5
1.2 Is there Enough Sun to Make the System Economic?
A well designed domestic solar system can save in excess of half a tonne of carbon dioxide per annum, a larger
system making a much greater contribution in emissions and costs.
Solar Energy works on the basis of solar gain or
global irradiance i.e. the sun does not have to be
shining for the system to heat. It is actually
based on direct sunlight (sun rays) and diffuse
sunlight (scattered sunlight through cloud &
aerosols) i.e. indirect sunlight. Solar energy in
Ireland and the UK receive an average of
between 950 and 1,200 kW of solar energy per
year.
Both direct sunlight (40%) and diffuse sunlight
(60%) provide the energy required for a solar
system to operate. So, even when the sky is
overcast and the sun is not visible, it’s radiation
(sunlight) is available at ground level and can be
converted into useful heat by your Firebird solar
collector. During the summer months the Firebird
solar heating system could provide the total
energy needs for heating all your water.
1.3 Application of Solar Systems
Solar Systems can be used for a number of applications which in turn have varying return periods.
•
Domestic hot water heating
is the common use for solar energy. Energy consumption for hot water
demands accounts for 6% of the total national delivered energy use.
•
Space heating
: solar thermal systems can make a contribution to the heating of a dwelling as
well as to the hot water heating. The application of using solar to heat the dwelling is best applied to
an under-floor heating system and designed in line with the hot water system.
•
Swimming pools
: the heating of swimming pools is one of the best established applications of solar
water heating. In some cases collector efficiencies of greater that 75% can be achieved.
•
Commercial and agricultural purposes
including hotels, guest houses, dairy farms, commercial
premises and food preparation companies. These make ideal candidates for solar due to the high hot
water demand. Commercial solar also has a quick return on investment.
Map Source: Solar T
rade Association
SOLAR ENERGY EXPLAINED
Figure 1.2
