Keeping the Lights On in Storm Season With an Off Grid Solar Power System

Being off grid during storm season has one obvious advantage. When the network goes down and the neighbours are dark for three days, your property carries on. That is not a small thing on country where restoration can take a week.

It also carries an exposure that grid connected properties do not have, because every piece of generation, storage and control equipment on the place belongs to you. CW Rural Power & Electrical installs and services off grid solar across rural New South Wales and Queensland, and storm season tests these systems three separate ways at once.

Three Different Tests

Surge

This is the one that does the most financial damage, and it rarely involves a direct strike.

A lightning strike a kilometre away induces a voltage surge in cabling, and on a rural property there is a great deal of cabling: between buildings, out to sheds, down to pumps. That surge travels in and finds the most sensitive component on the circuit, which is invariably the most expensive one. Inverters, charge controllers and pump electronics.

Protection on both AC and DC sides diverts most of it. It is inexpensive relative to what it protects, and it is the single most worthwhile thing on this list.

Days Without Sun

A multi day storm system is exactly the scenario the autonomy target exists for. The array produces very little under heavy cloud, and the property runs on the battery bank with the generator covering the gap.

This is where the design either holds or does not. If the system runs flat before the weather clears, the constraint is storage capacity or a generator that is not starting when it should.

Physical Damage

Wind loading on a ground mounted array is considerable, and a clamp that has worked loose over two years becomes a missing panel. Hail, flying debris, falling limbs and water getting into places that steady rain never reaches all belong to this category.

Before the Season

Worth doing once, properly, before the weather turns:

• Surge protection present and intact. Devices that have already absorbed a hit need replacing, and most have a visual status indicator.
• Earthing tested. Protection cannot clear a fault through a degraded earth, and dry ground changes earth resistance from what it was at commissioning.
• Array mounting checked. Frames, clamps and fixings, looking for anything loose.
• Vegetation cleared. Anything that could come down on the array, the plant room or a cable run.
• Generator proven. Serviced on hours, fuel confirmed, and auto start and changeover actually tested rather than assumed.

Our maintenance guide covers the wider routine, and off grid power systems covers how the pieces fit together.

When a Front Is Coming

Two practical things. Enter the event with the bank topped up rather than part charged, and defer the heavy discretionary loads until it has passed.

What not to do is shut the whole system down. A correctly protected system is better left running, and you want lighting and water during the event rather than after it. Unplugging sensitive appliances is sensible; switching off the system that keeps the pump going is not.

Afterwards

Before re-energising anything, look. Damaged cable, displaced panels, water where it should not be, any smell of burning around the switchboard or plant.

Keep well clear of fallen lines and anything touching them, and treat every one as live. If anything looks wrong, call rather than switching it back on to find out. Our guides to electrical breakdown in storms and emergency callouts cover what happens next.

Why People Choose Us

• Licensed in both states - NSW 163931C and QLD 1512016.
• CEC Solar Accredited - Accreditation S2931181.
• Surge protection specified as standard, on AC and DC.
• We respond to remote breakdowns, which is the point of all the preparation above.
• Allianz public liability insurance - Fully insured for work on working properties.

Get in Touch

For a pre season inspection, or after an event has already caused damage, call 0483 347 898 or send the details through the site.

Frequently Asked Questions

Does being off grid protect me from storm damage?

It protects you from network outages, which is a genuine advantage when the lines are down for days. It does not protect the equipment. An off grid property has long cable runs between buildings, an array in the open and expensive electronics, so induced surge and physical damage are if anything a larger exposure.

How does lightning damage a system it did not strike?

A strike some distance away induces a voltage surge in nearby cabling, and that surge travels in and finds the most sensitive component on the circuit. On an off grid property that is the inverter, the charge controllers or pump electronics. Most of the lightning damage we repair came from nearby strikes, not direct hits.

How many days without sun should the system cover?

That is the autonomy target, agreed at design. A multi day storm system is exactly the case it exists for. If your system runs out before the weather clears, the constraint is either storage capacity or a backup generator that is not starting when it should.

Should I shut the system down before a severe storm?

Generally no. A correctly protected system is better left operating, and you want power during and after the event. Unplugging sensitive appliances is worthwhile, but shutting down the whole system is rarely the right call and leaves you without lighting and water when you most want them.

What should I check after a storm has passed?

Before re-energising anything, look for damaged cable, displaced panels, water where it should not be, and any smell of burning around the switchboard or plant. Keep well clear of fallen lines and anything in contact with them, and call a licensed electrician rather than switching things back on to see what happens.