AC or DC – Which Is Best?

There are two different ways of configuring an off-grid power system, AC-Coupling and DC-Coupling, and each have unique advantages and work in different ways.

The configuration type that is used will have an impact on the life expectancy, efficiency and flexibility of your off-grid power system system.

AC Coupled configuration

The most recent innovation in stand-alone power is the AC (Alternating Current) coupled system. Energy generators (E.g. Solar array) are coupled into the system via regular 230V AC wiring.

Advantages

• Higher Efficiency as it provides direct power to household during daylight, bypassing the batteries
• Reduced battery cycling
• The excess power charges the batteries via the inverter
• Lower solar array wiring efficiency loss
• Increased off-grid power system performance
• Flexible placement of solar arrays and other equipment
• Battery bank life expectancy increased
• The fuel powered generator is also fully AC coupled. It provides a significant system advantage at times of high system demand or low renewable energy input.

Disadvantages

• The equipment cost is typically a little higher, but easily recoverable in medium to large stand-alone power systems.
• Inverter manufacturers that use the AC coupled configuration (Eg. SMA, Victron Energy) use the frequency shift method of solar output control. In some cases sensitive devices such as some inverter type air conditioners, low quality lights may not operate at certain times of the day. Digital clocks (Eg. oven and microwave clocks) also won’t keep accurate time due to the power frequency variation.

DC coupled configuration

Until recently the traditional method has been to use a DC (Direct Current) connection method in which energy generators are directly coupled into the off-grid power system battery bank via a regulator or charge controller.

Advantages

• Simple and has lower component costs for smaller systems requiring lower power.
• Considered to have some safety advantages.

Disadvantages

• Copper cables are required to carry power and can be very costly for larger systems.
• Cost cutting techniques can result in inferior off-grid power system performance.
• All power is delivered to the home via the main off-grid battery inverter. These inverters have limited capacity so may limit system performance at times as it cant transfer all available solar array power as its available.

Our consultants are off-grid power system experts and have an in-depth understanding of the different currents. We are happy to recommend the most suitable for each situation.

Off-Grid Power System Design

So, you’ve taken the first step in your journey toward off-grid power and decided to call. What now? What happens from here?

Our off-grid expert consultants will chat with you about your current situation and your vision for energy needs moving forward. They will gain basic information and insight, then set up a meeting with an Off-Grid Australia Power System Expert. From here, the expert will assess the nitty gritty of your current household energy usage as well as any expected growth or reduction of energy needs in the future. It sounds complex, but our team know exactly how to gather this information and complete an Energy Load Profile quickly and painlessly. We’ll also assess and determine with you the best location to install your equipment and then recommend ideal stand-alone solar system options and quotes.

Following contract acceptance we provide you with detailed infrastructure guides and plans to clearly communicate where the stand-alone solar system equipment is to be installed, requirements before installation and what Off-Grid Energy and the customer is responsible for.

All off-grid power system components and sizes are chosen for many factors; including capacity, performance and cost. Your Energy Load Profile information, or specific energy demand, forms the basis of all our equipment and system design recommendations.

Energy Load Profile
Completing an accurate energy load profile is an essential part of correctly designing an off-grid stand-alone solar system. The load profile is a list of all your appliances and utilities that require electricity, with an estimate of their usage frequency (e.g. how many days per week, and hours per day). Once we have this information, our system design team can accurately recommend appropriate stand-alone power system design and size for your needs.

Efficient appliance choices and efficient home design are by far the best way of minimising your electricity requirements, system size, and cost – meaning you don’t have to change your lifestyle to live comfortably off-grid.

For a more efficient first phone consultation, complete and send the Energy Load Profile Form below prior to speaking with us. Previous clients have loved us sending tailored information to them before hand and felt better equipped for the conversation. It also gives us some background for discussion.

Find our Energy Load Form here.

Our Considerations

Stand-Alone Solar System Location
Your equipment location is very important when designing an appropriate off-grid power system for your property.

Solar Array
Solar arrays should be located as close as practical to the standalone equipment enclosure. It must be capable of producing enough electricity (kWh) to replace what is used by your property on any given day – especially on days of poor weather.

Off-Grid Batteries
Sizing your off-grid battery bank is incredibly important when designing your system. Understanding when and how much electricity (kWh) is used will determine the battery capacity required.

Inverter/Charger
The inverter/charger needs to be sized to the peak power (kW) requirements of your property. If you boil the kettle, run the air conditioner and do a load of washing simultaneously, the inverter/charger needs to be capable of delivering this power all at once.

Generator
Generator sets require careful thought and planning when it comes to their installation and operation. The generator should be installed as close as is reasonably practical and convenient to the main residence and the other stand-alone power system equipment. We also give careful consideration to the possible noise level and safety requirements for when it’s in use.

Enlighten Us on your Juice Consumption

Green Benefits

An Off-Grid Energy Australia stand-alone power system proudly has the following ‘green’ benefits:

• Power is generated and consumed locally, greatly reducing losses in power transmission.
• Power is mostly generated from a renewable source. (Note: Our GenFree system does not include a fuel generator and uses 100% renewable energy)
• The carbon created during your off-grid power system installation is calculated by us and completely offset through tree plantings.
• Prior to designing your stand-alone power system our consultants will give you advice on reducing your energy usage, using clever house design and appliance choice.

Grid Connection Cost

Determining the ‘On Grid’ cost to connect electricity to your new property or new build is an important first step when deciding whether to live on or off-grid.

Often the power lines will appear quite close to your dream block of land but when you begin to chat with your electricity utility about the cost of getting power connected to a property that isn’t already on mains power, you get a nasty shock.

It is not uncommon for a quote to connect to mains power to be in the tens or even hundreds of thousands of dollars. This can make an off-grid power system a much more affordable option upfront and of course, long term.

Off-Grid Energy Australia can assist you in obtaining an accurate cost of connecting electricity to a new property with the electricity distributor for your area. Just contact our friendly team.