The same solar panels can sit in three different systems, and the parts list around them determines whether the lights stay on when the grid goes down.
An on-grid (grid-tied) solar system feeds a building through a grid-tie inverter and uses the utility grid as its backup, with no battery. An off-grid solar system runs on its own panels, charge controller, battery bank and inverter. A hybrid solar system adds a battery and a hybrid inverter to a grid connection, and only off-grid and hybrid systems keep backed-up loads running during a blackout.
The sections below define each system type and its parts, explain what each one does at night and in a blackout, and line up inverter, battery, charge controller and grid approval in one comparison table. They then match each system to cabins, sheds, RVs and small commercial sites, show how to judge an off-grid solar kit by its parts list, and close with six decision steps. For sites with no grid connection, LinkSolar sources the panels and charge controllers behind off-grid power systems for cabins and tiny homes.
What are the three types of solar systems, and what parts does each one need?
A solar system is grid-tied, off-grid or hybrid depending on whether it connects to the utility grid and whether it stores energy in a battery. According to the U.S. Department of Energy, panels make DC power, inverters convert it to AC for most household appliances, and batteries store solar energy for night or bad weather.
Grid-tied solar system
A grid-tied solar system is a solar system connected to the utility grid with no battery, so the grid covers any shortfall. According to Sandia National Laboratories (2008), the inverter in a grid-connected PV system handles every grid interface function.
- Grid-tie inverter: A string inverter or microinverters convert panel DC to AC that matches the grid.
- Meter arrangement: A net metering or export arrangement records power sent to the grid after the utility approves the interconnection.
- Charge controller: None is needed, because there is no battery.
A plug-in balcony system is a small grid-tied system; see plug-in balcony kits versus hard-wired arrays.
Off-grid solar system
An off-grid solar system is a solar system with no utility connection, so its panels and battery bank supply every load.
- Charge controller: A maximum power point tracking (MPPT) or PWM controller regulates charging so the battery is not overcharged.
- Battery bank: The battery stores energy for night and cloudy days.
- Off-grid inverter: An inverter is needed only for AC loads, since DC loads run without one.
- Fusing: Fuses or DC breakers protect the cable runs.
- Generator input (optional): A generator connection is common for long cloudy spells.
Hybrid solar system
A hybrid solar system is a grid-connected solar system with a battery, joined through a hybrid inverter. A hybrid inverter is one box that converts panel DC to AC, charges and discharges the battery, and manages the grid connection.
- Hybrid inverter: The charge controller is usually built in.
- Battery: The battery covers evening loads and outages.
- Transfer switch or critical-loads panel: This hardware separates the circuits that stay on when the grid goes down.
- Utility approval: Interconnection approval and export terms apply, as with a grid-tied system.
LinkSolar supplies the panel side of all three systems, charge controllers for off-grid builds and custom panels for unusual surfaces. Inverters, batteries and transfer switches are selected to match the chosen topology.
What happens at night and during a blackout with each solar system?
At night a grid-tied solar system draws power from the utility grid, an off-grid solar system runs on its battery bank and a hybrid solar system uses its battery first and the grid after that. In a blackout a grid-tied system shuts off even in full sun, while off-grid and hybrid systems keep their backed-up loads running.
Solar panels stop producing after sunset in all three layouts, so night power comes from a battery or from the grid. The full picture of where a solar home gets power after sunset has its own guide. The blackout case is where the three systems behave differently.
Islanding is a solar system continuing to feed power into a section of grid that the utility has switched off. Anti-islanding is the inverter noticing that the grid is gone and stopping its output, so line workers repairing the line do not meet a live wire. According to Sandia National Laboratories (2008), the inverter in a grid-connected PV system handles every grid interface function, including anti-islanding, and these controls have helped allay the concerns of utility protection engineers and line workers.
That stop is why a grid-tied system goes dark in an outage. According to the U.S. Department of Energy, traditional grid-following inverters need a signal from the grid to produce power, so panels on a grid-tie inverter stay idle until the utility is back.
An off-grid solar system has no grid connection to lose, so an outage on the utility network changes nothing for it. Its loads keep running on the battery bank at night and in bad weather for as long as the stored energy lasts.
A hybrid solar system with a battery keeps the lights on during a blackout when its inverter is set up for backup. According to the U.S. Department of Energy, solar-plus-battery storage systems rely on advanced inverters to operate without any support from the grid during outages, if they are designed to do so. Panels alone on a grid-tie inverter give no backup, even with plenty of sun.
A transfer switch or critical-loads panel separates the circuits that stay on from the rest of the building. It typically carries the fridge, lights, internet router and well pump, and sometimes medical devices. Whole-home backup is possible but needs a much larger battery than a critical-loads setup.
Specs to compare before you order an on-grid, off-grid or hybrid solar system
A buyer choosing an on-grid, off-grid or hybrid solar system should compare the inverter type, battery, charge controller, grid approval and blackout behavior before panel wattage, because those parts define which system is on the order. Panel wattage only matters once the system type is settled.
The table below compares the three system types by the parts each one needs and by how each one behaves at night and in a blackout.
| Spec | Grid-tied | Off-grid | Hybrid |
|---|---|---|---|
| Inverter | Grid-tie (string or microinverters) | Off-grid inverter, only for AC loads | Hybrid inverter |
| Battery | None | Required | Required |
| Charge controller | None | Required (MPPT or PWM) | Usually built into the hybrid inverter (typical) |
| Utility connection | Required, interconnection approval | None | Required, interconnection approval |
| At night | Draws from grid | Runs on battery | Battery first, then grid |
| In a blackout | Shuts off | Keeps running | Critical loads keep running |
| Extra hardware | Export meter arrangement | Fuses or DC breakers, often a generator input | Transfer switch or critical-loads panel |
| Typical fit | Homes and businesses on a stable grid | Cabins, sheds, RVs, remote sites | Grid sites with outages |
For a small 12 V off-grid build, start the parts list with a 10 A MPPT charge controller for 12 V banks and keep the array charging current within its rating.
The grid-tied column depends on the utility. According to the U.S. Department of Energy, net metering is an arrangement in which system owners are compensated for solar power exported to the grid, so the local export arrangement sets how much a grid-tied system earns from daytime surplus. Interconnection approval and export terms vary by utility, so check both with the utility before ordering.
The off-grid column depends mostly on system voltage. Small cabins, sheds and RVs typically run at 12 V, while larger battery banks typically move to 24 V or 48 V to keep current and cable size down. The charge controller, battery and inverter all need to match that one system voltage.
The hybrid column puts most of the electronics in one box. A hybrid inverter typically carries the charge controller inside, so the extra part to check is the transfer switch or critical-loads panel that sets which circuits stay on during an outage.
Which solar system fits a cabin, shed, RV or small commercial site?
An off-grid solar system fits cabins, sheds and RVs without a grid connection, while a small commercial site on the grid fits a grid-tied system if outages are rare and a hybrid system if some loads must stay on.
- Cabin: A weekend cabin using up to 800 Wh/day starts around 200 W of panels with a 20 A MPPT charge controller, and a tiny house at 1.0 to 1.6 kWh/day plans for about 300 to 400 W with a 30 to 40 A MPPT, as the page on cabin load profiles from weekend use to full-time living lays out.
- Shed: A shed that runs DC lights, a fan or a monitor typically works from a single panel, a small charge controller and a 12 V battery.
- RV: Weekend campers run 100 to 200 W on one or two flexible roof panels, full-time vans 200 to 400 W with a 12 V compressor fridge, and work rigs 400 W or more with a larger inverter for tools, per the guide to RV and campervan arrays by power range.
- Boat: A boat follows the same off-grid logic as an RV, with flexible panels on a bimini charging a 12 V bank.
- Small commercial site: A small commercial site on the grid fits a grid-tied system when outages are rare and a hybrid system when some loads must keep running during an outage.
A cabin system designed for the worst-sun months, with a few days of autonomy, runs LED lighting, a 12 V fridge, fans, pumps, LTE routers and cameras without a generator.
Flexible panels follow curved RV roofs and keep height and weight low, while rigid panels run slightly cooler with airflow underneath and can be tilted. Many RVs mix both formats.
A remote solar power system is a packaged power path from panel to controller to battery to load, with mounting hardware and weather-ready wiring. It suits cameras, sensors and gateways beyond the reach of the grid, and LinkSolar supplies packaged DC power for remote cameras and sensors for those points.
What does an off-grid solar kit contain, and how do you judge one by its parts list?
An off-grid solar kit is a bundle of solar panels, a charge controller, cables and mounting hardware, and some kits add a battery and an inverter. An off-grid solar kit is judged by whether each part matches the next part in the chain and the loads it will run. Check that first, then look at the headline wattage.
A mismatch anywhere along the path from panel to controller, battery, inverter and load limits the whole system, so the checks below follow that order.
- Panel open-circuit voltage: The panel's open-circuit voltage (Voc) must stay below the charge controller's maximum input voltage with headroom, since Voc rises in cold weather.
- Controller current rating: The controller's rated charging current should sit at or above the current the array delivers, or the controller caps the harvest on bright days.
- Charging profile: The controller's charging profile has to match the battery chemistry, since lithium and lead-acid banks charge to different voltages (see how LiFePO4 and lead-acid batteries compare off-grid).
- Inverter ratings: If the plan includes AC loads, the inverter needs a continuous rating above the running load, a surge rating that covers pump and fridge motor starts, and pure sine wave output for motors and electronics.
- Battery protection: A fuse or DC breaker belongs within about 18 cm of the battery positive terminal, so the kit should include one or state the rating to buy.
- Cables and connectors: Cable gauge should suit the current and run length, with MC4 connectors on the panel leads and extension cables.
- Mounts: The mounting hardware should fit the actual surface, whether a pitched cabin roof, a flat van roof or a pole.
RV kits usually favor roof panels that follow curved roofs and keep height and weight low, such as flexible panels for curved van and boat roofs. Shed kits often skip the inverter and stay DC, running LED lights, a fan or a monitor from a 12 V battery.
A kit listing that states the controller's input voltage limit, rated current, charging profiles and fuse rating gives enough data for these checks, and any missing figure is worth requesting before ordering.
How do you choose between on-grid, off-grid and hybrid solar in six steps?
An on-grid, off-grid or hybrid solar system is chosen by grid access first, blackout needs second and load type third, and the parts are matched to that choice last. Each step below settles one question, so the system type is fixed before any panel is picked.
- Check grid access: Confirm whether the site has a utility connection and whether the utility approves interconnection for solar, because a site with neither goes off-grid.
- List outage loads: Write down every load that must keep running when the grid goes down, such as the fridge, lights, router or well pump, because any entry on that list rules out a plain grid-tied system.
- Separate AC and DC loads: Mark which loads run on 12 V DC and which need AC, because a DC-only load list can skip the inverter while AC loads need one rated for running load and motor surge.
- Estimate worst-month energy: Add up the daily watt-hours the loads draw, standby draw included, and set that total against the sun hours of the darkest month at the site.
- Select the inverter and controller: Pick the parts the comparison table above assigns to the chosen system, meaning a grid-tie inverter for grid-tied, a charge controller plus an off-grid inverter for off-grid, and a hybrid inverter for hybrid.
- Choose the panel format: Match rigid panels, flexible panels or custom panels built to your outline and voltage to the mounting surface, whether that is a pitched roof, a curved van roof or the housing of a product.
Steps 1 and 2 settle the topology for most sites. The last four steps turn that choice into a parts list that fits the loads, the season and the surface.
FAQ: off-grid and on-grid solar systems
How does an on-grid solar system work at night?
An on-grid solar system draws its night power from the utility grid, because the panels stop producing after sunset and a grid-tied system has no battery. According to the U.S. Department of Energy, net metering is an arrangement in which system owners are compensated for solar power exported to the grid, so daytime exports can offset part of the power bought at night.
Do rooftop solar and home batteries keep your lights on during a blackout?
Rooftop solar with a home battery keeps the lights on during a blackout when the inverter and battery are set up for backup, usually through a hybrid inverter and a critical-loads panel. Panels on a plain grid-tie inverter shut off when the grid goes down, even in full sun. Backed-up circuits typically cover the fridge, lights, router and well pump.
How many solar panels do I need to go off-grid?
The number of solar panels needed to go off-grid depends on the daily watt-hours the loads draw and the sun hours of the worst month. In a worked example on the LinkSolar off-grid cabin page, about 980 Wh/day of loads becomes about 310 W of array in a 4-sun-hour month, paired with a 200 Ah 12 V bank for about 2 days.
What solar system should I buy to power an off-grid cabin?
An off-grid cabin needs an off-grid solar system with panels, a maximum power point tracking (MPPT) charge controller sized to the array, a battery bank and an inverter only for AC loads. Small cabins typically run at 12 V, and any cabin kit is judged by whether its panels, controller and battery match each other and the loads.
Next step
The choice between on-grid, off-grid and hybrid solar comes down to one rule: if the site has no grid, go off-grid; if it has a grid and must ride through outages, go hybrid; otherwise go grid-tied. Send LinkSolar the load list, site and mounting surface, and request a quote for the panels and charge controller through custom panel quotes from a load figure, which return a buildable spec with cell layout, target Vmp and Imp, lamination and connector.