Five billion reasons why independent power makes sense


Often described as modern, sophisticated and of course, sunny; a country with 22 million smiling and suntanned jokers.

What you may not know is that almost half a million Australian’s (1.8% of our population) are not connected to the National grid. A recent study by the Bureau of Resources & Energy Economics has given us new insights into this issue and the findings are eye opening.

The National grid provides centralised energy (mostly from coal-fired generation) to the vast majority of the population through one of the largest and longest electricity networks on earth. However, once you start to move away from the main population centres the cost of getting power to remote sites and maintaining the power lines dramatically escalates. Termites and Cockatoo’s don’t mix so well with wooden power poles and tasty plastic coated cables.

It is for this reason that so many people generate their energy locally; it is often simply the only option.

Historically, you simply bought a diesel generator, chucked it in the paddock and as long as you fed it with fuel it would generate electricity 24 hours a day, 365 days a year. This was fine as long as you could actually get the fuel to site, it didn’t cost too much and you happened to be a diesel mechanic so you could maintain it. Oh, and as long as you didn’t mind the constant noise of a generator.

Today, although technology has improved dramatically we still have an astounding 5GW (or 5 billion watts) of remote generation capacity, supplying these remote Australian homes and towns, and it’s growing.

Increasingly, the supply is from gas (almost 80% in fact) which has become far more accessible with the resources boom, but gas is not getting any cheaper.

Despite being a small proportion of remote generation, diesel use for generation remains massive. In Queensland alone for example, 38 remote diesel generators consume 28,000,000L of fuel each and every year. If we assume similar consumption levels across the remaining installed diesel capacity as an indication, it suggests Australians rely on around 415,000,000 litres of diesel each year for electricity, at a cost of around $560,000,000 each year, after subsidies.

Although scenarios vary, according to one guide at a subsidised cost of around $1.30 per litre for fuel, a diesel generator will produce electricity for a cost of between $0.58c – $0.90c a kWh. Think about that, next time you feel unhappy about our urban prices of around $0.28c kWh.

So, where does solar fit?

I spoke with a number of companies who have been in solar since the late 1990’s; (which means they grew up doing remote generation) to get their thoughts.

The biggest change of course is in the cost of solar panels. The reductions in there cost means that it is now highly affordable and a vastly better economic proposition to put solar in than to run a diesel. But we all know that.

The really interesting part is how inverters and storage technologies have changed.

In simple terms, inverters convert stored solar energy into 240V AC. However, today’s inverters are sophisticated computers that convert, re-charge, monitor, transfer and control energy flows. They are smaller, lighter, cheaper and more robust than the units I used to install 15 years ago too. Communications is a huge feature today that allows users to monitor and control a vast array of scenario’s from a computer or smart phone.

Inverters used to be a real stumbling block and a reliability weak point, but that has all changed.

And of course there is storage. One company told me about their recent decision to switch their main focus to Lithium-Ion batteries and have been astounded at the results.

“I sold Lead Acid batteries for decades. They were cheap and had respectable life if they were looked after, but large banks were enormous and dangerous. LiPo has arrived and is a superbly elegant solution.”

They described how three key things have changed that got the formula right for LiPo batteries. The first was the price. They are still more expensive than lead acid, but because you can cycle them so much more deeply without destroying them, the overall costs are similar.

Their team also spent a lot of time looking for the right chemistry; there are around 30 different Lithium based chemistries in the market and they ultimately settled on Lithium Iron Phosphate (LiFePO4) as offering the best combination of cycle life, safety, price and performance.

The second was the crucial safety and management controls needed. “Lithium batteries behave completely differently to lead acid, and we have dedicated years to designing controls systems that really work and cell management systems that maximise life and ensure they are safe.”

Lead acid batteries are dangerous because they contain corrosive acid and emit explosive gas. Lithium batteries don’t have these issues but can catch fire if you don’t have a really intelligent and robust Battery Management System (BMS). This team developed a BMS in conjunction with their suppliers that have built in redundancy, various protection modes and constant monitoring.

“This is the hardest part of the whole equation and where our experience in remote generation was invaluable. You can get cheap Lithium cells but the BMS has to be of outstanding quality, chemistry matched and reliable. We had to develop this in house to get it right”

Australian innovation isn’t dead after all, and I know there are lots of other great minds out there developing products down under to solve these problems.

The last art of the equation was a simple robust package. One company I spoke to has designed a sleek case and includes the BMS, cable coupling systems, relay drivers, monitoring and fusing.

The combination of low cost solar, intelligent inverters and now, robust and economical Lithium batteries is a revelation to anyone used to truckloads of acid filled batteries and hoping that customers will remember to manage their system properly.

Now, all we need to do is find those 500,000 remote customers…

© 2014 Solar Choice Pty Ltd

Nigel Morris