The proposed cuts to the UK solar feed-in tariff for large scale energy producers has been met by angry reaction from the industry who believe it could prove disastrous for fledgling solar projects. The plans are for the tariffs to be cut for more large scale solar projects such as those being set up on large solar farms or on the roof space of commercial buildings. The government has made efforts to distance itself from these more industrial scale solar projects and has instead publicly favoured micro-generation solar schemes for households and local communities.

The solar feed-in tariff works by offering guaranteed, premium rates for renewable energy both used and fed back into the grid by small scale renewable energy producers. The aim of this mechanism is to encourage investment in this once expensive industry by offering the opportunity of both long term revenue generation and savings on utility bills for households. Ernst & Young who have perennially made the connection between attractiveness for investors and the strength of feed-in tariffs believe that proposed changes to the mechanism at this point could be disastrous. Ben Warren, a partner of Ernst & Young commented that,

“The whole investor market was totally disengaged as a result of the feed in tariff being ripped up,”

Certainly the correlation between the strength of the UK tariff and the potential for investors to put their cash into solar projects in this country is significant and the warning from other countries is that where tariffs are rolled back, the solar industries in those countries fail as a result shortly after. Proposed government plans currently subject to lengthy consultation are for reductions of tariff payments for solar installations falling within the 250kw to 500kw bracket. This will affect larger scale schemes such as proposed solar farms based in the West Country where large areas of agricultural land are being set aside for the installation of solar pv systems.

The basic idea behind this plan is that more subsidies which essentially come from UK energy consumers are fed into projects which benefit the whole as opposed to wealthy investors looking to make a quick buck from solar farm investments. The move will certainly fall into Cameron’s cosy idea of a ‘Big Society’ whereby community projects, social housing and local services will all benefit from the revenue which will potentially be generated by tapping into renewable energy. Government spokesman Greg Baker said that he was keen to,

“Make sure that we capture the benefits of fast-falling costs in solar technology to allow even more homes to benefit, rather than see that money go in bumper profits to a small number of big investors”.

Engensa, a UK based solar company recently installed the UK’s first micro-converter system – a radical new technology that enables millions of otherwise unsuitable roofs to be used for solar PV by eliminating many of the problems associated with shading.

As thousands of families each month install solar PV systems, the crucial role of the inverter – the nerve centre of any system – is coming under increasing scrutiny.

A standard inverter has two distinct roles: the first is to convert the DC current produced by the panels into AC current that can be used in the home.  The second, crucially important, role is to manage the output of each of the panels and this is where traditional inverters can struggle.  The problems come about when even a small part of the installation is shaded by a tree or a nearby building.  Solar cells are essentially large semi-conductor diodes (similar to computer chips) which convert sunlight into electricity and are connected together to make a panel.  When even a single cell within a panel is shaded it limits the current that can flow in the whole system, because with a normal inverter the solar panels are connected in series.  This means that with a regular inverter the entire system performs to the standard of the weakest panel.

As the snows fell before Christmas, Engensa installed the UK’s first ever micro-converter – a radically different kind of solution manufactured by SolarEdge, an Israeli based leader in PV power optimization.

Instead of having a single inverter, the SolarEdge system is made up of multiple PowerBoxes, which sit under each solar panel and maximise the power of each individual panel and communicating this to a central inverter across the existing power lines.  In addition, PowerBoxes maintain a fixed DC string voltage, allowing optimal efficiency of the SolarEdge PV inverter at all times and enabling a significant increase in the amount of electricity generated over the lifetime of the system.

According to Dr. Toby Ferenczi, Engensa CTO, it is ‘the UK’s first of a kind installation with distributed power harvesting.  In plain English that means you get more energy output and greater PV monitoring capability compared with a conventional solar PV system because each panel is controlled separately.’  According to experts at Engensa, this new technology means that the impact of shadows falling on the panels is greatly reduced because only the output of the shaded panels are affected, rather than the whole system.  It also means you can install panels in different orientations giving much greater flexibility when designing the system.  A third benefit is that system owners have much greater insight into how their system is performing since it allows the output of each individual panel to be monitored in real-time, even from an iPhone.

‘SolarEdge’s product is a breakthrough that we have been waiting for,’ says Dr Ferenczi.    ‘Our focus, in the increasingly competitive solar market, is to provide our customers with the best technological innovations from around the world and as part of this commitment we are delighted to have installed the first SolarEdge system in the UK.’