Off-grid power for sheds, barns and garages
Power is often wanted in sheds and garages, but it can be awkward and expensive to run long cables from the nearest power point. Solar panels, or in some cases small wind turbines, can be the ideal solution. It might be a lone, small solar panel used to power occasional, low-energy lighting, or a bigger installation that gives enough power to drive an inverter to produce mains voltage for power tools and other appliances.For applications such as a garden shed or garage, framed solar modules tend to be the most appropriate power solution. The flexible modules we sell are better suited to expedition use (because they are light), or for use on boats where they can bend to the surface of a roof and have a low profile. Framed modules are generally cheaper for a given power output than flexible ones. They are also more easily mounted unless you have a flat space to glue down the thin, flexible panels. Framed panels tend to be very robust and you can expect a long working life with very little maintenance.
There are, however, two types of framed panel to choose from - crystalline or amorphous. Either will work fine for this application, and to be honest, there is little to choose between them, including price. Amorphous (or 'thin-film') panels are bigger for a given power output than crystalline panels, so if you only have a limited space, go for crystalline panels such as the framed solar panels. However, one advantage of amorphous panels is they are more efficient at low light levels than crystalline panels, which is an important consideration in the depths of a British winter! UniSolar are the biggest manufacturer of amorphous panels.
For best results, you should try to mount the panels facing south, at quite a steep angle - about 60 degrees is best for the UK. Don't worry if your shed has a roof that doesn't face directly south, or has a shallower pitch - you will get slightly less power from the panels, but the difference isn't enormous. One 50-60 Watt panel, attached to a couple of 100Ah lead acid batteries through a Victron or SunSaver controller, should give enough electricity to power lights for a couple of hours per night for most of the year. If possible, use low voltage fluorescent or LED lights - they are more efficient. If you only need lights occasionally, or for short periods, you can get away with smaller panels.
Running power tools from an inverter is also very practical because typically, the tools are only used for a few minutes or so at a time. The amount of energy used from the battery isn't as much as you might expect. However, if you want to run a fridge to keep your beer cold, you might need several panels, and even then, don't expect to be able to run it in winter - fridges are notoriously power hungry!
Wind turbines can also be a useful source of power, especially in winter when there is less solar power available. However, they do require a clear airflow, with few obstructions upwind of the installation in the prevailing wind direction. Unfortunately, for that reason they often perform poorly in urban areas. On the other hand, they can be an ideal solution for remote barns for example, especially when they can be mounted at a high level where the wind is stronger. The Rutland range of small wind turbines are ideal for this type of installation.