Choosing an Off Grid Solar System
Going off grid can be a big undertaking but one that is made easier by choosing the right off grid system. Making sure your system matches your power needs and uses high quality components can mean the difference between a long lasting energy source and a lot of unwanted maintenance. It’s also important to research your installer, finding one who is Clean Energy Council-accredited and experienced with the type of system you’re using.
An off grid solar system is a standalone power system that provides power for homes that are not able to connect to grid power. The system consists of solar panels, a battery bank and solar charge controller to regulate energy for use in household appliances. Many homeowners also use off grid solar systems to offset power bills and reduce their carbon footprint.
Solar panels work by using photovoltaic cells to convert the sun’s energy into a usable form of electricity when run through a solar regulator. As a main component of your off grid solar system, it’s important to research your panels before you buy.
Solar panels are graded on the quality of the cells used in their construction. Look for a high grade cell from a reputable manufacturer and always check the warranty. This should ensure you get maximum efficiency and energy production from your panel. It’s also important to know what type of cells your panel uses. Most modern solar panels use either mono-crystalline, poly-crystalline or amorphous cells in their construction and the type you need depends on the design and location of your system. Mono-crystalline cells work best in direct sunlight while poly-crystalline cells are designed for use in low-light conditions. Amorphous cells are less efficient than their crystalline counterparts and are made from a thin, flexible film.
The battery in your off grid system stores the energy generated by your solar panels, providing power for daily usage as well as ensuring you have enough power during periods of bad weather. The energy generated by solar panels is either run through a solar regulator for immediate use powering appliances or sent to the battery for storage.
Most off grid solar systems use large battery banks made up of tubular gel batteries. The batteries’ high cyclic life makes them ideal for use in off grid systems and the ‘gellified’ electrolyte limits the risk of acid leakage. Look for a high quality tubular gel battery that uses corrosion-resistant plates and has a high service life.
The charge produced by solar panels reaches fluctuating levels that would overcharge and damage batteries if transferred directly to them, making solar regulators crucial for any off grid system. Also known as solar charge controllers, the regulator adjusts the voltage to a level that can safely run appliances and charge batteries.
There are two types of solar regulator, the pulse width modulation (PWM) and the maximum power point tracking (MPPT) regulator. The PWM regulator reduces heating and the risk of sulphation when charging as well as prolonging battery life but is slightly less efficient than its MPPT counterpart. MPPT regulators are a newer design and function in the same way to the PWM model but with an efficiency rate of up to 97%. Instead of clipping voltage as the PWM regulator does, MPPT regulators transform excess voltage to the correct level with an increase in current.
The main consideration when choosing a solar regulator is sizing it to your solar panels and batteries. Find out more about sizing solar regulators.
Correctly sizing and estimating your power needs is the most important part of choosing an off grid system. The number of solar panels and the size of your battery will depend on your location, power usage, the efficiency of your electronic appliances and how many people are living in your home. The best way to estimate the size of your solar system is by arranging for a consultation with a Clean Energy Council-accredited installer, ensuring their designs comply with all relevant Australian standards. Aussie Batteries & Solar can provide a comprehensive analysis and quote for your off grid system as well as access to high quality build components if you choose to go ahead.
For an average family home of four or more people, a five kilowatt solar system is usually recommended. This should provide enough power for fridges and larger electronic appliances such as washing machines but consultation with an accredited off grid installer is the best way to accurately size your solar system.
Remember, when choosing an off grid system, it pays to do your research. Taking the time to find the best quality components and an experienced installer greatly increases the reliability of your solar system, letting you enjoy cheap and environmentally friendly energy for years to come.
Find out more about off grid solar systems at Aussie Batteries & Solar.August 8, 2014 | By Aussie Batteries | Comments