2 DIY solar energy projects that can slash your annual electric bill by over $1,300

The clean energy movement allows everyday people to take full advantage of natural energy for use in the home. Check out these two DIY-friendly projects you can do this weekend to start cutting your energy usage bill.

1. Solar air heater — save $1,022 per year

A solar air heating collector is one of the easiest ways to transition your home to an alternative energy hub. The modified heater uses the principles of light absorption and thermosiphon, a method of natural heat exchange, to turn light energy into heat energy. 

The unit is essentially a large wooden box with two air vents, one at the top and one at the bottom that leads into the home affixed through a window opening. The solar box must be encased in a dark-colored absorbant material, such as an aluminum screen, in order to capture heat from the sun, which is then absorbed into the air in the box. The most effective design uses a black metal window screen as the heat collector, as the screen is superior in terms of both surface area and passive air flow. 
As the sun heats the air inside the box, the hot air naturally wants to rise out of the box. As the warm air rises, thermosiphon principles, essentially working in convection, pull up cooler air from the home into the box. Pumping the air out at an average rate of 87 cubic feet of air per minute, the window-mounted solar heater could cycle all of the air in an average-sized living room in about 30 minutes. 

In a test, DIY builder Gary Reysa installed a 32 square foot box (8’ x 4’ x 6”) box in the window of his 2560 cubic foot living room on a 60-degree day. Recording the test data from 10 am to 2 pm—the peak sun hours of the day in winter—the heater sucked in air that averaged 60 degrees F and pumped it into the home at an average 109 degrees F, without any electricity. 

So besides saving the environment, how much money is this heater going to save you? If one heater can keep a living room at a comfortable temperature for all daylight hours, that’s 6 to 10 hours of not having an electric heater on. If an average living room would normally need a 3200-watt electric heater running 10 hours a day at 19 cents/kilo-watt, you can save over $6 per day or about $1,022 over the course of the cooler months (October to March).

Check out the video below for a step-by-step construction tutorial of the solar air heater:

2.Solar water heater — save $280 per year

Similar to solar air heaters, solar water heaters operate on the same basic energy saving principles, only instead of heating air, you are heating water. 

The water heater may be easily constructed using a coil of black hoses affixed to a plywood board using dowels, which captures the sun’s heat and transfers it to the cold water dispensed into the hose. As the water heats up in the hose, the thermosiphon effect helps to move the water from the hose into a holding tank. The same principle also applies to black PVC pipes or copper pipes painted black, which transfers the heat to the water much better than plastic.

The most common application for a solar water heater is to pre-heat water before it gets to your regular water heater. According to Energy Star, pre-heating your water with solar can cut your water heating bill in half, an estimated savings of $140 to $280 per year.

See the tutorial below for details:

These simple weekend projects can help you start putting free natural energy to use in your home.

Sources: MakeUseOf