The energy crisis is making headlines as I write this, with Queensland and NSW facing possible blackouts. Of course, the powers that be are scrambling to find a solution, but this problem won’t be quick, easy or cheap to solve.
Let me tell you about my own experience with renewables. About eight years ago, we installed a 24-panel solar system, which cost about $6000. The system now tells me it has generated 53,000kWh of power. At an average cost of 25c a unit. That means we have recouped more than $13,000 on our $6000 investment. So far, so great.
Then, 18 months ago, we found ourselves fairly cashed up thanks to some refunded overseas trips that did not occur due to Covid. We decided to spend the money on installing a solar battery. We chose the Tesla Powerwall, which at that stage had the biggest capacity available – 14kWh – and cost $12,000 to install. It’s a great asset to have, because it means that you always have backup capacity available in the event of a power failure. That in itself is quite a significant value – although it’s impossible to quantify.
But there is no way that the mathematics of the investment works. The battery might have a capacity of 14kWh, but because it always keeps 15 per cent in reserve, the effective capacity is only 12kWh, which at the going rate of 25c a unit is worth just $3. If we filled the battery every day for a year, the maximum savings it would give us would be only about $1000. The Tesla battery has a magnificent app that enables me to monitor my system’s energy generation and usage closely. One thing is obvious: on a cloudy day there is not much solar power produced, and on a rainy day almost nil. So even that $1000 saving is by no means guaranteed.
The press has been focusing on the cold winter that is with us, and what a huge use of power heating a house takes. But for Queenslanders, an encouraging fact is that the cheapest heating is reverse cycle air-conditioning, and it is far more efficient at heating a house than at cooling a house.
There is a lot of well-meaning advice telling low-income earners to get solar power and think about a battery. But there is no good news here. My solar people tell me the cheapest battery – which would be just 6kWh – would cost at least $7000 installed. After the 15 per cent reserve for power failures, this gives you just five extra kilowatts, worth just over $1. If you’ve got a dishwasher, a clothes dryer and air-conditioner on, you can easily go through 5kW in an hour. That’s the battery emptied.
Of course, things will change in the future as technology improves – but right now solar batteries are going up in price, not down. Battery cost will not become attractive quickly. To make matters worse we are being urged to buy electric vehicles, but because there have been no coherent national policies to encourage their uptake, their price is exorbitant, and they would be a further drag on our already overstretched electricity supply.
Wishing and hoping won’t fix climate change. The closure of the remaining coal-fired and gas-fired generators will not be determined by billionaires, affluent ideologues, or anyone else. They will shut down when a full suite of cost-competitive, cleaner technology, transmission and storage is available to replace them. NOEL@NOELWHITTAKER.COM.AU