Hi frnzz… many of us have a habit of drinking boiled water… it’s really an appreciable work. How do you boil the water? Well… we use geysers to boil the water… we even take shower using geysers. Frnzz… do we realise what are we wasting by using geysers? In one year, an 80-gallon (302-liter) electric water heater averages about $500 to run, uses 4,800 kWh of electricity and contributes about 6,600 pounds (2,993 kilograms) of CO2 to the atmosphere.

A natural-gas-powered heater does better, but it still accounts for about $400 and 3,900 pounds (1,769 kilograms) of CO2 per year

[sources: Energy Star, GNG, PGE]. Let’s see about solar heaters and decide what is better…

INTRODUCTION:

Solar is an excellent clean energy source: Its fuel, sunlight, is limitless, free and emits nothing when converted into energy. The problem with solar, as most of us know, is its efficiency. Solar photovoltaic technology, or PV, is less efficient at converting its fuel into electricity than, say, a wind turbine. But when you’re talking about heating water (as opposed to powering light bulbs or stereos), the sunlight doesn’t need to become electricity. It needs to become heat. And turning sunlight into heat is no problem.

Which is not to say solar water heaters have no drawbacks? In this article, we’ll find out how a solar water heating system works, which factors determine its efficiency, how you could make your own, and why you might or might not want to.

SOLAR HEATING SYSTEMS:

The core of a solar water heater is a solar collector and a storage tank. A solar collector is basically a glazed, insulated box with a dark-colored interior and, usually, a bunch of tubes or passageways for water flow. (Glazing is a coat of material, typically glass that aids in heat retention.) The solar collector turns the sun’s radiation into heat. A storage tank is exactly what it sounds like. It holds the water.

That’s the basic setup, and some systems aren’t much more complicated than that. The first distinction among solar water heaters is cut and dry: passive or active? An active heater uses electrical pumps and controls to move water around the system. A passive heater uses nothing but forces of nature. Passive is the simpler of the two.

Let us study about passive systems only… as they are used now-a-days.

There are two primary types of passive systems:

  • Batch: This is as uncomplicated as a water heater gets. It’s just one or more water tanks inside a solar collector (no tubes in this one). The water warms up right inside the tank, and either gravity or natural convection (the tendency of hot water to rise) moves water from the tank to a home’s pipes.

Thermo siphon: The water tank is separate from the solar collector. Cold water moves through the tubes of a solar collector, and natural convection pumps the resulting hot water into a storage tank. From the storage tank, the water travels into the home’s water pipes.


Watch This Video….

HOME MADE SOLAR WATER HEATERS:

Building a solar water heater isn’t exactly for beginners. It requires installing pipes, glass and, preferably, insulation. But for a do-it-yourself type, it’s an ideal money- and planet-saving project. You can build a batch water heater for less than $100.

A batch heater is also called an integral passive solar water heater — “integral” because the solar collector and storage tank are combined. It’s the simplest system to build at home, and it really only requires a few basic parts.

  • Electric water heater tank (used is fine, as long as it’s in good shape)
  • Black paint
  • Plywood box (large enough to hold the tank)
  • Sheets of glass
  • Hinged lid for the box (to reduce nighttime cooling)
  • Insulation material
  • Pipes/fittings
  • Mountings (for roof, side of house, or ground level)
  • Construction is pretty straightforward:
  • Paint the water tank black.
  • Secure glass to the top of the box.
  • Insulate the box and the additional lid and cut holes in the box for inflow and outflow pipes.
  • Secure the water tank inside the box.
  • Route incoming cold water into the bottom of the tank, and outgoing hot water from the top of the tank to the home’s water-heater tank
  • Mount unit in desired location (roof is usually best for sun-exposure).

While building the water heater may be pretty easy, there are other factors to consider. You have to determine the prime location for heater so it’s exposed to the most sunlight per day, which can take some calculating. You also need to make sure the ideal location can support the weight of the setup. And as with any other water heater, you need to figure out what size tank you need so you don’t end up running out of hot water in the middle of your shower — and determine how much glazing surface area you need to heat that water volume.

If you’re not comfortable making these determinations, you might want to shell out the cash for a professionally built setup.

Either way, there are some general pros and cons associated with solar water heaters. We’ll start with the upside.

BENIFITS OF SOLAR WATER HEATERS:

The benefits of solar water heating are numerous and considerable. First, you’re going to save money on your electric bill.

Most likely, your water-heating electricity use will be cut by at least half . How much you actually save depends on the climate where you live. If you’re in the U.S. Northwest, where the sun doesn’t shine much during a good portion of the year, your savings will be lower than if you live in an extremely sunny place like Arizona, because there’s less fuel available for your system. But if you live in Arizona, you could decrease your water-heating bill by up to 90 percent.

So there is corresponding reduction in pollution. A 50 percent reduction in traditional (emitting) energy use means a 50 percent reduction in CO2 emissions. So installing a solar water heater would reduce your hot-water carbon footprint by half. At the same time, you’re conserving nonrenewable fuels for applications for which there are currently no easily available renewable energy sources.

Because of the benefits of solar water heating, adding a unit to your home will also increase its value. So you could end up getting back whatever money you put into a solar heating system when you sell your house.

Which brings us to the primary negative: the money you put in? While sunlight is free, the system required to convert it into hot water for your home can cost a pretty penny if you go the professional route.

Watch This Video…

 

Posted By

Ravi Teja(3/4 ECE) MGIT

 

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