Solar Panels

Photo of solar panel installation at Alvesta HQ,
Mullacott Cross, North Devon

The solar panel is the simplest and most cost effective way of installing a renewable energy source.

Thermal energy obtained from the sun can be used for a number of applications including producing hot water, space heating and even cooling via use of absorption chilling technology.

It can also be used to lengthen the effective season for an outdoor pool and reduce the cost of heating an indoor pool.

Thermal energy can be used to passively heat buildings through the use of certain building materials and architectural design, or used directly to heat water for household use. In many regions, solar water heaters are now a viable supplement or alternative to electric or gas hot water production.

Using solar and other forms of renewable energy reduces reliance on fossil fuels for energy production, thus directly reducing CO₂ emissions. CO₂ emissions contribute to global warming, an environmental issue which is now of great concern. The average household can reduce CO₂ emissions by as much as 20% by installing a Solar Collector.

Flat plate thermal solar collectors have been in use for several decades, but only in relatively small numbers, particularly in Western countries. Evacuated tubes have also been in use for more than 20 years, but historically have been more expensive than flat plate collectors.

In recent years the production volume of evacuated tubes has exploded, resulting in greatly lower manufacturing and material costs. The result is that evacuated tubes are now similar in price to flat plate, but with the insulating benefits of the evacuated tube, they are set to become the default choice for thermal solar applications worldwide.

The evacuated tubes absorb the solar energy converting it into heat for use in water heating. Each evacuated tube consists of two glass tubes made from extremely strong borosilicate glass. The outer tube is transparent allowing light rays to pass through with minimal reflection. The inner tube is coated with a special selective coating (Al-N/Al) which features excellent solar radiation absorption and minimal reflection properties. The top of the two tubes are fused together and the air contained in the space between the two layers of glass is pumped out while exposing the tube to high temperatures. This "evacuation" of the gases forms a vacuum, which is an important factor in the performance of the collector.

The angle and direction of installation is also of great importance as it will affect the efficiency of the solar collector. Naturally you want the collector to receive the maximum amount of sunlight each day and throughout the year. As a general rule if you are in the Northern Hemisphere then the collector should face South.

The angle at which you mount the collector should roughly correspond to the latitude of your location. For example London has a latitude of 51° North, therefore the collector ideally should face south at a 51° angle. However if your roof angle is within 10°+/- of your desired angle you can just mount the solar collector flush against the roof surface. The added trouble of adjusting the collector to a precise angle is not warranted as it will not result in a great improvement in efficiency.

The choice of the right solar panel is an important decision and one that should be made in the light of all of the facts. Ensure that you make the correct choice by contacting Alvesta for a free discussion and assessment of your needs.