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”

Bergstrom’s Orange, Daintree ulcers and rainforest

Bergstrom’s Orange

Carolyn Little, 2015

A book described on its back cover as a “contemporary thriller [which] explores the growing interest in biodiscovery and the modern crime of biopiracy, against the back-drop of the beauty and challenges of the Daintree World Heritage site … and [the] popular resort world of Port Douglas” recently leapt from the shelf of my local library into my hand. It lived up to its promise, too, being both entertaining and informative.

The (perfectly valid) scientific background to the story is a search in the Daintree rainforest for a botanical cure for the affliction known locally as the Daintree ulcer or Mossman ulcer. It is a nasty flesh-eating ulcer with no known prevention or cure, caused by a bug (Mycobacterium ulcerans) related to those which cause leprosy and tuberculosis. Continue reading “Bergstrom’s Orange, Daintree ulcers and rainforest”

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”

Energy-saving gadgets

While I was putting together my suggestions on Negotiating Christmas three weeks ago I came across a tech website advertising its “Top Five Energy Saving Gift Ideas Under $50” and an “Energy-efficient slow cooker.”

I didn’t include either of them on my pre-Christmas post (and I’m still not going to give them free publicity by linking to them here) because I found them somewhat problematic, but they are worth examining.

Energy-saving gadgets

Osram DOT-it Battery Operated LED Light
Know someone who is always cursing when they can’t find something in a dark cupboard or cabinet? This low-cost battery powered LED light could be the answer.

It’s a permanently installed strip light, so it’s ‘new’ only because the low power demands of LEDs will let batteries last long enough to be a sensible option. Continue reading “Energy-saving gadgets”