Renewable Energy Installer February 2015 | Page 10

News: Profile
Standard deviation
Despite the number of power diverters fitted to PV installations increasing
exponentially, 4eco’s innovation director Jodi Huggett asks if meeting
Electromagnetic Compatibility (EMC) standards is one step too far for the
renewables industry?
ecent figures from DECC show that over 80,000 solar
PV systems were installed across the country between
January and August of last year - a 23 percent increase on
the same period in 2013.
To make the most of this trend and increase the potential of
renewable consumption, eco businesses nationwide have dedicated
significant resource into developing innovative cleantech products – to
increase the efficiency of energy generation.
R
Self-consumption technologies
There is now a proliferation of microgeneration power diverters that
are sold throughout the UK and Europe. These devices are rapidly
becoming highly desirable for eco-conscious homeowners looking
for new ways to save money and embrace ever-greater levels of
sustainability.
Power diverters help end-users self-consume the green energy
that is produced by their microgeneration system. These devices
monitor power being exported to the grid and divert this surplus power
to a designated load, normally an immersion heater.
Whether in a domestic or small scale commercial scenario, up to
100 percent of self-generated power can be consumed. This helps to
reduce reliance on the grid, reduce energy costs and reduce individual
carbon footprints. These devices require minimal initial investment
and are easily installed, either as a retrofit project or as part of a new
microgeneration set-up.
The latest insight from UK installers has identified that over
50 percent of new solar PV installations include such devices,
demonstrating the technology’s influence in the purchase decision
of consumers nationwide. This means that, in 2014 alone, around
50,000 devices have been installed as part of new microgen set-ups.
In addition to this, there are the many thousands of devices that have
been retrofitted.
Is it fit for purpose?
To say that all microgen power diversion technologies are comparable
is simply not true. These devices vary significantly in performance,
efficiency and durability.
The market currently plays host to over a dozen different devices
– all claiming to deliver the same results. This, unfortunately, is not the
case. In fact, as the development of many of these devices has been
rushed to meet market demand, a high percentage fail to meet the
EMC standard for harmonic emissions. Many of the 50,000 devices
installed so far this year, do not comply.
10 | www.renewableenergyinstaller.co.uk
The immerSUN’s truSINE power control technology diverts
self-generated renewable energy to its destination. This technology
employs pulse width modulation (PWM) which ensures the power is
delivered to the load as a true sine wave. This highly effective control
method means the immerSUN complies with all applicable parts of the
EMC directive 2004/108/EC, including EN 61000-3-2 - the harmonised
standard for regulating levels of harmonic emissions.
The same cannot be said for all devices, however. Of the fifteen
known systems currently on the market, only three use PWM. The
others use an alternative energy management technology called ‘phase
angle control’.
80 percent of the microgen power diverters
currently available to purchase in the UK
are not legally compliant
Phase angle control devices do not produce a true sine wave.
Instead, the waveform is severely distorted, creating vast amounts
of harmonic emissions. This practice can cause problems with
Dire warning: Many of the 50,000 microgen power diverters fitted in the UK
last year do not comply with safety standards, claims 4eco