Does An Off Grid Solar System Make Sense For You?

If you are thinking of adding solar panels and solar batteries to your home, then at some point you’ll probably ask yourself this question:

“Hmmm… Why do I need a connection to the electricity grid at all?”

Good question.

In theory, you can go 100% off the grid. You’ll need to buy more solar panels and lots more batteries than you would for a grid-connected solar and battery system. You’ll also need a petrol or diesel backup generator as a fall-back.

This is great in theory… however there are 3 big problems with taking the off-grid route:

1) Your system will be 2 to 4 times more expensive because you need to buy:

a. Much more battery-storage than if you were connected to the grid.

b. A fossil-fuelled generator for backup.

c. An expensive off-grid hybrid inverter to control your generator and batteries.

d. Lots of time from an off-grid expert to design the system so you won’t spend too much on batteries but you also won’t run out of solar electricity too often and burn lots of fuel.

2) Every so often, you will run out of solar electricity and will need to fire up that generator and keep it topped up with fuel.

3) An off-grid system is not a case of install-and-forget. They need regular checks compared to an on-grid solar system because you lose all your electricity supply if the system fails.

So, having said that – why would anyone be crazy enough to plump for an off-grid system?

Here are four reasons you might choose to go off-grid:

1) There is no electricity grid where you live. 

2) The nearest grid connection is a long way from your home, and your local electricity network wants to charge you an arm and a leg to connect you. In this case, it may be cheaper to go off-grid. However, be aware that a decent-sized off-grid system will start at approximately $40,000.

3) You are connected to the grid, but you suffer frequent blackouts that cause you grief. If this is you – I would encourage you to look into ‘grid-connected solar and battery system with backup’ as a much cheaper alternative than going fully off-grid.

4) You hate electricity bills. No grid = no electricity bills. But unfortunately you will have other bills. Your generator will have a fuel and maintenance bill. The rest of your off grid system will need maintenance and checks, and inverters and batteries will wear out. And remember – if you have a grid connected solar and battery system it is possible to have negative bills thanks to receiving a feed-in tariff for solar electricity you send into the grid.

5) You hate paying a grid connection fee and the only way to avoid it is to disconnect from the grid. This sounds rational on the surface. But that around $1 per day fee to connect to the grid is almost certainly cheaper than owning, fuelling and maintaining a backup generator.  It’s also less than the daily feed-in tariff received by most decent sized solar systems connected to the grid. 

6) You’re crazy. Your house is already connected to the grid, but you just like the sound of going off-grid. You think it makes you more “independent” and protects you from the forthcoming apocalypse and big bills. In fact, you’ve already got a big shed to put the batteries in. It’s the same one where you stored all the canned food in readiness for the Y2K bug / end of the world last time round – and you don’t mind spending $40k+ on an off-grid system that would only cost $15k if it was grid-connected. You also ignore the fact that the grid-connected system would probably save you more money (see point #4).

Unless 1) or 2)  above applies, it is both economically and environmentally insane to insist on an off-grid solution.

Economically insane because the cost of an off-grid system is far higher than solar + batteries + grid. An off-grid system with a similar level of convenience to a grid-connected home can easily run over $40,000 plus maintenance and fuel.

Environmentally insane because you can’t export surplus solar back into the grid – it all goes to waste.

For that reason, the rest of this guide will assume that you are considering buying a grid-connect system for your home, which may or may not include batteries.