Are you interested in reducing your reliance on fossil fuels and moving towards a clean and green energy setup, but unsure about the number of solar panels you would need to go completely off grid?
Solar energy is no doubt a clean source of energy on earth, but the number of panels needed to power a house would depend on your location, size, roof angle and the energy goals.
This blog would explain the process of calculating the number of solar panels based on your energy consumption level. Interested? Let’s learn and calculate!
How to Calculate Your Annual Electricity Consumption?
To calculate the number of panels needed to power a house, it’s important to figure out how much energy you consume in a year.
To calculate the annually consumed electricity, you may use two methods;
Electricity Bill
The easiest way of calculating the energy consumption in a year is to look at your monthly bills and multiply it with 12. For example, if your monthly consumption of electricity is 500 kWh, then your annual consumption would be 500 x 12 = 6,000 kWh.
Online Calculator
Another way to calculate the annual energy consumption rate is to use an online calculator, available on different websites like Going Solar and enter the details like the number of devices you use, how often they are used and the power rate they consume.
The average household consumption in a year is about 4,200 kWh, but it may vary based on the size, lifestyle and the number of people living in your house
Other Factors That Could Impact The Number of Solar Panels You Will Need
There are some other factors as well that could impact the number of panels needed to power a house in Ireland like;
- The size and efficiency of panels
- Sun hours per day
- Battery storage system
Size and Efficiency of Panels
The higher the size and efficiency, the less the number of solar panels you would need. The size of solar panels is measured by its power output in Watts (W), and efficiency is measured by the percentage (%) of sunlight converted into electricity.
The average size of solar panels available in Ireland is 300W and the average efficiency is 20%. This means that a single panel can produce 60kWh of electricity.
Considering this figure, the number of solar panels needed to provide 300 kWh of electricity would be 300 / 60 = 5.
Sun Hours Per Day
This is the average number of hours the sun shines in your location taking into account the cloud factor.
For example, if the sun shines for 2.8 hours in Dublin, then to fulfil the requirement of 4,200 kWh of electricity per year, you would need;
4,200 kWh / (300 W x 3 h x 365 days) = 12.78
This means that you would need 12 – 13 solar panels to power your house in Dublin.
Battery Storage
If you have a battery storage system to store excess electricity for later usage when there is no sunlight, you would need relatively less solar panels. However if you have a grid connection as well to sell excess electricity produced by your system, then you may need more solar panels.
How to Calculate the Number of Solar Panels You Need?
Once you have estimated your annual energy consumption, size, efficiency and peak sun hours of your location, you can use this formula to calculate the number of panels needed to power your home.
Number of solar panels = Annual electricity consumption (kWh) / (Solar panel wattage (kW) x Peak sun hours per day (h) x 365 days)
For your ease, we have calculated the number of solar panels required to fulfil the average energy consumption by Irish residents.
No. of solar panels = 4,200 kWh / (0.3 kW x 4 h x 365 days) = 9.59
As per this example, you would need 9 – 10 solar panels to get 4,200 kWh of electricity per year. Keeping this formula in mind, you may also figure out the number of panels you need for your house by checking the annual electricity consumption from your electricity bill.
How Much Does It Cost to Install Solar Panels in Ireland?
The cost of solar panels is determined by several factors, including;
- The size and type of solar panels
- Number of panels
- Installation fee
- Grants and incentives
In general, the cost of installing a 4 kW solar PV system ranges from €8,000 to €10,000. However, this cost could be reduced to €7,600 after the approval of the SEAI grant which is €2,400 for a 4 kW system.
Interested in Going Solar?
Are you looking to power your house with solar panel company and enjoy the benefits of lower electricity bills and increased value of your home? Unsure about the number of panels you would need?
Don’t worry! We are here to help you calculate the number of panels needed to power your house. We are determined to help you achieve your energy goals whether you need to cover 50%, 70% or 80% of your electricity consumption or want to go completely off-grid with solar panels.
Contact us and be one of our happy customers!
Frequently Asked Questions
Are solar panels long-lasting?
Solar panels are usually designed to last for 25 years. However, their efficiency could be reduced, which can be compensated by cleaning the panels regularly.
Do you need planning permission to install solar panels in Ireland?
In most cases, planning permission is not needed to install solar panels in your house as far as you meet the criteria set by SEAI according to which;
- The area covered by solar panels should not exceed 50% of your roof
- The distance between the edges of your roof and solar panels should be less than 15 cm.
- The installation does not affect any protected structure.
How much maintenance do solar panels require?
Just cleaning the panels periodically is enough to maintain the performan
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