Flywheel instead of battery storage?

[Sunking]

I didn't make the rules and don't like all of them, but that's how the game is run.

That is how the real world works, and no ideology will ever change that fact. Free market as long as man walked up right makes the decisions.

[J.P.M.]

Agreed there. Even China is realizing they have to clean things up.

At the end of the day, way down at the bottom of the analysis, like it or not, there is something called the bottom line. That's where decisions are made. Money, power, greed and self interest govern there more than altruism. I wouldn't hold my breath waiting for anyone to clean up anything until it's possible to get more money &/or power by doing so. I didn't make the rules and don't like all of them, but that's how the game is run.

[billvon]

Having said that, we do need to clean things up - but shipping coal for China to burn in a very, very dirty manner while having expensive and uncompetitive electricity at home does not really seem the way to go.

Agreed there. Even China is realizing they have to clean things up.

[russ]

And you get thousands of deaths in the US every year, the loss of watersheds, streams and forests, radioactive waste in the air, ground and water . . . . deciding which source is "superior" has to do with more than just availability.

I think that Sunking means that coal gets the job done - RE such as PV and wind are very minor bit players. All the terrible things blamed on everything from eggs to coal need to be taken with a grain of salt. An extra 5 minutes of search and there is always a counter claim.

Having said that, we do need to clean things up - but shipping coal for China to burn in a very, very dirty manner while having expensive and uncompetitive electricity at home does not really seem the way to go.

[billvon]

Coal is a conventional generation technology and conventional generation is far superior to solar. With Conventional you get round the clock generation everyday of the year with known amounts of capacity.

And you get thousands of deaths in the US every year, the loss of watersheds, streams and forests, radioactive waste in the air, ground and water . . . . deciding which source is "superior" has to do with more than just availability.

[russ]

In our desert areas where all the solar farms are the capacity factor is at least 30%. Wow - SA sun is super sun? For Phoenix, Arizona a 1 kW DC system will give you about 1700 kWh per year. Your sun and insolation are not that much different. I have looked at the SA insolation numbers before and they are good but 7 max as I remember.

In the desert you know how much sun to expect 90% of the time. That comes out in the annual insolation averages

Also most of the power demand is during the daytime when industry demands it and people in offices switch on the AC's. The evening peak is a bit of a problem admittedly. A bit of a problem or a major problem? Industry using interuptible power?

Wind is less predictable than sun I'll admit. But given the first two points I'd say 1000MW of solar makes more than just a 200MW impact. OK - so say 300 mW - not the answer. RE (outside of hydro) is cute but a little short on capability.

Comments in bold in the text

[J.P.M.]

In our desert areas where all the solar farms are the capacity factor is at least 30%. In the desert you know how much sun to expect 90% of the time. Also most of the power demand is during the daytime when industry demands it and people in offices switch on the AC's. The evening peak is a bit of a problem admittedly. Wind is less predictable than sun I'll admit. But given the first two points I'd say 1000MW of solar makes more than just a 200MW impact.

Probably, but without cost efficient storage most/all of the conventional generation means will still be necessary. To a 1st approximation, but only as a start, this limits the solar plant life cycle cost to something like the net present value of the fuel saved, maybe a bit more for the wear/tear etc. saved on the conventional plant(s). Without gov. largesse that's often a stretch.

[Dave3011]

With a capacity factor of between 10% and 35% - maybe averaging 20% or 200 mW.

The corruption is less with RE? I doubt that.

In our desert areas where all the solar farms are the capacity factor is at least 30%. In the desert you know how much sun to expect 90% of the time. Also most of the power demand is during the daytime when industry demands it and people in offices switch on the AC's. The evening peak is a bit of a problem admittedly. Wind is less predictable than sun I'll admit. But given the first two points I'd say 1000MW of solar makes more than just a 200MW impact.

[Ian S]

Could it be a similar story between batteries and other energy storage technologies for example?

Certainly that could be part of it. In the case of energy storage, although flywheels have been around for ages, their limitations for energy storage have been in large part due to materials limitations. Because the energy storage capacity increases with the square of the rotational velocity, you want the highest possible RPMs. Conventional metals are limited due to their comparatively low strength to density ratios - rotors simply won't hold together at the high RPMs needed. Advanced lightweight composites are far better in that regard - and that's the approach usually taken in today's flywheel storage - but that technology hasn't been around nearly as long and they require sophisticated design and fabrication processes to achieve their full potential.

[russ]

several wind farms, PV farms and CSP farms have been completed - some ahead of schedule totalling over 1000MW! These renewable projects take far less time to complete and because they are much smaller are far less likely to be plagued by corruption and industrial action.

With a capacity factor of between 10% and 35% - maybe averaging 20% or 200 mW.

The corruption is less with RE? I doubt that.

[Dave3011]

Coal is a conventional generation technology and conventional generation is far superior to solar. With Conventional you get round the clock generation everyday of the year with known amounts of capacity. Solar you only get a few hours each day, many days nothing, and capacity is unknown from one moment to the next. .

I could debate that one with you.

Our power utility Eskom has been racing against the clock since 2006 to add 40000MW of new capacity to it's aging fleet of power stations to avert a repeat of the power crisis we faced in 2008 when we had to endure daily power cuts lasting for over 4 hours at a time. Of the new capacity the bulk was to come from coal and nuclear with about 10-20% from renewables such as wind and solar.
So far their first power station Medupi (a 4800MW coal fired) is over 3 years behind schedule and has over-run cost by more than 100%. It is riddled with corruption and scandals. It has yet to produce a single megawatt of power.

Quietly in the background several wind farms, PV farms and CSP farms have been completed - some ahead of schedule totalling over 1000MW! These renewable projects take far less time to complete and because they are much smaller are far less likely to be plagued by corruption and industrial action.

Also we are already long past the age of cheap and abundant fossil fuels. Why build a new fossil fuel power plant now, with a lifespan of 50 years when you have no idea what that fuel is going to cost you over the life of the plant?

[Sunking]

It does not necessarily mean coal-fired is a better technology though.

Coal is a conventional generation technology and conventional generation is far superior to solar. With Conventional you get round the clock generation everyday of the year with known amounts of capacity. Solar you only get a few hours each day, many days nothing, and capacity is unknown from one moment to the next. .

[Dave3011]

The proof is in the MARKET. I design Data and Communication Centers professionally for the last 35 years, even was on a nuke sub for 3 years. Not a single commercial flywheel UPS out there. Batteries and generators are far superior, less expensive, more efficient, safer, and more reliable. Until that changes, flywheels are ancient technology like 8-track and cassette tapes.

I believe you are 80% correct, but unfortunately it goes so much further than that. The market is not the be all and end all of it.
Often the very reason why one thing is more widely found on the market than another thing is simply history. When you're a power utility in South Africa for example it's a lot easier to build a coal fired power station than a PV farm not simply because there's lots of coal here (sunshine is also in abundance), but because we've been building coal fired power stations here for 100 years and PV farms for only 10. You want a new coal fired power station? Sure no problem! We've got all the drawings, all the components and all the expertise you need! There are thousands of engineers and technicians with decades of experience all standing in line with their CV's. There are factories and constructions companies all over the place that will happily get things off to a flying start. A new PV farm will not be so easy yet, a lot has to be done from scratch and procurement is a bit harder.

It does not necessarily mean coal-fired is a better technology though.

Could it be a similar story between batteries and other energy storage technologies for example?

[inetdog]

?? Almost every MRI magnet in the country is made of superconducting wire. There are thousands of them, and operate at field strengths up to 7 tesla. Did you mean 'changing magnetic field?'

OK, it is a combination of both.
Some low temperature (less than 5 degrees K) superconductors can tolerate a constant or slowly changing field up to 25T or higher. But for rapidly changing fields, the eddy currents in the structure surrounding the superconductor add so much heat that it becomes too difficult to keep the conductor itself cool enough.
And as you go to higher transition temperatures, more practical for long transmission distances using DC, the critical field goes down drastically.
The ideal material with both high critical field and high transition temperature is still a distant goal.
Back when I was at Stanford the grad students contributed a skit to the annual show in which they applied for a grant to build a room cooled to liquid helium temperatures as an alternate way to produce a room temperature superconductor.

[Sunking]

Hi Dave... The guys at Energy Storage Solutions have been working on the above mentioned issues for years.. Guys at MIT, Texas A&M and the Univ of Toronto were working with us to develop this disruptive flywheel. I think when you drill down, you will see what we have devised. Development of a flywheel takes multi-level brain power..Electric Engineering Mechanical Engineering and many other understandings for it to be successful..Actually, it amazes me! There is nothing better than to prove everybody wrong. If done correctly, flywheels work....Cheers!

The proof is in the MARKET. I design Data and Communication Centers professionally for the last 35 years, even was on a nuke sub for 3 years. Not a single commercial flywheel UPS out there. Batteries and generators are far superior, less expensive, more efficient, safer, and more reliable. Until that changes, flywheels are ancient technology like 8-track and cassette tapes.