Solar Energy

How do solar cells generate electricity?

Photovoltaics cells (PV) is a direct current (DC) generator which gets its power from the sun. When light energy hits a solar cell, they knock electrons free in the silicon crystal structure forcing them through an external circuit , and then returning them to the other side of the solar cell to start the process all over again. The voltage output from a single crystalline solar cell is about 0.5V with an amperage output that is directly proportional to cell’s surface area . Typically 30-36 cells are wired in series in each solar module. This produces a solar module with a 12V nominal output (~17V at peak power) that can then be wired with other solar modules to form a complete solar array, the more solar modules you use the more power you can generate.

Will solar work in my location?

Solar is universal and will work virtually anywhere, however some locations are better than others are. Irradiance is a measure of the sun’s power available at the surface of the earth and it averages about 1000 watts per square meter. With typical crystalline solar cell efficiencies around 14-16%, that means we can expect to generate about 140-160W per square meter of solar cells placed in full sun. Insolation is a measure of the available energy from the sun and is expressed in terms of “full sun hours” (i.e. 4 full sun hours = 4 hours of sunlight at an irradiance level of 1000 watts per square meter). Different parts of the world receive more sunlight from others, so they will have more “full sun hours” per day. Conulting the solar insolation area map will give you the “full sun hours per day” for your location.

How much will a system cost for my 200 square metre home?

Unfortunately there is no “average” since the cost of a system actually depends on your daily energy usage, how many sun hours you receive per day and what other sources of electricity you may have available, IE wind or Hydro power. To accurately size a system, we need to know how much energy you use per day. If your home is connected to the electric grid, your monthly electric bill will usually give you a statement of daily consumption. With this information, coupled with detailed discussion on your power usage profile a system can be designed to meet your needs. Usually a combination of Solar and secondary power generation ( IE diesel/petrol or wind) is designed to get a balance between capital cost and affordable running costs. It would be true to say that a renewable energy system to meet your power needs is directly related to the amount of money you want to spend. Such a system is referred to as a “Hybrid” Solar system. Please see packaged system information for some guidline costings.

What components do I need for a stand alone renewable electric system?

There are many components that make up a complete solar system, but the 4 main items are: solar modules(PV), charge controller(s), batteries and inverter(s). The solar modules are mounted where possible to capture the most sunlight and the DC power they produce is transferred to a charge controller and then to the battery bank where it is stored for later use. The two main functions of a charge controller are to prevent the battery from being overcharged and eliminate any reverse current flow from the batteries back to the solar modules at night. The battery bank stores the energy produced by the solar array during the day for use at anytime of day or night. Batteries are the heart of the system and come in many sizes and grades, it is important that sufficient battery capacity is installed to meet power requirements . The inverter takes the DC energy stored in the battery bank and converts it standard electric power to run your AC appliances as if connected to the electrical mains. Well designed systems will also have a series of safety fuses and trips to ensure the system and your house is protected from failure.

What type of solar module mounting structure should I use?

There are four basic types of mount structures: roof or ground, medium height mast and tracking mounts, each installation requires its own type of mount. For example roof mount structures may keep the wire run distances between the solar array and battery bank to a minimum, which is good. But they also require roof penetrations (a potential source of leaks) and they require an expensive ground fault protection. On the other hand, ground mounted solar arrays require fairly precise foundation setup, are more susceptible to theft/vandalism. Mast mounted systems are relatively easy to install. Mast mounted PV arrays reduce the risk of theft/vandalism. They are also a better choice for cold climates because snow slides off easily. Solar trackers, significantly increase the daily Solar Production output. Trackers are extremely effective in the summer time, but typical home energy usage peaks in the winter when a tracker mount can make a big difference compared to a fixed mount.

Where should I mount the solar modules and what direction should I face them?

You need to aim your solar modules to the true south direction to maximize your daily energy output. The solar modules should be tilted up from horizontal to get a better angle at the sun and help keep the modules clean by shedding rain or snow. For best year round power output with the least amount of maintenance, you should set the solar array facing true south at a tilt angle equal to your latitude with respect to the horizontal position. If you plan to adjust your solar array tilt angle seasonally, a simple method would be to set latitude minus 15° in the summer, exact latitude in the spring,Autumn and latitude plus 15° in the winter. It is important to ensure that your proposed array site will not be shaded at any time of the day or year.

Should I set my system's battery bank up at 12, 24 or 48 VDC?

The PV industry really began with the 12V Caravan type market. These systems were typically small low powered with 12 VDC appliances mainly to run a couple of 12V lights and maybe a small TV. As the solar industry developed systems became much larger (16+ solar modules) and with modern day inverters can efficieny convert the DC power into usable home power. Most home systems today are 24 or 48 VDC since the higher system voltage gives you a lot more flexibility as to how far away you can place your solar modules from the battery bank as compared to a 12V system. For a given power output, a higher system voltage reduces your amperage flow (but not your power) which allows you to use a smaller and less expensive cable for your solar to battery and battery to inverter wire runs, Should a heavy duty load be placed on the system (IE pump load) this will also reduce voltage drop over the cables and system, minimising potential system trips. Most grid-tied systems operate at 24 volts or higher, with a 48V DC system being the optimum.

Should I wire my home for AC or DC loads?

We would recommend not, as DC appliances are typically more expensive and harder to find. Today most home systems are wired for AC loads exclusively. With improvements in inverter efficiency and reliability in the last 5 years, AC is the way to go for a home system.

Can I use PV to heat water or for space heating?

Well would we would have said Not recommended for the following reasons,. Photovoltaics converts the sun’s energy into DC electricity at a relatively low efficiency level compared to Solar water heaters, so trying to operate a high power electric heating element from PV would be very inefficient and expensive. But with recent development of Micro Inverters, we would now recommend a Phototvoltaic installation to provide power directly to your exisitng on Grid power system, the big advantage here is that one the water reaches the required temperature the surplus power is used to supply other appliances in your house reducing your electricity costs.

Should I fit a Wind generator to my system.

A wind generator (Typically 1000W) can be a valuable cost effective addition to a medium sized PV based system, providing additional power during night time and low sun availability periods. These tend to work best in mountain or coastal areas providing a lot of power relatively quickly. Modern day generators (24V/48V) can also be wired in such a way as to provide power to an auxiliary load (IE electric water heater) when the batteries have been fully charged, further improving system efficiency. Careful consideration should be given to the location of wind generators.


Petrol generators. (UP TO 10kw 230v)

Petrol generators are usually fairly small and portable, although we can supply these units up to 10KVA, The units are primarily intended for emergency power application, and the larger units above 5KA can be used quite successfully as the support unit in a properly sized renewable energy system. Petrol generators tend to lower cost than diesel, and in our experience tend to have a lower overall life expectancy than diesel generators. The running costs of petrol generators can be quite high particularly on the larger units. LPG conversion options are available on some units, significantly reducing running costs.

3000RPM Super Silent Diesel Generator 5KVA 230V

These units are suitable for use in applications where running times are infrequent and short. These units are not suitable for applications where sustained heavy loading is required. Extended run times or frequent heavy duty loading of these units will significantly reduce the operational lifespan. The units are ideal for use in a support application on a correctly designed Solar/Wind generator and Deep cycle battery installation.

These units are provided on the basis that they are used as standby support power for Infrequent and limited run hour and are not subjected to direct heavy loading or continuous run applications, The warranty will be invalidated if the generators are used in non standby applications. We now offer models exclusively from Hyundai Power generators. Priced from 1875 inc IVA

3000RPM Diesel Generator 5kva to 9.5KVA 230V

These units, our best, are fitted with the Yanmar L100 engine of robust build and good design. Proven to supply good levels of power under extended operating conditions and heavy load these generators are ready for serious work when required. We would always recommend these units for use when they are the sole source of power or in support of Solar power systems with an intermittent heavy power demand or extended running periods. The quality of build and ongoing reliability is reflected in the price compared to the generators imported from Asia. Priced from 4500€ Inc IVA

1500RPM water or air cooled Diesel generators 5KVA TO 75KVA 230V/440V

These generators are manufactured in the EU, are well designed and made to a very high quality standard. Generally of a very robust nature and rated for continuous running, these units when properly maintained will give many years of useful service. We recommend the 1500RPM units for heavy duty applications, in Solar systems, Standby power or “continuously on” power supply applications. HImoinsa ( our preferred supplier) We recommend the 1500RPM units for Solar system Standby or domestic power supply applications. Priced from 6,975.00€ Inc IVA

General Information

Generators typically have a warranty for 12 months or 500 hours whichever comes first. Supported by an extensive network of service centres with qualified engineers in Spain, These centres carry an extensive range of spare parts and will provide both routine maintenance and breakdown cover.

Please contact us directly for advice on selecting the correct generator for your needs.

A diesel generator may give you an option to purchase “Red or Gasoleo B” diesel in your locality, which can further reduce running costs.

All our generators are prewired for autostart and can be integrated into Solar or Hybrid systems for completely automatic operation

Satellite Television

What Channels will I get with the SKY Free to View System?

There are well over 60 TV and 50 Radio Stations that are English speaking and free. The TV channels are low budget and many are shopping channel derived. Others are News, Music, General entertainment, Sports & Religion. However, BBC & ITV channels. Ch4 and Ch5 are available provided you have the optimum dish size and an activated SKY Free to view card. BBC & ITV is free to view without a SKY card, however to receive CH4, CH5, it will be necessary to either obtain a Free to view card (One off cost with no subscription) or subscribe to one of the SKY packages.

Will I get all Sky Channels with the Sky package System?

Subscriptions are set up direct with Sky and you cannot subscribe if you declare you are out of the UK. Prices are found at You will NOT get all of the channels in Spain, only most. Movie channels are very difficult to receive and only available with very large dishes. Sky Sports channels are available, BBC, ITV, Ch4 Ch5 are also included with all our Sky packages. We can arrange Subscriptions, provided you have a UK or Spanish credit card. Please discuss with our installer your channel requirements.

Which is the best digibox receiver for use in Spain?

We believe the best box for consistent reception in Spain is the Pace DS430N, we use this box on all our installations and find it the best performer for some of the more difficult to achieve channels, for example CH4 fitted with a 2.4mtr dish correctly aligned will provide good reception with breakup occurring only in severe weather or atmospheric conditions.

Do I need a 2.4 Metre dish to receive BBC and ITV?

This region(CB and inland) requires a minimum 1.9 Metre dish. However there are reception limits for reception of some channels during some periods of the day and night. We recommend the bigger 2.4M dish for more consistent reception. However even with a 2.4mtr dish some programmes can be inconsistent, for example BBC2 only available in evenings, Channel 4 has recently changed satellites and now is virtually without coverage even on a 2,4m dish at some times during the day/night. Some of the “weaker” channels ( movie channels) can disappear in the evening and around midnight for a few hours. Extreme weather can affect all reception and may require a system reset.