off-grid solar and wind power specialists

Frequently Asked Questions

Guidance from the wind

Off-Grid Solar & Wind Power FAQs

A place for the more common questions we get asked - please take a scan through this section before contacting us, as this saves much time. In turn, this enables our staff to provide a even higher level of service to all of our clients and keep our prices competitive.

Does the EDC supply domestic solar & wind energy systems ?

That depends on your situation... if you are talking about a remote property, where there is no existing mains connection - then yes we can help you. If you are talking about a property which is already connected to the national grid, we do not get involved in grid-connected systems. We specialise in stand-alone power systems.

How much would it cost to power an off-grid house with renewables ?

A German study found that a renewable energy system to power a standard house, equipped with conventional appliances, would cost in the region of 40,000. However, when they approached the scenario in a slightly different way, by buying the most energy efficient appliances (washing machines, lights, TV's, VCR's etc.) currently available - they came up with an astonishing result....

The new energy efficient appliances cost in the region of 5,000 but the renewable energy system now required to power them only cost 10,000, thus reaching a total of 15,000 with new appliances throughout the house.

What is a 'hybrid' energy system, and what advantages do they have ?

A hybrid energy system usually consists of two or more energy sources used together to provide a better energy supply balance. For example, in the UK, a solar electric (pv) array could be coupled with a wind turbine, which would create more output from the wind turbine during the winter, whereas during the summer the solar panels would produce their peak output. Hybrid systems can make more economical sense than wind or solar alone.

What is an 'off grid' or 'stand-alone' system ?

A stand-alone renewable energy system is one that is not connected to the national power grid. This type of system is usually more expensive due to the batteries required to store the energy.

Do I need planning permission to install solar panels on my roof ?

Generally, planning permission is not necessary for the installation of solar panels. There are a number of exceptions to this. 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 beauty or with any other kind of special order. To find out if you need planning permission call your local council and ask for the planning department. You may also need planning permission if you intend to mount solar panels on a frame that is not flush with the roof itself.

How long do the technologies last in constant use ?

Many of the technologies we supply are expected to last more than twenty years. Technologies with moving parts such as wind turbines, will eventually require replacement bearings. Solar panels, which have no moving parts, last an extremely long time. Some of the earliest solar electric panels, made about 35 years ago, are still producing energy today. Recently, photovoltaic panel manufacturers have started offering 20 year performance warranties.

What type & size of cable should be used for my application ?

Most of the cables we use are HO7RNF double-insulated rubber neoprene cable. This high specification cable is multi-stranded, making it more flexible than most. The double insulation makes the cable suitable for external use and protects it from UV degradation. All main solar & battery cables need to be single core cable, thus providing more layers of insulation between any two cables.

The correct size of cable is essential to get the most out of any low voltage energy system. An under-sized cable can cause major headaches with voltage drops and in extreme cases it can be very dangerous. Cable sizing page here...