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Why buy electricity when you can make your own?

 

Despite transmission losses and the costs of transmission, domestic mains electricity is considerably cheaper than making your own.  Even with the latest increases due to the carbon tax and MRET it is still quite cheap (written in 2012); at around $0.26 cents per kWh; and less for off-peak.

You can’t easily match this by making your own electricity. 

Transporting energy from large efficient point sources is generally cleaner as well as cheaper than generating electricity locally on a small scale. 

The average Australian household consumes about six megawatt hours (MWh) per year but peak demand can easily exceed ten kilowatts (kW).  For example with:  the clothes washer and dryer; dishwasher; kettle; toaster; oven; cook-top; instantaneous hot water; and a room heater running; plus the more continuous loads like refrigeration, lighting, TVs, computers, pool pumps etc. peak power might be double this number.  If air-conditioning is also running ten kilowatts is totally inadequate.

If you install your own diesel generator capable of supplying peak power of say 10 kW and running continuously 24/7 you will have a big bill for the capital (opportunity cost); maintenance; and depreciation. 

Your fuel alone will cost you more than simply buying the same energy from the grid.  This is why the proponents of electric cars say they are cheaper to run than cars run on petrol.

You might argue, as some do, that solar energy is plentiful and free.  Proponents of this theory could test it by cutting themselves off from the grid and attempting to get their six MWh, plus their morning and evening peak electricity demand of 10kW, from solar panels.  They will need around 30 panels (these would totally cover a typical suburban frontage) and because domestic peak demand is when the sun is not yet up and in the evening, they will need some very big and expensive batteries as well to flatten out day to day peaks and troughs and to provide energy when the sun doesn't shine at all..  

My back of envelope estimate puts the cost of such a system, using prices presently quoted on-line, at well over five times that of buying the same energy from the grid.

Since I first wrote this article batteries have become cheaper and Electricity consumption has dropped as cost increased. By 2016 Li-ion batteries had surpassed lead acid as the cheapest 'whole of life' option.  The cost of batteries to car companies like Tesla dropped below the US$200 per kWh barrier for the first time (< $200,000  per MWh).

Yet based on these lower prices, to continue to behave as if they were still grid connected an average household would still need several hundred thousand dollars worth of batteries.

So off-grid country properties (that do rely on solar power for electricity) have to manage peak demand to well under 10kW; and use alternative energy sources like gas or wood for cooking and heating; in addition to oil and/or petrol for backup generation, farm machinery and some power tools.

But as electricity prices rise gas is beginning to be a local generation option; either as a complement or as an alternative to the grid.  Worldwide, this is increasing the market's demand for gas and thus the export and domestic price.

Nevertheless market equilibrium has resulted in gas co-generation in some large commercial buildings and industry becoming a real option.

Gas powered fuel cells are being trialled as a means of local grid demand/supply matching in several locations.  These units are very energy efficient with much better fuel utilisation than large scale thermal generation. 

When using natural gas the hydrogen goes to making electricity and water at around 60% electrical efficiency; while the carbon component is oxidised producing heat and carbon dioxide.  For every kWh of electricity they generate, around 1.2 kWh (4,000 BTU) of heat is produced.   This needs to do something useful, like heating water; to bring the total efficiency to around 85%

Like solar or wind the capital cost per kWh generated is still considerably higher than conventional coal generated electricity.  But with falling prices, as the technology is refined and as grid electricity prices rise, fuel cells may well become a competitive generation option for local peak smoothing within an integrated local distribution grid.

 

 

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Travel

USA - middle bits

 

 

 

 

 

In September and October 2017 Wendy and I took another trip to the United States where we wanted to see some of the 'middle bits'.  Travel notes from earlier visits to the East coast and West Coast can also be found on this website.

For over six weeks we travelled through a dozen states and stayed for a night or more in 20 different cities, towns or locations. This involved six domestic flights for the longer legs; five car hires and many thousands of miles of driving on America's excellent National Highways and in between on many not so excellent local roads and streets.

We had decided to start in Chicago and 'head on down south' to New Orleans via: Tennessee; Georgia; Louisiana; and South Carolina. From there we would head west to: Texas; New Mexico; Arizona; Utah and Nevada; then to Los Angeles and home.  That's only a dozen states - so there are still lots of 'middle bits' left to be seen.

During the trip, disaster, in the form of three hurricanes and a mass shooting, seemed to precede us by a couple of days.

The United States is a fascinating country that has so much history, culture and language in common with us that it's extremely accessible. So these notes have turned out to be long and could easily have been much longer.

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Fiction, Recollections & News

Lost Magic

 

 

I recently had another look at a short story I'd written a couple of years ago about a man who claimed to be a Time Lord.

I noticed a typo.  Before I knew it I had added a new section and a new character and given him an experience I actually had as a child. 

It happened one sports afternoon - primary school cricket on Thornleigh oval. 

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Opinions and Philosophy

A new political dawn

 

 

The State election on 26th March saw a crushing political defeat for the Australian Labor Party in New South Wales. Both sides of politics are still coming to terms with the magnitude of this change.  On the Labor side internal recriminations seem to have spread beyond NSW.  The Coalition now seem to have an assured eight and probably twelve years, or more, to carry out their agenda.

On April 3, following the advice of the Executive Council, the Lieutenant-Governor of New South Wales, gave effect to an Order to restructure the NSW Public Service. Read more...

It remains to be seen how the restructured agencies will go about the business of rebuilding the State.

 

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