FAQs - PV Systems
Mosscliff Environmental Ltd is an expert when to comes to PV equipment and solar pv panels. We've tried to include answers to some of the most prevalent questions about PV equipment here, but if you have a more specific query, do contact us>>
Is solar electricity proven technology?
Yes, definitely.Solar PV panels have a lonh history and played a significant role in powering space exploration, including space vehicles such as Sputnik III and Explorer VII. That doesn’t mean that it is sci-fi in any way though!
Over the last decade the German government in particular has invested in a number of major solar electricity programmes. These have been extremely successful and set useful precedents for other governments to follow. The Germans introduced a means by which people could earn money from solar PV panels, known as Feed-In Tariffs. This has led the way in stimulating a renewable energy revolution and become the benchmark by which other countries measure their own feed in tariff policies.
How do we get electricity from the sun?
When solar light shines onto certain semi-conducting materials, it excites electrons from their atoms in a single direction, inducing direct current (DC). The stronger the sunshine, the more electricity is produced by the PV equipment. This is referred to as the photovoltaic effect and was first observed over 150 years ago.
The DC current is then inverted to alternating current (AC) by an installed system. This current can then be used to power your property.
Or, to put it a little more technically... a PV cell is made up of two thin layers of semi-conducting material (silicon) that generate electricity when exposed to daylight. When light shines on the material, it absorbs some of the light particles or ‘photons’. When a photon is absorbed, an electron is released within one layer of the semi-conducting material. These ‘free’ electrons will be attracted towards the other layer of semi-conducting material , moving across the boundary between the layers .This movement creates a flow of electricity between the two layers within a cell.
What happens at night?
Although the solar PV panels can produce electricity during the day even under cloudy conditions, when there is no solar light at night no electricity is produced. At this time, when more electricity is required within the home than is being produced by the PV equipment, electricity is imported from the national grid in the normal way.
Why should I think about renewable energy options now?
The Government is incentivising renewable energy systems and has a payment system in place to reward renewable energy initiatives. These reward payments will start to reduce on new installations made from April 2012.
Install a renewable energy system through a micro-generation certified installer before April 2012 and you will be able to access the top rate of payback throughout the full term of the agreement.
Find out more>>
Will I qualify for any grants or incentive payments?
The Government no longer offers grants for PV systems, though it is always worth checking with your local authority about local initiatives or bulk buying possibilities through local green groups.
Feed-In Tariff payments were introduced to pay for renewable electricity generated by house holders using PV equipment. They offer a good return against the capital cost of the installation .
Find out more>>
Just how green will my solar PV panels and PV equipment be?
By installing a solar electricity system you will be producing your own clean electricity, therefore offsetting the production of carbon dioxide from electricity generation using fossil fuels such as gas, oil and coal.
The amount of CO2 saved is dependent on the size of the system installed - a typical 2kWp solar electricity system will save almost 1 tonne of carbon dioxide each year (based on the emission factor used by the UK government of 0.43kg of CO2/kWh).
Are solar PV panels right for my property?
Solar PV panels need to be installed on a south facing or 90 degree of south. They should not overshadowed by trees or other buildings and the roof structure should be strong enough to take their weight. They work well on new builds or as a retro fit on older properties.
How much space is required for the solar PV panels?
Each kWp requires an area of approximately 8m2.
My house isn’t south facing – could I have split panels, one on the front and one on the back?
This PV equipment arrangement is possible but most likely to be cost prohibitive as the number of panels required is doubled and a slightly larger system may be needed to deal with the losses.
Can I have solar PV panels on my garage or shed?
This is dependent upon the strength of the roof. Systems can be fitted to garages or permanent out buildings in most circumstances.
What are the components of a solar PV system?
The PV equipment includes the PV panels and mounting framework an inverter that converts the direct current (DC) produced by the solar panels into alternating current (AC) required by the electrical system within a home, a total generation meter, some switchgear and some wiring. Find out more>>
Are there different sorts of PV systems ?
PV cells come in many different shapes and sizes. Each option has advantages for different styles of property. For aesthetic reasons the planning office may prefer certain cell types.
Types include hybrid, monocrystalline and polycrystalline cells (definition>>) ; framed models that can be retro-fitted on top of the existing roof; semi-integrated modules which can be fitted within the roof tiles and photovoltaic slates which blend in with the roof slates.
Who makes the solar PV panels installed by Mosscliff Environmental Ltd?
We source our PV equipment from UK manufacturers wherever possible and install systems which we consider to be best value for money, reliable and very good quality. Our panels include big brand names. Find out more>>
How big are the solar PV panels?
The panels all vary slightly in size, weight and appearance; typically they are around 1.40m2 each and weigh around 17 kg per panel. Find out more>>
How much electricity will the solar PV panels produce?
This is influenced by a number of factors: the total size of the solar panel array, the type of panels used, their orientation, the angle of the panels from the horizontal (ideally 30°-45°), and whether the proposed location is overshadowed at all.
We have put together a number of examples based on different property sizes to show predicted energy consumption / production, cost savings and potential return on investment. See examples>>
How many kilowatts of system can I have?
We can install up to 16 amps per Phase, (any more requires permission from the national grid operator). Standard residential supply is single phase and 16 amps equates to a 3.6kW system. Systems up to 4kW currently attract the best Feed-In Tariff payments>>
What happens if I invest in a PV system and it is not producing enough electricity for my needs?
Unless your property is in a particularly remote location and is not currently served by the national grid, renewable energy systems will allow energy to come into your home from the national grid to supplement energy production. At Mosscliff Environmental Ltd, our site survey will establish the type and size of system best suited to your property and energy requirements and give a predicted figure for the amount of energy you can expect to generate.
What if the system is producing more electricity than my needs?
As long as your property is served by the national grid, the system will export your additional electricity back into the national grid for redistribution and you will receive payment for it. Off-grid properties may employ battery systems to store excess energy for future use.
How is the solar PV system connected to the national grid?
This is all done as part of the installation. Permission is required to connect a system to the distribution network but this is usually not a problem for any system up to 4kWp.
I have a three phase supply, how does this effect a potential system?
If you have a 3 phase supply, we can install 3 x 3.6kW. The Feed-In Tariff reduces upwards of 10kW therefore 10kW is the most sensible size system on 3 phase.
What happens to the solar PV system in the case of a power cut?
In most cases solar PV systems for homes are entirely grid connected. If there is a power cut the solar PV system is automatically switched off as a safety measure. This is designed to stop electricity leaking on to the national grid and to protect individuals who may be working to restore the power supply.
How do I get my power back on?
Mosscliff Environmental Ltd provide an extensive manual which includes instructions on how to turn your PV equipment back on again, if necessary.
Can I extend my solar PV system in future years?
If space and conditions are appropriate, there is no problem with adding panels to your system in the future to enhance your generation power, although there may be a need to upgrade some components in the original system.
How long does it take to install a solar PV system?
This will depend on the site and size of the system, but once requirements have been agreed through the site survey, Mosscliff Environmental Ltd will undertake the installation at your convenience.
Find out more>>
How much will it cost?
All systems provided by Mosscliff Environmental Ltd are bespoke - designed, supplied and installed to maximise energy efficiency. PV equipment suitability and cost are dictated by the nature of each property and the requirements for energy to be generated. Find out more about costs and saving opportunities>>
What level of VAT do I have to pay on the installation?
A reduced level of VAT - currently only 5% - is applicable to renewable energy systems for domestic properties..
What is the warranty period?
Systems have a 2 warranty on materials and a guarantee that the system will still produce an 80% performance after 25 years.
What is the design life of a renewable energy system?
Systems with no moving parts such as PV panel arrays have a lifetime expectancy of up to 35 years, although in some instances, inverters may need to be replaced.
What regular servicing is required?
PV systems do not need any servicing, although it is advisable to clean down the panels when appropriate.
Are technical product details available of the different systems and equipment?
Our technical team are on hand to discuss any detailed questions you may have and the site survey is an excellent opportunity to explore your options. Contact us>>
Technical product specifications are available for download on some units >>