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Grid Connect Systems


These systems allow a wind turbine or photovoltaic array to be used in synchronized connection with a grid supply. No battery store is required. Power generated is first used by the house loads etc. and any surplus exported (sold) to the grid. In times of low wind, at night or when power consumption exceeds power generated, power is imported from the grid as normal. All power flows are ‘seamless’ from the point of view of the user.

Over a period it is possible for a property to achieve numerical electricity autonomy if energy generated equals that which is consumed. In this situation the grid effectively acts as an ‘energy store’ instead of a site battery system, avoiding the problems and expense of managing and replacing batteries. A downside is that the renewables system does not act as a back-up power supply in the event of power cuts. In many cases this may not be considered a big issue.

The photovoltaic array or wind turbine are connected to the grid supply by means of special inverters. To ensure safety these inverters automatically shut down in the event of: High/Low grid AC-voltage; High/Low grid frequency; Grid Failure; or Inverter Malfunction.

In PV applications the inverters automatically adjust PV array loading to provide maximum efficiency of solar panels by means of a maximal power point tracker (MPPT).

Versions are available which can be used with wind turbines.

Your Own Power Station


Instead of simply being consumers of electricity, ordinary domestic properties, offices and workshops can now generate their own power on-site to reduce both their electricity bills and their impact on the environment.

The sun is the source of all renewable energy and can be used directly as heat or electricity; or indirectly as biomass, hydro-electricity or wind energy.

By harnessing renewable energy sources other resources can be conserved. The combustion of fossil fuels with it’s release of carbon dioxide and danger of climate change can be reduced; and the risks of nuclear energy avoided.

Sufficient renewable resources must be available at a given site to make the use of wind or solar systems feasible. Once installed a wind or solar system will supply electricity cleanly and quietly; year in; year out; - providing an investment in the future.

Operation is fully automatic - when the sun comes out or wind blows they produce power. When the sun goes down, wind stops or there is a power cut the systems shut off.

System operation can be kept track of by periodically reading energy output meters. Various options exist for these including displays which show instantaneous output and record daily production.


Turning the Meter Backwards


Connection of a Wind/PV electrical system to the grid must have local electricity company approval and installation method and protection must meet their standards.  Wind & Sun are accredited installers for these types of system and approved equipment is used.

Once connected to the grid, when the wind or solar power system is generating more power than needed excess energy is sold back to the electricity company. When it is not generating enough to meet energy requirements the utility provides the difference.

Different electricity suppliers offer differing schemes to reward this generation. Some pay for all electricity generated (or payments called Renewable Obligation Certificates (ROC’s) can be claimed) measured using a genneration meter, some pay for exported power only (using an export meter). Often the rate paid for electricity generated is considerably less than that charged for electricity consumed, so best economics are obtained if all power generated can be consumed on site.

In some instances a ‘net-metering’ arrangement may be possible allowing all renewables generation to be given the same value as energy provided by the utility - so letting the meter spin backwards!

Often a wind or solar electrical system results in a new approach to using electricity. Electricity, and wind or solar electricity in particular is energy of such high quality that using it rationally and making sure none is wasted is imperative.


Solar Systems


Solar systems generate electricity in proportion to the amount of sunlight received, so unshaded, preferably south facing areas are best the roofs of many houses are ideal!  As a guide, 1kWp of well sited grid connected PV array in the UK will produce approx. 700-800 kWh of electricity per year and can be achieved using an array area of about 8 square metres.

A 2.5kWp system covering 20 sq. m can supply approximately 1900 kWh of electricity - almost half of the average annual electricity consumption for a household of four.

All generation is during hours of daylight and most in summer, least in winter. Best use is obtained when electricity consumption runs in parallel to electricity generation. Eg. Appliances such as washing machines or dishwashers, which do not have to operate at a certain time can be operated when the solar system is supplying plenty of power.

Wind Systems



The best sites for utilising windpower are often rural with open aspects to the prevailing winds. Urban sites are generally unsuitable due to lower average windspeeds and increased turbulance.

Different tower heights and types are available to suit different site conditions - higher towers will give better performance. Planning permission is required, however, this is not usually a problem in appropriate locations for small wind turbines.

For properties with good wind sites these systems are the ideal way to reduce electricity demand. Maximum generation is usually over winter months when demand is highest and power can be produced 24hrs per day. For example, a 2.5kW Windy Boy system can produce between 2,500 - 5,000 kWh of electricity on an ideal site with 5 m/s average annual wind speed.

In contrast to solar electric systems, heating can be an appropriate load for the larger grid-connected wind systems.
 your own power station

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Distributors for: BP Solar Modules SMA inverters OutBack inverters NRG wind monitoring equipment                       dti accredited installers  Clear Skies accredited  REAL Member