*take nothing for granted!
Unless otherwise indicated all photos © Richard McKie 2005 - 2015

Who is Online

We have 30 guests and no members online

Translate to another language

 

 

As the energy is essentially free, renewable electricity costs, like those of nuclear electricity, are almost entirely dependent on the up-front construction costs and the method of financing these.  Minimising the initial investment, relative to the expected energy yield, is critical to commercial viability.  But revenue is also dependent on when, and where, the energy can be delivered to meet the demand patterns of energy consumers.

For example, if it requires four times the capital investment in equipment to extract one megawatt hour (1 MWh) of useable electricity from sunlight, as compared to extracting it from wind, engineers need to find ways of quartering the cost of solar capture and conversion equipment; or increasing the energy converted to electricity fourfold; to make solar directly competitive.

Similarly if a technology produces electricity when consumers don’t want it; or produces it so far from the consumer that most of it is lost in transmission; then the revenue available will be proportionately less than a similar investment that better matches demand; or is located close to where it is consumed.

 

In most developed nations, including Australia, electricity is a traded product with the market price fluctuating from hour to hour; day to day; season to season; in five minute intervals, according to supply and demand.

 

Without government intervention in the market, supply and demand determines the return that is available to an investment; while the engineering solution and qualities of the resource determine the energy that a particular investment can theoretically deliver.

 

Before intervention, current renewable technologies, with the exception of hydro- electricity, are substantially less competitive, in terms of return on investment, than fossil fuels or nuclear electricity.  It follows that wherever alternatives are in use there are other factors at play: such as the cost or practicality of a grid connection; or a government intervention in support of renewables.

In Australian electricity markets this intervention takes the form of Renewable Energy Certificates (RECs) described later. Other governments have other instruments such as cap and trade carbon reduction schemes; carbon taxes; energy buy-back schemes; and tax breaks; to achieve similar ends.

 

In Australia grid losses are of particular concern. Australia’s population of just over 21 million is highly concentrated in a few large cities; just eight cities accounting for over 70% of the population. The largest Sydney; Melbourne; Brisbane; Perth and Adelaide account for 63% but are separated by distances of between 670 and 3,600 km; ‘as the crow flies’. This is similar to the continental USA and a substantially greater area than the entire EEC.

Transmitting electricity over such distances results in significant losses.  The market price received by a generator is therefore influenced by transmission costs and the point on the grid into which electricity generated is injected.  A renewable energy project remote from the points of high demand will receive a lower price than one adjacent. 

Very high voltage DC (HVDC) technology can reduce the net grid loss problem over long distances, and this is in use for links to Tasmania and South Australia, but it adds at least two costly voltage translations and the additional capital cost, together with the low capacity factor of wind and solar, precludes its use in most, if not all renewables dedicated situations.

 

Even with the present substantial and probably increasing REC cross-subsidies from electricity consumers, transmission factors limit the economic distance an exploitable wind or solar resource can be from the main electricity grid and electricity consumers.

 

Add comment


Security code
Refresh


    Have you read this???     -  this content changes with each opening of a menu item


Travel

Berlin

 

 

 

I'm a bit daunted writing about Berlin.  

Somehow I'm happy to put down a couple of paragraphs about many other cities and towns I've visited but there are some that seem too complicated for a quick 'off the cuff' summary.  Sydney of course, my present home town, and past home towns like New York and London.  I know just too much about them for a glib first impression.

Although I've never lived there I've visited Berlin on several occasions for periods of up to a couple of weeks.  I also have family there and have been introduced to their circle of friends.

So I decided that I can't really sum Berlin up, any more that I can sum up London or New York, so instead I should pick some aspects of uniqueness to highlight. 

Read more ...

Fiction, Recollections & News

The U-2 Incident

 

 

 

In 1960 the Russians shot down an American U-2 spy plane that was overflying and photographing their military bases.  The U-2 Incident was big news when I was in High School and I remember it quite clearly. 

The Incident forms the background to Bridge of Spies a 2015 movie, directed by Steven Spielberg and starring Tom Hanks and Mark Rylance from a screenplay written by Matt Charman together with Ethan and Joel Coen that centres on these true events. 

Spielberg and the Cohen Brothers.  Who could miss it?

 

 

Read more ...

Opinions and Philosophy

Climate Change - a Myth?

 

 

Recently, an increasing number of friends and acquaintances has told me that Climate Change is a myth.  

Obviously they are talking about 'Anthropogenic Global Warming', not disclaiming actual changes to the climate.  

We don't need climate scientists to tell us that the climate changes. Our own experience is sufficient to be quite sure of that. 

During my lifetime the climate has been anything but constant.  Else what is drought relief about?  And the ski seasons have definitely been variable. 

In the longer term we all have to rely on others. For example on scientists who have themselves examined ice cores or tree rings or sea level records or other physical evidence that can be dated. 

So I'm prepared to believe the scientists who have determined sea levels showing that fourteen or fifteen thousand years ago a hypothetical Australian could walk from Tasmania to New Guinea or an Irishman all the way to Java.

 

Changing sea levels during the past 20,000 years
 Source Wikipedia: Early Human Migration & Sea Level change

 

This rise has not stopped.  During my lifetime the average sea level in Sydney Harbour has risen by nearly a foot, in keeping with long term trends.  More water in the Harbour on average obviously has temperature and therefore microclimate implications.  There are thousands of well documented examples of changes that have climate impacts.

But like the tides there is great variability that masks the underlying trends.   For example 2014 was a record warm year in Sydney.  But in mid 2015 we are going through the longest cold spell in 45 years.  It is snowing in Queensland!

Read more ...

Terms of Use                                           Copyright