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FAQ's

Will Alpha Renewables organise the DNO connection (permission to connect to the electricity grid)?
How long will be required from order to installation?
Can I get help with project costs?
Are your products certified?

PHOTOVOLTAIC SYSTEMS(PV)

What does kWp mean?
How much electricity does a typical PV system generate in a year?
How much roof area is required for a PV system?
What proportion of electricity will a system produce?
What is a kWh?
How reliable is a PV system?
What is the optimum roof angle and orientation for solar panels?
Do I need planning permission to install solar panels?

WIND TURBINES

What proportion of my electricity will a wind system produce?
How large is a wind turbine?
Where should the wind turbine be located?
Where shouldn't a wind turbine be located?
How long do your systems last?
What happens when little or no electricity is being generated?
What happens if the system is generating more electricity than is being used at that time?
When should I have a grid-connected system?
Do I need planning permission to install a wind turbine?

SOLAR THERMAL

What's the difference between a solar thermal (ST or solar hot water) system and a photovoltaic (PV or solar electric) system?
Are solar thermal systems suited to our climate?
Will I need to re-plumb my whole house?
Can I install a solar system with a combi boiler?
Does Alpha Renewables offer a choice of panels or represent just one supplier?
How do we know which system is right for us?
Do I need planning permission to install solar panels?


Will Alpha Renewables organise the DNO connection (permission to connect to the electricity grid)?
Yes, we can apply on your behalf when you place an order is confirmed with us.

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How long will be required from order to installation?
This will depend on the system chosen as time for some products to be delivered is longer than others. However, 4-8 weeks should generally be allowed for equipment ordering.

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Can I get help with project costs?
There are grants available for most projects, whether they are for domestic, public sector or commercial clients, through the government's Low Carbon Buildings Programme. Some projects are also eligible for additional funding from other sources. We can advise you on the funds available and assist you with the grant application process. If you have any queries we are of course happy to help. Further details on the grant scheme are available from the Low Carbon Building Programme or by calling the grants helpline free on 0800 915 0990

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Are your products certified?
All equipment must be certified to be eligible for the grants scheme and the Feed In Tariff. We have signed up to say we will provide this and the DBERR's (incorporating the DTI) grant scheme management team will check a proportion of our installations to ensure that all are of good quality. We are a member of the Renewable Energy Association and as such have signed up to the REAL Code of Practice

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PHOTOVOLTAIC (PV)

What does kWp mean?
The power of a PV system is measured in Watts just like all other electrical devices (e.g. 100W lightbulbs).  A kilowatt or kW is a thousand Watts. However, because the power generated by a PV system is dependent on the weather, Standard Test Conditions are defined under which the power is measured. The power of a system is normally quoted therefore under these test conditions and is know a Kilo Watt power.

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How much electricity does a typical PV system generate in a year?
In optimal conditions i.e. facing south and tilted at an angle of 30-40 degrees to the horizontal, a typical 1 kWp domestic PV system in the UK will generate 800 kWh per annum. 1kWh is equivalent to 1 unit of electricity on your electricity bill.

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How much roof area is required for a PV system?
A typical standard household 2 kWp system would typically takes up approximately 16m2 (4m x 4m) when using crystalline silcone modules. 

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What proportion of electricity will a system produce?
All buildings consume vastly differing amounts of electricity. Electricity bills will be lower because often electricity from the PV system will be used instead of taking electricity from the mains. A typical UK three-bedroom family home built to 2006 Building Regulations uses 3,000-4,000kWh of electricity per year. This can vary considerably dependent on electricity consumption and how energy efficient the electrical appliances in a house are. It is possible for a 2 kWp PV system to supply all electricity needs if all possible energy saving measures are implemented.

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What is a kWh?
kWh stands for Kilo-Watt Hour, and this is a measure of energy (in this case electricity) used or generated.
1 kWh is the same as 1 unit on your electricity bill, and is enough power to light a 100W light bulb for ten hours (or fifty hours for a typical 20W low-energy light bulb). 1 kWh costs approximately 15p for domestic customers.

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How reliable is a PV system?
PV systems are very reliable. PV systems have no mechanical moving parts so minimising potential faults.

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What is the optimum roof angle and orientation for solar panels?
In the UK, the optimum roof pitch is at an angle of 30° to 40° above horizontal, facing due South. However, this is rarely the angle available on the roof of the building; the diagram below shows the percentage of the standard figure that might be generated at given angles and orientations.
For example, a roof with a pitch of 20° facing South-West would generate around 96% of its potential (equating to around 3,840kWh/yr for a typical 5kWp system). There are mounting systems available to increase the incident angle for flat roofs.
Percentage generation at different pitch angles and orientations
Source: Guide to the Installation of Photovoltaic Systems, 2nd Edition

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Do I need planning permission to install solar panels?
Planning permission is not generally required but may be necessary if your property is listed or in a conservation area. The current regulations appear to vary from area to area but planners are being encouraged to accept renewable energy installations whenever appropriate.

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WIND TURBINES

What proportion of my electricity will a wind system produce?
Your electricity bills will be lower because you will be using electricity from the wind system instead of taking electricity from the mains. The exact proportion depends on the size of the wind turbine, the actual wind conditions experienced and your site consumption. You can determine your annual electricity consumption by examining one year of electricity bills.
For example, a typical UK three-bedroom family home, uses 3,300 kWh of electricity every year. This can vary considerably dependent on the household and how energy efficient any electrical appliances are. Thus a 15 kW turbine would generate electricity equivalent to the consumption of six or seven reasonably efficient three-bedroom homes.
It is important to note that a grid connection or some form of energy storage is normally still required, even if the predicted generation is higher than the planned consumption. This is for several reasons:
Peak site consumption and wind conditions rarely coincide
Wind speeds may be lower than average for a protracted period of time
Consumption rates are likely to increase with time

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How large is a wind turbine?
Blade shape and size and mast sizes vary widely with the site requirements and turbine model used. Generally, the larger the turbine kW rating the larger the wind-swept area of the blades and the taller the mast is. The height of the mast or the size of the blades is often one of the restrictions in choosing a system, and our designers will attempt to find a suitable system to comply with these requirements. Conversely, we sometimes specify taller masts than usual in order to maximise the output from the site.
Our standard range of wind turbines have blade diameters of 1.6m on a 1.5kW turbine through to 9m blade diameter on a 15 kW turbine. The mast heights of our standard systems are between 6.5 and 15 m.

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Where should the wind turbine be located?
A wind turbine should be located in an open non-sheltered space where it will experience as much wind as possible. There should be few nearby obstructions to the path of the wind (e.g. buildings and trees) to restrict turbulence, as this can reduce output and shorten the life of the turbine. In particular, the area to the south-west should be clear of obstructions, as this is the prevailing wind direction in the UK. The electrical connection is likely to be made within your building; hence the distance from the building should be taken into account (usually within 500m). The total length of land required to raise and lower the turbine is just over twice the height of mast (13m for our smallest turbines); this space must be kept free for maintenance.

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Where shouldn't a wind turbine be located?
While a lot of people would like to generate electricity from the wind not all sites are feasible. The following is a list of commonly requested types of site for which our engineers normally recommend other technologies.

  • Low wind: while subjective, anecdotal evidence may suggest a site is windy compared to its surrounding area, this might not mean it has sufficient wind to generate power. When this might be the case, a long-term wind study is suggested at the site and we can perform or help with this study.
  • Little space: as with any mechanical machine running all year round, wind turbines require regular maintenance. For tilt-up masts this means a clear, unobstructed area for raising and lowering of the mast must be reserved for the lifetime of the equipment.
  • Urban areas: wind in urban areas, especially at or near roof level is both slowed by friction and highly turbulent. This means there is less energy to harvest and the turbine is stressed, reducing its working life. In addition, in residential areas a potential for noise and visual flicker can cause complaint.
  • Forests: as with urban areas, dense areas of tall trees can result in slow, turbulent wind

These are not hard and fast rules, but if your site might fall into one of the above categories, it may be to your advantage to consider another renewable technology.

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How long do your systems last?
The systems typically carry a 25 year life expectancy. After this time the system would be expected to continue to function

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What happens when little or no electricity is being generated?
When little or no electricity is being generated by the system, electricity is automatically taken from the National Grid. You will not need to turn the system on or off - the service will be seamless.

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What happens if the system is generating more electricity than is being used at that time?
Most installations are grid-connected systems, so the electricity will be fed back to the mains. Grid-connected systems use an electrical inverter to connect to the mains.

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When should I have a grid-connected system?
In the majority of installations, it makes sense to connect to the electricity grid and operate the system in parallel with it. There are a number of reasons for this, which include the following:
In most circumstances, it is both expensive and space-demanding to size a system that will be able to provide sufficient power through all months of the year
Batteries currently require a lot of space, are heavy and expensive, and require a lot of maintenance
You can use the grid in a similar way to a near-infinite battery: You can sell excess unused power to your provider, and buy it back when you need it most
In general, unless the site is to be extremely remote and away from a grid connection, it is almost always cheaper to have a grid-connected system.

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Do I need planning permission to install a wind turbine?
Yes planning permission is required. The current regulations appear to vary from area to area but planners are being encouraged to accept renewable energy installations whenever appropriate.

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SOLAR THERMAL

What's the difference between a solar thermal (ST or solar hot water) system and a photovoltaic (PV or solar electric) system?
Solar water heating panels or solar collectors are completely different to solar photovoltaic panels. In a solar water heating system, water runs through pipes in the solar collector, and is heated up by the sun. A solar thermal system will only produce hot water, and installation may involve some changes to your plumbing system. In contrast, photovoltaic panels generate electricity, which can be used by a wide variety of appliances in your home. PV panels are based on the semiconductors used in the electronics industry. During installation of a PV system, there is little disruption to your home - all the components are on your roof or in your loft, apart from a meter and switch which can be installed by your main fusebox.

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Are solar thermal systems suited to our climate?
Correctly sized solar hot water systems can provide around 60% of the domestic hot water for a property. This will vary depending on the way the hot water is used in the household. Businesses that have a high hot water demand in the summer such as the tourism sector can provide the majority of their needs from a solar system.

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Will I need to re-plumb my whole house?
The only part of the existing plumbing that has to be changed is the hot water cylinder. In swimming pool heating applications a heat exchanger has to be added to the filtration pipe-work.

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Can I install a solar system with a combi boiler?
Most older combi boilers will not accept pre-heated water so are not suitable, but many manufacturers are now developing solar compatible boilers. Please contact us for advice if you have a combi system.

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Does Alpha Renewables offer a choice of panels or represent just one supplier?
We are an independent installer of solar thermal panels and can offer products from a range of suppliers to suit each individual property and customers' requirements.

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How do we know which system is right for us?
We will visit your home to discuss your needs and carry out an initial survey. This survey will include looking at your roof structure, its orientation, your hot water cylinder, your current heating system and your home's layout. From this we will be able to prepare a system design and quotation.

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Do I need planning permission to install solar panels?
Planning permission is not generally required but may be necessary if your property is listed or in a conservation area. The current regulations appear to vary from area to area but planners are being encouraged to accept renewable energy installations whenever appropriate.

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