Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Grid-connected Renewables => Topic started by: AllanMcDonald on December 18, 2008, 10:32:18 AM



Title: Sunny Boy 1100 Inverter
Post by: AllanMcDonald on December 18, 2008, 10:32:18 AM
Can some one give me a bit of advice I am creating around 1kw from my hydro turbine and was wondering if its practical to fit a Sunny Boy 1100 Inverter to reduce my bills whilst staying on grid and not exporting?
What is involved?
Thanks
Allan


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 18, 2008, 06:10:00 PM
 ::) thought the waterturbines are AC ?

Billi


Title: Re: Sunny Boy 1100 Inverter
Post by: AllanMcDonald on December 18, 2008, 06:28:51 PM
::) thought the waterturbines are AC ?

Billi
Mine is AC 230-240 volt what can I do to use the power ? I am running an 800w storage heater at the mo and some lights but whats the best plan long term?
Allan


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 18, 2008, 06:41:43 PM
Allan

I am  from the off grid section  ;D , and have too little knowledge about how to connect to the grid  to advice

But  i would  with a 1 kw always  producing turbine go off grid   connect it to an Inverter /charger  and a small but good battery that  then  " powerassists (controlled by the inverter/charger)  the 1 kw (from your waterturbine) if you need more then 1 kw  say 3 or more KW for a short period


if you donot need more then the 1 kw from the Waterturbine ( that power is switched through into your house) then the battery is not touched = this can provide a very long live of the battery


Billi



Title: Re: Sunny Boy 1100 Inverter
Post by: Ivan on December 18, 2008, 07:15:35 PM
Yes, you can rectify it and turn it into high voltage DC. This is what the Sunny Boy needs on its input. You'd need to smooth it, so that it has less than 10% ripple - which means a bank of capacitors.


Title: Re: Sunny Boy 1100 Inverter
Post by: AllanMcDonald on December 18, 2008, 07:39:19 PM
Saddly it isnt always  producing 24/7 I dont know how often it will produce as its only been going a couple of weeks.
I am just looking for the best way to use what I have.
Allan


Title: Re: Sunny Boy 1100 Inverter
Post by: guydewdney on December 18, 2008, 09:49:53 PM
I have the competitors aurora inverter - this just needs rectifying from 3 phase to work. But they only do a 3.8kw version (or6kw) - so its a bit OTT for you.

1kw isnt to be sniffed at - at 10p / unit from good energy it soon pays back.


Title: Re: Sunny Boy 1100 Inverter
Post by: Ivan on December 18, 2008, 10:43:52 PM
You won't need the capacitors with SMA either if you have three phase to start with. When rectified there isn't much ripple, but there's big bits missing with rectified single phase, hence the need for the capacitors. SMA will cope with 10% ripple (unless they've changed the spec) - any idea what the maximum ripple tolerane is with Aurora?

I'm going to be testing the Aurora grid tie inverter in a few weeks, as Navitron is planning to stock it.


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 19, 2008, 07:38:43 AM
 ::) So why are most waterturbines AC single  phase then ? perhaps because the cheapest

And not DC  and connected direct to a sunny boy grid tie inverter or via a MPPT charge controller to a battery
Or 3 wires  wild AC  and connected to the windy boy grid tie inverter or via a  charge controller to a battery ?

Wouldnt that increase the possibilities to harvest energy independent from the varying flow rate ?


Billi



Title: Re: Sunny Boy 1100 Inverter
Post by: stephend on December 19, 2008, 07:59:40 AM
I'm guessing here, but if the turbine produces AC, then you might be able to use the SMA sunny backup system by connecting the turbine as if it was the grid and connect the grid as if it was a generator.  If the turbine stops producing then the system should automatically switch over to grid power.  You can then also install a battery bank to store some of that excess energy. 


Title: Re: Sunny Boy 1100 Inverter
Post by: guydewdney on December 19, 2008, 09:00:19 AM
Billi

turbines are generally AC as that means they can be brushless and not have the wearing out problems of DC brushes.


As said - I have a wild AC generator (up to 500 odd volts) which is rectified, and fed to an inverter. It generates mains at anything above 50 volts input (which = 50rpm).

Alllan -
Why are you not exporting? The likes of Good Energy pay 10p / kwh of everything GENERATED - let alone exported. Im not even sure you need to export to get paid! If you do, all you need is a 7 quid meter wired in (from here http://www.universalmeterservices.co.uk/store/ ) and a tiny bit of paperwork for G83 compliance - oh - and a G83 export type inverter or similar (somthing to prevent the system exporting if the grid is down). Talk to your DNO (western power for me). http://www.nationalgrid.com/uk/Electricity/AboutElectricity/DistributionCompanies/ some are more 'regulatory' than others. 

If you dont want / cant export, then what options are there?
1) heat water. theres only so much hot water you can have. Get a second tank?
2) charge batteries - talk to Billi ;) I suspect he might tell you to get a victron charger ;) :p
3) pump water to header tank like dinorwig(sp?)
4) um....


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 19, 2008, 07:16:37 PM
thanks guydewdney

i do appreciate your Post , thanks again

Billi


Still i cannot shut up  ;D , .....   what happens to a 240  AC volt turbine when  the flow off water is reduced  ?
Compared to a DC one connected to a good charge controller 

Billi




Title: Re: Sunny Boy 1100 Inverter
Post by: guydewdney on December 19, 2008, 07:29:57 PM
guessing here - but if the turbine is fixed voltage output - that means its a fixed speed.

two things can happen - the nozzle size is altered (or similar) to make the same speed, but at less power. or the voltage drops.... The alternative is the AC->DC->AC route, which seems madness, but allows the variable flow.


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 19, 2008, 08:03:52 PM
Still  .... Windturbines start to produce at 3 meteres /s ,,,,, PV starts at low light  ::)     and what is a  AC waterturbine doing at low flow ?   I guess holidays   8) 

something wrong there or me ....


Billi




Title: Re: Sunny Boy 1100 Inverter
Post by: guydewdney on December 19, 2008, 08:14:55 PM
and on a cold, not windy night - the turbine keeps going ;)


Title: Re: Sunny Boy 1100 Inverter
Post by: billi on December 19, 2008, 08:26:23 PM
guy thats not my point .... i ordered a waterturbine  and its here ... is it still providing 240 V AC   when  water is only flowing half  of the required flow ?  i doubt that


billi


Title: Re: Sunny Boy 1100 Inverter
Post by: guydewdney on December 19, 2008, 09:38:06 PM
then you ordered a turbine too big! You need to size the turbine like a wind turbine - for the 90% of the time flow rate...




anyway - wheres Allan?


Title: Re: Sunny Boy 1100 Inverter
Post by: AllanMcDonald on December 21, 2008, 01:08:36 PM

anyway - wheres Allan?
I am here in South west Scotland.
Allan


Title: Re: Sunny Boy 1100 Inverter
Post by: roys on December 21, 2008, 01:34:48 PM
So am I, are you near Stranraer?
Cheers Steve


Title: Re: Sunny Boy 1100 Inverter
Post by: AllanMcDonald on December 21, 2008, 03:45:51 PM
I am near Dalbeattie.
Allan


Title: Re: Sunny Boy 1100 Inverter
Post by: qeipl on February 23, 2009, 04:07:14 PM
Allan,

I'm trying to do the same as you (but in NW Scotland) and have bought the following kit:

Navitron 750W high head turbine
REUK 600V bridge rectifier
SMA Windy Boy grid tie inverter

As Ivan says the DC out of the rectifier isn't smooth enough so you need a smoothing capacitor between the rectifier and the Windy Boy.
According to the reading that I've done an electrolytic capacitor rated at least 400V and 1200 microFarads will do the job for me. You might need more Farads as you are generating 1kW (see http://www.kpsec.freeuk.com/powersup.htm#bridgerectifier (http://www.kpsec.freeuk.com/powersup.htm#bridgerectifier) - scroll down for the 'Smoothing' bit).

You might have to consider going for the 1700W inverter.
The 1100W model recommends a maximum generator output of 800W for 5000 hours/year. I hope to be generating 750W for 70% of the year, which is 6000 hours.
The 1700W model is 1240W for 5000 hrs/yr, which is probably more suitable for your 1kW machine.


Ivan,
You talk about 'a bank of capacitors' - can you explain why more than one and how we should be sizing them (or it)?

Cheers,

Malcolm


Title: Re: Sunny Boy 1100 Inverter
Post by: northern installer on February 23, 2009, 04:17:58 PM
A bank of capacitors is just a means of assembling the required capacitance from what is available;ie 12 x 100 microfarad connected in parallel = 1200 microfarad.Make sure that the voltage rating is well above the highest peak to peak voltage;nothing finishes a capacitor quicker than over voltage ! sh*tfan:


Title: Re: Sunny Boy 1100 Inverter
Post by: Ivan on February 26, 2009, 02:05:16 AM
perhaps someone with greater electronics knowledge than me can work out the required capacity for you. I did it a few years ago for a 1.5kW water turbine and worked out, at Farnell prices, it required about 200 worth of capactors. The Sunny Boy needs ripple voltage to be below 10%. If you're rectifying single phase, the 'ripple current' ie what flows to/from the capacitor to keep things smooth, will at times reach much higher levels than the current flowing. So if you have a 1Amp current from the water turbine, you'll see 8 (I think) Amps at times to/from the caps. As a result, you need to over-rate the capacitors to prevent over-heating. Large caps have a ripple current rating, and like batteries, I think it reaps dividends to over-spec the caps if you want them to last a long time. If you're running them at temperatures of 70C, you can't expect them to last more than a couple of years.

Anyone care to do the calculations? I think you'll need a lot more than 1200uF