One day, while walking I stumbled upon illegal dumping ground in the outskirts of the village - a familiar scene in Bulgaria: green meadows, blue sky and... piles of garbage dumped by fellow villagers. "One's trash is another's treasure", I said to myself and started collecting empty plastic bottles. This is to be my experimental environmentally friendly solar heater.
Step 1: Here's My Treasure
About 100 empty bottles are required. The more - the better.
Step 2: This Is the Wood Drill Bit
This is the wood drill bit I used to drill the bottles. You can buy it from any hardware store. This particular one is 18mm.
Step 3: Drilling the Holes
I drill a hole at the bottom of the bottle and in the cap
Step 4: Passing the Hose
For heating the water I used old garden hose. The bottles are strung together like this.
The bottle creates a greenhouse effect - the heat from the sun is trapped inside the bottle and is warming up the water that runs through the hose.
Step 5: The Pump
For circulating the water I used a 12V DC Hot Water Brushless Circulation Pump. Got it from Ebay for about $14 with free shipping. It consumes just half an amper, so it can be connected to a 10W solar panel and make the solar heater self-running.
Step 6: The Heater
Here's the finished heater. An old barrel was used to keep the water. The pump circulates the water from the bottom, through the black hose to the top of the barrel.
On a sunny day it makes hot water. It would be more efficient, I presume, if the barrel is insulated to keep the heat in.