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Feed-in Tariffs - An explanation
Feed in Tariffs are generally described as those fees that the
microgenerator - who is normally the power supplier's customer - will be
paid when they can show that they are putting power back into the
grid.
At the moment these are low and reflect an amount such that the power
company at least breaks even but can identify the microgenerator's
electricity as contributing to their renewable supplies. So, the power
company looks greener, potentially at the expense of the microgenerator
who has made the initial capital investment.
A microgenerator can also claim payment for ROC's. Put simply, these
are Renewable Obligation Certificates which are paid at the rate of about
£40 per 1000 units of electricity or effectively per Tonne of CO2 that has not been emitted in the generation of
electricity. More recently, Scottish
and Southern Electricity have introduced an 18p /kWh feed in tariff.
This is based on exported electricity and the nominal value of the ROC
combined in one tariff.
In Germany, feed in tariffs for microgenerated exported electricity,
are in the order of 45p per unit. This additional payment has transformed
the renewable energy market (microgeneration) in Germany which is many
times larger and far more advanced than that in the UK.
March 2008 Budget Statement on Feed-in Tariffs
The UK is committed to tripling the contribution made by renewable electricity by
2015. The European Commission has now brought forward an EU-wide target for 20 per cent
of energy production to come from renewable sources by 2020, and the Government will
consider a wide range of measures to enable the UK to play its part. In the summer, the
Government will launch a full consultation on what more the UK should do to increase
renewable energy use and meet its share of the EU target. The Government will also consult
on the most appropriate support mechanism for microgeneration at individual and
community level, including the option of a feed-in tariff. The Government will also consider
how to address barriers such as planning and grid access. |
How does electricity exporting work in practice.
The first requirement is to have an acceptable means of generating
locally, this usually means a grid connected solar PV (Photovoltaic)
system. Many of these solar electric systems that have been professionally
installed over the last few years and have been part funded through grants
such as clear skies will most certainly be grid connected.
The almost standard system where solar PV has been installed as above
will include an inverter such as the "sunny boy" which needs a 230volt
mains connection to function.
A Simple Description: The Sunny boy is setup so that
it detects the voltage coming in from the grid and when being charged up
by the sun, puts that power back into the local mains circuit at a
slightly higher voltage. Thus, the solar PV generated energy / electricity
is used in preference to the mains electricity. A fairly basic
understanding of V (volts) over I (amps) equals R (resistance) can
help.
Where the property is using less electricity than the Solar Panels are
generating, the electricity is effectively pushed out into the wider grid.
In very simple terms, this would cause the consumers meter (old fashioned
meters with the spinning disk) to run backwards. Modern digital meters do
not show this exported electricity.
 To measure exported electricity, it is necessary to
install an export meter which of course indicates the amount in units of
electriity that is being put back into the grid.
The export meter shown to the right is an Elster A1700, which is
located at the point where the mains eneters the property and measures the
actual units being exported. This works alongside the Elster A100 which is
positioned at the point where the solar generated electricity is fed into
the household supply, usually connected through a consumer unit.
How much electricity is likely to be exported?
 My Elster shows 2440.07 kWh over a period
of about 2 years. Which at the nominal 8.5p that I am paid by Eon
represents a little over £200.
There was a recent project EAMA Energy that was run through 2005 to
2007 that monitored the levels of energy generated, used locally and
exported for a range of solar, wind and hydro systems.
The results can be seen by going to the EAMA
website which generally show that during the summer months, there was
a noticable and consistent amount of electricity generated and exported to
the national grid on a daily basis.
Considering the results, it shows a consistent and predictable amount
of energy being generated and exported by Solar PV systems. Wind and
microCHP came a poor second.
Feed in tariffs: Links
Good Energy who have a range of feed-in tariffs including one aimed at the Commercial customer.
Wikipedia : Renewable
Energy World : Friends
of the Earth
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