A solar electric system is typically made up of solar panels, an inverter, a battery, a charge controller, wiring, and support structure. The three most common types of solar electric systems are grid-connected, grid-connected with battery backup, and off-grid or stand-alone. Each has distinct applications and components.
Grid-Connected -
This is the most widely applied in Hawaii. The solar panels are connected to your local utility electrical grid to complement your normal power supply from your utility company. Grid-connected systems consist of:
Solar panels mounted on the roof
An AC converter to convert electricity produced by the system from direct current (DC) energy into alternating current (AC) energy.
A junction box that extends from the solar panel wiring to the AC disconnect and then the breaker panel on the home.
A power meter that displays how much power the home produces and used, the meter is owned by the local utility company.
Grid-Connected with Battery Backup -
Very similar to the grid connected system, this system adds a 'battery bank' to collect the power generated from the solar panels. Power stored in the batteries can be used during power outages. The battery bank collects power produced by the solar panels, sends it to the breaker box, and then into the house power system. The components of this type system consist of:
Solar panels mounted on the roof
An AC converter to convert electricity produced by the system from direct current (DC) energy into alternating current (AC) energy.
A battery bank for power storage
A charge controller to prevent overcharging the batteries
A junction box that extends from the solar panel wiring to the AC disconnect and then the breaker panel on the home.
A power meter that displays how much power the home produces and used, the meter is owned by the local utility company.
Off-Grid or Stand-alone –
These systems are not tied to any utility power lines and are most common in remote areas where connecting to the utility grid is more expensive then purchasing an off-grid system. In off-grid systems the solar electric represents the homes main source of power. Batteries store unused energy for use at night. Generators, small wind systems, and other backup fuel sources are sometimes used as backup power when the solar power stored in the batteries is not enough to meet household needs.
The components of this type system consist of: Solar panels mounted on the roof, An AC converter to convert electricity produced by the system from direct current (DC) energy into alternating current (AC) energy, A rectifier, sometimes used to change AC to DC and back again to get the most use out of a system, A battery bank for power storage.
When we are talking about a Portable Solar Power System, it is a sophisticated combination of components and raw materials that, when integrated into a system, will produce electricity and store energy from sunlight. Each complete system consists of a basic set of components, namely a solar panel, solar charge controller, battery, wiring, a carrying case or pack, and sources for 12-volt DC and/or 120-volt AC power, all of which are chosen to match eachother functionally. The solar charge controller is chosen to match and optimize the performance of the solar panel and the battery. The goal of each system is to provide power for electronic devices in the absence of the grid.
The word "portable" means different things to different people. To one person, "portable" means lightweight enough to bring along on a mountaineering or backpacking expedition where every ounce matters. To another person, "portable" means that four strong men can move the system from point A to point B. Portability is something we can discuss on the telephone. The more power and stored energy one requires, the larger and heavier the system becomes.
Certain components of each system are waterproof, and others are not. In general, solar panels are waterproof. Inverters and many other electronic devices are not waterproof at all, and must be treated like your laptop when it comes to rain, water, snow, and saltwater mist. The details of one's application determines how much waterproofing an individual system may require.
In the photos below, one can see the typical components of one of our smaller, lightweight, and more popular portable solar power systems called Lucciola. To the right is the lightweight foldable solar panel, unfolded, in direct sunlight, and being used to recharge the battery pack that is located inside the black carrying bag. The black carrying bag sits to the left front of the solar panel, and its top is unzipped and opened, showing the cigarette lighter socket adapter on the end of a shart extension cable. To the left front of the carrying bag sits a small silver 150-watt inverter that plugs directly into the cigarette lighter socket for power.
The inverter changes 12-volt DC power from the battery to 120-volt AC power. For portable electronic devices that one would plug directly into a cigarette lighter socket in an automobile, they can be plugged into the cigarette lighter socket that comes with the system. For electronic devices that require AC power, the inverter is used. Everything fits inside the carrying case, except the solar panel which is carried separately. In the lower photo, one can see a close-up of the carrying pack, and that the inverter is ready to plug into the cigarette lighter socket.