Uploaded May 2024 | Updated September 2026, 1 week ago
🎁 Free Diagrams: cleversolarpower.com
📖 My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
In this video, I'm going to show you how many batteries you need for a 5kW solar system.
If you have an off-grid cabin with a 5kW solar panel system. You need to use this website: pvwatts.nrel.gov to find out the minimum amount of sunhours you have at your location. We need to plan for the worst-case scenario, which means we'll use a minimum of 3 sun hours per day.
Now, onto the calculation: Your 5kW solar panel system will generate 15kWh of power on an average day in December. And yes, that needs to fully recharge your battery in a single day. So, we need a 15kWh battery to store all that power. That's roughly 3 48V server rack batteries, considering an off-grid scenario.
But here's the thing: sizing a solar system isn't as simple as matching battery size to panel capacity. It's actually the other way around. You start with a load analysis, then size the battery based on three days of autonomy, and finally size the solar panels based on the battery capacity.
To illustrate, let's walk through an example: Say our off-grid home consumes 10kWh of energy daily. Multiply that by 3 days for autonomy, and you've got a total of 30kWh of battery storage needed. That translates to about 6 server rack batteries, costing around $7,000. Then, we size the solar panel array to recharge those batteries in one day, considering our average of 3 sun hours.
So, how much power can you actually consume from that 15kWh battery while maintaining 3 days of autonomy? The answer: 5kWh of daily energy consumption. That's because the battery needs to store enough energy to last through three days of bad weather.
🎁 Free Diagrams: cleversolarpower.com
📖 My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
In this video, I'm going to show you how many batteries you need for a 5kW solar system.
If you have an off-grid cabin with a 5kW solar panel system. You need to use this website: pvwatts.nrel.gov to find out the minimum amount of sunhours you have at your location. We need to plan for the worst-case scenario, which means we'll use a minimum of 3 sun hours per day.
Now, onto the calculation: Your 5kW solar panel system will generate 15kWh of power on an average day in December. And yes, that needs to fully recharge your battery in a single day. So, we need a 15kWh battery to store all that power. That's roughly 3 48V server rack batteries, considering an off-grid scenario.
But here's the thing: sizing a solar system isn't as simple as matching battery size to panel capacity. It's actually the other way around. You start with a load analysis, then size the battery based on three days of autonomy, and finally size the solar panels based on the battery capacity.
To illustrate, let's walk through an example: Say our off-grid home consumes 10kWh of energy daily. Multiply that by 3 days for autonomy, and you've got a total of 30kWh of battery storage needed. That translates to about 6 server rack batteries, costing around $7,000. Then, we size the solar panel array to recharge those batteries in one day, considering our average of 3 sun hours.
So, how much power can you actually consume from that 15kWh battery while maintaining 3 days of autonomy? The answer: 5kWh of daily energy consumption. That's because the battery needs to store enough energy to last through three days of bad weather.
