Inverter Sizing for Lifts/Elevators:: Badly need help

[Shapath]

Dear All,

Can anyone suggest me how to determine Inverter size for elevators of 30KW? Since the starting torque of lifts/elevators is pretty high, so will it be wise to install solar system to operate this lift during the day time only from 10 am to 3 pm. ?

I badly need help...!!!

Thank you and with best regards,

[Sunking]

You are kidding right?

[russ]

That would be an extremely large system and ındustrial/utility size storage.

Very, very, very costly and impractical.

Russ

[john p]

After you find a suitable mounting place and purchase the 300 x 200w panels (they will cover an area about 400 sq m. Then just purchase some 12v 200 ahr deepcycle batteries I would suggest about 36 per string and about 8 strings ,Total of 288 (about 9,000kg)that should be enough to provide power to the motor .As you need a buffer between the panels and the charge controller and the motor.I cant advise on inverter as that size is going to be a little bit higher than the biggest ones I have anything to do with, they only 5kw.
The above is just a very rough estimate. it may be advisable to get a bit more advise from a local electrical engineer. or just forget about the idea as as already posted by others its totallly impractical. I estimate cost at about 1/2 a million dollars. You cant hate the grid power supplier that much you be willing to spend that much and another huge amount every 5 years for replacement batteries to do him out of a few thousand dollars per year?//

Any of the above quoted figures may not be valid for the country you live in .And do not take into account any changes in weather conditions,availability of parts, the land necessary and its cost to mount the panels.floods,riots or acts of God.

[Mike90250]

Much better idea to go with grid tie.
Running an elevator, especially if it carries people, likely can't be done safely with storage batteries and PV. The power involved is too big.

[Shapath]

Clarifications

Dear all,

Thanks for your replies. Now let give you all a few clarifications:

1. the building already has grid connection.
2. the authority has decided to install a 100KWp system on the roof-top of that building.

Now initially, I proposed them an on-grid system where they will sell the power generated from the PV system to Government. But now the authority wanna use this system to operate their elevator when there is no power supply, i.e approx 4 hours per day. So they have requested to redesign the system with battery backup and Inverter.

Now while designing this system, the problem I am facing is that, since elevator has a high starting torque so what should be the size of the inverter? In my initial design I have decided to use two 17KVA inverters but I am not sure 100%. Since I cant take the risk and my expert personal is out of station right now, so I figured out to ask this question in this forum, where I believe I am interacting with a group of highly experienced engineers.

So I hope I have clarified the confusion now. My client can pay, so no big deal and also it will be really great if anyone can give me suggestions regarding working on this 100KWp project.

Thanks to all...

[Mike90250]

Before you can design this, you need to know EXACTLY how much power the "high torque" motors use for starting and running. Are they direct/gear drive, or hydraulic drive? Transmission solenoids ?

Then you need a qualified engineer to tell you the human safety factor
(headlines - Solar powered elevator plunges 12 stories, all 6 cabinet members and senator killed, local vendor sought for questioning) required to make it safe.

What will happen on a rainy day ? 3 rainy days ? It may prove to be better to install a conventional power plant for this important elevator.

Is the roof area even large enough to support enough solar panels ?

Where will the battery be located ? here's an idea for battery: BOB http://inhabitat.com/bob-americas-bi...-a-texas-town/ Big Old Battery
& http://www.popsci.com/technology/art...y-backup-power

[john p]

A diesel generator could run the lift safely at a fraction of the cost of batteries and inverters and charge controllers.. Plus the maintainance and replacement costs of the batteries. And diesel generators work just as well on rainy and cloudy days..

[Sunking]

I am having trouble believing this thread as it contradicts all engineering and life safety protocols. I guess India does not place value on peoples lives and require public buildings designs to be certified by competent engineers.

In the USA any building over 3 stories with elevators are required to have generators to power elevators, egress lighting, Fire Marshall communication, and fire protection systems independent of all other electrical systems. No one in their right mind would use solar for emergency life support systems.

[Shapath]

Dear all,

They already have diesel generator as backup, but now the concept of green power generation is what actually making them to think of using solar power instead of diesels during power outage.

I have inquired about the details of the elevator and will be provided by them within two/three days. I will get details about the human safety factor also.

Dear Sunkin, here the laws are much more sophisticated then you can think of. All these stuffs are already there but in this one the problem is when this building was designed there was no thought of installing solar systems of 100KWp on its roof-top. So now we have send written request to the design authority for approval. The other safety factors are also followed, but as Mike suggested the human safety factor for solar elevators, I initially didnt have any idea about that. So I have requested the authority for details also.

Also as I mentioned earlier, I till now believes systems like this (100KWp) should be on-grid system where PV will generate power and will be supplied to the local grid. Gen backup system is much more reliable comparing battery storage system..!!! But lets see what my clients wants...!!! :S

Thanks to all again,

[Shapath]

Dear Mike,
thanks for the link. I like the BOB...

Dear Sunking,

how does the system contradicts engineering protocols except the safety features. Sir please explain to me.

Thanks to all,

[Sunking]

First thing is this system for the elevator being means if has to be separate from the rest of th esystem as you cannot have both battery and grid tied, at least not on this scale.

Second problem is: just where do you plan to buy such massive components? It will all be custom designed and manufacture and lead times will be a year or more if you can even find anyone to take on the task.

[dvhenry]

They already have diesel generator as backup, but now the concept of green power generation is what actually making them to think of using solar power instead of diesels during power outage.

If the environment is what is driving the decision, you may be able to point out to them the loss of efficiency compared to grid tied and a generator for a few hours a day, the environmental effect of the production and disposal of the batteries, etc. There are likely to be plenty of "imaginative" environmental impact studies out there to back you up, stretch the truth if needed, the greenies do!