# Speed and Volt and Ampere

Registered Users Posts: 12
Hello;

With wind generator, if the fan is rotating slow or high, the volt is constant and only the current is changing?
And the generated current is AC or DC? Because, I need to know if we need to charge the battery, then we need to have rectifier or no need?

Regards
Bilal

• Solar Expert Posts: 963 ✭✭
Re: Speed and Volt and Ampere

bilal
I will give this a shot. The batery voltage has to be reached by the turbine for it to start charging. There is math associated with what speed a certain lenght blade will be going to what speed the wind is blowing. This is based also on tsr of the blade or how fast the blade is made to turn compared to the wind. The volts of the turbine are controlled by the battery and raise with the battery as it charges. the speed it charges is based on the wind speed causing the amps going to the battery to rise as the wind raises. Now to you question. It depends on what you are using for a turbine. If you are using a dc motor it may already be rectified. If you are just using a magnet motor it would be putting out wild ac and would need to be rectified. If you have a very cheep volt meter that you can check dc volts with, the turbine when you spin it by hand should put out dc volts to the meter if it is rectified. It should put out nothing if you have the meter set for dc if it is not rectified. Most turbines have to be rectified unless it was already done by the manufatuer.
I hope I am right and hope this helps.
gww
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

Thanks a lot for your kindly help and advise.
The batery voltage has to be reached by the turbine for it to start charging. There is math associated with what speed a certain lenght blade will be going to what speed the wind is blowing. This is based also on tsr of the blade or how fast the blade is made to turn compared to the wind. The volts of the turbine are controlled by the battery and raise with the battery as it charges.

That means, if the wind speed was low, then the generated volt will not be enough to charge the battery?
the speed it charges is based on the wind speed causing the amps going to the battery to rise as the wind raises.

That means, if wind raised, then generated volt of the turbine will be increasing, right?
So, the generated volt is dc but its value is changing based on the wind speed (higher speed will generate higher volt and lower speed lower volt). Right?
And charging the battery should be through charger and not directly from the turbine to the battery?
Most turbines have to be rectified unless it was already done by the manufatuer.
So by default (normally), then generated volt is DC and no need for rectifier?

Again, I am fully thanks for your kindly help and advise and looking to hear from you.
Regards
Bilal
• Solar Expert Posts: 963 ✭✭
Re: Speed and Volt and Ampere
The batery voltage has to be reached by the turbine for it to start charging. There is math associated with what speed a certain lenght blade will be going to what speed the wind is blowing. This is based also on tsr of the blade or how fast the blade is made to turn compared to the wind. The volts of the turbine are controlled by the battery and raise with the battery as it charges.
That means, if the wind speed was low, then the generated volt will not be enough to charge the battery?

Correct

the speed it charges is based on the wind speed causing the amps going to the battery to rise as the wind raises.
That means, if wind raised, then generated volt of the turbine will be increasing, right?
So, the generated volt is dc but its value is changing based on the wind speed (higher speed will generate higher volt and lower speed lower volt). Right?
And charging the battery should be through charger and not directly from the turbine to the battery?

Incorrect.
That means exactly what you originally thought. The battery clamps the voltage to its voltage. The wind as it increases causes the battery to raise its voltage due to the higher amps that higher wind produces. You can hook a properly rectified turbine strait to the battery, however you will need someway to keep the battery voltage below what will damage it. This is usually done with a charge controller that either diverts power from the battery to keep its voltage at a set point or turns the turbine off by shorting it out.
So by default (normally), then generated volt is DC and no need for rectifier?

There is no way to know if the turbine has been rectified except to test it or if it came with a manual to look it up. If you can't look it up then you need to use a multimeter and test it. You would need to know what voltage battery the turbine was made for also. That is why the math on blade lenth and speed is important. If you hook a 48 volt turbine to a twelve volt battery it probly won't hurt but it also wont produce. If you hook a 12 volt turbine to a 48 volt battery it is going to overspeed and could cause real damage.

Why ask these questions with out telling what you are using as a turbine or maby post a picture of it. It would then be much easier to answer. Also if you hook a turbine to a battery that has not been rectified you will have some kind of motor that could be hurt or hurt someone. It needs the easy test before it ever gets near a battery.
Hope this helps
gww
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

OK. My questions about the turbine, because I need to build electrical generator to provide electricity for the house. Of course not only depending on the turbine, but also depending on the solar panels and the electrical company provider. So I was need to understand how the turbine is working and what is the principle (the working volt, does it generate AC or DC and so on).
What I understood from you that there is a designed volt that based on it the turbine is designed. And based on this volt, the maximum allowed speed for the turbine is determined (and the turbine is designed).
So, if we said that our working volt is 96 V then we need a turbine that is working based on this volt (so, it will not rotate faster than the speed that will generate 96 volt, and any less speed will not cause to charge the battery). I am right?

But what if the turbine is rotating at low speed and does not generate the 96 V, but it is generating less volt .. How can we get a benefit of this volt which is less than the 96V? Or it will be useless?

Thanks for helping me.
Regards
Bilal
• Solar Expert Posts: 963 ✭✭
Re: Speed and Volt and Ampere
But what if the turbine is rotating at low speed and does not generate the 96 V, but it is generating less volt .. How can we get a benefit of this volt which is less than the 96V? Or it will be useless?
It will be useless but there wouldn't be much wind so you wouldn't be making much power.

I must say that unless you live in a very windy place (like you have to hold your cap on if you go outside) you would probly do much better and do it cheeper with solar and probly just buying electric from the power company would be even cheeper.

Also the wind turbine will not be the most exspensive part of your wind system. The wire, tower, controller and dumpload will cost even more.

I don't know where you live but if you don't have power outages and want to produce some electric and if the power company is ok with it you could grid tie. Then you wouldn't need a battery and charge controllers but you would not have electric if the electric company went down.

If you want wind anyway then maby you should buy Hugh piggotts book "wind turbine hand book" I paid \$27 for it. It really is a plan for building wind turbines but even if you don't build one it has a few, rule of thumb, math formulas dealing with the use of wind.

You can do the same for free on the internet but it will take longer and you have to be careful of what you listen to. I also bought a book earth for energy for \$40 bucks and feel it was a compleete rip-off.

You might try websites like "otherpower" and read through some of the threads posted on their forum and look at some of their projects on their web site. "Thebackshed" Is another ausrailan website. "greenpower" website does more on bought turbines. I am not trying to get you to build a turbine but more to relize how little wind gives and all the things a person doesn't think of cost wise when wanting one.
Just serf those sites a bit and hopefully it will help your knowlage.

I type to slow and am really not smart enough to really help you as I barily grasp part of it myself. I do have solar and two wind turbines and where I live solar is lotsssssss cheeper then wind.
Cheers
gww
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

First of all, I need to say I am fully thanks for you because you gave me right vision and you helped me by this information.
So, you have solar system, is it connected to the electrical company service provider? If yes, so when the controller decides to charge from the electrical company or from the solar panel? What if there is not electrical is generated from the solar panels but the battery if full or 90% full, does it charge from the electrical company or need?

How much it costed you the solar panel and how much it is generating wat?
The charger and invertor is same device or two devices? Do you recommend certain suppliers?

Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

See if this thread helps you understand Grid Tied, Off Grid, and Hybrid Power systems for you:

Battery-less Outback Radian (GT/Off Grid/Hybdrid Inverter options explained)

It used to be much easier to explain--But the wonders of electrical/electronic engineering has blurred the lines between many products. Add the ever changing laws regarding Utility Power and GT/Off Grid/Hybrid power--The answers tend to be very specific to your location as to what is legal and how things can be done.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 12
Re: Speed and Volt and Ampere
BB. wrote: »
See if this thread helps you understand Grid Tied, Off Grid, and Hybrid Power systems for you:

Battery-less Outback Radian (GT/Off Grid/Hybdrid Inverter options explained)

It used to be much easier to explain--But the wonders of electrical/electronic engineering has blurred the lines between many products. Add the ever changing laws regarding Utility Power and GT/Off Grid/Hybrid power--The answers tend to be very specific to your location as to what is legal and how things can be done.

-Bill

All of these components are USA manufactured?
Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

Some are, some are not. Some are designed in the US or Europe, and built overseas/elsewhere.

I suggest to design your system on paper first, then look for products that support your needs. And your wallet.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

So I have to read the link that you gave me to find the suppliers for batteries, inverter, charger, solar panel and so on.
Do you believe there is good chinese batteries and solar panels?
Also, I heard there is batteries of 10 years lifetime and it 12 V & 200 AH with about 200\$, did u hear about this and is it reliable?

Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

Where are you located?

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 12
Re: Speed and Volt and Ampere
BB. wrote: »
Where are you located?

-Bill

I am located in Lebanon (Beirut). It is recommended to be big manufacture to be able to provide competitive price because we need these batteries for the selling solar systems for our customers, so it is for trading (sales) and not for one customer.

I am fully thanks for your kindly help and replying.
Regards
Bilal
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

I read the link that your provided Bill and thanks a lot for the information as it is really containing a lot of information.
All the components are USA or Europe manufactured, I need to ask if there is any Chinese or Taiwan manufacturer for Batteries, Charger Controller, Solar Panels and Inverters? Of course, to be reliable.

This is because I need to get something costly effective ... But, if it is not reliable, then it is bad even if it is zero cost.

Appreciate the kindly help.
Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

Bilal,

I am not in the solar business... Us moderators are all here because we want to help folks with conservation and solar.

You can start with our host's website (Northern Arizona Wind & Sun):

http://solar-electric.com/

They have (from what I know) a pretty good reputation around here and stand behind the equipment they sell--They also are willing to work with their customers to help ensure that the designs and equipment ordered will work well together.

However--NAWS, and us moderators, are really only able to help with equipment that is common in the North American Market. There are lots of European mfg. that make very good product too--But "we" never really see it.

And, even good equipment, put together wrong, can be a real problem... For example:

Is the system set up right

In the above case, there was (from what I could see) very good equipment, but an electrical engineer that was in over his head that caused lots of problems.

When working with big power systems--There are a lot more issues that can cause problems--And getting a good engineer involved is very important (finding a good engineer, is not easy either).

And--Size matters. A supplier/product that would work well for a small home or cabin will probably not work well for a large home/office/etc...

My help here--Lets see if we can better understand your goals... How much energy are you talking about (typically Watt*Hours or KWH per day). Are you looking to save money or be (mostly) generating power locally and not using "Utility supplied" power?

Consevation and clever ways of "adjusting your loads" can also save lots of money... For example, in many regions, irrigation & water for homes (pumping water) can take a lot of energy--And historically has been done with diesel generators and utility power.

You could design a battery based system to pump your water--Or, if you can pump most of your water during daylight hours--There are new products that can connect a solar array directly to a 3 phase electrical motor to pump water where needed during the day--And pump the water to a holding pond/tank, then use smaller pumps to move the water to the house on demand.

WELL PUMP and Inverter QUESTION
Wind/solar for large scale pumping etc (out of my depth!)
could use knowledge - using Gould jet pump - transfering from 230vAC to ? DC (new link/thread 10/27/2012)
Help required to design off grid system (information on possibilities to connect "standard VFDs direct to solar panels) (new link 1/13/2013)

That is just one example of where conservation/changing requirements would save about 75% of the cost of solar power because batteries+chargers+inverters are not used at all (more efficient, less maintenance, etc.).

If we can identify what you are trying to do (size the power needs), then I am sure we have folks here that can give you specific suggestions for hardware that may meet your needs.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

Hello Bill;

Your reply helped me a lot and I have to read well.
In our country (lebanon) and in our region, the electrical is disconnecting a lot and this is the main problem. Also some areas does not have electrical because the electrical company did not reach to these places specially the places that are used for agriculture and I believe in this areas the water pump is important.

So, I am looking to be solar energy provider but the cost is playing important role !
People are going to accept paying \$10K to get 24 KWH system and that means, I have to be able to provide the solution with less than this amount as cost, so I can sell at \$10K for 24KWH.

One of the main problem that I am afraid about it is the winter season as the sky will be clouded all the day (starting from sun rising and until the sunset), actually we do not see the disk of the sun but of course it is morning So, in such day where the morning is 10 hours, can I consider it as 4 hours? For example, if the solar panel is able to generate 300 watt, then I can consider that this solar panel is able to generate in such clouded day an 4 x 300 = 1.2 KWH? Or it is not generating any Watt because of the clouds?

Again, thanks a lot for the help and kindly support.
Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

I have a grid tied system--So every Watt my system generates, goes to the grid (unlike a battery system which "turns off" the panels when the battery bank is full and there are no active loads).

In very dark/cloudy/poor weather, my array will generate as low as 5% of it rated output--To generate power, the array needs lots of sun light.

If you have a fixed solar array for Beruit, tilted 56 degrees from vertical (34 degrees from horizontal), if you assume that noontime sun is around 1,000 Watts/square meter for one hour (which we call "1 hour of sun"), then add up all the hours of "real sun" during the day and divide by 1,000 WH/sqmtr:

Beirut Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 56° angle:
(For best year-round performance)

Jan
Feb
Mar
Apr
May
Jun

3.81
4.48
5.50
6.22
6.80
7.00

Jul
Aug
Sep
Oct
Nov
Dec

6.94
6.95
6.74
5.88
4.47
3.58

In general, I look at 4 hours of sun or more as "good sun" and (for much of north America), I suggest designing a system to "break even" at 4 hours of sun per day. At less than 4 hours of sun per day, use a generator (or reduce power usage) during streaks of bad weather....

Remembering that these are "averages" over 1 month period. You may have three weeks of good sun and 1 week of poor weather, or you may have 4 weeks of "marine layer"--Really depends on your region.

So--Designing a conservative full time off grid system that will work rain or shine... Using 2 days of "no sun storage" (1-3 days typical range) and 50% maximum discharge (usually a good optimum for flooded cell lead acid battery bank) and 24 kWH per day:
• 24,00 WH * 1/0.85 inverter eff * 2 days storage * 1/0.50 max discharge * 1/48 volt battery bank = 2,353 AH @ 48 volt battery bank
We suggest a 5% to 13% range of solar panel charging on a lead acid battery bank (5% for weekend/seasonal use, 10%+ for daily use):
• 2,353 AH * 59 volts charging * 1/0.77 panel+controller deratings * 0.05 rate of charge = 9,015 Watt array minimum
• 2,353 AH * 59 volts charging * 1/0.77 panel+controller deratings * 0.10 rate of charge = 18,030 Watt array nominal
• 2,353 AH * 59 volts charging * 1/0.77 panel+controller deratings * 0.13 rate of charge = 23,438 Watt array "cost effective" maximum
And sizing the array based on 4.0 hours of sun minimum (some generator use in December and January)(note 52% efficiency is based on 81% panel derating * 95% charge controller eff * 80% battery efficiency * 85% inverter efficiency):
• 24,000 WH per day * 1/0.52 end to end system efficiency * 1/4 hours sun per day = 11,538 Watt array minimum
Obviously, based on my (relatively conservative) rules of thumbs, there is no way a 24kWH per day system for 10+ months of the year is "cheap" or even really affordable.

So, we start looking at loads... For a typical off grid home with LED lighting, clothes washer, TV, laptop computer, full sized refrigerator, and a small water pump--You can fit all of that into around 3.3 kWH per day.

The rest of the power for such a large system (24kWH per day * 30 days = 720 kWH per month) is close to what the average north American home uses per day (little air conditioning, mostly natural gas/propane for heating/cooking/hot water).

So, for Beirut, it appears that May through October are anywhere near "warm" months--So, perhaps you only need A/C during that time--Pretty much ~6.0 hours a day minimum...

And perhaps, you only need A/C (mostly) during daylight hours and 1 day of storage, so the battery bank could be 1/2 the size I suggested earlier... That could cut the battery costs by 1/2, and the solar array by almost 1/2 too (getting power from solar array to A/C, without 80% battery efficiency, 6 hours of sun vs 4 hours, etc.).

Anyway--That is how I would start the design process.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

Thanks for declaration. Again, I have to read well.

But, why not to use lithium battery? The lifetime is not better? And the DOD is not better?

Regards
Bilal
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

The above is based on common design rules that "we" have found work well--And are quick and easy to do a back of the envelope design without going into too much detail.

Also, try to show all of my work--So you can see what my assumption were and what drives the size/cost of the system. And you can make changes that better meet your needs.

Regarding Lithium batteries... Do you have have a particular brand/model/type that you like? There are many different types of Lithium batteries out there--And they can have quite different operational properties and issues.

The ones that have been discussed here a lot are the LiFePO4 (lithium Iron Phosphate) type--A bit bigger and less energy dense than some other Li Ion types--But seem to work well (and appear to be relatively safe) for off grid power needs with minimal amount of changes to the hardware and programming used for off grid solar power systems. And, LiFePO4 batteries are much easier to charge/maintain than flooded cell lead acid batteries which do not like the reduced charging time that we see with solar power systems (especially in winter).

However, Lithium cells do tend to be a bit expensive at this time--Maybe 4x the cost of lead acid, and 2x the costs of AGM. But, if the LiFePO4 batteries last as long as claimed--Their actual \$\$\$/kWH cycling costs may end up being less than Lead Acid.

There is also the issue that these (and any rechargeable) batteries can be damaged through miss-use by the owner--Which means a very expensive mistake.

Could you get away with a 1,000 AH @ 48 volt battery bank vs the 2.4 kAH @ 48 volt battery bank--Very possible. However, I don't know enough about your load profiles to make much in the way of an education suggestion...

If your storage needs were small (say you needed A/C only during the summer/daylight hours)--A 400-500 AH @ 48 volt LiFePO4 battery bank could work....:

(0.80 max charge - 0.20 minimum charge) * 500 AH * 48 volts * 0.85 inverter eff = 12,240 WH of AC energy storage

Is 12kWH of storage for over night use "good enough" for you needs? How much would such a battery cost?

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 963 ✭✭
Re: Speed and Volt and Ampere

Bill
You are dedicated, know what you are talking about and helpful. I always try to read what you post hoping some of this will rub off on me.
Thanks
gww

PS Apparently you can type really really fast
• Super Moderators, Administrators Posts: 32,008 admin
Re: Speed and Volt and Ampere

Fast is one thing--Accurately and in English, not so much sometimes.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 9,361 ✭✭✭✭✭
Re: Speed and Volt and Ampere
Thanks for declaration. Again, I have to read well.
But, why not to use lithium battery? The lifetime is not better? And the DOD is not better?
Regards
Bilal

It's new for solar use, and maybe not all the bugs out of it. And expensive. I'd suggest learning on a cheap set of flooded batteries, and when they die, upgrade to better ones.
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,

• Registered Users Posts: 2
Re: Speed and Volt and Ampere

As far as I know, If you are using a motor for your turbine, the maximum rated voltage of the turbine will be reached when the motor hits its maximum rpm, that is why low rpm motors are better suited to wind turbines. AC will be generated, you will need to make or buy a rectifier.
• Registered Users Posts: 12
Re: Speed and Volt and Ampere

Hello Bill;

I started believe in your sentence that let us look for the load. It seems that it is very important to use appliances that save electrical power. I can understand that led light is saving electrical power and the Led TV is also saving electrical power.
I got to hear there is new technology for the engines to save the electrical power and this technology is applied for refrigerator, cloth washer, A/C and maybe for water pump. So we can advise the customer to buy such appliances in case they aim to use solar energy and need to save energy.

My experience in these engines is few and I do not know if these appliances are reliable and have long life time and if it is effective really. Can you advise me and direct me to know what this technology that is used in the engines to have low watt appliances and if it is effective with reliable appliances or not and if there is water pump that operate in this technology.
By the way, what is the name of this technology that is used with the engines to have appliances that save power ?

Thanks a lot for your kindly help and advise and directing us.
Regards
Bilal