How should I size my Solar System to convert my factory to green energy?
In an age where sustainability and environmental consciousness have become paramount, businesses increasingly seek innovative ways to reduce their carbon footprint and transition towards cleaner energy sources. Among the most promising solutions, solar power stands tall as a beacon of hope, offering a renewable and eco-friendly alternative to conventional energy sources. Solar energy can lead to significant cost savings and conservation of energy for industrial facilities and factories and demonstrates a genuine commitment to a greener and more sustainable future.
In this blog, we dive into commercial solar energy and explore the crucial steps involved in sizing a solar system tailored to power your factory. Whether you’re an eco-conscious entrepreneur looking to positively impact the environment or a business owner seeking to mitigate rising energy costs, our comprehensive guide will equip you with the knowledge and insights to navigate the transition to clean, renewable energy sources. Join us as we unravel the complexities of solar system sizing and unveil the key considerations that will pave the way for a brighter, greener tomorrow.

How Big Are Commercial Solar Panels?
Unveiling the Dimensions and Capacities
When it comes to converting your factory to run on green energy, understanding the size and capacity of commercial solar panels is essential. These panels come in various dimensions, each designed to optimize energy generation while accommodating the unique spatial constraints of industrial settings. The typical size of a commercial solar panel ranges from approximately 77 inches in height and 39 inches in width for a standard monocrystalline panel.
However, advancements in solar technology have led to the development of larger panels with dimensions of around 81 inches by 40 inches or even more. It’s important to note that the size of the panel directly impacts its power output, with larger panels generally capable of producing more electricity under optimal conditions. As we delve deeper into solar panel sizing, we’ll explore how to determine the correct panel dimensions and quantities to meet your factory’s energy needs while maximizing efficiency and minimizing installation complexities.
Which Form of Solar Power is More Commonly Seen on Commercial Buildings?
Exploring Photovoltaic Systems
When it comes to powering homes and commercial buildings with solar energy, photovoltaic (PV) systems are the most commonly adopted solution. These systems harness the remarkable ability of solar panels to convert sunlight directly into electricity through the photovoltaic effect. Photovoltaic panels, often called solar panels, are strategically installed on rooftops, facades, or ground-mounted arrays to capture sunlight and generate clean, renewable energy.
Their popularity stems from their versatility, efficiency, and scalability, making them a practical choice for both residential and commercial applications. As we venture further into solar energy adoption, we’ll uncover the mechanics behind photovoltaic systems and delve into the factors driving their widespread use on homes and commercial buildings alike.
How Many Solar Panels Do I Need for 1,000 kWh per Month?
Calculating Your Commercial Solar Power Requirements
Determining the number of solar panels needed to generate 1,000 kWh (kilowatt-hours) of monthly electricity in your region is essential before switching to a more sustainable green energy source. The answer to this question depends on several factors, including the efficiency of the solar panels, the amount of sunlight your location receives, and your energy consumption patterns.
On average, a standard 300-watt solar panel generates about 0.3 kWh per hour under ideal conditions. Taking this as a baseline, you would require approximately 30 solar panels to produce 1,000 kWh per month. Larger 400-watt commercial rooftop solar panels would produce the same amount of energy using 21 solar panels. To best estimate how many kWh of clean energy you’ll need to replace your current traditional energy provider (responsible for draining Earth’s finite fossil fuels and causing greenhouse gases contributing to global warming), you can request your current provider for the kilowatt-hours (kWH) usage for a full calendar year based on your past electricity bills and consumption.
However, when it comes to installing and optimizing rooftop solar panels, real-world conditions vary, and it’s crucial to consider factors such as shading, panel orientation, and efficiency losses.

What Direction Should Solar Panels Face?
Optimizing Solar Panel Orientation for Maximum Energy Yield
Choosing the optimal direction for solar panel placement is a pivotal decision that significantly impacts their energy-generating potential. The ideal orientation varies depending on your geographical location, maximizing exposure to sunlight throughout the day. In the northern hemisphere, solar panels should generally face south to capture the most sunlight. Similarly, in the southern hemisphere, a north-facing orientation is preferred. This positioning ensures that panels receive ample sunlight from sunrise to sunset, optimizing energy production. However, factors such as roof angle, shading, and specific energy goals can influence the best orientation.
Unveiling Solar Panels’ Energy Production
How Much Power Can You Expect?
The amount of energy that solar panels produce, also known as their energy output, can vary widely based on several factors. These factors include the size and efficiency of the solar panels, the geographic location and climate of the installation site, the orientation and tilt angle of the panels, and any potential shading or obstructions.
On average, a standard solar panel with a capacity of around 300 watts can produce about 250 to 300 kWh (kilowatt-hours) of electricity per year under optimal conditions. This estimate is based on a panel’s capacity and assumes it receives full and direct sunlight for about 5 hours daily.
To find your location’s peak sun hours, you can search for peak sun hour map of your location and look at the “Global Horizontal Irradiation” index for the daily peak sun hours per region. Peak sun hours, also referred to as peak sunlight hours, serve as a metric for quantifying the amount of sunlight received at a particular location.
A peak sun hour is defined as a single hour during which the sunlight’s intensity (solar irradiance) averages 1,000 watts per square meter. For those familiar with electrical terms, this equates to an accumulation of 1,000 watt-hours (or 1 kilowatt-hour) of sunlight per square meter.
Here is a map of Thailand’s peak sun hours per region:

However, it’s important to note that actual energy production can deviate from this average due to real-world conditions. Factors such as cloudy days, partial shading, panel degradation over time, and system inefficiencies can impact the overall energy output.
To determine the specific energy production of rooftop solar panels for your location and circumstances, it’s recommended to consult with a solar professional or use solar energy calculators that take into account all relevant variables. These tools can provide a more accurate estimate of the energy your solar panels will likely produce based on your unique situation, empowering your company to harness the sun’s power and journey towards a more sustainable, energy-efficient future for your factory.
Constant Energy empowers companies to convert your factory’s rooftops (starting from 5000sqm) into a powerful energy-producing asset, using commercial solar power purchase agreements so you can start saving immediately after your rooftop solar power plant is installed at zero cost. Join us as we delve into the intricacies of solar panel calculations, guiding you through the process of accurately sizing your solar array to meet your monthly energy goals while embracing a cleaner, more sustainable future.
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Wondering how you can save more while remaining eco-friendly? You can save more than just money with Constant Energy. We offer solar power solutions that save you time, reduce your use of fossil fuels, and protect you from power outages. With renewable solar energy, you can power your operations for years to come. We install solar rooftop power plants for factories and large industrial operations with roof sizes of minimum 5000sqm.
1. Select your roof size ( sqm )
- 5,000
- 10,000
- 15,000
- 20,000
- 25,000
- 30,000
- 35,000
- 40,000
2. You Save
Savings per year (THB)*
Reduction of Carbon Emissions in Tons
Trees saved
*These savings are only an example. Actual savings depend on the demand profile of the off taker and the credit profile amongst other factors