Gas Technical Services can provide expert advice on sourcing the correct
renewable energy package for your home. You can also walk around our
showroom where we have working renewable energy products, enabling you to gain a
better understanding of exactly how it will look in your home.
Live Solar Hot Water Display
4 Vaillant VTK570/2 Vacuum tube collectors being installed in Narberth
A Vaillant EcoTEC Plus Condensing Boiler connected to a Gledhill Thermal
The sun is by far the most abundant source of energy available on earth.
Energy arriving at the earth's surface by way of solar radiation over a period
of 40 minutes is the equivalent of the power used by the entire population of
the earth in one year.
A well designed solar water heating system installed in a family house which
previously used an electric immersion heater to heat water can save in excess of
half a tonne of carbon dioxide emissions per annum.
How do we compare to Europe?
Approximate area of solar collectors installed in
2004 (in square metres)
Source: ESTIF, June 2005
Environmental issues and the spiralling rising prices of oil, gas and
electricity are now giving a new impetus to the UK solar thermal market.
As the energy costs of homes increases, it is reasonable to expect that a solar
water heating system will add value to a property as long as it is designed and
installed properly. Unfortunately, the lack of local experienced
installers has meant that most solar water heating systems have, to date, been
installed by "HARD SELL" companies with their own travelling installation teams.
This sales and installation technique has resulted in extremely high prices
being charged and low consumer confidence in back up service.......until now.
The quality manufacturers have, for a long time, wanted their product
installed by competent local installers, and now most will only supply their
goods to bpec qualified companies. Gas Technical Services have invested in
this training and are now qualified and approved to design and install Solar Hot
Water Systems approved by the Solar Trade Association.
Do we get enough sun in the UK for a system work?
There is a widely held opinion that the UK does not have enough "sun" to make
solar systems worthwhile. But, in fact, parts of the UK have annual solar
radiation levels equal to 60% of those experienced at the equator.
The Department of Trade and Industry (DTI) commissioned a two year monitoring
programme of four domestic hot water solar systems located at Troon, Tewkesbury,
Luton and Croydon. The results showed that systems provided an average of
approximately 70% of the annual hot water requirements at the four
locations. All four systems worked in Winter as well as Summer with 16
- 18% of hot water needs being met in December and January and almost
100% of hot water needs being met in both July and August.
A further recent project supported by the DTI monitored eight solar water
heating systems side by side. The project involved taking a daily draw of
150 litres (33.3 gallons) of hot water from the solar hot water cylinders
of eight systems mounted side by side at Cranfield University and measuring the
heat contribution provided by the eight systems. The annual heat energy
contribution of the systems was then predicted from the results with the
projected contributions ranging from 1,000kWh to 1,350 kWh per annum.
How much energy do I use now for hot water?
For water heating, a typical UK house uses 5kWh per day of useful energy
(that is the energy content of the water leaving the taps). This figure
can vary considerably from house to house, dependant on household size and water
The actual amount of delivered energy (the energy registered on a gas or
electricity meter) can be considerably higher, particularly in summer.
Running a boiler with a continuously burning pilot light and uninsulated hot
water pipe runs for small quantities of hot water reduces efficiency
considerably. Even electric immersion heaters may only manage 50%
How much solar radiation do I receive where I live?
Maximum power on a cloud free day occurs at solar noon at any location.
The Meteorological Office has been recording solar radiation for more than 30
years and has produced maps showing the geographical distribution of solar
radiation for the UK.
This graph shows variation in annual mean values of
solar irradiation on a south facing 30 degree incline plane in the UK in
kWh per metre square.
As you can see from this, we are fortunate in West
Wales as being the second highest in the country, receiving
approximately 1,100 kWh per metre square.
But what if it is a cloudy day, will I still
When the sun's rays hit the earth's atmosphere some of the radiation will be
scattered due to cloud cover. A portion of this scattered light reaches
the earth and is known as diffuse radiation. It is usually assumed to come
equally from all over the sky. Without diffuse radiation the sky would
appear black. What we normally call sunshine, i.e. the proportion of the
sun's rays appearing to come straight from the sun, is known as direct
radiation. So the simple answer is yes, even with cloud cover, some
diffused radiation will still find it's way to your solar collector.
How does a solar hot water system work?
|From the diagram, you can see that one
of the main differences to a conventional hot water system, is that the
hot water cylinder (Thermal Store) has two coils inside it, whereas a
conventional system normally has just one.
Fluid is pumped from the coldest part of
the cylinder (bottom), up to the solar collector, where the fluid picks
up heat from the suns radiation, before being pumped back down to the
lower coil in the cylinder
The boiler is then coupled to the top coil
within the cylinder to provide back up hot water if required. The solar
fluid contained in the solar circuit is made up of water, inhibitor and glycol
ethylene to protect the inside of the pipework from corrosion and freezing.
The fluid in the heating circuit remains the same as any conventional system and
contains water and inhibitor. The water surrounding the two coils within
the hot water cylinder never makes contact with the fluid within the coils, as
this is the water which will be delivered to your hot water taps.
Because it is not uncommon for
the water temperature within the solar collector to exceed boiling point,
pipework to and from the solar collector cannot be simply soldered, it must be
brazed or compression joints used.
Reliability of Solar Water Heating Systems for Households.
An independent survey of domestic hot water
solar systems installed in the UK between 1970 and 1994 was undertaken on behalf
of the DTI.
A sample of 700 systems was analysed. The
sample was designed to be representative in terms of major/minor manufacturers
and installers and also type of collectors (flat plate and evacuated tubes).
The main conclusions were:
- Solar systems can work reliably for 20
years or more.
- There is little, if any, difference between
current system performance and that when the system was new.
- System performance has improved
significantly over the years.
- Half the systems have needed no new
components and only 1% are considered unreliable. More modern systems
have less problems. 68% of systems installed since 1986 have not
needed new components.
Ongoing product development and product
refinement means that there is now a wide selection of high quality and highly
reliable solar water heating system products and components available in the UK
Why we prefer the Vaillant product.
Whilst it is true that there is a large selection available within the UK
market, we prefer to favour one particular Manufacturers product. As with
their condensing boilers, the quality and reliability is legendary, and Vaillant
have not disappointed us in the Solar market either. Everything is of the
highest quality and beautifully designed so that each component compliments the
next. In addition, they have a sound and strict environmental policy in
relation to the materials used to produce their equipment.
of all Vaillant products takes into account the subsequent recycling and/or
eventual safe scrapping of each component used. Vaillant’s in-house rules
set strict standards in this respect. The selection process used for
choosing raw materials includes full consideration of their recycling
characteristics, and of the breakdown and separation properties of
subassemblies. We also take fully into account the environmental and health
hazards involved in recycling and in the disposal of non-reusable waste
Ozone Depletion Potential
(ODP) is a number that refers to the amount of ozone depletion caused by a
particular substance. All Vaillant boilers have an ODP rating of 0.
The Global warming
is a measure of
how much a given mass of
is estimated to contribute to
Vaillant’s boilers have an official rating of 0 in this category.
insulation used in all Vaillant boilers is manufactured using substances
that do not contribute in any way to the ODP and subsequent disposal of the
foam will not release any harmful emissions that lead to global warming.
endeavours to keep the amount of transport packaging used for its equipment
to the bare minimum necessary. Subsequent re-use is
taken into account when selecting packaging materials. High-quality
cardboard has long been a valuable secondary raw material for the card and
paper industry. The sections of EPS are required in order to protect
equipment in transit. EPS is 100% recyclable and CFC-free. The foil-wrapping
and securing straps are likewise made of recyclable plastic.
The auroTHERM exclusive vacuum tube solar collector have been
designed to give maximum energy absorption and are easy to
install in various applications. As the collectors work on
diffused solar radiation as well as direct sunlight, they will
even generate small amounts of energy on partially cloudy days.
Multiple panels can easily be fitted together as required for
The auroTHERM plus flat plate collector has a special
anti-reflex coated toughened 4mm thick glass. The collector
consists of an ultrasonically welded copper grid with a high
selective absorber coating and 60mm rear and side insulation.
The whole assembly is encased in a polished aluminium frame for
a neat construction. The collectors can be connected in series
in horizontal or vertical orientation to suit the available roof
Instant hot water with the auroSTOR cylinder.
A stainless steel storage cylinder available in 3 different
volumes to meet all of your requirements.
This twin coil unvented solar cylinder manufactured from
stainless steel has a 25 year warranty on the shell. Each
cylinder features two sensor pockets for simple straightforward
connection of the control sensors and a 22kW rated coil for a
rapid heat up, and is delivered with a 3kW back up immersion
heater as standard.
Insulation exceeds CHeSS best practice and heat loss is as low
Easy and intelligent control for your solar system.
auroMATIC offers three time periods for auxiliary cylinder
heating giving the end user total control over the availability
of hot water. The control monitors the temperature of the
collector and of the cylinder. When sufficient solar energy is
available the control switches on the solar pump unit to charge
the cylinder. If there is insufficient solar energy available
the control will automatically determine when the auxiliary heat
source is required.
For a FREE survey and no obligation quotation contact
us on (01646) 683845.
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