Everything Rural Property Owners Should Know About Off Grid Power Systems

Going off grid is usually a decision made once, under time pressure, with quotes that are hard to compare. This is the plain version of what we tell property owners before they commit, written for someone weighing it up rather than someone already sold on it.

CW Rural Power & Electrical designs and installs off grid power systems across rural New South Wales and Queensland.

Start With the Grid Extension Number

Before anything else, ask the network for a connection quote.

Grid extension is charged largely by distance. Within a short run of an existing line it is often the sensible answer. Past a few hundred metres the figure climbs steeply, and it regularly lands well above the cost of a complete standalone system.

You need both numbers to make a real decision. We would rather tell you the grid is cheaper in your case than sell you a system you did not need.

What Actually Drives the Cost

One decision dominates the quote: how much autonomy you want.

Autonomy is how many low sun days the system carries before the generator has to run. Going from two days to four does not add a little, it roughly doubles the storage, and storage is the largest line on most quotes.

After that, in rough order:

• Peak load and motor starting - the biggest motor on the property sets the inverter, and inverters are not cheap
• Cable runs - distance to sheds, pumps and bores drives conductor size and trenching
• Site access - what can physically be delivered and craned into position
• Plant location - whether there is a suitable cool, ventilated space or one has to be built

What to Ask Before You Sign

Quotes are hard to compare because they often avoid stating the things that matter. Ask every contractor for:

• Array size in kW
• Battery capacity and chemistry, plus the depth of discharge the design assumes
• Inverter continuous rating and surge rating, separately
• The autonomy the design targets, in days
• What commissioning includes, and what documentation you receive
• Electrical licence number for your state and CEC Solar Accreditation number

A quote that will not state those numbers is a price, not a specification. Both licence and accreditation numbers are checkable, and they matter for compliance and for warranty claims later.

What Maintenance Looks Like

Less than most people expect, but not nothing:

• Panel cleaning in dusty country, because a dust film is a continuous loss rather than a seasonal one
• Generator servicing on run hours, not on calendar months
• Termination checks periodically, since vibration and heat loosen connections and a loose connection is a heat source
• Monitoring glanced at occasionally, so a developing fault surfaces early rather than at the worst possible moment

What Lasts How Long

• Panels carry long performance warranties and generally outlast everything else on site
• Inverters and controllers are electronics, and will usually be replaced at least once during the life of the array
• The battery bank is the consumable, and its life depends heavily on cycle depth and temperature

That last point is where most of the long term cost sits. A bank sized tightly and cycled deep every night in a hot shed will not reach its rated life. Our guide to designing for harsh rural conditions covers why, and battery installations covers the storage side.

Plan for What You Will Add

Properties grow. The shed, the second dwelling, the bigger pump. Headroom designed in at the start costs very little. Retrofitting capacity into a system that was sized exactly to the day it was commissioned costs a great deal.

For the generation side specifically, see off grid solar, and our earlier guide to off grid power systems covers how they work and what they cost.

Why People Choose Us

• Licensed in both states - NSW 163931C and QLD 1512016, one contractor either side of the border.
• CEC Solar Accredited - Accreditation S2931181.
• High Voltage Cable Jointer qualified - For larger rural infrastructure.
• Honest comparisons - Including when the grid is the cheaper answer.
• Allianz public liability insurance - Fully insured for work on working properties.

Get in Touch

Call 0483 347 898 with your location, what you need to run, and the network’s connection quote if you have one. We will tell you honestly which way makes sense before anyone talks about equipment.

Frequently Asked Questions

Is off grid cheaper than connecting to the grid?

Past a few hundred metres from the nearest line it frequently is, because grid extension is charged largely by distance while a standalone system is not. Get the network’s connection quote before deciding, since that is the number that makes the comparison real. We are happy to look at both figures with you.

What drives the cost of an off grid power system?

Autonomy more than anything. How many low sun days you want to ride through before the generator starts determines battery capacity, and storage is the single largest line on most quotes. After that it is peak load, motor starting requirements, cable runs and site access.

How much maintenance does an off grid system need?

Less than people expect, but not none. Panels need cleaning in dusty country, the generator needs servicing on hours, terminations should be checked periodically because vibration and heat loosen them, and monitoring should be looked at occasionally so a developing fault surfaces early rather than at the worst moment.

How long does the equipment last?

Panels typically carry long performance warranties and outlast everything else. Inverters and controllers are electronics and will be replaced at least once in the life of the array. The battery bank is the consumable, and how long it lasts depends heavily on how deeply it is cycled and how hot it gets.

What should I ask a contractor before signing?

Ask for the array size, battery capacity and chemistry, inverter continuous and surge ratings, the autonomy the design targets, what commissioning includes, and the electrical licence and CEC accreditation numbers. A quote that will not state those numbers is not a specification, it is a price.

Can an off grid system run a working farm, not just a house?

Yes, provided it is designed for the real load. Irrigation, dairy plant, cool rooms and workshop equipment have starting characteristics that must be accounted for in inverter sizing. This is routine work rather than an exception, but it has to be specified properly from the start.