Home solar update after seven years

The rooftop PV system we installed seven years ago has just passed another good round number – 16 000 KWh – having produced 4 000 KWh since my last update, in September 2016.

The daily average in that period is therefore 5.9 KWh/day, a little lower than the average of the first five years.  The drop in output is so small that it’s not really worth worrying about but three explanations come to mind, and all may have contributed to it:

  • We don’t bother cleaning the panels, so full-sun output may have dropped;
  • Our trees have kept on growing, so the panels may be shaded for longer, especially in winter;
  • The period we are considering includes two full Wet seasons but not quite two full Dry seasons (the month-by-month variation is shown here).

How much money are we saving now?

Continue reading “Home solar update after seven years”

Are rainwater tanks useful in Townsville?

Townsville’s ongoing drought has encouraged many of us, especially the keen gardeners, to think seriously about bores, grey water systems and rainwater tanks. This post attempts to arrive at a credible answer to the first question we must ask about tanks: are they even useful?

We have been hearing from two schools of thought on the question for as long as we have been in Townsville, more than 25 years: “Yes, of course!” and “No! The dry season is so long and so dry that no tank will last through it.” One group must be wrong, and the only way to find out is to crunch a few numbers. Continue reading “Are rainwater tanks useful in Townsville?”

Renewable energy update

Green Path tries to keep up with what’s happening in the renewable energy sphere, since it’s so important to our battle against global warming, but so much is happening that we don’t often pause to take stock. Fortunately, the Climate Council has done that for us, producing a report, Fully Charged: Renewables and Storage Powering Australia. 

Its key points are:

  • The cost of lithium-ion batteries has fallen by 80% since 2010. Costs are expected to halve again by 2025 (under 7 years).
  • 6,750 new household batteries were installed in 2016. The market is predicted to have tripled in size in 2017, with over 20,000 new installations.
  • Renewable energy now represents 16% of Australia’s electricity generation.
  • VIC, QLD and the NT are also investing in grid scale battery storage technology.
  • Federal, QLD and TAS governments are also considering developing pumped hydro projects.
  • The Australian electricity grid (NEM) and old fossil fuelled power stations are increasingly vulnerable to worsening extreme weather events, particularly as these power stations age.
  • More than 50% of Australia’s coal fleet will be over 40 years old by 2030.
  • Australia could reach 50% renewables by 2030 without significant new energy storage.

That is (nearly) all very good news, of course, but we need to keep it in perspective: 50% by 2030 is good but, globally, we need to reach zero carbon emissions before 2050 to avoid the worst of climate change, so there is still much more to be done. Continue reading “Renewable energy update”

Renewable energy – all the good news

Most of us know by now that we need to decarbonise the global economy – fast – if we are to have any hope of avoiding catastrophic climate change. Fortunately, the technology to do just that is booming, charging ahead so quickly that merely keeping up with the news is difficult.

Solar and wind power are demonstrating astonishing growth rates, with or without government incentives, now that their costs have dropped below the costs of new coal and (in many cases) gas; some time last year we even began hearing of cases in which it was cheaper to build and run new wind and solar power plants than just to run old coal plants.

Last year, for most of us, was the Year of the Battery. Tesla’s big South Australian battery did something its many little Powerwalls couldn’t, i.e., make battery storage seem like a serious option for the real world rather than just a cool idea. Bloomberg’s 2018 outlook report sees this continuing and allowing electric vehicles to undercut conventional, internal combustion engine cars on both lifetime and upfront cost by the mid-to-late 2020s.

The Green Path facebook page does its best to keep up with all this news but anyone wanting it all, and unfiltered, should bookmark or follow these sites:

RenewEconomy

Launched in 2012, RenewEconomy.com.au is an Australian website focusing on clean energy news Continue reading “Renewable energy – all the good news”

Extreme upcycling

We all know about recycling, re-using stuff which might otherwise have been thrown away (and we all know that there is no “away”, don’t we?) and “upcycling” is the next refinement of the idea. Many of my favourite examples are in the arts and crafts area – Waste to Wonder‘s inner-tube jewellery, for instance – but the National Gallery of Victoria’s Triennial (Dec 2017 – April 2018) had some extreme examples.

upcycling - cabinet
Computer cases become drawers

Dutch design studio Formafantasma exhibited several pieces of furniture created primarily from tech waste, such as the computer-case drawers at left.
Their design and construction was superlative, and I enjoyed their quirky decorative use of small items of tech junk.

The designers’ notes on the project point out that “by 2080 most remaining metals will have been extracted from the ground” and that, therefore, “the era of above-ground mining is upon us.” Continue reading “Extreme upcycling”