How to purify water using solar energy

Solar Purification: How to Purify Water Using Solar Energy

Table of Contents
Table of Contents

Solar energy can be a safe and effective way to treat water, making it safe for drinking. The UV radiation from the sun results in solar disinfection that kills waterborne diseases that are often transmitted through contaminated water.

Fortunately, the solutions to your water problems in a SHTF scenario may not be all that complicated: solar-powered purifiers exist already. Solar power generates renewable electricity that can tackle even the most stubborn bacteria in polluted water sources such as rivers or ponds.

You will be shocked to realize that solar energy is a viable solution to the water crisis, but you will be just as surprised to see how simple it is to make a solar-powered purifier.

In the past, we have discussed the different types of water filtration methods and how to purify rainwater, but in this post, you will learn what solar water purifiers are and how to purify water using solar energy.

rainwater bucket

What are Solar Water Purifiers?

Solar water purifiers are devices that remove harmful bacteria and viruses from the water through solar energy.

They use a small solar panel to power a water purification system, allowing them to work even in remote areas where large electric generators are not readily available.

You can make a home solar-powered water purifier using a few materials or buy it from a reputable supplier.

However, it is important to know that solar water purifiers do not remove sediments, so you will also need filters to benefit from clean, safe drinking water in your home.

If you desire to live off-grid, solar-powered water purifiers are an excellent investment without the hefty upfront cost of buying an entire solar power plant. Solar-powered water purifiers are energy independent and run by the energy they collect from the sun. There is no limit to how much water you can purify if there is enough sunlight to charge it.

safe drinking water

How does Solar Water Purification Work?

Solar water purification, also known as solar disinfection (SODIS), is accomplished by mixing electricity created by photovoltaic panels (solar PV), solar heating (solar thermal), and solar UV radiation collection. 

The electricity created by photovoltaic panels utilizes an electric current to offer electrolytic processes that clean water, for instance, by creating oxidative free radicals that destroy pathogens through their chemical structure. Also, stored solar electricity from batteries can power UV lamps or heating elements. When heat and UV-L are added to the process, it targets and kills bacteria in water with increased effectiveness.

The solar thermal method utilizes sun heat to heat the water for a short period to almost 212°F (100°C). Solar heat collectors use reflectors, or they may have lenses that concentrate and focus direct sunlight onto the water source. You will find that solar thermal purifier processes function nearly constantly while it is sunny, while others are batch-based.

The ultraviolet part combines with raised temperature for purifying water utilizing sunlight and repurposed PET plastic bottles. The process of purification consists in filling up a plastic bottle with water and leaving it in the sun. The UV-L emitted by the sun kills bacteria, viruses, and other microorganisms in the water within an hour. After it has been disinfected, you can drink the water immediately or keep it for later use.

river water for drinking

How to Build a Portable Solar Purifier at Home

Using a solar purifier is quite simple and does not consume much electricity. To build a solar-powered water cleaner, you will need to collect essential components, such as a solar panel, batteries, a small pump, a storage container, and UV lamps. The process will take roughly an hour to complete and is not very demanding or hard to do. The steps in detail are explained as follows:

  1. Begin by setting up a tripod for the solar panel. This can be achieved by finding a good spot for it and then driving stakes into the ground for positioning. Ensure that the solar panel has a clear view of sunlight for at least 8 hours a day. This is to ensure that the solar panel can perform at optimal levels.
  2. Next, mount the panel and connect it to the batteries via wires. A waterproof covering usually protects the solar panel. Still, if you want to ensure that it will not get damaged during the purification process, you can use plastic sheeting to protect it from direct exposure to sunlight.
  3. Once the panel is securely mounted, the next thing to do is connect the solar panel to the batteries. You will have to have the batteries nearby to do this. You will have to connect one side of the batteries to each terminal on the solar panel and wrap wires around them.
  4. Attach a clear plastic tube to the pump from a water bottle and attach it to the storage container. The pump is usually available as an attachment for water bottles, but if you want, you can easily make one yourself using your hands or an old tube similar in size to the tube from the water bottle.
  5. Finally, ensure you set up a facing window to the sun by attaching the panel and batteries to a frame. Using this frame, it will be easy to position everything to focus on the right spot. You can use pieces of plywood or something else lying around your house to make a frame.

Once you follow the above steps, you can build your solar-powered purifier in less than 60 minutes. You can also use other materials around the house to make the frame. It is important to note that not all UV lamps are the same, and using one of lower intensity may result in less effective results.

Also, consider that the purification process will occur only under direct sunlight, so you may need to find a spot with ample sunlight and, therefore, a good solar panel.

From then, you will collect clean water from your solar-powered water purifier.

It is important to note that you can use solar-powered purifiers to create and store drinking water by utilizing various containers like glass containers, BPA-free plastic, etc. The process described above works best with clear glass or BPA-free plastic bottles since they have the right shape and size for this process. You may have to adjust with other containers to make them fit properly.

water filter

Pros and Cons of using a Solar Water Purification System

Although we covered how a solar water disinfection device works and how to build one, it is important to weigh the pros and cons to decide if it’s the best water filter system for you. Below is a list of the pros and cons you should consider before making your decision.

Benefits of Solar Water Purification

Here are some of the benefits of using a solar water purifier:

  • Low cost and easy to use-Investing in this technology save you a lot of money and time. You will be able to generate safe drinking water on the spot while avoiding the effort of walking a long distance to the well or river.
  • Environmentally friendly and low carbon footprint-Solar power is renewable, sustainable, and efficient. These features make it a good option for those who want to live off-grid and reduce dependency on public services.
  • Low maintenance-Like any other device, a solar water purifier requires minimal maintenance, but you will need to check on the condition of the filters from time to time. You will also need to check the storage of batteries, solar PV panels, and UV lamps.

Downsides of Solar Water Purification

The following are common downsides of using a solar water purifier:

  • Long wait Time to Purify Water – The biggest drawback of this purification method is the long wait time to purify it. Depending on the amount of sunlight exposure, it could take anywhere between 6 and 24 hours to make water safe for drinking.
  • Not applicable in every situation-it is not suitable where there is limited sunlight for an extended period of time. Also, some types of water may not be ideal for purification under solar-powered purifiers. For example, not all chemicals can be removed through this filtration method.
  • Aging and replacement of hardware– The hardware used in solar-powered purifiers does not last forever, but it will likely last for at least one year before replacement is necessary.
  • High initial investment-You will need to invest a lot of money in solar-powered purifiers when you compare them with other water purification technologies. You will have to spend more to get a good quality cleaner with a long lifespan.

How do You Know if Solar Purification is Right for You?

Determining whether solar purification is ideal for you depends on several factors. First, you need to know if there is access to sunlight in your area. If you are in an area like Alaska, where you can go months without much sunlight, it may be in your best interest to find an alternative purification system.

Also, consider the size of your family and the amount of water they will need. Each person in your family should drink about 3.7 liters of water per day. Unfortunately, most solar purification systems cannot filter large quantities of water at once. If you have a large family, you should consider a full-home filtration system.

Another important consideration is how long you are willing to wait for clean water. As mentioned earlier, one of the main drawbacks is the long wait time, where it can take over 6 hours for the water to purify. Other purification systems, like gravity filters and UV light filters, purify water in minutes.

After considering some of the points above, it is possible to know whether solar purification suits you. If yes, you can opt to buy one. If not, you continue with other alternatives.

solar purifier

Final Thoughts

A solar water purification system can be considered a safe method to purify drinking water. Solar water purifiers are increasing in popularity worldwide, offering convenient access to clean drinking water for those who live in outlying areas where electricity is not easily obtained or no electricity exists. This makes it a good option for people living off-grid or hoping to reduce their dependency on public services.

High efficiency, stable operation, and durability make these attractive device choices. Solar water purification devices can potentially eliminate not only diseases of the water supply but also the pollution of our drinking water sources to an extent where they can provide an alternative source of potable water supply to many millions worldwide.

Therefore, you should not consider solar water purification a gimmick but a good investment. It will give you clean, safe, and fresh drinking water without any side effects.

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