How To Make A Portable Hydroelectric Generator?

Thanks to improvements in green energy, homeowners can now build a portable hydroelectric generator in their backyard. In this article, you will learn about hydroelectric generators and how to build an easy and compact unit. 

Here’s how to make a portable hydroelectric generator:

  1. Gather all of the materials needed for the hydro generator
  2. You need to attach a radiator fan to an alternator rotor.
  3. Connect both the alternator and inverter to the battery.
  4. Secure the parts together to keep the electronics from getting wet before putting the fan into the moving water.
  5. Test that the generator works when spinning.

This will provide endless power for you. To learn more about how to build your own hydro power, read more details in our guide below.

The Growth of Renewable Energy

Hydropower is a major force in the green revolution. Almost all renewable energy produced this past decade was from hydroelectric power plants.

In the past few decades, consumers became more aware of how climate change is impacting our world. More and more people use renewable energy sources. Some consumers also use natural home generators to save money and become more self-sufficient. 

There are three main renewable energy sources: solar, wind, and hydroelectric. For consumers who are near a body of flowing water, hydroelectric generators can reduce the electric bill significantly. 

According to the Center for Climate and Energy Solutions, 17% of US electricity generation in 2018 is from renewable sources. Experts expect this amount is expected to balloon to 48% in 2050. Based on available data, renewable electricity sources are growing faster than nonrenewable electricity sources.

Two of the major contributors to renewable energy generation are solar power and hydroelectric energy. Hydroelectricity is one of the largest contributors to the green revolution. In 2018, hydroelectric power generated 1,132 gigawatts of electricity or 4,210 terawatt-hours. 

You too can participate in this green revolution by adding hydropower to your home. Hydroelectric generators can power a device wherever water is available. Continue reading to find out more about hydroelectricity and how you can utilize it.

What Is Hydropower?  

Is it really possible to create electricity by using water? The answer is a resounding “yes,” but the process is not that simple.

Water alone doesn’t produce energy. Instead, it is the driver that helps produce mechanical energy. Flowing water creates movement as it hits a turbine, causing it to spin. As long as the water is flowing, the turbine will continue moving.

Of course, a spinning fan will not create electricity on its own. The fan is attached to a generator, which is made out of magnets and coils of copper wire.

As the magnet inside the generator rotates, it creates a stream of electrons, which becomes electricity. The faster the turbine spins, the faster it can make hydropower. 

Since the energy is produced by movement, having access to flowing water is very important.  You cannot create hydropower in a pond or a calm lake without doing a workaround. You can do this workaround by erecting a wall and making the water artificially flow from a higher place to a lower one. 

Redirecting water directly to the turbine is also a good option. This way, you don’t need a lot of power to move the turbine or wheel. 

Using gravity as an additional force is also a good move. It adds to the power of the turbine spinning without installing additional equipment.

Hydropower is actually a more sustainable renewable source. This is because you can always use the water and create clean energy whether it’s raining or not. 

How Does A Portable Hydroelectric Generator Work? 

Most bulk-energy hydropower uses dams and powerful turbines for efficient mass production. On the other hand, Portable Hydroelectric generators use smaller fans with efficient generators. Portable Hydroelectric Generators usually come with power banks and a built-in inverter for AC appliances like phones and flashlights. 

In theory, portables work the same way as bigger generators. Moving water makes contact with the smaller fan, causing it to spin continuously. While this happens, the generator produces a current of energy that is stored in a battery or power bank.

All of these components can be used on a portable and practical package. 

How To Make A Portable Hydroelectric Generator?

Making a portable hydroelectric generator is easy. If you have the tools and materials available, you can produce power for free. However, you might need a little know-how on electronics, especially if you’re using components from old machines instead of buying new ones. 

Materials Needed:

  • Radiator fan
  • Alternator / Generator
  • 12V DC to 220V AC inverter
  • 12V lead-acid battery (capacity depends on your needs)
  • DC Wires

Step 1: Get The Materials Needed

These materials are often available in electronic shops all around the world. If you have an old car, chances are you can salvage the radiator fan and alternator (make sure it has a voltage regulator). 

Remove the battery if you’re not using it anymore, or need to use it in other places to power things temporarily. DC wires are easy to find, especially if you shop on the internet. Inverters make powering up AC electrical devices possible. 

Step 2: Attach The Radiator Fan To The Alternator Rotor

For step two, you need to attach a radiator fan to an alternator rotor. Although it is frustrating, there is no universal way to attach a fan or a turbine to an alternator rotor.

Some devices should be welded to attach the fan to the alternator. Others require you to drill to the center of the fan and push it downwards into the rotor. If you’re using other turbines other than a radiator fan, instructions can vary a lot.

After you attach the radiator fan to the alternator rotor, you need to connect both the alternator and inverter to the battery. Then, you need to secure the parts together, so you can keep the electronics from getting wet before you put the fan into moving water.  

Step 3: Connect The Battery And Inverter Together

To complete step three, get some DC wires and connect the battery and inverter together. Usually, the wires are marked with (-) for negative and (+) for positive. If the wires are color-coded, the red ones are positive while the black ones are negative.

Tie the wires to the negative and positive terminals of the inverter first. Then, proceed to connect the other end of the wires to the battery.  

Step 4: Connect The Alternator To The Battery

The last thing to do is to tie up everything together in a small cohesive system. With the remaining cables, connect the positive and negative wires to the alternator’s terminal. The other end should go once again to the battery. 

Step 5: Secure Your Electronics

Since the alternator converts the mechanical energy from the fan, consider making a case to protect it from water. Use plastic or wood to box up the electronics. Seal the gaps properly with a silicone sealant. Make sure that the water will only get in contact with the fan. 

Step 6: Put The Fan In Moving Water

There are a lot of ways to achieve this feat. The easiest way is to use the natural terrain in the area to build up speed and momentum and redirect the flowing water to the radiator fan’s path. With this, the fan can move faster, and the alternator can create more electricity with less water pressure. 

For flat bodies of water, or when the water doesn’t move fast, you can use a water hose to redirect and strengthen the work.

Depending on your hose, you might need to attach an additional splitter to make the generator more efficient. The first spin needs more water power, but once the wheel is spinning, it needs less power to continue moving. 

Step 7: Enjoy Your Portable Hydroelectric Generator

Turn on the inverter and use your device. The reason you need a battery is to ensure that you will consistently have enough electricity to power your device.

If you directly wired the fan to the inverter, your devices might get damaged due to an inconsistent electric supply. This is because most bodies of water can change their momentum during a windy or rainy day. 

This setup will be very useful in lighting up small areas like sheds and small rooms. Find out more on this tutorial

How About USB Portable Power Kits? 

You can skip making your own portable Hydroelectric Generator by buying ready-to-use kits online.

One of the best kits known for portability is the Waterlily USB Portable Power. This kit can charge phones, flashlights (USB) on the go. This portable hydroelectric generator uses a small fan that spins when submerged in moving water. 

You cannot really ensure the same output each time you use renewable energy. Rivers and streams will not always have flowing water each season, so choose the best option according to your needs. If your renewable energy source is not sustainable, then make your system a supplementary source of power instead of the main source. 

If you plan to live off-grid for a long period of time, make sure to get higher capacity batteries. You can use these to power up your appliances.

It’s better if you have one or more renewable energy sources. Solar and wind turbine options are becoming more and more popular in the market and are worth considering. 

How Much Electricity Does A Portable Hydroelectric Generator Produce? 

There is a lot of factors that affect the amount of electricity produced by hydroelectric generators. For instance, a powerful unit won’t be able to produce a lot of electricity if the water in the area is not sufficient. Meanwhile, portable units can create decent output if the water flowing causes the fan to spin faster. 

It also depends on the type of wheel or fan in the system. According to the US Department of Energy, an old wooden water wheel will still work as a hydropower system. However, a wooden wheel’s performance is not comparable to other modern turbines like Pelton or Turgo Impulse wheels. 


I'm trying to make the world a bit greener every day, whether that's through my day job or helping others make green choices for their homes.

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