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As demonstrated at Fukushima.Quote:
Originally Posted by Bushmiller
In that case it was a stray tsunami, well an underestimated probability of a tsunami of that magnitude (9 Mw) and a seawall that was built too low for the resulting tsunmai with a wave that was up to 40m above sea level, which knocked out its cooling plant.
That makes renewables seem very cheap!
The proposition of nuclear electricity for Australia is a complete non-starter, and Voldemort knows it. He also knows that they will be condemned to likely 6 or more years of Opposition, which means that he can say or propose what he likes in these early days of Opposition and it'll be forgotten. It seems to be a last gasp at keeping the climate wars going and paying some sort of homage to previous leaders. Somewhere in this thread the lead time for nuclear power has been mentioned, and around 20 years comes to mind – maybe a little less.
Apart from the fact that we just don't have that long to sort out our power woes, renewable power will be ready at proper large scale way before that. That's before we even get to the frightening cost of setting up nuclear power, and that's before we get to the enormous political difficulties of convincing the public that it's a good idea. Then we have to find Federal members who are keen to have a Nuke plant in their electorate.....:no:
Me either. I used to be a complete NIMBY on nuclear power, but now I am also a NIYBE - Not in Your Backyard Either.Quote:
Originally Posted by Bushmiller
A single rocket or smart bomb - all conventional - hitting a reactor could be as effective as a nuclear weapon. But if you closed down the reactor due to imminent threats, then you would still have to store the uranium rods. Guess that rocket hitting the nuclear fuel storage site would be just as effective?
Thanks Woody, quite interesting.
PHOTO VOLTAIC Farms or Rooftop are certainly getting cheaper, but battery storage is still rather expensive, and their are those old fossils like me who like to turn on their lights when it is dark.
GEOTHERMAL. Have a friend who did a PhD on geothermal electricity at MIT in the early 1980's, and then worked as a consulting engineer until he retired before lockdown. It is a fascinating subject:
- The centre of the earth is molten rock - it is hot,
- Drill a hole anywhere and it will eventually get hot, very hot, the heat is near the surface in places like New Zealand and Iceland and much deeper in places like Australia, but it varies,
- Drill a hole into a heat source, pump cold water down and suck hot water or steam out, simple,
- Run the output through a heat pump to concentrate the heat,
- Use it to run a "conventional" power station.
The problems are mainly metalurgical. The solvents coming out of the well, at heat, will usually attack all/most metal fittings and corrode them. And the solvents keep changing; appparently the chemistry is extremely complex and research is ongoing. With shallow wells, the solution to corrosion is simply to monitor and replace the metal work frequently. With deeper wells this is very expensive so they are still researching better metals - but the solvents are not consistent. He still thinks that geothermal will eventually be the major energy source, but not in our lifetime. Forty years ago he thought he would be involved in the transformation.
That graph also shows that of the methods that rose in minimum price to sell, Nuclear was the runaway, at 33% increase. Next closest in rising was GeoThermal at 5% increase.
WPQuote:
Originally Posted by woodPixel
Those are interesting statistics, but I am not sure where they relate to and is it a wholesale price or a retail price? An average for world wide perhaps, but not Australia. For example, the average wholesale price for power stations in 2009 would have been $30 to $40 from memory. Coal would have been generating all the time with the other sources of power only when the price was high or they were absent.
Regards
Paul
GraemeQuote:
Originally Posted by GraemeCook
You are on the money (not an intentional pun) with the cost of storage. I believe we have reached saturation point with solar and wind until we talk of storage (battery, pumped hydro or anything else) in the same breath. I am not sure what is considered a deep well, but those that were bandied around in recent times in Australia were around four kilometers deep. I can imagine that there are technical issues associated with that depth.
As for converting existing coal fired stations as in point No.5, while I would like to believe that is possible, I am a little sceptical. Firstly the geothermal well would have to be located adjacent to the station. Secondly the heat generated may only be sufficient to produce low pressure steam at comparatively low temperature. The HRSG on the back end of a gas turbine utilises this technology. Steam in modern coal fired power stations is at a temperature of around 550°C and a pressure of 15,800KPa in drum boilers and 24,000KPa in supercritical boilers. The reheat steam, which is the exhaust gas from the HP cyclinder used in the IP and LP cylinders after first being returned to the boiler, in both types will be closer to 590°C. Geothermal steam just would not be able to deliver this.
Regards
Paul
I agree Paul, and for me the research $$ need to go into batteries (not that pumped hydro et al are unimportant). Batteries are in everything these days – the ubiquitous 18650 rechargeable cell is in Power Walls, cars, lamps, torches, tools etc etc etc. The more efficient that particular storage is, the better, and the easier it is to swap out a dud cell the better. Don't change the form factor, just improve the storage capacity and/or recharge time, then we can continue to use them in the same appliances.Quote:
Originally Posted by Bushmiller
As a side note, NCArcher has just checked 18 of my 18650 cells from two tool batteries which had refused to recharge (one with 15 cells, the other with 3), and only 3/18 were duds, meaning I have 15 spares to replace other duds as they come up. Makita and DeWalt would, of course, prefer me to just dump the two entire battery packs and unnecessarily buy new ones from them. The problem with that is the replacement cells need to be mini-welded into the "grid" which requires expertise and specialised equipment (both of which he has), when the process really needs to be as easy as it is to change AA batteries in any given appliance. One has to wonder how many millions of still-usable cells have been binned because just one cell stops the battery grid from recharging.
That was the point, I think, Paul. The depth of the hot rocks varied all over the world - from quite shallow on the Ring of Fire to very deep in geologically mature places like Australia, but even there there were variances. eg A "hot rock" zone was found in the vicinity of St Helens, NE Tasmania, at a depth of 800 - 1,000 feet. Those problems existed in wells at any depth, but it was easier to deal with them in the shallower wells. Plus costs, of course.Quote:
Originally Posted by Bushmiller
Sloppy wording by me, Paul. Power station would, of course, be a new one located on top of the geothermal field. Steam created would be used to power an existing type of conventional steam turbine. I am an economist, not an engineer, so on this I am strictly big picture and non-technical. It sounded like an "interesting project in the pipeline", but it has not arrived yet, except for some particularly favourable sites such as NZ and Iceland.Quote:
... As for converting existing coal fired stations as in point No.5, while I would like to believe that is possible, I am a little sceptical. ...
GraemeQuote:
Originally Posted by GraemeCook
The New Zealand sites are perhaps the most commonly known, although I think Italy and at least one other place has had self sustaining sites for some while. One issue is that the heat diminishes after a period of time. However, with geothermal power I am a little out of my depth ( :rolleyes: ) as it is not my area.
I realised after I had posted that you could be referring to new "conventional" power stations to take advantage of geothermal heat. I believe the temperatures are rarely above 180°C so it would certainly be low pressure. The other issue is that I have read the efficiency is low at 10% - 16% so I don't know how that would stack up against other forms of renewable power.
Regards
Paul
My brother-in-law was the consulting geophysicist (geologist-physicist) on the early hot-dry-rocks trials here in SA over twenty years ago. The primary motive behind those trials was the remote location away from any grid source of power.Quote:
Originally Posted by GraemeCook
As I understand it, two adjacent bores were drilled and cold water was pumped down the bores with the intent of the hot rock between the two bores fracturing to allow a flow between them so a circuit could be formed; colder water down one and heated water up the other.
The trials failed for one reason and another, not least a failure to create enough fractures between the base of the two bores to get the necessary water flow, if I remember that correctly. The cost of boring to the required depths is significant and perhaps recouped over time if it was always successful. However, putting aside any ongoing maintenance costs of successful bores, with an unpredictable failure rate at the depths required in our old geological zones this form of geothermal power generation may never be economically viable in those areas.
I expect with the dropping cost of solar, wind and storage (or combinations of those) over the last two decades would make those options far more favourable now for very remote locations.
PS - I enjoyed a dip in the artesian thermal springs at Moree a few years back. Good enough for a warm bathe, but not hot enough keep any lights going...:)
Neil
Thanks for the additional perspective on geothermal. As I said before, it is not my area.
Regards
Paul
Just been trying to think through a risk assessment for storage of electricity from solar and wind sources.
Best available is hydro which can ramp up and ramp down very quickly with variances in the wind and sun light. But this is very limited because you need the right topography for a hydro dam.
Otherwise you essentially have three options:
- Battery storage,
- Pumped hydro, and
- Exotics - hot sand storage, etc.
Battery storage is not yet cost effective, except in off-grid areas, so any analysis might conclude: "Good idea, but not yet - WAIT and monitor battery prices."
Pumped hydro has a very long lead time - 10 years ? from go decision to build dam and commission it. Risk is that within that period battery prices could plummet, either new technology or cheaper manufacturing - and the project could be superceded before it is completed. So any analysis might conclude: "Good idea, but not yet - WAIT and monitor battery prices."
Exotics - nothing is really out of the laboratory yet, but there can always be surprises.
As Malcolm said: "Life was not meant to be easy."
The three best things in life are a beer before and a dip in the hot springs after.:DQuote:
Originally Posted by NeilS