After 6 months using on-grid solar system at our home, we decided to share our experiment about designing and usage. We hope this can help you to design on-grid solar system to get exact electricity amount at your location, from this calculation, you can balance between cost of system vs money from saving energy.
We tried to summarize steps in video, please watch it or read instruction detail
Let's ask yourself that how much power you want solar system will cover your electric bill each month.
For example, each month your home consumes 560kWh, now you want solar system can produce electricity with amount 80% of that 560kWh. Then, solar system must produce 0.8*560=448kWh each month at your location
If you want to save more or less, just do a simple math to find how much solar system have to produce.
Of course, the larger solar system, the bigger budget you need to prepare!
Step 3: Size Solar System
Now, for example, you want solar system that can produce 448kWh each month at your location. So, what kind of solar system can meet that requirement? How to calculate?
At this page, choose your location, then input install direction, angle and total power (of PV panels)
Normally, the page will automatically show best direction, angle at your location in which solar will get biggest energy from sun. The only thing you need to do is adjust total power at "Installed capacity" from 1kWp (default) to 4kWp
Let's see: 4kWp system will produce 5521kWh/year ~ 460kWh/month which is near our requirement (448kWh/month). This number is acceptable for us.
If you custom the requirement each month, then adjust "Installed capacity" until total producing power meet your custom requirement.