Make A Diy Solar Panel For A Paddling Pool

By Author: Phil Teare
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As part of a green science project, we had the notion to build a do-it-yourself solar panel that also worked as a heater for a kiddie pool.

That's not a lie. I was talking a big game while I was planning this with my kids, but I wasn't really sure how effective it would be. Surprisingly, the handmade solar panel continues to deliver excellent performance even in Ireland. It can use just solar energy to warm a wading pool or outdoor bath to an acceptable temperature. It seems that my time studying engineering wasn't entirely wasted.

It has a surprisingly lengthy lifespan, allowing for countless hot outdoor showers and backyard paddling pool sessions. This was a great green science project for the kids to work on. It continues to work after three years.

What we did is as follows.

Here's what's needed:

plywood measuring 8 feet by 4 feet

Black plastic pipe measuring 50m

Suitable pillars to fit the pipe

A dark color

large bubble wrap roll (1m wide ideally)

Animal tape

Pond fountain energized by the sun

2 pieces of wood for the solar panel's supports ...
... (approx. 1 m long)

1. Blacken a plywood piece that is 8 by 4 feet.

As a starting point, purchase an 8 by 4 foot sheet of plywood (costing approximately €25 from B&Q or any builder's store) and paint it black.

2. Zigzag the black water pipe together.

The next step is to attach some black plastic pipe. I spent about €20 for the cheapest 50-meter coil of water pipe I could find on Amazon. We used it all up quite quickly, so I'm pleased I didn't go much shorter.

We had to be cautious not to bend the pipe. We covered the pipe with huge twists to secure our safety. They are supported by pillars. If we tried it again, I could try to acquire the pipe-holding strips that are utilized when installing underfloor heating plumbing. That could be a smart decision.

As they must both fit into the wading pool, ensure that both pipe ends have a sufficient amount of tail. It will need to be lowered into the wading pool a few meters.

3. Add legs to help it stand

In order for the solar panel to face the sun directly, it must be lifted. You should be able to position the panel such that it faces us at around a 45-degree angle (located in Cork, Ireland). Two 1-meter legs are hingedly attached to one side so that we can adjust the angle. We additionally fastened a length of rope from the solar panel to the ends of the legs in order to prevent the kids from kicking the legs out and overturning the panel.

4. Wrap the face in bubble wrap.

The bubble wrap front cover of the panel does a good job. It provides insulation and gives the inside a wonderful green house aspect. For about €20, large rolls (1 m wide) are offered on Amazon. Wrap the front of the solar panel in bubble wrap. The heated air around the pipes can be maintained by using duck tape to seal the edges.

You can see the greenhouse effect even though the air in the panel above is just 65°C; nevertheless, I have measured it to be as high as 85°C.

5. Make your wading pool unique to enhance heat

In order to add a little extra heat, we also worked on the wading pool. It is fantastic if your paddling pool is dark in hue, if not entirely black. The kids and I used a $20 plasterer's bath that we had leftover from another scientific experiment. In essence, it looks like a black plastic bath, but there is no bottom plug (which is fantastic because it prevents younger children from emptying the water in the first three minutes)

We set the bath on an old yoga mat to provide insulation from the bottom. We also cut a bubble wrap sheet of the right size and shape to make a cover for the bath. Covering the paddling pool as the water is becoming warm makes a big impact. In addition to serving as a little extra solar panel, it also stops all heat losses through evaporation.

6. Fill the solar panel's pipes with water using a hosepipe.

The new solar panel plumbing needs to be filled with water after the bath or kiddie pool is. Before installing the pump, you must first add water to the tubing that is attached to the solar panel because the pump lacks the force required to push through airlocks.

The trick in this case is to connect a hosepipe to the pipe's end and spray water through it until all of the air is removed. After removing all airlocks, put your thumb on one of the pipe ends to keep air from entering again, then totally submerge it in the water.

7. Include the water feature with solar electricity.

I bought a 5W solar-powered Pond Fountain (around €20) from Amazon, and as it is also driven by the sun, it works perfectly as the main pump. You can then attach that while submerged (to stop air from entering the system) and get started.

Do you genuinely require a pump, just as an aside?

Think about convection.

In a nutshell, you do need a pump. Convection is often considered as a possible substitute. Couldn't you leverage the fact that hot water rises to power the system? But only if the wading pool is significantly lower in elevation than the solar panel. There must be a vertical separation for the hot water to rise from the panel to the bath above.

My hypothetical engineering skills make me think that you would also need a significant variation in height. It's more than a few feet because the friction in a 50-foot pipe run is extremely high. A pump is absolutely required since, in my opinion, everything in the garden must function at the same level.

Performance of Solar Panels

Taking three hours to heat.

In Ireland, I've observed that it takes roughly 3 hours for the cold tap water to warm up to a relaxing bath temperature. We can play in a warm paddling pool by the middle of the day if I set it up in the morning and take the kids outside for a little while to do something.

Reached temperatures: Nice & Toasty.

If you give the technique enough time, it will warm up your wading pool to a pleasant temperature. The paddle pool can be quickly heated to the 36° to 40°C range that is perfect for a hot tub.  

At 40°C, hot tubs used for business stop operating. The swimmers cannot be heated above that point. I always keep a thermometer on hand for that purpose, so make sure to check the temperature before someone enters.

Maintaining the same temperature: Only slows the cooling.

After the kids are in the bath and are splashing around, the panel is not sturdy enough to hold the water at a temperature in the high 30s. Without the bubblewrap cover, the water begins to chill before the panel can reheat it. This has a big impact since it reduces heat losses through evaporation.

Even if the solar panel slows down the rate at which the bath cools down, it is still beneficial to keep it on after the kids jump in.

The best days have a clear, blue sky. Even broken clouds may seriously impair the performance. The air does not have to be that hot, though. In my experience, the system works well from early April through the end of September if you choose a bright, sunny day, even if the air is a touch on the cool side.

Test findings: The Sciencey Bit

We performed a number of tests and recorded the outcomes in keeping with the tradition of school science projects with the goal of involving the kids in eco-related science projects.

52 °C is the record bath temperature.

The temperature of the bath once reached 52°C after we set it up in the morning and left it running for the majority of the day. However, bear in mind that no one should go into a room that is hotter than 40 degrees. Prior to usage, it needed to cool.

Bucket temperature record: 67 °C

We tried heating a single bucket of water using the panel, left the bucket to heat up, and then monitoring the panel's peak temperature. In our case, the bucket reached a blistering 67°C temperature. You could boil an egg in that if you had a lot of patience.

For each cycle of water, the homemade solar panel produces 5°C of heat.

In our tests, the water leaving the solar panel had a temperature that was around 5°C higher than the water entering.

No bubble wrap yields mediocre outcomes.

The question of whether the greenhouse effect of the bubble wrap outweighs the fact that it also prevents sunlight from penetrating was raised.

The performance benefits of utilizing bubble wrap are substantial. Without the bubble wrap, the tests performed performed at least 50% poorer.

I've seen some online users just utilize a coil of black tubing. That would be possible for a DIY solar panel in warmer, more southern nations, but in my tests, the strength of the sun in Ireland was insufficient. It's likely that the cooler air also contributes to the low pipe temperature. The greenhouse effect inside the solar panel, which can reach temperatures of 70 to 80°C, greatly outweighs any drop in solar intensity striking the solar panel pipes inside the DIY solar panel.

Costs

I spent roughly €85 on this, even though I'll admit that I also took a few little items from the shed. Items we bought:

Plasterer's Bath ($20) (to serve as the bathtub or wading pool

5w Pond Fountain Powered by Solar: €25

8 × 4 foot of plywood costs €20.

Bubble wrap in bulk (enough for roughly 4 solar panels): €20

Lifespan

For the kiddie pool, my DIY solar panel has so far lasted three years. But it seems to be coming to a close. Because it spends the entire year outdoors, the Irish winters haven't been kind to it. However, three seasons is not much to be upset about.

It's amazing how much use it's gotten. It began as a straightforward science and environmental project for children. They flat-out refused to go back to paddling pools that had been heated to hosepipe temperatures once they had become accustomed to a warm outdoor bath, though! It is utilized rather often, and for us parents, it only extends paddling pool sessions.

If you liked this article:check out how we reduced carbon footprint in our house: https://www.purevolt.ie/eco-stories/halving-co2-of-house-in-cork.php