How many solar panels do I need for my home or company? I have come across this question several times. The number of solar panels you need is determined by your objectives for going solar, the kind of solar panels you will install, your budget allocation, the capacity of your roof, your current and future energy needs, the sunny days in your state and the size of your premises.
A standard solar system should meet your daily energy needs. You should only install a system to produce surplus power if your state has a good net metering system or you have a solar battery to store the excess power. Noteworthy, solar panels are influenced by the weather and do not produce consistent amounts of energy throughout the months.
Calculating Number of Solar Panels Needed
The number of solar panels needed for a house, office, institution, or factory will depend on the factors discussed below.
1. Your Objectives For Switching to Solar Energy
Most organizations and individuals that switch to solar have two major goals; to reduce or eliminate their energy bills while also reducing their carbon footprint. In such a case, a solar system that meets your current energy needs will do. That means installing a system to meet between 70% to 100% of your energy needs. How to calculate number of solar panels required will depend on your energy needs. You will determine number of solar panels based on kW.
You should compare solar energy during cloudy and sunny days over your energy needs. This is how to go about it, take two months in a year when the weather is extreme, the hottest month and the coldest month. Compare the energy needs for those two months, using your utility bills. Then divide the bills by 30 days to determine how much energy you use per day. If for example during the coldest month you used 1500kW, it means you require 50kW per day. Compare that with the hottest month. Noteworthy, if your intention is to just meet your energy needs, then you will install solar panels that correspond to the daily energy requirement especially during months when your energy consumption is high.
However, if you intend to get a ROI on your solar investments, then you need more solar panels. You may need to install solar panels that will not only meet your energy needs but exceed so that you can sell the surplus solar power to your utility company. And for you to make money from any surplus solar power generated by your solar system depends on your state’s net metering policy.
2. Your Roof’s Capacity
Did you know that some organizations, go ahead and install solar panels on the walls of their tower building? Basically, you may want to install many solar panels, yet you may not have enough room on your property to do so. In such a case, it is advisable to install solar panels with a high capacity.
3. Your Current and Future Energy Needs
How many kW per day are you currently using during winter and summer when the weather is hottest and coldest?
Typically, you should install a solar panel system with a capacity to meet your current energy. Your solar panels should produce enough power that can meet your day and night energy needs. You should also consider those months that you need more energy to power your heating or ventilation systems. In this regard, you can evaluate your energy needs for the last two years and check if there are months you consume more power than others.
That said, as much as it is important to use your current energy needs, you can also try to determine your future energy needs. For organizations, what if going green will increase your sales per month and you will produce more goods using solar energy? For homes, maybe your family size will increase or decrease tremendously in the next five years and will affect the amount of energy you need per day. Or maybe you have plans to construct a heated pool. You can try to consider other factors that can affect your future energy needs.
4. Your Budget
As much as you may want to install a solar system that can give you return on investment, you should consider how much you can afford to pay the company financing your solar system. More solar panels mean that your monthly payments to the solar financial institution will be high. In other words, how much you can allocate to solar panels payments per month will influence what kind of solar system you will install on your property.
As you may probably know, different solar panels have different capacities. So, first determine the kW production capacity of different solar panels. You need to know the power each panel can produce in a day. Some solar panels produce between 45 watts and 315 watts. If you purchase lower capacity solar panels, then you will need more solar panels. The kind of solar panels you install will determine their efficiency and how much power they can produce. This will help you to determine how many solar panels you need.
6. The Number of Sunny Days in Your City in a Year
The climate of your residential area determines the number of sunny days in your city. What is the average direct sunlight in a day in your state? Cloud cover and the position of your state in the earth determines the amount of sunlight you get per day. Some states get an average of 5 hours of sunlight per day while others get much more. When installing solar panels you have to maximize on the hours your property will get direct sunlight. If the number of peak sunlight hours is low, then you need more solar panels.
7. Are You an Organization or Individual?
Homes and firms have totally different energy needs. Most companies require large scale solar systems that are at least 10 times what a regular home requires. Therefor,e the number of solar panels needed to power a house are much less than the solar panels needed to run a firm especially if it has a factory.
You can contact Sunstra for a free solar quote. We will evaluate your energy needs and provide an estimate of the cost and type of solar panels you require.