Solar PV: Frequently Asked Questions
General Questions | Questions about Solar PV
General questions about solar energy systems back to top of page
What's the difference between the two types of solar energy systems?
Solar Thermal panels heat water using the warmth of the sun and then transfer the heat collected to your domestic hot water system, whereas Solar Photovoltaic (PV) systems are "solar cells", using the sun's light to generate electricity for use in the home. Excess electricity can also be exported to the grid if sufficient is produced.
Is my home suitable for solar energy?
The basic minimum requirements for both solar water heating and PV systems are much the same, calling for unobstructed exposure to the sun during the brightest part of the day - typically between 9am and 3pm – and the opportunity to mount the panels or cells at an angle around 20-50 degrees to get the most benefit. A south-facing roof which enjoys direct sunlight during the two hours either side of noon is particularly ideal.
Will the system work at night?
No, the system only works in daylight. At some times of the year there will be insufficient daylight and that is why your systems have a fossil fuel back up that will cover your needs at these times.
How much roof-space will it take up?
You'll typically need to allow about 4 square metres of available roof-space for solar water heating panels, while a PV system will demand three or four times as big an area.
Will I need planning permission?
For the majority of homeowners the addition of solar panels fall within 'permitted development rights', which means that the panels will be more or less flush with the roof. If your property is in a conservation area, an "Area of Outstanding Natural Beauty" or is a listed building, you may need to apply for full planning permission. We recommend checking with your local council to see what their position is on solar panels.
How long does a system take to install?
Installation time depends on the size of the system. Average residential systems rarely take more than 2-3 days to complete.
Who will install the system?
Our installation partners have team of fully MCS (Microgeneration Certification Scheme) accredited installers for the installation of both solar thermal and solar PV systems. The MCS is an independent scheme that certifies microgeneration products and installers in accordance with consistent standards and is designed to evaluate both products and installers against robust criteria providing greater protection for consumers. An MCS approved installer must be used in order for the householder to qualify for the government grant or the Feed in Tariff.
Do you sell both types of system?
Yes, we sell both types of solar systems: Solar photovoltaic (PV) systems which generate electricity from daylight and solar thermal systems to heat water.
What about insurance and storms?
If you buy solar panels and add them to your house, your insurance company will be obligated to insure them, just as they insure the rest of your household items. You should take sensible precautions against storm damage, but of course rooves are naturally more susceptible to this kind of damage.
Will solar systems add value to my home?
Solar systems of either kind can increase the value of your home by an average of 9% (source: The Guardian). Research carried out by The Energy Saving Trust confirms that 85% of buyers will pay up to £10,000 more for the same property if is more energy efficient. Solar technology has never been more affordable, and the cost is subsidised by government grants - money that would be going to the energy companies.
Questions about Solar PV energy systems back to top of page
What is PV?
PV stands for Photovoltaic. The PV process converts sunlight, the most abundant energy source on the planet, directly into electricity. The equipment required for this process has no moving parts and as a result requires minimal maintenance. In addition, the electricity is generated with no emissions and no noise.
A PV cell consists of two or more thin layers of semiconducting material, most commonly silicon. When the cell is exposed to light, electrical charges are generated and this can be conducted away by metal contacts as direct current (DC).
The electrical output from a single cell is small, therefore multiple cells are connected together to provide a more useful output. Cells connected in this way are encapsulated (usually behind glass) to form a weatherproof module or panel. Multiple modules can likewise be connected together in order to provide sufficient power for common electrical appliances.
What are the components of a PV system?
Each PV system is constructed from different components. These include PV modules (groups of PV cells, which are commonly called PV panels); a charge regulator or controller for a stand-alone system; an inverter for converting direct current (dc) into alternating current (ac), the cabling to connect components together, and mounting hardware for the PV panel itself. This panel must be fixed to a roof or sited to get maximum daylight.
How does a PV system work?
Daylight hits the photovoltaic cells and is converted to clean electricity. This is fed into the inverter, which converts the electricity from direct to alternating current, for use in the home. When the solar energy system is producing more power than is needed it can often be exported to the national grid. In such a system, during the night, power is imported from the grid in the normal way.
Doesn't PV technology need bright sunshine to work properly?
The electrical output of a PV cell is dependent upon the intensity of the light to which it is exposed. So PV cells will tend to generate more electricity on bright days than when skies are overcast. However, PV panels do not need to be in direct sunlight to work, so even on overcast days the panel will be generating some electricity.
Is PV suitable for use in the UK?
In the UK, we get about 60% of the sunlight received at the equator - so there is still a lot of potential energy available! PV has been used in the UK over the last 20 years or more for many applications, particularly in remote areas where grid connection is impractical, such as weather monitoring stations, marine navigation aids, etc. Over the last few years PV technology has become more common in urban areas, often seen incorporated into the roofs and facades of homes, offices and factories.
A modest sized domestic grid connect system will provide a substantial portion of a household’s electricity needs for over 6 months of the year. Installations on commercial buildings are particularly effective, meeting the daytime demands of an office. Over 1.5 MW (1,500,000 Watts)of building-integrated PV system is already installed in the UK.
How much will I need to power my home?
A typical domestic system of 1.5 kW (1500 Watts) in the UK would produce around a third of the annual electricity needed for an average family household (taking the average demand to be around 10 kWh per day). However, calculating the required system size would need to consider other factors too, for example whether the system is grid connected, and what the energy demand of the household is, etc.
Do Solar PV systems need batteries?
Not normally. Since the system produces AC power from daytime solar radiation, it can power domestic appliances independently as long as there is sufficient daylight. If the system is also connected to the national grid, at nightime when the cells are not generating energy, electricity is taken from the grid in the normal way. Any excess electricity generated during the day, for example when you are at work, is sold back to your electricity supplier.
Batteries are only required if you want a truly off-grid solution and independence from any power cuts that might occur. They are also required if you own a property which is not attached to the grid in order that power produced during the day can be stored for use in the evening. Batteries add significant costs to a solar system so are normally only offered on specific request.
How long will my PV System last for?
A well designed system will operate well in excess of the manufacturers 20 year warranty. The PV module with no moving parts has a lifetime expectancy of at least 40 years.
Why Should I Invest In A Solar PV System Now?
There are a number of compelling reasons to make this investment now:
- Reduce or eliminate your net electricity bill
MyPlanet Solar PV systems, combined with the feed in tariffs (FITs) from your electricity supplier, create very favorable financial incentives for installing a solar system NOW. - Declare clean energy independence!
By investing in a solar PV system you generate your own electricity from daylight, a clean, silent, renewable energy source with no emissions. - Enjoy long-term, trouble-free performance
MyPlanet Solar PV panels come with a 20+ year warranty and 40+ year life expectancy, so your system should last for years to come, sheltering you from ever rising electricity prices. - Add value to any property
The value of your solar PV system is added to the appraised value of a property. It’s one of the few home improvements that can be justified in terms of return on invested pound.