Solar-powered generators transform sunlight into electricity, suitable for powering a range of devices from LED lights, mobile phones, and laptops to larger appliances like refrigerators and medical equipment such as CPAP machines.
It’s crucial to match the device’s wattage with the generator’s output, remembering that some devices have a higher starting (surge) wattage.
The effectiveness of these generators hinges on their battery storage and the available sunlight, so having a backup power source is advisable.
At Bloom Centre, we primarily promote portable solar solutions, but it’s valuable to understand the differences between solar and gas generators. Now, let’s explore various solar generator types.
- Solar gennies are versatile and serve various purposes, from charging phones to powering homes.
- Some solar generators provide backup for essentials, while others fully power off-grid properties.
- Some are portable, and others are permanently connected to building circuits.
- Before purchasing a solar generator, decide its purpose and power requirements.
Types Of Solar Generators
The difference between the various systems relates to whether the system is permanently installed or whether it is a portable solar generator and the amount of power it supplies. Four levels of capability are available:
- Portable backup for essential equipment
- Complete backup systems
- Grid Tied Systems
- Off-grid systems
Portable Backup For Essential Equipment
Portable solar generators range in size from small 3-watt panels that can be used to charge a cell phone to much larger units that can run complete backup systems.
The chief characteristic of this equipment is that it is fully mobile and can be used on-site (at home) or off-site (camping trips or work sites).
Some units have storage batteries that can be concurrently charged by the solar panels while being used.
Complete Backup Solar Generator Systems
A full backup system is a system that is wired into the home and can be used as emergency power to keep the home running when there is a break in the utility power supply.
It activates it automatically when the main power supply is interrupted. The system comprises of an inverter, charge controller, solar battery, and solar panels.
Grid-Tied Solar Generator Systems
Grid-tied systems are an expansion of the previously described backup systems. These are generally used as the house’s electrical supply and are designed to power a household.
If the solar equipment is compromised (by insufficient sunlight), the system makes up the difference from the utility power supply.
If the system produces an excess of current and the state (utility) has a net metering program, the excess current is fed back to the utility, which pays an agreed rate for it.
The system comprises an inverter, solar battery, and solar panels.
Off-Grid Solar Generator System
These systems’ power properties are not connected to the utility grid. By necessity, they are generally larger than the other system types, particularly in battery storage capacity.
Power Output Of Solar Generators
When you start researching solar generators, you will be bombarded with terms you may not be familiar with.
The main terms used to describe the system’s capability are listed below.
- Volts (Voltage)
- Amps (Amperage)
- Watts (Wattage)
- Kilowatts (kW)
- Watt Hours
- Kilowatt Hours (kWh)
The electrical current moves from the power supply’s negative terminal (pole) to the positive.
The voltage is the amount of energy available to move the current in the circuit.
If you consider the water behind a dam wall. Voltage is similar to the effect of gravity on the water at the top of a waterfall.
Before the water begins to fall, it only has potential energy. It is the equivalent of voltage.
The force of gravity determines how much and how fast the water falls down. The bottom of the waterfall represents the electrical circuit’s positive terminal.
When the gate is opened, it is the same as pressing the on/off switch in an electrical circuit. If the water falls over a water turbine, it will turn it, and so start to do “work.”
The effect of the turbine will be to slow the water down, reducing the speed at which it hits the ground. This is because some of the water’s energy has been transferred to the turbine.
In the same way, if a light is inserted into a circuit, the voltage is converted into heat and lights the bulb’s filament.
An ammeter (a device used to measure amperage) measures the speed of the electrical current (electrons) passing a fixed point in the circuit.
One ampere equals one coulomb of electrical current passing a given point per second. One coulomb consists of 6.242 x 10^18 electrons.
Let’s use an example from road traffic. A single road can carry a certain number of vehicles. If the number of cars increases, a traffic jam will occur.
The same applies to a circuit. If the number of amps (coulombs) increases beyond the circuit’s capacity, the wire will heat up and may start a fire.
The watts are the “pressure” produced by the energy source. Using the road traffic example, if the road is widened, the same number of cars may still travel on the road, but the “pressure” will be reduced.
Similarly, if roadworks are on a 2 lane road and one lane is closed off, the same number of cars may travel through, but the “pressure” increases.
If the voltage (the number of cars) is reduced, or the cars slow down (amps,) the pressure (watts) in the system is reduced.
Kilowatts is a simple way to describe 1,000 watts. Therefore 1,000 watts is described as 1 kilowatt (kW.)
Watt-hour refers to two measures:
- It represents the maximum number of watts the battery can provide in 1 hour.
- In electrical consumers, it represents the number of watts a component uses in an hour.
Kilowatt Hours (kWh)
Kilowatt-hours is watt-hours multiplied by 1,000.
A 2kWh battery can power a 1kWh appliance for 2 hours.
Types Of Appliances And Electronics That a Solar Generator Can Run
The size of the solar generator determines the type of appliances that can be run. The metrics above will be used when determining what equipment they can power.
Small Appliances and Devices
Solar generators easily power small devices such as laptops and cell phones. In most instances, they only need a 110-120V (In North America) power supply and have a very low wattage need.
Although they run on a standard voltage, they require more watts. They use induction motors that require a quick burst of additional power (surge) to make the motor move.
The induction motor’s surge requirements range between 1.5 to 3 times the normal power consumption. A fridge running on a 400-watt system may require 1.2kW to start moving.
You need to know what size solar generator you need to enable this. Some of the power tools, devices, and appliances that use induction motors include the following:
- Fridges & freezers
- Air Conditioners
- Angle Grinders
- Table Saws
- Borehole pumps (Drilled well)
- Pressure pumps
Very High Consumption Equipment
Solar generators can power all equipment, even those wired for three phase supply, if the solar generator is suitably equipped.
If you need to power a typical four-plate stove and oven, it can consume up to 8 kWh of electricity. A properly sized generator can supply this power efficiently.
This poses the question of if it’s a worthwhile investment, requiring more batteries and a higher-capacity inverter to provide more power. These are the two highest-cost items in a solar system.
A more cost-effective method may be to switch the electric stove to gas.
Maximum Power Load Of Solar Generators
The maximum power load of a solar generator is defined by the number of watts the generator can provide simultaneously.
The inverter will trip if the equipment connected to the solar generator’s inverter attempts to draw more watts than the maximum power load capacity.
This is particularly problematic for equipment that requires a surge current to start.
Factors Affecting Solar Generator Efficiency
The four primary components of a solar generator are listed below.
The Solar Panels
Solar panels convert sunlight into electrical energy. The solar panels generate a DC current sent to the charge controller in the inverter.
The number and capacity of the panels must be sufficient to recharge the battery in a predefined time span on a sunny day.
The system’s needs determine the panel size (inches) and output (watts).
The capacity of the battery is defined in kilowatts and kilowatt hours. This determines how long the system can provide power without sunlight.
The DC from the battery is converted to AC power by the charger. The inverter connects the system to the home electrical system.
The Charge Converter
The charge converter connects the solar panels to the battery and ensures that the batteries are not overloaded or overcharged.
In bigger systems, the charge converter is housed in the inverter box.
The typical weather patterns at the solar generator’s location will determine how much power the system can provide.
Areas at the equator, with ample sunlight, will require fewer panels to provide an equivalent level of power as systems in the northern hemisphere with continuous cloud cover.
Choosing A Solar Generator
Choosing the optimal solar generator will be determined by the following:
How much power you need – this includes how much continuous and surge power is needed. A useful exercise is listing all the appliances and their continuous and surge power requirements.
Work out the watts used by the appliances you want to run concurrently and check the power needed.
It is possible to spend thousands of dollars on a system. My recommendation is to size the system, purchase the one that comfortably meets your needs, and then add additional capacity (batteries, solar panels) as required. To help you out, this article on the best portable solar generators is a great start.