Having to choose from different configurations of solar power systems may be a daunting task. Solar power systems are usually categorized based on its connectivity to a commercial power distributor, often called grid. Largely, three types can be encountered in the market: (1) on-grid, (2) off-grid, and (3) hybrid. Each has their own merits and suitability on complexity of setup, duration of coverage, customer demands and resources like budget, type of property and components available.
On-grid solar power type is tied to the grid system, hence it is often also called grid-tied. One of the main advantages of this type is its relatively simple installation. The very basic setup would include a solar panel, charge controller, DC to AC inverter, and connection to grid meter. Typical use case would be to use the solar power during day time when the sunlight is supplying energy, while to use the grid power when there is no supply such as nighttime or when the weather is bad.
The Renewable Energy Act of 2008 (RA 9513) enables the household consumers to supply not more than 100kW of power to the grid. This means that a household producing solar power with a grid-tied system can be compensated when enrolled in the Net Metering program through a bi-directional meter. Proper sizing for user needs is more critical when not enrolled in the program as excess power production as compared to your consumption may be seen as usage also. Limiters are used to limit the power that a household can supply.
On-grid solar power systems are perfect for residential homes with stable grid power which is used during night time or shortage of energy production. Rest houses and alternative properties which have minimal usage are also usually installed with on-grid solar power enrolled in the Net Metering program to supply power to the grid as its main purpose.
Off-grid solar power type is an independent system and does not connect to the grid power. Aside from the usual solar panel, charge controller, DC to AC inverter, backup battery storage is needed for the period when there is no supply of energy such as night time. It is advisable to compute for the component sizing properly depending on usage and frequency of appliances, taking into consideration the desired off-grid days of independence. Risk of having a low supply is high so other power sources may be incorporated like wind power or generator sets. On the other hand, excess supply may be wasted when the battery is full and usage is low. With the additional battery backup, this type is typically more expensive.
Off-grid solar power systems are perfect for remote locations with unstable to no grid power supply. It is also widely chosen for supplying a specific appliance with high power consumption such as air conditioners, motor pumps, or heaters. Solar powered street lights are usually off-grid.
- Hybrid (On-grid with battery backup)
Hybrid solar power type is the combination of the two types and is also called on-grid. with battery backup. As with on-grid type, hybrid type is also connected to the grid but also has independence through its battery backup. More complex controllers are needed for the switching between charging the battery and grid usage.
Among all the types, this is usually the most expensive but also the most reliable as it covers almost all electricity usage times: when the solar power is supplying in the daytime, when supply is not available at night and also during grid blackout through the battery backup.
Hybrid solar power systems are perfect for residential homes and businesses that rely critically on power such as with home offices, cooling and heating businesses, and emergency facilities.
This table summarizes the options described in this article.
|Solar panel, controller, inverter
Optional: bi-directional meter, limiter
|Solar panel, controller, inverter, battery backup
|Solar panel, hybrid charge controller, inverter, battery backup
Optional: bi-directional meter, limiter