Photovoltaic (PV) Solar Panels as alternative energy source for homes
The most popular choice in the UK for renewable energy in the home is using Photovoltaic Solar Panels, commonly referred to as PV Solar Panels.
Here you will find information about Photovoltaic Solar Panels and answers to the questions you are most likely to ask:
Photovoltaic solar panels are built up of PV cells; which are crystalline cells of a semiconducting material, such as silicon, in an aluminium frame with a glass sheet protecting the cells and letting the light through. There are different types of semiconducting materials used to make PV solar panels with varying costs, silicon is the most common material used. The silicon PV cells also vary in type, they tend to be differentiated by the way they are cut and treated, two of the most common types used in the UK are monocrystalline and polycrystalline.
The PV cells generate electricity when exposed to photons of sunlight. PV Solar panels do not need to be in direct sunlight, daylight will produce solar energy, this works exponentially; the more sunlight exposure, the more solar energy produced. Therefore PV solar panels are most efficient when tilted in a southerly direction.
Semiconducting materials, such as silicon, are able to undergo a process known as the 'photovoltaic effect'. What this means is that when they absorb photons of light it causes them to produce electrons. The electrons produced are then captured as a DC current and are converted into an AC by an inverter. This current is then either used straight away by the home or it can be sent to the national power grid for energy suppliers to use.
A PV generation meter can be placed in the home or workplace so there is a visible real-time monitor of the amount of electricity the system is generating. If the system is set up to send electricity to the grid, then the meter will also monitor this.
The cheapest, but least efficient type of solar power derives from the technology that powers solar power calculators or watches. This type of Solar PV is known as armorphous or 'thin-film' silicon, as a basic explanation it is a thin layer of silicon coating a material such as glass. This technology is cheaper than others but to get a good return a large surface area is required as its efficiency is low. The thin-film silicon technology is not very popular in the UK. It is the same type of technology used to create solar roof tiles, which can be used to either cover a whole roof or part of a roof. Being thin-film though solar roof tiles are not very efficient compared to other types of PV solar.
Widely available in the UK and a popular choice for PV solar power is polycrystalline. This is made up of many small crystals of silicon that are cut from a wafer. It is relatively efficient and cheaper than monocrystalline making it a popular option for photovoltaic solar panels.
Monocrystalline solar panels are made up from a single silicon crystal, so they are purer than the previous two. This type of PV solar panel is the most efficient mentioned so far but tends to be the highest in cost.
Hybrid solar panels, or their official name 'heterojunction incorporating thin-film' (HIT) are produced from a monocrystalline cell covered with a thin-film. By having the two materials working together it can create greater energy conversion efficiency. This is seen as a premium option for solar panels and is the most expensive technology.
PV Solar panels can be installed on the roof of a building or wall that faces within 90 degrees of south. It is important that the proposed area does not have any other buildings or trees that over shadow it, the less exposure to sunlight the less electricity will be produced.
Installation will require scaffolding to be erected at the property, it is important when getting quotes to make sure this cost is accounted for. Once the scaffolding is in place the installation is possible in one day, but will sometimes take longer depending on the size of system being installed. PV Solar panels can also be installed at ground level if a property has enough land that an un-shaded area is available.
PV Solar systems are measured by their kilowatt peak rating (kWp), this is how much power is generated in a peak controlled environment, the more efficient the cell the less solar panels will be needed. How close to peak a panel will perform depends on the amount of light the panel is exposed to. The industry is rapidly evolving, so it is important to speak to a number of companies about their technology before choosing the right solar panel for your home.
A standard solar panel has an area of about 1.2m x 1.8m and will produce between 180 and 250 watts. To produce 1kW of power, 4 to 5 solar panels will be required. Figures show that a 1kW solar panel system would supply about 25% of an average family's energy demand in a year, this would be classes as a smaller installation, the more panel space available on the roof, the greater return will be seen.
PV Solar panels are producing your own resource of solar energy, electricity, so in the first instance, this is saving you money. It is important to consider how much time is spent at home in the day when looking to save money on electricity, as in most cases solar panel systems are not set up to store energy, therefore if it is not used in the day it is either wasted or the better option, exported to the national grid. Any excess energy that is sent to the grid for use by energy companies is paid for using a Feed-in Tariffs (FITs).
The FITs scheme will guarantee you a minimum payment for all electricity you generate and will also pay you a bonus for any electricity that you send to the national grid. The most common PV solar panel system used by homeowners is made up of eight panels and can generate up to 2.5kW. The Energy Saving Trust estimate these panels could generate approximately £700 a year from a Feed-in Tariff and save about a £100 a year on energy bills.
It is not normally necessary to get planning permission for PV solar panel systems; but if you are unsure it is important to check with your local authority. You are more likely to need planning permission if your property is listed or in a conservation area.
More solar pv information can be found in the articles below:
If you are looking for Solar PV Panel Kits have a look online at Saving Energy Online