Off Grid Energy Systems
Also known as Remote Area Power Systems (RAPS, or SAPS), Off-Grid energy is what its all about at Saltwater Solar. This is our main area of interest and expertise. We have been helping farmers, tree-changers, remote communities, mountain villages and fringe dwellers meet their energy needs since 2007. Technology has changed a fair bit, but the requirement to match energy consumption with energy production, and the need for reliability and user-friendliness, remain the same. Off-grid system owners are also power-station operators - whether they like it or not - and it is a high priority to make sure they have the knowledge and confidence to play this role. It is not that hard. Saltwater Solar selects components that last for years and are easy to use, and provides appropriate training and ongoing mentoring to keep your power supply operating without hiccups - and without callouts.
Where to start
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Work out how much energy is required by completing a load audit.
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Saltwater Solar can help tweak your planned energy consumption to make good use of available resources
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Where customers are converting from generator-only supply, as part of the design process we will install an energy use data logger to get a clear picture of time-of-use energy needs. This is especially useful in larger systems to accurately match the size of battery banks, seasonal energy use, and acceptable generator run times.
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Agree on a system size and budget.
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After installation, Saltwater Solar provides ongoing technical advice and care.
Terms explained
The difference between Energy (kilowatthours) and Power (kilowatts) is an important distinction to make. A property's Energy consumption - kilowatthours per day (kWh/d) - is the most important number and the starting point for the design process. From this we can determine the amount of energy storage required, and with local historical climate data, the size of the solar array. The number of appliances - pumps and air-conditioners and kettles and computers - and how often they are turned on at the same time, adds up to a property's Power requirements. This determines the size of your inverter, and back-up generator - measured in kilowatts (kW).
Things to consider
We can supply all your energy needs with 100 per cent renewable energy. Obviously, if you use a lot of air-cons you will need a lot of solar panels. The only real limit is how much you are willing to pay.
However, all solar (with battery storage) all of the time is not always the best option. Energy use varies throughout the day, and throughout the year, and so does solar irradiance. If on a rainy day in January we keep using energy the same as on a typical sunny day, the battery state of charge (SOC) will fall. If the rain continues the next day, and so do the loads, those batteries will get lower and lower. We need to use very big batteries to supply our normal loads for a cloudy week. If we do that, throughout the dry season, when solar input is consistently high, these big batteries will hardly get used.
Our aim is to design a balanced system. Loads match resources. And all the equipment selected is employed to the best of its ability, without being overly taxed. For this reason, a diesel backup generator is usually an important component in all remote area power systems. Some years it may only be turned on a handful of times (in many systems it will start automatically). The ratio of energy supplied by renewable power sources versus generator is an important thing to consider. When the balance is right, the majority of energy is supplied by solar, keeping generator runt-times down - and ensuring a big generator is not running to supply a laptop and a single light globe - and allowing the generator to save the day on a rainy week, keeping battery size and costs manageable.