Comparing On-Grid, Off-Grid, and Hybrid Options
Types of PV systems
There are three main types of solar PV systems, On-Grid, Off-Grid and Hybrid. This article discusses the difference between these three types.
On-Grid system:
An On-Grid system powers the load with solar / grid and exports excess off-peak units to the grid
through net metering. The excess units exported in daytime can be utilized at night in off-peak hours. On-Grid system has lower upfront cost compared to hybrid or off-grid as they don’t
require battery and are easier to setup. This type of system is grid dependent and requires connection to grid in order to operate which is why it is also known as grid tied system.
Advantages:
- Save money with net metering
- Lower initialcost
Disadvantage:
- No generation in case ofgrid disconnection
Off– Grid System:
Off-Grid system are usually used in areas without grid connection. They use large battery banks to store power. Off-Grid inverters are independent of grid so they cannot export units to the grid. Off-Grid inverters are usually connected to a large battery bank and in some cases a backup
generator is also installed with it to ensure load requirement is met when solar and battery cannot fulfill it. The cost of off-grid system is higher compared to on grid due to the addition of battery bank and generator. Batteries can have a maximum life of 2-5 years in most cases so they have to be replaced after some years.
Advantages:
- Can be setup in areas without anygrid connection
Disadvantages:
- No net metering
- High initialcost
- Require battery bank
- May require backup generator
- High maintenance cost
- Low savings andlong payback
Hybrid System:
Hybrid inverters are connected with grid which allow for net metering and they can also utilize batteries to provide backup. Hybrid systems are cheaper than off-grid because they can export excess units and the battery bank used with it is smaller than offgrid.
Advantages:
- Net metering
- Production continues even ifgrid is disconnected
Disadvantages:
- Higher initial and maintenance cost compared toon-grid
- Require more space
- Load management and balancing
Comparison:
|
|
On-Grid |
Off-Grid |
Hybrid |
|
Cost |
Low |
Maximum |
High |
|
Net metering |
Yes |
No |
Yes |
|
Battery backup |
No |
Yes |
Yes |
|
Grid required for generation |
Yes |
No |
No |
|
Return on investment period |
short |
longest |
long |
