Many times we create projects that have to work with electrical power, but we do not have a nearby power outlet and the batteries may not be enough to power our project if it is a high consumption one. Therefore, we have to think of a Electric generator to obtain the solution in these cases, and not have to run cables over long distances.
Here we are going to see the possibilities that you have at your disposal…
What is an electric generator?
Un Electric generator It is a device designed to produce electricity from another type of energy. Its description is as simple as having a private power station wherever you want. Now, it is true that there are many types of electric generators, and it depends on the amount of energy generated, size, the type of energy used to generate the electricity, etc. But basically they all have a common element, which is the heart of the electric generator or alternator, although the whole set is called by the same name.
Well, as you know, Generators are electric motors, yes, motors. When you apply an electric current to an electric motor, you get a rotation. On the other hand, when you manage to rotate the motor shaft, it becomes a generator of current, generating electricity. Therefore, we have to get a source to generate this movement, as I have mentioned before, that is, a combustion engine, wind turbines, a water wheel, pressurized gas such as steam, etc. This is also how power plants work, except that the generators in these plants are enormous, on a much larger scale.
Amongst the types of electric generators that we know, the most common ones stand out:
- Internal combustion generators: They use a gasoline or diesel engine to move the generator or alternator to generate electricity from mechanical movement. In the case of gasoline, it will consume fuel more quickly compared to a diesel of the same specifications, but it also emits less polluting gases than diesel.
- Gas generators: similar to the previous ones, but they use natural gas or propane as fuel. These gases are used to generate the energy to move the alternator.
- Solar generators: they transform solar energy into electricity using photovoltaic panels. In this case, they are different, since here it is the semiconductors that do the work of converting the photons of light into electrons, and an alternator is not involved.
- Other: There are also thermal, wind, hybrid (LPG/CNG + gasoline) generators, etc., in which an alternator is also used to generate electricity from thermal energy or air respectively. It is true that there are generators based on thermoelectric couples or the Seebeck effect, in which an alternator is not involved either. On the other hand, we also have chemical generators, which are basically fuel cells that obtain electrical energy from chemical reactions, similar to batteries, and where an alternator is not used either.
How does an electric generator work
Without going into generators that are not based on alternators, let's focus on the alternator or electric generator, which is the "soul" of the most well-known and popular generators. Well, the generation of electrical energy by these devices is based on the principle of electromagnetic induction of Michael Faraday.
For the motor or generator to work, a rotor is needed, which is a moving part that has a coil of copper wire insulated by a varnish; a stator, which is a fixed part with a magnetic field generated by electromagnets or a shield of permanent magnets; and the collector-brushes, where the generated electrical energy is "collected" and transmitted to the terminals.
Once this is known, to generate electricity with these parts, the process is:
- When the shaft of the electric generator rotates, it is connected to the rotor, so it rotates within the magnetic field of the stator. This is how electromagnetic induction occurs, when a conductor moves within a magnetic field, an EMF or Electromotive Force is induced in the rotor conductor. This EMF will be proportional to the speed of rotation, the number of turns of the conductive coil, and the intensity of the magnetic field. If we have a constant magnetic field and constant number of turns, then the faster the shaft rotates, the more energy is generated.
- EMF is nothing more than a movement of electrons inside the conductor, i.e. an electric current inside the conductor. In alternating current or AC generators, the current will change direction periodically, such as those of 50 Hz, changing 50 times per second. On the other hand, in direct current or DC generators, the collector and brushes rectify the current to maintain a constant direction at its poles.
How to choose the right electric generator for your project
FOR Choosing a suitable electric generator For your case, it will involve taking the following points into consideration:
Budget
The first is decide how much money you can invest in your electric generator, since you will find them in very different prices, depending on their characteristics. Also keep in mind the maintenance costs, for example, a solar generator will practically not need maintenance, except keeping the solar panel clean. On the other hand, combustion generators will need fuel and engine maintenance...
Power evaluation
First of all, you need to evaluate what it is the total power you need, Not only the continuous power at which the connected equipment works, but also the starting power, since some equipment needs extra power to start and the generator must be able to handle these demand peaks. Add up the power of all the devices you plan to connect to the generator and you will get the result. Also, consider that you might need extra power in the future if you decide to expand your DIY project. Likewise, select the electric generator that provides the appropriate current intensity and voltage. You have them with 5v, 12v,… up to 220v sockets.
For example, imagine we have to connect a 50W device, another 1000W, and another 650W, then the total would be 1700W, and it would not hurt to choose a 2000W or 2kW one so as not to force it to the maximum or to allow for a future expansion. As for the amperage, remember that I = P / V, so if it works with 220V and the power is 2000W, then we would have 9A. Or, also, Intensity = (Nominal power Power factor) / Voltage, and you can also help yourself with the formula Apparent power (VA) = I V. For example, if we have 9A at 220 volts, the apparent power would be: Pa = 9 220 = 1980VA.
Type of energy source
As I mentioned before, there are several types of electric generators depending on the energy source used to generate the electricity. You must choose the most suitable one for your case. For example, Gasoline ones can be perfect for occasional and short-term uses.. Instead, For longer use, a diesel engine would be best., whose fuel will last longer with the same fuel tank capacity.
Those of Gas are quieter and less polluting, but they also require proper installation, with gas cylinders or bottles, and should not be used in places where they are exposed to direct sunlight, high temperatures, sparks or flames, etc., as they could explode in the event of a gas leak.
In the case of Solar panels will require minimal maintenance, clean energy, and are completely silent., but they may also be more limited in terms of the amount of energy generated. However, everything will depend on the model chosen and the surface area of the photovoltaic panels.
Portability and environmental conditions
Sometimes you want a generator for stationary use, while other times you will need a portable unit that can be easily carried from one place to another. It must be said that, Generators are usually not very light, but there are some that are more portable than others…
Not all generators can withstand rain or changing outdoor conditions. Keep this in mind, read the working conditions recommended by the manufacturer, including the operating temperature range, relative humidity, protection from rain, etc.
Connector types
Some electric generators have power outlets type:
- Schuko: which are the plugs we have at home in Europe, with two pins and a ground contact on the side.
- IEC (International Electrotechnical Commission):These plugs are standard for electronic and computer equipment. They include several types, such as IEC C13 and C191.
- NEMA (National Electrical Manufacturers Association): Common in North America. Includes several types, such as NEMA 5-15 (standard 3-prong plug) and NEMA L14-30 (4-prong plug for high-power applications).
- USB: Some modern generators include USB ports for charging small electronic devices, with 5V outputs, either a USB-C or USB-A.
- Industrial plugs: include high capacity plugs such as 16A, 32A, 63A and 125A used in industrial applications.
Depending on what you need, you will have to choose one generator model or another, although you also have the option of purchase additional converters or adapters...
Purchase Recommendations
Finally, we are going to see some recommendations that we make for you to choose the best electric generators, with the best features and quality:
- Best combustion generators:
- Best Solar Generators:
- Best gas generators and one of them hybrid:
- Best Adapters:
I hope I've helped!