Showing posts with label active solar energy. Show all posts
Showing posts with label active solar energy. Show all posts

Saturday, April 25, 2009

Types of Solar Pool Collectors


Solar pool collectors are available on the market in many different types to accommodate the many different varieties of pools and conditions. Generally, there are two main solar pool collector types - unglazed collectors and collectors with a glass covering (glazing). The type you need depends on the climate in your region. Unglazed solar collectors operate only when temperatures are above freezing and they are highly cost effective for outdoor pool heating. They are generally made of thermoplastic rubber (types of solar pool collectors called flexible rubber mat) or polypropylene plastic treated with an ultraviolet (UV) light inhibitor to extend the life of the panels. Currently, the solar industry is widely using black polypropylene plastic collectors. These solar panels may be either rigid or have individual pipes running lengthwise. Individual collectors are normally 4'x8', 4'x10', or 4'x12'.

Glazed solar collectors are similar to domestic hot water heating systems but they are not normally used to heat swimming pools. Glazed collector systems are generally made of copper tubing on an aluminum plate with a sheet of glass covering to prevent heat loss but it increases their cost. They can be two to three times more expensive per panel than unglazed solar panels. In addition to high costs, high levels of chlorine, or having a salt-water pool, can be extremely corrosive to the copper piping inside glazed panels. But if you plan to use your solar pool collectors in colder climates, or they need to operate all year-round even in sub-zero temperatures, you will probably need glazed collectors.

Before you purchase and install a solar pool heating system you need to determine the size of the collectors. Basically, you should take into consideration the following factors:
  • your pool’s location and size
  • average regional temperatures
  • desired pool temperature
  • all year-round uses or uses restricted to a part of the year
  • the system’s type, model and efficiency

Solar Pool Heater
VORTEX 4x12 Panels
Standard System Kit

Friday, April 17, 2009

Solar Pool Heaters


Roof mounted solar pool heating system
Photo credit: DOE/NREL and Aquatherm Industries

The summer season is approaching and owning an outdoor swimming pool is an important part of the family’s lifestyle. A swimming pool means not only cooling off on a hot day and a lot of summer fun, but it's also a great way to exercise and relax. However, the water to be used in swimming pools needs to be maintained at a comfortable temperature. If you are also planning early morning or romantic late night swims, a swimming pool heater is undoubtedly needed. And also, with pool heaters you can extend the swimming season by weeks or even months.

If you are concerned about the environmental impact and big expense of heating pool water you may want to consider solar heating for your pool. Solar pool heating is a great way to reduce your energy bills, protect the environment and extend your swimming season. A solar pool heater can work in conjunction with a natural gas or electric pool heater as back-up on cool or cloudy days.

Solar water heaters are simple devices that capture the sun’s energy to heat water for ordinary use. Most solar pool heating systems include the following:
  • solar collector(s) - the device through which pool water is circulated to be heated by the sun
  • filter - removes debris before water is pumped through the collector
  • pump - circulates water through the filter and collector and back to the pool
  • flow control valve — automatic or manual device that diverts pool water through the solar collector
Pool water is pumped through the filter and then through the solar collectors, where it is heated before it is returned to the pool. In hot climates, the collectors can also be used to cool the pool water during peak summer months by circulating the water through the collectors at night, when air temperatures are lower.

It typically costs between $2,000 and $4,000 to install a solar heater for an outdoor swimming pool (cost of pool heaters can vary based on the size of your pool). The advantage of a solar pool heating system is obvious - the energy of the sun is free, the price of installation is a onetime fee, payback can be as low as 2 years, very low operating and maintenance costs, and 15-25 year lifespan (depending on the panel and manufacturer).

In one of my next posts, I’ll write about different collector types of solar pool heaters and factors determining the size of the collectors.

Solar Pool Heater
VORTEX 4x12 Panels
Standard System Kit

Thursday, May 1, 2008

Passive Solar, Active Solar and Photovoltaics


There are three different ways to harness the sun's energy: passive solar, using architectural design and natural materials to absorb the sun's energy; active solar, utilizing the sun's heat by means of solar collectors; and a third way in which solar energy can be harnessed is through the use of photovoltaic systems.

Passive solar is the capturing and storing the suns' energy - light and heat - without the use of any mechanical devices. As the solar radiation strikes windows, walls, floors, and other objects within the room it is converted to heat. A good example of a passive solar energy system is a greenhouse.

Active solar uses devices to collect, store, and circulate heat produced from solar energy. Active solar energy technologies convert sunlight into heat by using a particular energy transfer fluid. This is most often water or air but can also be a variety of other substances.

Photovoltaic systems directly convert sunlight into electricity using a semiconductor material such as silicon. The electrical energy from PVs can be stored in batteries for use when there is no sun (during cloudy days or at night).