On the surface, this looks promising. OTOH, often when you look below the surface, things aren’t what they are advertised to be. A good example is Elon Musk’s solar battery boondoggle in Australia. Large mega-batteries are difficult to implement, and very expensive to build and maintain, they also require special hookups to the grid and a fair amount of landscape. They are also a single point of failure that could take down the entire grid if it fails to switch on when needed.
However, a distributed solar battery approach right at the solar cells might be far better strategy. From the University of Texas at Austin:
Solar Energy Storage Problem May be Solved in New Single-System Technology
Generating power from the sun isn’t the problem. The technology has been there for decades. Storing that power efficiently, however, has been a challenge. Until now.
AUSTIN, Texas — Generating power from the sun isn’t the problem. The technology has been there for decades. Storing that power efficiently, however, has been a challenge.
That’s why the Department of Energy has awarded $3 million to engineering researchers at The University of Texas at Austin to overcome the Achilles’ heel of the solar power story since Day One: how to store its energy.
To date, most major solar energy systems are bulky and expensive, with inefficient storage capacity. Energy coming from existing solar power systems must be housed in storage systems outside of the generators that create the power. In other words, two separate systems are required to ensure successful operation.
But experts from UT’s Cockrell School of Engineering have developed a way to integrate solar power generation and storage into one single system, effectively reducing the cost by 50 percent. The UT project will develop the next generation of utility-scale photovoltaic inverters, also referred to as modular, multifunction, multiport and medium-voltage utility-scale silicon carbide solar inverters.
Collectively, the combined technologies are known as an M4 Inverter – their main function being the conversion of the direct current output of solar panels to medium-voltage alternating current, which eliminates the need for a bulky and expensive low-frequency transformer.
Electrical and computer engineering professor Alex Huang, who directs the Semiconductor Power Electronics Center in the Cockrell School and works with the UT Center for Electromechanics, is the lead principal investigator for this DOE-funded project. He believes the M4 Inverter will create efficiencies in a variety of ways.
“Our solution to solar energy storage not only reduces capital costs, but it also reduces the operation cost through its multifunctional capabilities,” Huang said. “These functionalities will ensure the power grids of tomorrow can host a higher percentage of solar energy. By greatly reducing the impact of the intermittence of solar energy on the grid and providing grid-governing support, the M4 Inverter provides the same resilience as any fossil-fuel-powered grid.”
One such additional functionality is the ability to provide fast frequency control, which would prevent a solar-powered grid from experiencing blackouts on days when large cloud cover might obstruct solar farming.
To achieve the level of efficiency needed to convert the solar energy to the power grid, new silicon carbide power electronics switches will be used in the M4 Inverter. The need for a bulky 60-hertz transformer is also eliminated in the M4 Inverter to further increase the efficiency and to reduce the capital and installation cost. Construction of the system will be based on the modular building block concept that further reduces manufacturing costs and provides reliable operation through a power backup. The team will partner with the Electric Reliability Council of Texas, Toshiba International, Wolfspeed and Opal-RT, as well as Argonne National Lab.
The DOE awarded $20 million in funding for nine projects to advance early-stage solar power electronics technologies. The projects chosen were deemed critical to addressing solar photovoltaic reliability challenges, lowering the cost of installing and maintaining a photovoltaic solar energy system and achieving the DOE’s goal to cut in half the cost of electricity for a solar system by 2030.
###
h/t to WUWT regular, Roger Sowell
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Does anyone have a realistic estimation of the life of a solar panel.
Current warranties are in the range of 20 years.
… and … a chart illustrating the degradation of wattage with age. The rate of degradation. Life-cycle cost of replacement is an essential economic variable (well, for all us poor non-elite, working class anyway).
I am still using ARCO solar panels manufactured in 1979. Obviously, not Chinese! I guess that fact dates me. Oops!
It seems possible the Aussie battery is actually doing pretty well?
https://247wallst.com/energy-business/2018/05/13/teslas-giant-australian-battery-is-a-more-massive-success/
https://reneweconomy.com.au/the-stunning-numbers-behind-success-of-tesla-big-battery-63917/
http://www.abc.net.au/news/2018-04-06/tesla-battery-outperforms-coal-and-gas/9625726
https://theconversation.com/a-month-in-teslas-sa-battery-is-surpassing-expectations-89770
https://futurism.com/teslas-australian-battery-shows-can-make-huge-profits/
https://interestingengineering.com/teslas-massive-battery-in-south-australia-is-outperforming-conventional-generators
But it’s always good to know technology keeps improving. Thanks for keeping abreast of it
Bill,
It seems highly probable that you are sucked in by bullsh*t.
Still, I guess that’s what happens when bullsh*t is your prime form of communication.
You must be a big fan of Musk.
This just an ad hominem attack, and constitutes abuse.
Who is being abusive or abused?
However, the laws of thermodynamics will always favor the fewer energy conversions.
The battery is SA does a good job at providing frequency control ancillary services (FCAS), short term load control…seconds to minutes. It cannot and does not provide long term load leveling needed for wind and solar power. It replaces the system inertia that large fossil plants have and wind turbines lack. It does this job very effectively but it cannot do the job the media implies, and maybe thinks it can do.
Exactly Doug. I looked far and wide for a description of what that $100M AUD battery near Jamestown, SA is intended to accomplish. I don’t think there is such a description. But at 100MwH storage/109MW max output, it is far too small to handle a major outage such as failure of the 460Mw Heywood connector to Victoria.
It appears that the only problem(s) it can possibly address are the need for something to buffer wind/solar generation burstiness and/or the fact that neither wind nor solar are “spinning reserve” that adjusts output to match fluctuations in demand. If that’s what it does, it’s a good thing and every grid with a lot of wind/solar generation probably needs one or more of them. (Wind/Solar fans should remember to adjust the cost of grid scale electricity from those sources upward to cover capital ind maintenance costs for the buffer batteries). But it does NOT solve the problem of delivering adequate electricity during periods of low wind and low sunshine.
Yes Bill and Electranet are adding batteries with the help of some more slush funds-
https://www.electranet.com.au/electranet-awards-contract-to-build-yorke-peninsula-battery/
and another $80 mill in frequency condensers to get the unreliables up to scratch-
https://reneweconomy.com.au/cheap-condensers-to-displace-gas-as-renewable-energy-back-up-29544/
and the millions just keep on coming on top of the dearest power prices in the world already but don’t you worry about the power poor
Bill,
Promoting an article that impkies a battery is the same as a generator, which you do, demonstrates a high level of confusion on your part.
Some more interesting battery numbers, out today
https://www.teslarati.com/tesla-jb-straubel-energy-storage-milestone/
And I will reiterate, all this comes at an extra cost to the consumer, making South Australia’s electricity costs, at A$0.47 c/unit, one of the highest in the world. Is this what you call good news?
AEON appears to be solely using their 30MW portion to make money by charging when costs are low and discharging when costs are high. All this does is increase consumer electricity costs, so the poor consumer is being charged for the battery site development, and continues to be charged more for its use. I don’t believe this is progress.
If they are going to put that power onto the grid, they have to convert it to 60Hz at some point.
The article goes on and on about using high frequencies. Does this new battery of theirs store AC power?
If so, they need to apply for next years Nobel in physics.
If they are putting the power from this system onto the grid, of what advantage is converting it to high frequency give them? They have to convert it to DC to put it into the battery, and 60Hz to put it onto the grid.
Most likely the high frequency is for the step up of voltage from low voltage solar cell output to adequate for grid use. These circuits are more efficient and require smaller, less expensive components at high frequency.
You can do that more easily by putting the solar cells in series. I’ve worked with systems that output over 1000VDC.
If memory serves me, the energy loss from conversion is significant.
Energy conversion loss >30%
http://www.solardesign.com/solar-panels.html
there is no battery … you can’t store AC electricity …
50Hz in Australia
The article discusses an M4 inverter. I am not sure of the details, but it is a solid state transistor based inverter.
None of us can be sure of the details because none are provided. Did I miss a link to their prospectus or grant application or whatever?
Science by press release. As usual, written by a journalist without a clue on anything about science or engineering.
The typical result, as usual, garbled nonsence.
They start out explaining that storage is the weak point of photovoltaic, OK so far.
Then they claim the problem will be solved with a new inverter.
But inverters do not store anything. They just convert DC to AC.
If this PR really is a fair representation of the investigator’s position, then it seems they will say anything at all in pursuit of federal grant money.
I was also trying to figure out what they were claiming. “Solar Energy Storage Problem May be Solved in New Single-System Technology.” It’s hand waving that could have been written concisely as:
Smaller lower cost inverters, one for every solar cell could obviate the need for larger inverters. Done.
No need to talk about storage since I don’t get how this addresses the storage issue.
What I always want to know when talking about small inverters is what the voltage waveform looks like. Usually small, light, cost-effective comes with the cost of a very square-ish waveform, often not even usable by most electronic equipment.
I don’t think that’s true these days Jeff. Most modern inverters generate a high frequency square wave, pulse width modulated and filtered to produce an accurate 50/60 Hz waveform. I include cheap Chinese generators in this description.
Err “The UT project will develop the next generation of utility-scale photovoltaic inverters, also referred to as modular, multifunction, multiport and medium-voltage utility-scale silicon carbide solar inverters.” sounds like nothing more than a solar panel with a switching power supply. Don’t see how those can store a joule.
This seems to be a mish mash of poorly communicated ideas. It starts out talking about storage , but quickly switches to frequency control. Then there is “the M4 Inverter provides the same resilience as any fossil-fuel-powered grid.” and nowhere decribes how or why this would be providing me power at 4AM in the dead of winter, absent fossil or nuclear supply.
Yeah. Just what are they using to store the electricity? Better inverters do not deal with that minor little problem. /sarc
Actually, the /sarc tag is entirely unnecessary. This is a completely factual non-ironic statement.
This is good (though obvious) but where is the storage in this scheme? The major problem with wind and solar generation is their inability to provide electricity at all times. And because of poor storage options – Li-O batteries have only 1/8th the storage capacity of petrol per kg – won’t you still need base loading capacity that can satisfy the demand during the night and when the wind isn’t blowing since you can’t store enough electricity to satisfy demand? Won’t this result in expensive duplication of generating capacity? Will costs double? Is nuclear generation the only practical answer?
See my comment below.
???????
Anybody know?
Those plants in the photo with the big flowering spikes.
Are those Aloe Vera? Or perhaps small Century Plants?
I’m pretty sure it’s one of these, or a derivative. They are a bit of a pest in Australia, but common enough. https://keyserver.lucidcentral.org/weeds/data/media/Html/furcraea_foetida.htm
Looks like one of the Agaves that have unbranched inflorescences, possibly a native to the area like Agave lechuguillia. So yes, probably a Century Plant aka Shin-sticker, but just a guess.
The do not know that even shadow from an Agave stalk on one piece of the module will reduce power for the complete interconnected line of cells.
This are the triffids….. And God bless you if you are blind …….
The idea is nice … integrate an inexpensive, efficient, reliable, compact, environmentally non-toxic battery into the same panel-and-frame system that presently serves to empower municipal scale PV energy plants. Good idea, at many levels.
• Decentralizes storage
• Scales with plant capacity
• Satisfies the “n–1 / n” problem¹
• Rests on afforability, durability, efficiency
¹ the “n–1 / n” problem is “how well does a ‘solution’ based on repetitions of some unit function handle the elision of one unit?”. If the battery-and-photocell units are truely independent of each other nominally, then (assuming the designers didn’t blow a gasket and forget to put it in) the “bypass self on self-detction of failure” mechanism does a lot to keep the whole system functional.
The real problem tho — whether at the scale of one’s rooftop, or the scale of a municipal multi-hectare installation — has always been the same.
Namely how to hook up the panels, and then arrays-of-panels into a reliable substrate for power generation?
_______
Give it a whirl: (first the “easy case” of a well heeled suburbanite’s solar rooftop)
You’ve infused yourself in the mystic charts, the counterintuitive recommendations for system sizing, and the prevailing wholesale prices for both high-efficiency and high-reliability / weather stable ÷ 25+ year cells. You want to hook ’em all up in a way that tolerates the failure of part of a panel, a whole panel, and because there are quite a few panels, hopefully a whole section of panels if they are attacked by vandal ravens and bad acting monkeys.
You have 96 panels. Each generating a peak of 275 watts – with direct-overhead sunlight at your latitude. The roof just so happens to be at almost the exact right angle to accomplish this without fancy panel frames. Each panel generates over 36 volts at 7.5 amps at that point. Ideally (subject for another discussion), you’d like the output DC power of the whole array to be more or less the peak voltage needed by the DC-to-AC power converter. It makes them hyper-efficient that way. Your house is 240 V, split phase.
Using PEAK = √(2) • RMS voltage, you get 1.414 × 240 → 339 V. That — or a bit below that — would be the optimal battery stack voltage level. So how to arrange the panels? There are 96 of them. Well, pretty easily! 336 V ÷ 36 V = 9.33 … but since you can’t have “⅓ of a panel”, taking 9 panels at a go is just fine. Taking 96 total panels ÷ 9 = almost 11 rows of them. Just a few short! Its ok.
Each ‘row of 9’ panels will be hooked like elephants in a chain: series connected, so that the total output of a row is 324 or more nominal full output volts. At 7.5 amps (since in series, volts add, but amps stay mostly constant). Likewise, if the situation were Tinkertoy simple, you would then hook all 11 chains of 9 panels each row to a supergrid outputting 324 volts, and 11 × 7.5 = 82 amps or therabouts. Right?
Well no… not in practice. In practice big things (trees, rooflines, stuff in your neighbors’ yards) can shadow parts of your massive array. Moving shadows, predictable as “the wind”, covering parts of the system up. The problem there is that when a panel (minimally) is partially shadowed, either (or both) its voltage or its current output will dip. While that doesn’t sound like much of a problem, it turns out to be critical: any underperforming panel acts … instead of as a generator … at worst like a big power consumer, chewing up power for the row its in.
And if the panels are hooked in rows, and the rows are hooked in parallel … and there are underperforming panels, well, the whole system can become hopelessly vexed by the low performers.
_______
Thing is, this is just the tip of the iceberg. Ideally — if you’ve not been exposed to a bunch of product advertising and propaganda — you would like a panel to be “load and generation transparent”. Way more like the tinker toys. Hook ’em in series to rows … and get 324 volts out, and hook rows into parallel ladder-steps, without dead panels, shadowed panels, out-of-spec neighbor panels and sub-performing chains … taking down the system (or ideally, not losing their sub-par generating output either!).
So the industry has come up with a lot of little dohickeys that address this. They’re small, pretty darn efficient, and at least a few of them are “plug and play”, nearly (ideally) to be forgotten and just keep on working right. Sometimes they’re called buck-inverters, or impedance matchers. Sometimes other words are used. The idea tho’ is that each full panel is hooked to one, and ‘it’ takes the panel’s output, and matches the expected voltage and allows pass-thru current that keeps the whole leg working at whatever top efficiency is even possible for the chain. Likewise, when hooking the 9-panel chains to each other in parallel, yet another kind of inverter is used to match the varying output of each leg, to produce a harmonious whole-system output.
_______
These things work! Ultimately, even non-geeks can be relatively assured that every kilowatt-hour of juice created “on top” by the panels is being absorbed and used by both the captive house-and-property uses, and all excess either diverted to a battery capture system, or “just the grid” for sale.
But how does the Municipal scale system work? The same way? It is MUCH bigger, with many more layers of small-scale fault tolerance, chain fault-tolerance, parallel-grid balancing tolerance and sudden-patch loss (overhead clouds passing by).
Will this battery system — integrated to the cells at a one-per-panel basis — be able to handle this level of geometric fault tolerance?
I think that THAT is the question.
Not just a rosey pair of glasses.
GoatGuy
no “storage” in their design …
The real issue is “peak” occurs for about an hour or so around solar noon and builds to it or declines from it during the day. Throw in the fact the Sun varies ~46 deg in angle from summer to winter and back and doesn’t shine at all 12hrs on average, well …
Then inside your house someone or something is running 24×7. The two just don’t match up.
GoatGuy, thanks for the lucid explanation. It sounds like the only innovation here is the use of silicon carbide inverters (smaller, cheaper, running at higher temperature?) and a “multi-port” design. Kind of a ho-hum given the huge structural problems you outline.
You beat me to it. This is even worse than usual. It makes no sense whatsoever. It’s like the postmodernism generator applied to engineering.
???? Not even wrong.
My big laugh of the day!!!!
“Not even wrong”, Perfect.
That bit you blockquoted is what convinced me that I was reading chain-linked buzzwords.
Here are a few more:
“also referred to as modular, multifunction, multiport and medium-voltage utility-scale”
I see those, and keep yelling BINGO! Cheapskates never pony up my prize, though.
OT – NOW my reply has the account info filled in (although not hidden, at least to me). I don’t know whether Anthony poked something on the widget, or it was simply a propagation delay issue. Anyway, seems to be fixed.
They talk about direct-to-alternating current conversion via new silicon carbide ‘power switching’ inverters….. but there is nothing in this article about ‘new batteries’ or energy storage…. WUWT?
See my comment below.
I don’t know if this post is a result of an email I sent recently to Anthony, perhaps not.
To clear up some confusion regarding storage in the comments above, here is the DOE’s statement about the technology: https://www.energy.gov/eere/solar/advanced-power-electronics-design-solar-applications-power-electronics
“UNIVERSITY OF TEXAS AT AUSTIN
Project Name: Modular, Multifunction, Multiport, and Medium-Voltage Utility Scale Silicon Carbide PV Inverter
Location: Austin, TX
DOE Award Amount: $2,999,400
Awardee Cost Share: $840,452
Principal Investigator: Alex Q. Huang
Project Summary: This project is developing the next-generation utility-scale photovoltaic (PV) inverter referred to as a modular, multi-function, multiport, and medium-voltage utility-scale silicon carbide solar inverter. Called the M4 Inverter, it directly converts the direct current output of solar panels to medium-voltage alternating current, eliminating the bulky and costly low-frequency transformer. The inverter also has a direct current port to interface with an additional energy storage device. The device has multiple functionalities and can be used for reactive power support, fast frequency regulation, and peak power reduction, and enables synthetic inertia to be integrated into the inverter for grid support. Taken together, these advances will enable the inverter to drastically reduce the levelized cost of energy.”
Extracting the pertinent part: The inverter also has a direct current port to interface with an additional energy storage device.
Hope this helps.
Thanks Roger. This excerpt is referring to that energy storage device:
“…and enables synthetic inertia to be integrated into the inverter for grid support.”
Much better. Although with all of that functionality that it supposedly delivers, I’d be tempted to call up Rube Goldberg for his input…
I suppose another Carrington event or a neutron bomb air burst would destroy the entire grids generation capacity and prevent it from ever being restarted? CO2 footprint reduced in a flash.
I fail to see how the stated ultra fast frequency control ‘feature’ makes up for lack of power made when/if dark clouds come along. Pretty hard to come up with energy when there is none.
did the 4min edit feature go away?
Project Summary: This project is developing the next-generation utility-scale photovoltaic (PV) inverter referred to as a modular, multi-function, multiport, and medium-voltage utility-scale silicon carbide solar inverter. Called the M4 Inverter, it directly converts the direct current output of solar panels to medium-voltage alternating current, eliminating the bulky and costly low-frequency transformer. The inverter also has a direct current port to interface with an additional energy storage device. The device has multiple functionalities and can be used for reactive power support, fast frequency regulation, and peak power reduction, and enables synthetic inertia to be integrated into the inverter for grid support. Taken together, these advances will enable the inverter to drastically reduce the levelized cost of energy.”
Extracting the pertinent part: The inverter also has a direct current port to interface with an additional energy storage device.
Hope this helps.
It doesn’t. Medium-voltage is 1 kV to 35 kV. Medium-voltage is the lowest voltage before it is
stepped down to the end user. The upper range of medium voltage is primarily used in rural areas where distribution lines are long. Transmission line voltage are typically 135 kV to 765 kV. They are still going to need a transformer to step the voltage up from medium to high. So instead of having a transformer that goes from low to high they will have a transformer that goes from medium to high.
…unless you work in Facilities. Your statement is true if you work in Transmission. If you work in Facilities low voltage is 0-50 volts (the controls and communications) medium voltage is 50-500 (the power to everything inside the facility) and high voltage is everything >500 volts (from the Facilities perspective, the voltage that must be transformed in order to be useable, thus all transmission voltages). So the press release makes sense if you replace “…medium voltage…” with words like “…the voltage the equipment uses…”. See, it’s only a matter of your frame of reference!
The article talks about storage of power, but does not identify how the electricity is stored. If it’s the usual lithium battery, then nothing has changed and no extra reliability is gained. Just distribution of costs and an increase in battery replacements.
Project Summary: This project is developing the next-generation utility-scale photovoltaic (PV) inverter referred to as a modular, multi-function, multiport, and medium-voltage utility-scale silicon carbide solar inverter. Called the M4 Inverter, it directly converts the direct current output of solar panels to medium-voltage alternating current, eliminating the bulky and costly low-frequency transformer. The inverter also has a direct current port to interface with an additional energy storage device. The device has multiple functionalities and can be used for reactive power support, fast frequency regulation, and peak power reduction, and enables synthetic inertia to be integrated into the inverter for grid support. Taken together, these advances will enable the inverter to drastically reduce the levelized cost of energy.”
Extracting the pertinent part: The inverter also has a direct current port to interface with an additional energy storage device.
Hope this helps.
A inverter using wide bandgap technology can operate with less internal resistance making them able to handle higher switching currents more efficiently. Boosting the output voltage means less loss due to resistance of connections. Having an inverter that could boost the voltage of each solar panel to a kilovolt or more would allow connections between cells to be made with smaller gauge wire. Combining the power of multiple solar panels could be done by using a simple diode bridge rectifier at the output of each inverter making it pulsed DC. All pulsed DC lines could be hooked together without expensive phase conversion. That 1kvolt line could then feed into one larger inverter at the location 240v split phase is needed. The ability to have highly efficient inverters capable of dealing with high voltage and current makes electricity transmission much more efficient.
The reason AC was chosen over DC was for its ability to use transformers to efficiently boost the voltage for long distance transmission and then reduce the voltage at its load destination using other transformers. This was Tesla’s legacy.
Some people think that AC is better at long distance transmission of power but that is not true. It is the voltage, the higher the better, that makes long distance transmission of electrical power more efficient.
you still can’t produce more watts than the panels … and no storage
Project Summary: This project is developing the next-generation utility-scale photovoltaic (PV) inverter referred to as a modular, multi-function, multiport, and medium-voltage utility-scale silicon carbide solar inverter. Called the M4 Inverter, it directly converts the direct current output of solar panels to medium-voltage alternating current, eliminating the bulky and costly low-frequency transformer. The inverter also has a direct current port to interface with an additional energy storage device. The device has multiple functionalities and can be used for reactive power support, fast frequency regulation, and peak power reduction, and enables synthetic inertia to be integrated into the inverter for grid support. Taken together, these advances will enable the inverter to drastically reduce the levelized cost of energy.”
Extracting the pertinent part: The inverter also has a direct current port to interface with an additional energy storage device.
Hope this helps.
For extreme distances and undersea cables, the AC losses are too high (seawater works as a capacitor) and they go back again to UHVDC (ultra high voltage DC) lines. That is currently the case in China where they just finished a 1100 kV DC line with a length of over 3,000 km:
http://www.eenewseurope.com/news/record-1100kv-uhvdc-power-link-rolls-out-china-0
The connection was finished a few weeks ago and after tests will be set in use by the end of this year…
This video explains how it works: https://www.youtube.com/watch?v=rLDgQg6bq7o
Trying out a new comment system here….bear with me.
it seems to have eaten all my links, at least viewed in opera
firefox seems not to have the same issue
When I hover over a link in the comment section, then the link text disappears. Apparently the link text becomes white (or a very light color), therefor blending into the background. It is possible to click on the link and follow it.
I use Opera v52 and the same is happening when using Firefox v59 (both on Linux).
Yes, I’m working on a fix for that. Odd that this comment system does that right out of the box.
Thanks Antony
I had some time and tried to figure out where the issue could originate from. It doesn’t seems to be a right out of the box issue to me. I couldn’t find anything in the wpdiscuz css that would cause the hovered links to go white.
The issue seems to come from a custom css page that overrides the theme CSS. It says on line 13: “edited version by Jim”. Not sure who that Jim is, could also be a wordpress or wpdiscuz developer.
On line 224, it defines the default link style over the complete site. It is an orangy-brown color when hovering over a link. Which is what I would expect.
I think the problem originates for the definition of two special styles. On line 256, the link style of the masthead is defined, but it also seems to wrongly redefine a:hover and a:visited as white. The same with the link style of the main menu (line 262) in which a:hover and a:visited are also wrongly redefined as white.
I think the solution is to specify the a:hover and a:visited as specifically belonging to the site-title in the masthead definition (line 256). Change:
.site-title a, a:hover, a:visited {in
.site-title a, .site.title a:hover, .side.title a:visited {And doing the same for the definition of the menu (line 262):
.menu a, a:hover, a:visited {in
.menu a, .menu a:hover, .menu a:visited {That seems to solve it, at least on my test page.
I see I made a syntax mistake. The correct line (256) is:
.site-title a, .site-title a:hover, .side-title a:visited {(there should be a hyphen between site and title, not a point)
I worked industrial service and was an inverter specialist for 8 or 9 years.
The best I can guess from this vague article is to:
1) Use high frequency inverter to convert solar panel output to medium voltage. This uses a much smaller transformer than at 60Hz and therefore costs less and is more efficient.
2) Convert the high frequency medium voltage AC to DC.
3) Use another inverter to convert medium voltage DC to 60Hz AC to send to the power grid. No bulky transformer needed.
Converting AC to DC to AC is commonplace in industrial inverter applications. Inverters are very efficient. In many applications use of inverters can realize significant energy savings over running the application without the inverter set up.
Hope this helps
David: My experience with similar UPS and VFD power electronic technology is that a high frequency carrier in the range of 3 kHz to 12 kHz is manipulated by Pulse Width Modulation into a roughly shaped 60 Hz AC sine wave. Is this the HF the article refers to?
You would be correct Ron.
In power supplies such as in computers switching carrier frequencies can be in the range of 20kHz to 70kHz. The only limit is design requirements and component limitations.
It has been a while since I was an inverter specialist but motor driver inverters at that time had carrier frequencies into the lower 20kHz range. The largest I worked on was just under a megawatt power output. I am still amazed that so much power can be switched on and off so quickly. But then I see a lightning bolt and remember that this is small potatoes compared to what nature does.
I think everyone in the thread is missing the point. First you give them $3million then in a couple of years they’ll tell you it didn’t work. It’s basically just a funding ploy.
In a similar vein, were, or are, other fuel technologies given the nice free investigative handouts to promote their advancement.
I’m confused. The new inverter doesn’t help the storage problem. It doesn’t even help the intermittency problem, only the conversion of DC power to AC. The problem is the drop in power every time a cloud passes in front of the sun, and the boost when the cloud passes again.
Roger Sowell,
Thanks for the clarifications! The inverter system has a DC tap, allowing routing of DC electricity from the solar panels to charge a local battery. It also allows DC-to-AC electricity conversion, either directly from the solar panel or from the battery, to grid supply. And the combined system reduces conversion/transmission losses, when compared to more conventional systems. Got it.
Yes. As someone stated earlier, the posted article is rather poorly written. I found the DOE article that has a better explanation. Thus appears to be distributed storage, and that might be economic with enough small batteries to achieve economies of production.
Time will tell if the sales price at the bus-bar is reduced over today’s technology.
A lot of small, cheap batteries sound great until you look at their life expectancies. Even if you had batteries that could last twenty years, highly doubtful, you would soon be replacing 5% of them a year. That would be a tremendous problem, particularly for rooftop placements. Balancing labor costs with material costs is important.
Has nickel iron Edison battery technology been totally eliminated from large fixed power storage use? People rave about Lithium ion, a solution for mobile use, and lead acid, another mobile solution.
When real estate and weight are not the prime motivations while longevity and smaller pollution footprint are more of a consideration it would seem a 30 to 50 year battery bank would outshine lithium ion or lead acid, regardless of efficiency levels.
Combined with newer wide bandgap semiconductor technology it would seem to be a more long term match of capabilities.
Anthony,
I can see the ‘reply’ buttons attached to each comment, as well as the +/- toggles. I can ‘up vote’ but I cannot ‘reply’. The reply button is not working for me.
I have the same comment as Loren.
The reporting is inaccurate. Their research has nothing to do with storage.
Storage has everything to do with finding the magic battery. There is no battery that is even close to being able to store the amount of energy required for reasonable cost.
Also it is not clear what engineering or commercial advantage there would be to combine solar cell with inverter.