How to choose solar panels

How many solar panels do I need?

To determine how much energy you want your solar panels to generate and choose panels that can meet those requirements, follow these steps:

  1. Assess your energy consumption
    Start by understanding your current electricity consumption. Examine your past electricity bills to determine your average monthly and annual usage in kilowatt-hours (kWh). Identify any seasonal variations in your energy consumption.
  2. Set your energy generation goal
    Decide how much of your energy needs you want your solar panels to meet. Some homeowners aim to offset a certain percentage of their electricity usage, while others aim for full energy independence. Determine the percentage or amount of energy you want your solar panels to generate.
  3. Consider available roof space
    Evaluate the available roof space for solar panel installation. The size and number of panels you can install depend on the area of unobstructed roof space that receives sufficient sunlight. Consider factors like shading from nearby structures or trees that may impact the efficiency of your panels.
  4. Calculate the required capacity
    Calculate the solar panel capacity needed to generate the desired amount of energy. Solar panel capacity is measured in watts (W) or kilowatts (kW). On average, a solar panel has a capacity of 250-400W. Divide your desired energy generation (in kWh) by the average daily sunlight hours in your area to estimate the required capacity. For example, if you want to generate 20 kWh per day and your area receives an average of 5 hours of sunlight, you would need panels with a total capacity of 4 kW (20 kWh ÷ 5 hours = 4 kW).
  5. Consider panel efficiency
    Take into account the efficiency of the solar panels. Higher-efficiency panels can generate more electricity in the same amount of space. This is particularly important in areas with lower sunlight levels, such as Ireland. Look for panels with higher efficiency ratings to maximize energy generation within the available roof space.
  6. Consult with solar installers
    Seek advice from professional solar installers or renewable energy experts. They can assess your specific situation, perform an on-site evaluation, and provide accurate calculations based on your energy needs and available roof space. They will consider additional factors such as panel orientation, tilt, and local weather conditions to determine the optimal solar panel configuration for your requirements.

By following these steps and consulting with experts, you can determine the energy generation goals and select solar panels that are capable of meeting your specific needs in Ireland.

Choosing the Right Solar Panels

When choosing the right solar panels in Ireland, there are several factors to consider. Here are some key points to help you make an informed decision:


Look for solar panels with high-efficiency ratings. Higher efficiency means the panels can generate more electricity from the available sunlight. This is particularly important in Ireland, where sunlight levels are lower compared to sunnier regions.

Quality and Reliability

Opt for reputable brands and manufacturers with a proven track record of producing reliable and durable solar panels. Check for certifications such as the International Electrotechnical Commission (IEC) standards to ensure the panels meet industry quality standards.


Pay attention to the warranty offered by the manufacturer. Solar panels typically come with two warranties: a performance warranty and a product warranty. The performance warranty guarantees a certain level of power output over a specific period, while the product warranty covers defects and malfunctions. Choose panels with longer warranty periods for added peace of mind.


Consider the appearance of the solar panels, especially if you have specific architectural or aesthetic requirements for your property. Some panels have sleeker designs or can be integrated into the roof more seamlessly, while others are more noticeable.

Size and Output

Assess your electricity needs and available roof space. Determine how much energy you want your solar panels to generate and choose panels that can meet those requirements. Keep in mind that larger panels with higher output may require more space but can generate more electricity.

Financial Considerations

Compare the cost of solar panels from different suppliers and consider the return on investment. Calculate the payback period based on potential savings on your electricity bills and any available government incentives or grants for solar installations.

Seek Expert Advice

Consult with professional solar installers or renewable energy experts. They can assess your specific situation, provide recommendations, and help you choose the right solar panels for your needs.

Remember, selecting the right solar panels is just one part of the overall solar system. The quality of installation, inverters, and other components also play crucial roles in the performance and longevity of your solar energy system.

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