SOLAR 101

Solar Power System.

Clean, Quiet. Reliable , renewable source of energy

by: Metrogreentech

3 types of commonly use solar power system that Metrogreentech Provides:

1. On-Grid or Grid Tied System
2. Off-Grid or Stand Alone System
3. Hybrid System

On-Grid or Grid Tied System
On-grid or Grid tied system is the very basic and cost effective system, it does not use storage battery thus makes this system cost effective and less maintenance system. This generates power from your PV modules and convert the DC power to AC power just like from your utility.
This system works in parallel with the utility (meralco) power. If your load is bigger than your solar production(cloudy days) the grid will give additional power to compensate it but if your production is bigger than your load, the excess power will return back to your Utility and if the “Net-metering” is applied to Distribution Utility the excess power will be credited to your next monthly bill but if not this will be debited to your bill, this issue can be avoided by using limiter device to limit the production of you solar power system to be equal to your load requirements.
This system can be utilized during day time and automatically transfer to the grid power during night time.
We recommend this system if you have stable utility power.

Advantage:

- Cost Effective, Low start-up cost
- High Efficiency
- Less Maintenance
- Simple and easy installation
- Can sell excess power production
- Best for daytime operation businesses
- No limit on the appliance that you are going to connect.

Dis-advantage:
- Grid tie power can utilized only daytime
- No back up battery during black out
- If grid is down solar power system also is down

Off-Grid or Stand Alone System
Off-grid system is a stable system which is completely stand alone, this system is more effective in the
areas where power is not available. It uses battery to store power for night time use. This system generates power from your PV modules to charge the storage battery and at the same time supply
power to your load. Battery will be charged for later use.

Advantage:
- Not affected by black out
- Not affected by power cost fluctuation
- Not affected with utility rules
- Best for remote areas
- Has storage battery for night time use

Disadvantage
- High Initial cost
- Low efficiency due to battery and other equipment
- Careful maintenance and monitoring are need to prolong battery life
- Need to balance the load to the calculated system design

Hybrid System
Hybrid solar system is a combination of On-Grid and Off-Grid system, you can sell you excess power or
store them for later use. System work with or without the grid. You can utilize your generated power
and at the same time charged your battery for later use, otherwise excess power can be also export to
utility to be credited to your monthly bill.

Advantage:
- Best for household were power demand is vary from time to time
- No more black outs
- Monthly bill can be zeroed
- With storage battery for nighttime use
- Can be use in areas where power is either stable or intermittent
- Best for businesses were power is essential

Disadvantage:
- High initial cost (hybrid inverters are costly)
- Low efficiency due to battery and other equipment
- Maintenance and monitoring are need to prolong battery life