Solar + flywheel + ac genny

I assume there might be some folks in here than know a bit about power generation. I would like to put together a batteryless solar array. Phase one, 6kw worth of panels, which will constantly provide on demand power to the home and grid. Phase two is storage. The only two technologies I can find that I think are really feasible for long term are flywheels and hydrogen. Hydrogen is cool but requires massive outlay of capital, and specialized equipment.

The flywheel however, is about as simple as it gets. The main reason I want to do this with rotary motion is the simplicity of connecting a new source to the input should should you lose your panels... Or maybe you want to supplement with wind... Anyways..

On the motor side.. Basically speaking, your going to spin the flywheel at varying speeds... How do you get the ac generator to put out the 60hz we all know and love (assuming you're driving the flywheel with DC motor) secondly... Once the sun sets and the flywheel is spinning faster than the DC voltage is driving the drive motor... How would you continue to use the power coming from the panels (again without batteries)

Lastly.. On the flywheel. Would using maybe centrifugal weights to maintain constant speed be a good idea?

I want to do a YouTube series building this. I've seen the high speed beacon fly wheels but those are out of reach

Motorsports-X said:

only two technologies I can find that I think are really feasible for long term are flywheels and hydrogen. Hydrogen is cool but requires massive outlay of capital, and specialized equipment.

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So do flywheels if they are to be any use.

Go Ogle them. Kevlar reinforced. Insane RPM. About thirty grand ..and up. Waaay up. get it 'right' they can HELP power a hybrid motorbus.

Unless you have a thousand or so square feet of space spare to use the OLDER Telco/Grid type.
Which resemble Iowa-class battleship prop shafts, ignorant steel being cheaper than Kevlar.

BTW.. with a motor off the grid driving them and generator tapping the power back into the grid, d'you know how long that flywheel is engineered to deliver sag-free power?

Not through the dark of night.

Just long enough for the massive Diesel gen set at one end of each of those shafts it to fire, come up to full-gallop, and carry the load on ignorant hydrocarbons.

Batteries - lead, lead-carbon, etc - remain the least-costly 'small' storage on a dollar per density basis. Pumped water storage prolly the cheapest overall.

Go Ogle "Smith Mountain Lake" and "Lee lake". They do the peaking response so Dominion Power's nukes at Lake Anna can run 24 X 7 at a steady rate.

Bill

This sounds like how to make a million dollars. First start out with 10 million.....

Before being concerned about switching and controlling power from which device, you better determine how much energy to store and for how long to use. The will determine the magnitude of the flywheel.

Tom

TDegenhart said:

This sounds like how to make a million dollars. First start out with 10 million.....

Before being concerned about switching and controlling power from which device, you better determine how much energy to store and for how long to use. The will determine the magnitude of the flywheel.

Tom

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Sure agree the ratio on that one..

A mere six kay effing dubbyah? Solar array, not exactly an 'always on' source, so yah don't GET peak power for but a fraction of the day.

Start with a pair - yes TWO - $100 or less Costco Marine/RV lead-acid units in series for 24 Volts and a Chicom 4 kW inverter 24 VDC to 120 VAC.

Call us when it starts over-filling storage on a 3-day average.

If yer lucky, it can run a fridge-freezer round the clock, a TV, and a toaster-oven or microwave now and then.

Air con is a different animal.

Bill

I Was Thinking Of Getting my hands oN One Those Mid 1800s Massive Saw Mill Flywheels. i Have To Study Up On The Calculations.

(my Keyboard on My Phone Is Going Crazy. . . Sorry)

If There Is No Or Very Little Demand For Power, Then Wouldnt You HaVe a Almost Freewheeling System? (ignoring Friction)

Monarchist said:

Sure agree the ratio on that one..

A mere six kay effing dubbyah? Solar array, not exactly an 'always on' source, so yah don't GET peak power for but a fraction of the day.
.

Bill

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Its For a Weekend Farm/camp Cabin. Ultimately scaling when I Build My House On The Property

Motorsports-X said:

Its For a Weekend Farm/camp Cabin. Ultimately scaling when I Build My House On The Property

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Solar thermal heating and hot water recommended. Storage is just ignorant water, insulated tankage.
I used Sunmaster evacuated tubes back in the day. Scald yerazz even on an overcast day had I not blended-in well-water.

Solar photovoltaic for refrigeration. Deep cycle batteries.

Too small a system to mess with any storage more complex than the above + great insulation + Mother Earth as free thermal flywheel.

IOW "Dig in".


Bill

I appreciate the comments, but batteries are absolutely 100% NOT a consideration. I'd rather run a natural gas well with a Internal combustion engine at night. Batteries are a real hassle. I'd rather put battery money into either more panels or a different storage solution.

How would you reclaim the extra heat energy from the water without adding more heat and using it for steam power? I can underfoot hot water and winter heating but what else? Even stirling engines aren't efficient enough to use hot water with out filling them with gas (ie expensive)

I have NO clue why you would assume batteries are a "real hassle". Sounds like you have been listening to the wrong people, who have made up your mind for you.

I've had battery solar in operation for 20 years, no "hassles". Two friends have had battery solar for years as well. One as long as I have, as his SOLE power source. the other had generators before getting battery solar. They LOVE the battery solar, it is FAR less hassle than the gensets, and they also have no other power sources, neither is grid-connected.

The worst "hassle" exists with ANY storage system, and that is the fact that no matter how much storage you have, it;s always too little.

So, just some basic first cut numbers. 8 x 6V 225 AH batteries, connected however you prefer, for 12.24. or 48V, will hold approximately 10.8 kWh. That is about 38 megajoules.

An equivalent flywheel, using (I am lazy) a flywheel calculator, would be, for instance, about 1.2 metres diameter, mass of 100kg, sinning at 20,000 rpm. I have not checked to see if those numbers even make sense for strength of materials, etc.....

Now, YOU get to figure out how to get 60 Hz power out of 20,000 rpm, without having enough drag on the flywheel to slow it down in a week or so.

Meanwhile, 8 batteries, Trojan T105, wil, cost you somewhere around $1100, they will sit there and work for years, and if asked to store power for a week, will happily do so without losing very much.

If YOU can do a 20,000 rpm flywheel system for $1100, more power to you. I'd bet you cannot get an engineer to design it for you for $1100, let alone you buy materials and build it. And build it in such a way that it retains more than 90% of the original energy for even a week.

My advice to you is to forget about the flywheel, and get some better advisors than the ones who have filled you up with BS about batteries.

http://www.calculatoredge.com/mech/flywheel.htm

Motorsports-X said:

I appreciate the comments, but batteries are absolutely 100% NOT a consideration. I'd rather run a natural gas well with a Internal combustion engine at night. Batteries are a real hassle. I'd rather put battery money into either more panels or a different storage solution.

How would you reclaim the extra heat energy from the water without adding more heat and using it for steam power? I can underfoot hot water and winter heating but what else? Even stirling engines aren't efficient enough to use hot water with out filling them with gas (ie expensive)

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You 'cherry pick'. Skim the cream. Use it frugally.

Use only the solar (or any other..) energy source at its best value-for-money, not for ever' damn gadget Trump might have in his Tower.

Low-tech, all of that is.

Your cabin ain't in Alaska, is it? How much energy d'you need that the Amerindians didn't have?

Bill

I'm on board with JST. Batteries are not a bad thing. Forklift batteries have lasted up to 40 years if properly maintained. Put a little thought into proper ventilation for the storage area and keep things clean.
Last I checked solar dont perform well in hours of darkness. The flywheel strategy requires energy to start and maintain. Last time I read up on flywheel energy for data centers, etc... they were merely to carry the load until the emergency generator could come online. Going to be tough finding one to run overnight.
Spend a little time at otherpower.com Those folks live off grid and have great discussion on simple yet effective methods to harness and store power.
Solar is cool (no pun) and Tesla has some very nice architectural solar stuff in development however, the cost to connect is a major factor.

Just my thoughts

Take a look at the web site for Tonoph Solar Reserve you may be able to modify their technology. Good luck John

I have posted this several times before and had no response at all. To get a constant 60 cycles from a flywheel, use a small generator with a field identical to a three phase motor and a rotor that has same winding pattern. Use the output of that as an exciter for the main generator which is wound the same way but excitation is fed to the armature instead of the stationary windings. Excite the small generator field with 60 cycles and it will generate an excitation voltage that is the sum of 60 cycles and the RPM of the flywheel. That produces a rotating field from the armature that produces a 60 cycle output. If available, you can lock it onto the grid or have a solid state three phase oscillator.

You can also use the generator as a motor to spin it up by adjusting the excitation voltage and phase angle to match 60 cycle power applied to the main stator.

I thought this up on my own and then found that it had been done a long time ago. This type of equipment has gone out of style with modern solid state and computing, but they are just as valid as they were then.

Run the flywheel in a vacuum. It doesn't require a fancy system with pumps. Enclose it and position a scoop close to the OD of the wheel. By the time it gets up to 20,000 RPM, most of the air will be pushed out through the scoop. Nikola Tesla could tell you all about the effect.

Bill

Plus magnetic bearings.

Tom

TDegenhart said:

Plus magnetic bearings.

Tom

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Wot the hey .. if a PM-Pilgrim is to literally "reinvent the wheel", why skimp on the finer details?

9100 said:

I have posted this several times before and had no response at all. To get a constant 60 cycles from a flywheel, use a small generator with a field identical to a three phase motor and a rotor that has same winding pattern. Use the output of that as an exciter for the main generator which is wound the same way but excitation is fed to the armature instead of the stationary windings. Excite the small generator field with 60 cycles and it will generate an excitation voltage that is the sum of 60 cycles and the RPM of the flywheel. That produces a rotating field from the armature that produces a 60 cycle output. If available, you can lock it onto the grid or have a solid state three phase oscillator.

....

Bill

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So you generate a first difference frequency for excitation, and then take OUT the resulting second difference frequency from the main winding as power. Yes, I seem to recall something similar, but not identical as an old system of speed control. Might have to be careful with winding inductance at higher first difference frequencies.

The scoop vacuum pump is a goodie!

Still can't imagine the OP is serious. One WHALE of a lot-o-tech to avoid stone hammer simple batteries that just plain work and demand very little attention. Talk about hassles. Just oiling systems for high speed bearings are a hassle, without even considering the rest of it.

Looked once at a similar system that a potential client wanted to use for a special linear motor system. Racks of "stuff" to control the "charging" of the rotor, plus extracting power, etc... We turned it down for a host of reasons on a number of levels, including pass-through liability resulting from the client's target market, as well as the way the client insisted it should be done.

Perfectly "do-able", but did require a LOT of development of multiple subsystems, without including ANY mechanical issues.

Like I said, "talk about hassles".....

JST said:

Still can't imagine the OP is serious.

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Serious? Maybe he figures he can beat the market prices?

APC discontinued this one.

Flywheel Energy Storage System 3kW Rating, for EPS7, EPS8, Galaxy PW, Opt. Level 2, Seismic - APC - United States

Must have had a hard time finding folks willing to pay over $65,000 per-each for them.

These folks still have them on-offer:

Flywheel Energy Storage, Battery-Free UPS, Active Magnetic Bearing, Magnetic Bearings, Kinetic Energy, Magnet Motor Generator, Bi-Directional Power Converter | Calnetix

One just MIGHT.. want to check the specs for how long they provide hold-up... until a Diesel starts.



Bill

This is "practical machinist"

if you've got access to a gas well, use it for heat, and
run some of those thermocouple type remote power systems
on the gas well.

Most everything can probably be sourced used/surplus.

And they still make gas lamps (in stylish new modern styles...)

Check with the local amish crowd.

The Calnetix folks are storing 4,000 to 6,000 kilowatt-seconds, which is 4 to 6 megawatt-seconds, which is NOT very much. Figure out how many T-105 batteries that is.....

Of course, they are outputting industrial voltages, and so forth, which is harder with battery systems of low voltage, and their peak power output levels are much higher. Different items for different uses.

They are full of "Facts" about what you need to use batteries, with climate controlled rooms, etc, etc. Which looks a bit sillier as a design-it project when you figure out how many standard batteries it really takes to equal the energy storage of this commercial unit.

The 4 Mw-sec of storage is 1100 watt-hours (1.1 kw-h), which is somewhat less than the actual storage capacity of ONE 225 AH 6 volt battery. (225 hours of one ampere*, at 6 volts (6W). So 225 x 6 = 1350 watt-hours. The difference is that they can extract it at a higher maximum rate (300kW.....for 16 sec), and the charging efficiency is higher.

I do not know how long the "charge" can be retained, which is another consideration. A week for a battery is not too long. You'd be wanting a top-up charge in a month, for sure, with a battery. No idea for the flywheel.

A flywheel may be quite reasonable as a short term backup to bridge to a genset. As the sole storage for a remote location, it is so "overtech" as to be ridiculous, with an insane cost difference., and lesser performance.

* the rating of the battery is normally at a 20 hour rate, which would be around 10A continuous draw. At 1A rate, the 225 AH would probably be considerably longer, by 10% or more.

Motorsports-X said:

I'd rather run a natural gas well with a Internal combustion engine at night.

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Having HAD wells of our own, no, no need.

Gas heat. Gas HW. Gas cookers. Gas fridges, Gas Lights with bright Wellsbach mantles, and in latter years, gas air-con, too. Gravity water supply. Cased-in spring & cistern uphill, septic downhill of the house

Not a great deal left as needs electricity, so when we finally got it (1953) we had only a $12, later $22 a month electric bill for the TV and a few electric lights to use the gas ones less, a replacement for the hand-cranked cream-separators and hand ice-cream maker.

If you HAVE gas, follow that model and solar plus thermoelectric unit rather than noisier, higher maintenance IC engine.

LED lanterns can go 40 hours to the recharge, 'gadgets' have spare batteries, be charged sunny days, power tools as well.

Hopefully THOSE batteries don't get your knickers in a knot, but if so, take heart.

Humans got along without any 'lectricity at all for a very, very long time, and many still do.