|
|
| Home | About us | Hydro | Wind | Solar | Biodiesel | FAQ | Contact us |
|
Solar PV Renewable Energy FAQsWhat is the difference between PV solar panels and Solar Hot Water panels? The panels in a PV system contain semi-conducting materials that generate electricity when exposed to sunlight. This electricity can be used to power household appliances or, if the property is mains connected, surplus electricity can be sold back to the National Grid. The panels in a Solar Hot Water (SHW) system have pipes running through them and the sun's energy heats water as it flows along these pipes. The hot water is then stored in a cylinder until it is needed.
Is the British climate suitable for PV? The amount of electricity generated by a Solar PV panel or array depends on the intensity of the sunlight to which it is exposed. A solar cell will generate more electricity on bright summer days when the sun is stronger than on sunny winter days. In the south of Britain the sun's power, or irradiation, available at the surface of the earth averages around 950 watts per square meter. With typical solar cell efficiencies of around 14-16%, this will generate about 140-160W per square meter of panel, providing they are placed south facing into the sun and inclined between 30º to 50º from horizontal.PV cells do not need to be in direct sunlight to work and will generate electricity even on overcast days and so can be used all year round. In the UK electricity generation will decrease during the winter months when the sun is lower and the days are shorter and darker but energy requirements can be supplemented by the National Grid.
Can I use PV to power & heat my whole house? It is not cost effective to use PV to heat your hot water but PV can be used to power household electrical appliances and for lighting. On average, a household in the UK consumes around 10 kWh of power each day. A domestic system of 2kWp should provide approx half of this annual demand. However, calculating the system size depends on many factors, such as the roof area of the property, financial constraints, the energy demand of the household, etc. All of these factors will be taken into consideration by our surveyor when they visit your property.
What happens when little or no electricity is being generated? (e.g. during the night) During the times when your PV system is not generating sufficient, if any, electricity your energy requirements will be supplemented by your local electricity network, also known as the National Grid. This temporary switching of electricity supply is done automatically and does not require you to turn anything on or off on your Solar PV system.
Is Solar PV expensive? The cost of Solar PV has decreased significantly over the last 20 years. In 1980 the price of a PV module was around £15 per Wp compared to current prices of approx £4 per Wp.An installed 1kWp grid-connected system will typically cost around £6,500 plus VAT and a 2kWp system around £11,500 plus VAT.
How do I know if my property is suitable for PV? Our site surveyors will discuss all the options during his/her visit. The major considerations are:
Roof orientation - panels should face S, or between SE and SW and be tilted between 30-50 degrees to horizontal. Financial restraints - how much money does the property owner have available to pay for a PV system? Is the roof shaded? - Even a small amount of shading has a serious effect on power output from the modules. Roof ownership - does the roof belong exclusively to the property owner or is there a shared right/access? Planning permission - is the property a listed building or in a conservation area?
What maintenance does a PV system require? One of the key advantages of Solar PV systems over other renewable energy systems is the minimal maintenance required. There are no mechanical moving parts within the system that will get worn and need to be replaced. Any bird droppings or dust that settles on the modules will be washed off by rainfall, however, we do recommend a periodic thorough cleaning of the modules with an environmentally friendly cleaning agent. We also strongly recommend a periodic inspection/testing of the PV electrical system as would be required for any other electrical installation within the home.
Do I need planning permission to install PV panels on my roof? You should consult with the Planning Department at your local Council to confirm whether planning approval is required for the installation of solar panels on your property. Normally permission isn't required but there are some exceptions. If you live in a listed building, a building with any kind of conservation order on it or of any historical value, or if you live in an area designated as National Park, an area of outstanding natural beauty or with any other kind of special order. Planners will be concerned about issues like appearance and visual impact. Often, when there are concerns they can be alleviated by careful positioning of the panels on the roof or in extreme cases, in the property grounds.
How long will a PV system last? Solar PV modules made from crystalline silicon have an average life span of 25-30 years and can continue to operate for longer. A Solar PV System has no moving parts that will get worn and need replacing. Periodic inspections by a qualified technician will help to alleviate any electrical faults.
What does 'grid-connected' mean? Most PV systems in the UK will be grid-connected, which means that the systems are connected to the local electricity network via the customer’s "consumer unit" or "fuse box". During the day, the electricity generated by the PV system can either be used immediately to power electrical appliances in the home or workplace, or can be sold to one of the electricity utility companies. During the night when the solar system is unable to generate electricity, power can be bought back from the network. In effect, the grid is acting as an energy storage system, which means the Solar PV system does not need to include battery storage.Connecting a PV system to the distribution network will require permission from the Distribution Network Operator (DNO). The DNOs in the UK have different policies when it comes to connecting PV systems to their networks, and so different rates will be paid for exported electricity. You will be required to contact your DNO to let them know that you plan to install a grid-connected Solar PV system to their network, and must also inform them when the work has been carried out, by submitting the appropriate electrical test certificates and forms to them.
Can I make enough money selling my excess power to offset my costs? When you consider the initial cost of the PV system compared to possible energy savings and payments to you for any excess power, your total energy costs will likely be higher using a PV system. Therefore, the average customer should not purchase a PV system with the expectation of generating and selling enough excess energy to recover the purchase, installation and maintenance cost of the system in the short term.
Is funding available? Grants are available for the installation of Solar PV systems, providing the installation is carried out by a DTI approved installer, and the total power output of the system exceeds 1kWp. Please discuss this with our surveyor when on-site. Our single Solar PV systems have a power output of 600Wp, and so more than one kit would need to be installed in order to be able to apply for a grant. These systems cannot be self-installed if you plan to apply for a grant.
|
|
Copyright © 1996 - 2008 Northern Tool + Equipment Catalogue Co. All Rights Reserved. Northern Tool + Equipment Co (UK) Ltd • Unit 2, Interchange Park • Portsmouth, Hampshire, PO3 5QD |