Photovoltaic (PV) System

PHOTOVOLTAIC (PV) – HOW DOES IT WORK?

Solar PV systems are popular and we install them across Suffolk and neighbouring areas, includings Essex, Norfolk and Cambridgeshire.  But how do they work?

It has been known for some time and in practice since the 60s that if you expose silicon to solar radiation electrons jump off. It is catching them that is the difficult part.

Now this has been achieved for the mass market since the first NASA projects. The modules on the roof produce DC power at a fixed voltage and an increasing current as the sun’s ray’s intensity increase. Up to a max current limit of typically 8 Amperes. The electronic inverter produces usable AC power from the DC supplied from the panels in a number of stages.

MPPT – Zero volts X max amps = no power so does max volts X zero current. So the first stage is to manipulate the volts and current available from the array in real time to maximize the power output. This is done by the Maximum Power Point Tracking circuits. The beat quality inverters we use have 2 MPPT circuits.

DC to AC – The inverter then chops up the DC into very small parts electronically and creates a Sine wave

Synchronization – As well as producing AC power the inverter is monitoring the AC on the power grid so in can put its generated Sine Wave exactly onto the grids giving usable power. Safety – The inverter is constantly checking the national grid and if it goes off or out of voltage or frequency range it will automatically shut down in 3 seconds and come back to life when the grid is ok.

INVERTER TYPES

Unit inverter – all the electronics on one unit within the building or outside, for clear sky view roofs and capable of dealing with a split east west array.

Micro inverters – one inverter per panel mounted under the panel increase cost by about 12% but overcome multi directional arrays and minimums the effects of shading.

ADVANTAGES

  • A solar PV system is a very reliable method of heating. They can be used to power satellites and PV panels sold in the UK have a guaranteed performance of 90% after 15 years and 85% after 20 years.
  • A great accessory to a Ground or Air Source Heat Pump particularly if the water heater function is added. Turning them off for half the year and eliminating the on/off running for water heating during the summer.
  • There are no running or maintenance costs.
  • If considering for a new build it will improve the SAP rating.
  • Simple to install with cost steadily reducing this is a great product.
  • For a few hundred quid can also be made to operate as a simple and powerful Solar Water Heater.

GOVERNMENT FINANCIAL INCENTIVES

Yes the Feed In Tariff has reduced, but ½ your money back seems reasonable, plus the power savings. This is a meaningful product and saves more than what is generated when fitted at point of use when considering the line losses on the national grid.

HIGHER QUALITY EQUIPMENT INSTALLED BY US

As solar PV installers, we can guide you and help yo decide on the most appropriate option for you out of the equipment available on the market.  We use SMA unit inverters or EnPhase micro inverters, and various panels depending on availability while always checking the quality and warranties .

THE SERVICE

We give a beginning to end service including all documentation for the DNO through to the FIT application.  When seeking photovoltaic systems for a new building, contact us early to plan a tidy install.

FREQUENTLY ASKED QUESTIONS

Where is the best place to put a PV panel?

The roof of a building is usually the best spot, particularly if it is south facing and is in a reasonably good condition. If you have a flat roof then this may not be ideal, as there can be difficulties in keeping them watertight.

What size do PV systems come in?

The size of a system is usually down to the either the property’s energy requirements and its available roof space. If you are having a standard 1kWp PV array installed, then you should expect it to occupy at least 8m² of roof.

How much electricity can they generate?

This will vary, depending on the site, and we will have more of an idea after we have carried out a site visit. Broadly speaking, a 4kWp system generates an average of 3,400 kilowatt hours of electricity a year.

Will my PV system come with any form of warranty or guarantee?

Yes it will. The details of this will depend on the brand of system we install.