The use of solar energy need not simply be the preserve of those wishing to spend thousands to reduce their electricity bills and carbon footprint. Often overlooked, is the ability of solar power to provide reliable, cost effective power in situations and locations where mains power is unavailable or impractical.
Potential Uses for Solar Lighting
Solar power can be used to provide reliable power in remote locations throughout the year, even in the UK. There are many situations where a mains free power supply may be required. These range from recreational garden lighting through to essential remote communications and street lighting.
Solar lighting is a relatively new concept to most people and yet has huge potential to bring light to buildings where before electrical power was unavailable for either practical or economic reasons.
Solar lighting systems are ideal for stables, farm buildings, remote dwellings, garden sheds, garages, kennels, summer houses, garden studios and offices, log cabins, greenhouses, beach huts, children’s play houses, garden lighting, street lighting… the list goes on and on!
Solar Lighting Benefits
Solar lighting can be put to good use anywhere that the sun shines. The cost often compares very favourably with a new mains power connection or the installation of a generator, and in addition to this the power produced is totally silent and free.
The other great thing about solar panels is that they have no moving parts and as a result are virtually maintenance free. All they need is a bit of a clean once or twice a year to prevent a build up of dirt reducing their output. They usually have a life expectancy of in excess of 15 years and very often come with a guarantee to this effect. In addition to this they produce no polluting emissions and do not to contribute to climate change.
Solar lighting is simple and safe to use and there are complete kits available that make installation a straightforward and fast DIY job. As they run at 12 volts DC, a qualified electrician is not required and building regulations do not apply. Compared to a generator, a solar lighting kit has the added advantages of being totally silent, having minimal running and maintenance costs and is more secure. Criminals find highly portable generators all to easy to carry away and sell on.
In situations where remote buildings are used to house horses, farm animals or pets, having effective reliable lighting is essential for routine tasks such as feeding, mucking out and most importantly to aid good husbandry and care of the animals. In these situations a solar lighting system makes winter and morning tasks easier and safer to carry out. Solar lighting can also provide light for extended periods of time in the case of an emergency, for insyance if an animal is giving birth, or if an animal needs to be examined by a vet.
How Solar Lighting Works
Solar photovoltaics (Solar PV) is the process of capturing the energy from the sun and converting it into electricity. Solar lighting systems capture energy from the sun with a solar photovoltaic panel and then store it in a battery until it is required to power the lights.
There are three main types of solar panel widely available on the market today : monocrystalline, polycrystalline and amorphous. Most solar lighting systems use polycrystalline panels as these provide the best balance in terms of price and efficiency.
Using a solar lighting system needs a slight change in mindset from our usual gung-ho attitude to using mains power! The power that is taken from the battery, when the lights are switched on, needs to be replenished from the Solar Panel when the sun shines. You may have noticed that the sun doesn’t shine every day(!), so the battery is sized to ensure that there is enough power stored on a sunny day to provide power for a series of overcast days. The size of the solar panel and battery therefore, should be dictated by the estimated typical daily requirement for light and the estimated daily provision of sunshine. In general terms, the lower the requirement for power, the cheaper the system.
Most solar lighting systems use low energy lights and very often run these as at 12V rather than the usual mains 230V as this is the most efficient way to use the stored power. If 230V lighting or power is required this can be achieved with the use of an inverter that can be bought separately and easily added to the system.
Providing lighting for 2-3 hours per day in the winter and in excess of 7 hours per day is very easily achievable at a cost effective level in the UK. Extended requirements for power in the winter months can add significantly to the cost of a system, but this often still compares favourably with the cost of installing a new mains power connection. In situations where winter demand for power is high, it is often cost effective to add a small wind turbine to help with winter battery charging and to keep the cost of the total lighting system down.
The time of year has a major effect on the amount of sunshine we receive, so winter lighting requirement tends to be the starting point for designing a system.
Conclusion
Solar lighting is a practical solution to the lighting requirements of many people who have buildings that cannot be served by mains power or where the provision of mains power is prohibitively expensive. DIY kits are available that are relatively cheap and are simple to install or, for more complex situations, bespoke systems can be designed and installed.
The solar energy used does not contribute to climate change, produces no pollution, and is completely silent. Solar panels have no moving parts, so they are reliable and virtually maintenance free. And to top it all, there are no running costs, so once installed the electricity doesn’t cost you a penny.
IC endorses Chris Tyrrell who writes for Ecofreak, specialists in solar panels and other solar technologies. Visit the website for more details.