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Solar PV could provide 10,000 times
more energy than the world currently uses.
If you install a solar PV tiled
roof, you could prevent over 34 tonnes of greenhouse gas
emissions during its lifetime.
The average household uses the
equivalent of 3000kW hours of power per year to heat water. In
the south of the country we can collect up to 1300 kW hours per
square metre of solar panel per year. This is free energy
waiting to be collected and used all year round.
Solar energy is better for the
environment than traditional forms of energy.
Solar energy is a renewable resource (it may go away at night,
but we will always have it).
The earth receives more energy
from the sun in just one hour than the world uses in a whole
year.
Solar energy has many uses such
as electricity production and heating of water.
Shell Oil predicts that 50% of
the world's energy will come from renewable sources by 2040.
Solar energy can also be used to
heat swimming pools, power cars, mobile phones, ipods and other
small appliances.
You can cook food using solar
energy with a solar oven.
Solar Energy is becoming more and
more popular. The worldwide demand for Solar Energy is currently
greater than supply.
Two billion people in the world
have no access to electricity. For most of them, solar
photovoltaics would be their cheapest electricity source, but
they cannot afford it.
Solar energy will not pollute our
air with carbon dioxide and other harmful greenhouse gases and
bad emissions. If you would like to do your bit for the
environment and install your own solar panels but don't want to
spend a fortune.
Solar PV FAQs
How do we get electricity from
the sun? When certain semi conducting materials, such as kinds
of silicone, are exposed to sunlight, they release small amounts
of electricity. This process is known as the "photoelectric
effect" .The photoelectric effect refers to the emission , or
ejection , of electrons from the surface of a metal in response
to light. It is this basic process that a (PV) cell converts
light into electricity.
Sunlight is made up of photons or particles of solar energy.
Photons contains various amounts of energy, corresponding to the
different wavelengths of the solar spectrum. When photons strike
a PV cell they may be reflected or absorbed, or they may pass
right through. Only the absorbed ones generate electricity. When
this happens, the energy of the photon is transferred to an
electron in an atom of the PV cell which is actually a
semiconductor).
How does it work? A huge amount of solar energy falls every year
from the sun to the Earth, we can use this energy to power
electrical energy for our Homes and Businesses , The energy
falls onto the panels, which creates DC electricity, an inverter
then converts this into AC electricity, which is then used to
run your household or business needs.
How much will it cost? The
size of the installation will of course depend on the size of
your roof space available. For example 8sqm of roof space can
house a 1kw system which cost £5,000 to £7,000.
How much energy does the
average home need? This depends on you the consumer,
obviously the less you waste the less you need. To assess your
current needs add up your units consumed on your last 4
electricity bills, or contact your supplier and ask them what is
your average electrical consumption is per annum. This is by far
the best way to size a system rather than individual use. An
average size 3 bed roomed semi-detached house can produce 30-50%
of its electrical needs using a 2kw system.
Do I need constant sunshine
for my PV system to work? Your PV system does not need
direct sunlight for it to work, even on cloudy days your PV
system will still produce electricity.
What if it is not producing
enough electricity for my needs? In this case the system
will allow energy to come into your home from the national grid.
This will be necessary on winter days and of course night time
when your PV system turns itself off.
What if the system is
producing more electricity than my needs? In this case the
system will export your additional electricity back into the
national grid and of course you will be paid for it.
How long will my PV System
last for? A well designed system will operate well in excess
of the manufacturers 20 year warranty. The PV module with no
moving parts has a lifetime expectancy of at least 30 years.
What are the FITs? The
tariffs are payments to anyone who owns a renewable electricity
system, for every kilowatt hour they generate. They are
applicable to households, businesses and, indeed, virtually any
property owner.
How much is paid? Up to
43.3p/kWhr, depending on the type and size of the system used to
generate renewable energy.
Plus an additional 3p/kWh when
you export any surplus back to the grid.
Also, you reduce costs on your electricity bill when you use
your own energy.
For how long? Tariffs are paid for 20 years, except solar
systems which qualify for 25 years. Tariffs are index-linked to
RPI.
Is that enough? These
tariffs should cover the initial capital cost of installation
and, according to the Government, earn a return up to 8% p.a. In
practice that means you should earn back the capital cost at
least two to three times over the duration of the tariffs.
When do they start?
Tariffs became payable in April 2010. All qualifying systems
installed now are eligible.
Any restrictions? The
tariffs apply to all the technologies shown in sizes up to 5
megawatts (plenty for most consumers and businesses). There are
technical and accreditation requirements but our recommended
suppliers will cover all this on your behalf.
How can I benefit? Anyone
who owns a property can benefit from the Feed-In Tariffs
offered.
It takes roughly eight years for
the Solar PV system to repay for its installation and start
becoming a worthwhile investment, although this obviously varies
on the size of the panelling installed and will be dependent on
how much energy bills rise over the next few years. This
statistic was formulated taking into account the average 7% a
year increase in utility bills that has been noticed over the
past decade.
Other ways of saving money through implementing greener
technology at your home include insulating walls, roofs and
windows which can keep a significant amount of heat in. Grants
are available from the government to make this happen; who
recommend every household has 26mm of loft insulation. Cavity
insulation is something that many houses built after 1920 can
benefit from as well. By taking these measures and becoming
greener, this offers greater protection from price hikes and
ever increasing energy bills, while also doing the environment a
good turn at the same time.
Shading
The Solar PV Panels work based on
the amount of light they receive from the Sun, and thus, shading
and/or to a lesser extent cloud cover can result in the
generation of less power.
If only one of the panels is
shaded, the performance of all of them is liable to dropping.
This is because all of the panels are connected in series, and a
bottleneck is created, because of which the bypass diodes drop
the power of the whole unit, as to protect the shaded cells from
damage.
Moderate shading is likely to
reduce the panel's capabilities by about 20%, although this can
be as much as 40% if the shading is vast. With this in mind,
sometimes in areas prone to shading, a smaller unit that doesn't
get covered by shade can produce more than a bigger unit which
gets slightly darkened. Our surveyors will talk over the best
option for you upon your free site survey and installation of
your panels.
The kWp is the maximum power that
your Solar PV system is able to work at, based on it functioning
under perfect conditions in the lab. This figure is usually
between 1.5kWp and 4kWp and is determined by the number of
panels you have and their respective power output.
Shading describes the proportion of panel which is not receiving
full exposure to sunlight. 1.0 describes a system where no part
is shaded, 0.8 when there is slight shading and 0.6 where there
is moderate shading.
Irradiance is the amount of energy that the panel receives from
the sun.
An example calculation for a 3.5kWp system which is slightly
shaded, on a property facing south, with a roof slope of 30°
would be:
Predicted Generation (measured in kWh/year) = 3.5 x 0.8 x 1042 x
0.8 = 2334kWh/year
While this is useful to deduce
the capabilities of a panel in general, it gives no idea as to
how the effectiveness changes at different stages of the year.
It is reckoned that a panel is five times more effective in
summer months though, due to the brighter sunlight and longer
days.
It is common for installations to come close to but less than
the 4kWp limit to take advantage of the higher rate. For
example, a 3.9kWp system will earn more money than a 4.01kWp. If
you are not sure how much space is available on your roof, each
kWp takes up roughly 8m2 which is about the size of two family
saloon cars. Some example installations are shown below:
Based on the system size entered, the calculator will estimate
the space required to locate the panels.
Estimated Export
The Export Tariff is paid by the
Utility Company of your choice. It does not have to be whoever
supplies your electricity. Some Utility companies assume a 50%
export and do not measure the actual amount fed back into the
grid. If you think you will export all of the electricity (i.e.
not use any) and providing the Utility company fits an export
meter, choose 100% Exported. Similarly, if you think you will
use all of the electricity choose 0% Exported. The latter is the
best option because by using the electricity you save around 13p
per kWh by not purchasing it from your supplier. Exporting
electricity only pays 3p per kWh.
Electricity Generated
A 2kWp system might produce
1667kWh of electricity per year. Other factors affecting the
amount of electricity generated are the region you live in (as
explained above). The direction and tilt of the panels can also
affect output, as explained in the assumptions section below.
Generation Tariff Income
This amount is paid for every kWh
of electricity produced. So for example, a 2kWp system producing
1667kWh of electricity each year will earn £688 per year from
the Generation Tariff (1667 x 43.3p per kWh).
Export Tariff Income
As explained above, some Utility
companies do not fit an export meter and assume 50% of the
electricity is exported. If you use all the electricity and
there is an export meter, this figure will be zero. If you
export all the electricity, you will be paid 3p per kWh so a
2kWp system producing 1667kWh each year will yield £50 (1667 x
£0.03). If 50% of the electricity is exported and 50% is used,
you will receive a £25 Export Tariff payment. As above, the more
electricity you use from Solar PV the better because you are not
having to buy it from the grid at around 13p per kWh.
Electricity Bill Savings This value depends on how much
electricity you use and how much is exported. If you don't use
any of the electricity, this figure will be zero. If you use it
all, you will save 13p per kWh as you're not having to buy
electricity from the grid. In the above 2kWp example, if all
1667kWh was used, you'd save £216 per year on your bills (1667 x
£0.13).
Total Income & Savings The total of the Generation Tariff,
Export Tariff and Savings made on electricity bills over a
period of one year.
Lifetime Savings The Total Income & Savings per year multiplied
by the Feed in Tariff period of 25 years. After this time you
will continue to save on bills if you use the electricity
produced.
Payback Time This is an approximation of the length of time it
will take to recover the initial cost of the system.
Return On Investment This is the annual return on investment,
calculated as a percentage of the initial installation cost.
Panel Space Required An estimate of the amount of space you will
need to install the panels for the size of system required. As
mentioned above, each kWp requires approximately 8m2 of space.
An average electricity price of
12.95p per kWh is assumed. If you pay less for your electricity
you will not save as much money by using the electricity
generated. Conversely, if you pay more than this you will save
more. The calculator also assumes that the roof faces due South
and the panels are angled at 30 degrees which is the position in
which they will generate the most electricity.
Providing there is some tilt and the panels face somewhere
between South East and South West (through South), you will
still achieve a good return on investment that will make the
installation of Solar PV panels worthwhile. |
