# How to calculate solar panel power

Do you want to know how to calculate solar panel power? Solar panels indicate the amount of power they will produce under ideal conditions as their maximum power rating. The amount of electricity your solar panel will produce depends on many factors. They include the amount of direct sunlight hitting your roof, the average amount of sunlight that your roof gets and how big and efficient your solar panels are.

Keep in mind that weather conditions and seasons affect the amount of sunlight hitting your roof while its intensity changes depending on the time of the day. It means you can’t just rely on the solar power ratings to know how much energy your solar panel will produce. This post looks at steps of how to calculate solar panel power.

When calculating how much power your solar panel will produce, you should bear in mind that that one kilowatt-hour is a basic unit of energy that’s equal to power (1000 watts) times time (hour). On your electric bills, the kWh refers to your average usage per month.

For instance, if you left a 50-watt bulb on for one hour, it will result in 50-watt hours. The same applies if you left 20 60 watt bulb running for one hour, which will lead to 1-kilowatt hour kWh. The average residential utility customer consumption is 903 kWh per month. That’s according to the United States energy information administration.

### How Your Solar Panels Save You

One step of how to calculate your solar panel power is by dividing your monthly usage using 30 days to get your daily usage. You can also use the average US usage of 30 kWh per day. The next step is finding out the amount of sunlight you get in a day. The United States average is 4-6 hours of sunlight per day.

If you get 5 hours of sunlight a day, it means you generate 30 kWh to use per day. You should then divide the number of hours to know the amount of kW that you need, for example, 30 kwh/5 hours of sunlight, which gives you 6 kW of AC that’s required to convert your energy use.

### How Much Solar Panel Power Do You Need (solar panel Kwh)?

When deciding on how much solar panel power you need, you should first calculate how much electrical energy you want to substitute with solar panel power. It means you first need to determine how many solar panels you need.

### Number of Solar Panels

Modern solar panels produce between 250-270 watts of power, for example, 250wp DC in controlled conditions. However, remember that solar panel wattage varies depending on the efficiency and size of your model.

It means you also need to choose the best brands of solar systems. Solar panels produce direct current DC while your home runs on alternating current AC.

### Losses When Converting Energy from the Sun to DC

One factor you should bear in mind is that there are losses when converting energy from the sun into DC, then to AC. It’s referred to as derate ratio and averages 0.8. It means you get to convert an average of 80% or DC into AC.

As a result of physics, you need to know that this loss is unavoidable. Therefore, if you need 6kw and divide by the average of 0.8, you will get 7.4kw DC. That means you will need 30 250wp solar panels.

### Average Monthly Savings Using Solar Panel Panels Power

Due to wiring, your solar panel will lose 20% of energy, which means you will end up getting about 80% of energy. The best way to finding out how much kWh your system produces per year is by multiplying the size of the panel in KW DC times the .8 derate factor times the number of hours of the sunlight.

It means if you have a 7.5 kW DC system that works an average of 5 hours per day for 365 days a year, you will get 10,950 kWh per year. Divide this number by 12 months; you will reduce your monthly bill by 912 kWh per month. It results in you saving about \$100 on your monthly electric bill.

### Final Thoughts

The above informative post on how to calculate solar panel power should make it easier for you to decide whether to install this system. Bear in mind that it’s better to use a year’s data than the last six months. You can also contact solar power installers to understand how various factors affect solar panel power output.