In some cases, you can easily access the metrics of the factors on your own or with little research. Sometimes, you would have to call in solar panel experts to review your house and explain the results.

The determinants of how many solar panels in Ireland you need are:

  1. Daily energy consumption
  2. Your house’s orientation
  3. Your roof dimensions 
  4. The number of sunlight hours in your area
  5. The type of solar panel 
  6. Wattage/power rating of the panel 


Daily Energy Consumption 

Before you look at your solar panel’s wattage, it is essential to determine the daily and annual amount of energy consumed in your house. This singular factor directly impacts the power output of the panel and the number that will suit your home.

The only things that affect your daily energy consumption are your electrical appliances. Consider how many devices you own and how much you use them daily.

A great way to ascertain your annual energy consumption is to refer to your utility bill from the previous year. It will contain your yearly power consumption in kWh. 


Your House’s Orientation

It’s no news that solar pv panels run on energy derived from the sun. So, the design and architecture of your house can play a huge role. The overall construction of your roof is also important. The inclination of your roof determines what specification of panels you will need. Also, the level of tree shade or any obstruction of sunlight will affect the number of solar panels you get.

We suggest an expert consultation to determine what kind of solar panels can work for you and where.


Your Roof Dimensions 

The angle of your roof is one thing to consider; the other is how much space it has. Solar panels need secure and adequate accommodation on your rooftop to function efficiently. A smaller-sized roof may entail small high-efficiency panels, while a larger roof leaves room for further deliberation.


The Number of Sunlight Hours in Your Area

Ireland is a country that enjoys a fairly good level of sunlight, making solar panels a great energy choice. Generally, though, the summer season from May to September see a 15-25% increase in the level of sunlight.

The issue with the above statement is that it varies from location to location. The daily sunlight your house experiences greatly affects how many solar panels you will need.


The Type of Solar Panel

The technology of your selected photovoltaic panel determines the panel size and how much space it will take up on your roof. According to the Sustainable Energy Authority of Ireland, there are three major solar panel types. These are:

  • Mono-crystalline silicon panels: These types are extremely efficient at converting light into electricity and are in high demand in the environmentally friendly energy market.
  • Multi-crystalline silicon panels: These set are less expensive but less efficient than mono-crystalline panels.
  • Thin film panels: Despite their appealing appearance, these panels are rarely used in Ireland.


Wattage/Power Rating of The Panel

This is the same as the amount of power an average solar panel produces. Based on your energy consumption, the panel-rated output will factor in the number of solar panels you require.

First, ascertain the solar panel wattage you will need—most range from 250W to 400W—then check your annual power consumption and calculate how many watt panels you will need (depending on your selected solar panel power output).


How Do I Calculate How Many Solar Panels I Need for My House?

You can calculate the number of solar panels needed using a pre-defined formula. The related components in this formula include:

  • System size
  • Production Ratio
  • Panel Wattage

After you have gathered the above information, use this formula to calculate how many solar panels you need in your house:

Solar panel count = (system size x panel wattage) /production ratio


What Size Solar System Do I Need in Ireland?

There is no standard solar system size for houses in Ireland. It is simply particular to the house location and electrical needs.

Some factors in determining the number of solar panels you need ring true for your estimated solar system size. These are:

  • Your average annual power consumption
  • The abundance of sunlight in your area
  • The size of your roof

You need a solar panel system that conveniently produces the power consumed in your house daily.


How Much Does It Cost To Acquire A Solar Panel System?

The expenses associated with acquiring social panels depend on how many and the quality you need. 

It is also based on your power requirements. For instance, it may be relatively cheaper to acquire solar panels as a backup option in case of a blackout than an exclusive system.

A home photovoltaic solar panel system can cost anywhere from €1,500 – €2,000 per kW installed (ex-VAT). The expense may vary depending on the type of social panel, the manufacturer, and even the installer.  Get an instant cost here.



Installing the right number of solar panels for your home is worth it despite the initial acquisition cost. In the long run, you only need to pay for possible maintenance while enjoying an uninterrupted power supply. Get in touch with AEI for the best advice on installing solar panels.