PV SystemsPV Systems, Oxford

Solar PV Technology

The technology was invented in 1839 by the French Physicist Alexandra Edmund Becquerel (24th March 1820 – 11th May 1891). He discovered the Photovoltaic effect which is the physics behind the solar cell.

The word Photovoltaic was derived from “Photo” which is the Greek word for “Light” and “Volta” coming from Alessandro Volta who is the Italian Physicist who invented the chemical battery.

The first efficient PV Cells were produced and used by NASA for use on their Satellites as there is an inexhaustible source of sunlight in space.

Solar PV and Sunlight

The performance of Solar PV can change due to the intensity of the sunlight hitting the cells. Basically, if it is a bright sunny day with no clouds in the sky then the irradiance from the sun will give us more power and output than on a duller cloudier day.

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Solar PV Systems

Solar Photovoltaic (PV) modules harness the sun’s energy and convert it into electricity. Solar PV modules come in different shapes and sizes. The most common types are Monocrystalline, Polycrystalline and Thin Film (Amorphous). The lifespan for Solar PV modules depend on the type used. As shown below:

Monocrystalline – 30 Year Durability/85% power output over 25 years
Polycrystalline - 25 Year Durability/85% power output over 25 years
Thin Film (Amorphous) – 20 Years Durability/90% power output over 20 years

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Grid Connected Solar PV System

A “Grid Connected” Solar PV system is best sized on your budget and available area for the array. The system consists of PV modules and a grid connected inverter. The PV modules are usually roof mounted but can be ground mounted fixed to frame work if available land space is an option. The inverter would be located in the loft space and connected to the consumer unit on its own dedicated circuit. The system will generate electricity that is used in the home reducing your electricity bill, you will also be paid for “ALL” the energy generated by your energy supplier and any surplus energy generated can be sold back to the national grid, thus generating further financial benefits.

The following figure shows a typical “Grid Connected” Solar PV installation. The Solar PV Modules convert energy from the sun into electricity, in DC (direct current) form. The Solar Inverter converts DC output into simulated AC (alternating current) form to match the incoming mains for regular residential and commercial use.

Solar PV diagram

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Energy Cash Back

The UK Government have committed to decreasing our dependence on fossil and nuclear fuels and have legislated a Feed In Tariff, "FIT" sometimes called "Energy Cashbacks," effective from April 2010. This FIT obliges energy companies to pay a premium price to you, the energy generator, for all the energy produced by your Solar PV system, whether it is consumed at your property or exported back to the grid.

...and there are good financial reasons to go solar now

Scale of PV systems installed

  • – The rates will last for 25 years, long after the system had paid for itself.
  • – The rates are set to rise with inflation annually.
  • – Feed in tariff income is tax free.
  • – An additional tariff from 3p per kW will be paid for all surplus energy fed into the grid.
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Why a Solar PV System is a good choice of renewable energy at your home or business?

A Solar PV System will not only reduce your energy bills, but wil alsol earn income from the FIT giving you a 7% -10% tax –free return on your investment that will rise in line with inflation. At the same time, you will be doing your bit in reducing the UK’s carbon emissions.

The system itself has no moving parts so there is little maintenance required or things to go wrong. The inverter equipment needs to be well ventilated and the PV modules can be cleaned in the same way as standard building glazing.

The following illustration shows a typical size Solar PV system and the returns in investment are achieved:

Feed-in tariff (FITS) example diagram

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Off Grid Connected Solar PV System

A “Off Grid Connected”  Solar PV system is an ideal way of producing electricity in remote locations, for example if you have a stable in the middle of a field where it is not viable to have a mains supply from the grid then a small off grid system would be ideal. The system consists of PV modules, a charge controller, DC/AC inverter and a battery bank.

The buildings energy consumption needs to be calculated and a PV array sized to produce enough power to charge the batteries and supply power to the appliances. In addition the battery bank needs to supply enough power when there are periods of little or no sunshine.

An Off-Grid domestic or commercial PV system in the UK would need to have generator back up for the winter months.

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Planning Permission

Residential Permitted development rights
In England and Scotland, changes to permitted developments rights for renewable technologies introduced on 6th April 2008 and 12th March 2009 respectively, have lifted the requirements for planning permission for most domestic micro generation tehcnologies. Customers must check with their local planning office if their property is listed or in an area of outstanding beauty, conservation are or World Heritage site.

The General Permitted Development Order (GPDO), or the Town and Country Planning (General Permitted Development) (Domestic Micro generation) (Scotland) Amendment Order 2009 grants rights to carry out certain limited forms of development on the home, without the need to apply for planning permission. The scope for the GPDO in England and the TCP (GPD) in Scotland now extends to solar PV.

Solar PV (Grid Connected)
Permitted unless;

  • – Panels when installed protrude more than 200mm.
  • – In Scotland only: installed on any part of the external walls of the building if the building contains a flat
  • – In Scotland only: panels when installed on a flat roof are situated within 1 metre from the edge of the roof or protrude more than1 metre above the plane of the roof
  • – In Scotland  only: panels when installed project higher than the highest point of the roof

Solar PV (Off grid)
Permitted unless:

  • – More than 4 metres in height
  • – Installed less than 5 metres away from any boundary (England Only)
  • – Above a maximum area of array of 9m2
  • – Situated on a wall within any part of the curtilage of the dwelling house and would be visible from a highway in Conservations Areas and World Heritage Sites.
  • – In Scotland only: installed a distance from the boundary of the curtilage of the dwelling house which is less than the height of the array
  • – In Scotland only: within the curtilage of a listed building
  • – In Scotland only: results in more than one free standing solar

Visit Energy Saving Trust: http://www.energysavingtrust.org.uk/Generate-your-own-energy/Getting-planning-permission for more details.

Commercial and public buildings should contact their local planning office for planning regulations.
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Contact us today and invest in a highly reliable system which has a typical lifetime of 25-30 years.