The three system types use the same panels. What changes is the inverter, whether there are batteries, and what happens when the grid goes down.
| On-grid | Hybrid | Off-grid | |
|---|---|---|---|
| Batteries | None | Yes | Yes, larger |
| Connected to the grid | Yes | Yes | No |
| Power during load-shedding | No | Yes, for backed-up loads | Yes |
| Can export surplus to the grid | Yes, with net-metering approval | Depends on inverter and approval | No |
| Cost per kW | Lowest | Higher | Highest |
| Best for | Lower bills where the grid is reliable | Homes and businesses with outages | Sites with no usable grid |
An on-grid system has solar panels and a grid-tied inverter, and no batteries. During the day the panels run your building. If you need more than they produce, the rest comes from the grid. If they produce more than you need, the surplus can be exported to the grid where a net-metering connection is approved.
On-grid is the least expensive way to go solar because there is no battery bank to buy or replace. It suits factories, offices and homes that use most of their electricity in daylight and mainly want a lower bill.
The limit is outages. For safety, a grid-tied inverter shuts down whenever the grid goes off. If your area has regular load-shedding, an on-grid system alone will not keep the lights on.
A hybrid system adds a battery bank and a hybrid inverter that can manage panels, batteries and the grid together. In the day, solar runs your loads and charges the batteries. In the evening or during an outage, the batteries take over for the loads you have chosen to back up.
This is the most common choice for homes in Karachi, because it deals with both problems at once: the bill and the load-shedding. The trade-off is cost. Batteries are a large part of the price, so the amount of backup you ask for matters. Backing up lights, fans, a fridge and internet needs far less storage than backing up air conditioners.
An off-grid system is not connected to the grid at all. Everything you use has to come from the panels and the batteries, so both are sized larger, and many off-grid sites keep a generator for long cloudy spells.
Off-grid makes sense where there is no grid, or where the supply is too weak to rely on: remote facilities, coastal posts, farms and some construction sites. Where a reasonable grid connection exists, a hybrid system is normally the better value.
Ask two questions.
Then size it. The system size depends on how much electricity you use in the day, how much unshaded roof or ground you have, and, for hybrid and off-grid, how many hours of backup you want and for which appliances. As a planning figure, each kW of panels in Pakistan produces roughly 4 to 5 units (kWh) a day, depending on season, tilt and shading.
Exporting surplus power needs a net-metering connection approved through your distribution company, which in Karachi is K-Electric, under NEPRA's regulations. The rules and the rate paid for exported units have been under revision, so check the current terms before sizing a system around export income. We can advise on what applies to your connection when we quote.
Mastoor Energy installs all three types and supplies the equipment for them: mono and bifacial panels, on-grid, off-grid and hybrid inverters, and LiFePO4 lithium batteries. Tell us your location, your monthly bill and whether outages are a problem, and we will recommend a system type and size.
No. A grid-tied inverter shuts down when the grid goes off, so that it cannot send power into lines that people may be working on. To keep power during outages you need a hybrid or off-grid system with batteries.
Often, yes. If a hybrid inverter is fitted from the start, a battery bank can be added later. A plain on-grid inverter usually has to be replaced or paired with a second inverter before batteries can be used.
Mastoor Energy imports and supplies LiFePO4 lithium battery banks, which handle deep discharge and many charge cycles.
All three. Examples include a 1.2 MW on-grid system at Aijaz Industries in Karachi, a 300 KW hybrid system at Jinnah Naval Base, Ormara, and 500 KW of hybrid solar for naval creek posts.
Turnkey solar installation in Karachi: on-grid, hybrid and off-grid systems for homes, offices, factories and government sites. AEDB No-Limit enlisted.
Open →Solar plants installed by Mastoor Energy: 100 KW to 3 MW on-grid and hybrid systems for industry, the armed forces and public bodies in Karachi and across Pakistan.
Open →Tell us about your site and what you need. Our team in Karachi will get back to you.
