Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: al_uk on October 16, 2014, 11:54:51 AM



Title: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 16, 2014, 11:54:51 AM
Hi all,

We are on grid with a standard Sunny Boy 4000TL and 3.6kW G83 PV system. We typically have 3 power cuts per year during the winter lasting between 8 and 36 hours. We also have brownouts lasting up to a few seconds at least weekly.

I have a Honda 2kVA generator converted to propane and we have a 100A transfer switch fitted upstream of the main CU. The Solar PV is also fed into an RCBO on the main CU. This means that I can either isolate the PV, or keep it in circuit when the transfer switch is switched to generator. Up to now, I have always isolated it to avoid the risk of backfeeding into the generator.

This all works reasonably well, however I would like a little more peak power available without going to the expense and maintenance of a 2nd paralleled generator.

The extra power would let me comfortably run the washing machine (we have a baby with another anticipated) or the microwave as well as the base load. We also use rainwater for 2/3 of our usage with a pump that doesn't have soft start.

I have a 3kVA APC Smart-UPS which protects the computer equipment in the house. I am considering replacing this with the 48v 3000VA Victron Multiplus downstream of the generator and before it feeds into the transfer switch. The Victron would take its mains grid feed from another CU which is upstream of the transfer switch. This means there is no risk of connecting the unit's input to its own output. My reasoning is as follows.

1.     I can use the dynamic current limiting and power assist to smooth the load from the generator to allow it time to throttle up and down on eco-throttle, while not risking damage to "instant" startup loads such as the microwave and water pump.
2.     The power assist will provide the extra power from batteries to run the washing machine or microwave without overloading the generator.
3.     The batteries will give me some capability to run small loads (eg gas boiler) for a few hours during a power cut when the generator is off at night.
4.     I don't really need 3kVA of boost capability, but I do think I want 48V, and this is the smallest 48V model.
5.     Although the existing line interactive UPS syncs happily with the generator, it cuts in and out of battery power when the generator spins up and down on eco-throttle as the house loads vary.
6.     I don't believe it is worthwhile to try and configure this in a "self consumption" way by using the stored power overnight and recharge from PV. The round trip efficiency losses and battery cost per kW/H don't add up. So just looking for standby use.
7.     There is no risk of trying to power up the grid in a power cut situation as the transfer switch will disconnect the house
6.     I work from home 50% to 75% of the time, so being able to continue working in the event of a power cut goes a long way to justifying the cost. Also with small children, being able to continue as normal does wonders for my standard negative brownie points balance with my Wife!

Looking for help with the following questions.

1.     Any holes in my reasoning above?
2.     I am thinking of 4 x 12V approx 100ah batteries. This is a standby application so the batteries will only be discharged a few times a year, which can be limited to 50% SOC or higher. What would be the most appropriate battery type for this application, and how many years could I expect them to last?
3.     Can I bring the PV in circuit when on Generator power? The PV will be downstream of the Multiplus. If the PV remains in circuit when running from generator, then I think the Sunny Boy will sync, and that the Multiplus will proportionally increase the output mains frequency up to 52Hz when the Generated power = Load power. I think the Sunny Boy will then sense this increase, and throttle back the generated power so that back feeding doesn't occur. Has anyone tried this, and will the Sunny Boy work like this in standard G83 mode?

Here's a pic of the configuration today, with the Victron replacing the APC.



Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billi on October 16, 2014, 02:25:50 PM
Hi
If you go the Victron or similar  Inverter road with batteries , i would  try an approach to   have  all year round and night ,  electricity from your FiT harvesting  system  not only for  the eventual power-cut

Regards Billi




Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 16, 2014, 09:51:21 PM
Hi Billi, thank you for responding. I hadn't really looked at using it to reduce grid import at night, because of all the discussions concluding that the total cost per kW/H for battery power is greater than grid import.

However, in my case, I actually only need to consider the incremental cost between a battery pack suitable for standby usage, and a battery pack suitable for cyclic usage, because I'll be buying the rest of the kit regardless!

To do the cost comparison, I am not sure what batteries I should be looking at for either standby or cyclic use - any suggestions? Does Li-Ion stack up yet?

My base load is 300 to 400 watts (yes this is higher than I would like).

I do have spare roof capacity for another 3.5kW Southwest facing panels which I could add at some point.

Thanks.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: nowty on October 16, 2014, 10:24:05 PM
I agree with Billi, think big !  tumble:

More PV, big forklift batteries and run your house off it every night, you wonít regret it.  exhappy:

Also think about power diversion to water / storage heaters with an Immersun type device too, cos with more PV youíll find you too much power in summer.  :fume


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: RIT on October 17, 2014, 01:12:14 AM

3.     Can I bring the PV in circuit when on Generator power? The PV will be downstream of the Multiplus. If the PV remains in circuit when running from generator, then I think the Sunny Boy will sync, and that the Multiplus will proportionally increase the output mains frequency up to 52Hz when the Generated power = Load power. I think the Sunny Boy will then sense this increase, and throttle back the generated power so that back feeding doesn't occur. Has anyone tried this, and will the Sunny Boy work like this in standard G83 mode?


Do you have a link to where it is detailed that the Multiplus operates in this way (changing the output frequency). I'm no expert of the device, but its the first time I've seen someone comment that it can do this.

I also have a question for everyone else, will the Sunnyboy keep operating in this configuration, or will it shut down because the 'SMA grid guard' will not like the power it sees from the Multiplus?


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 17, 2014, 04:31:15 AM
General config information around self consumption here
http://www.victronenergy.com/upload/documents/Whitepaper-Self-Consumption-and-Grid-independence-with-the-Victron-Energy-Storage-Hub-EN.pdf

Victron Wiki page here
http://www.victronenergy.com/live/ac_coupling:start

Old Manual here-I think this has been withdrawn though, but has some details.
http://www.flinkenberg.fi/batteries/material/victron/Manual%20-%20Assistants%20-%20Self-consumption%20Hub-2%20-%20rev%2002%20-%20EN.pdf

On the Sunny Boy there are settings for power control by frequency shifting but I am not sure if these have any effect in G83 mode.



Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: Tinbum on October 17, 2014, 08:14:58 AM
On the Sunny Boy there are settings for power control by frequency shifting but I am not sure if these have any effect in G83 mode.
You have to set it off grid mode. Then it no longer complies with G83 so has to be controlled by a G83 approved device that is compatible.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: biff on October 17, 2014, 10:22:20 AM
I just don,t know guys,
                     All these expensive machines are like a trap,once you get sucked into them you have to keep buying them compatible toys,,for that year,,for that model.
  The whole idea of renewable energy is that life can be more simple,more compatible ,more renewable.
  I have been as you all know,Off-grid for years. I use multiple 2kw chinese wind turbine controllers to handle the excess energy from the PV, Once they see 138volts they automatically divert it to our immersions.They support one another without any fancy Island and they do not cost a fortune. I believe that you can actually buy them with laptop connections. They honestly seem to be a bullet proof way of doing business.
 One of the big advantages of having multiple controllers is that if one goes down (it has not happened yet) the others can carry on,the only difference is the voltage creeps up but you can see that at a glance and there is no reason to panic because they are still working happily and give you time to get things in order.
  Some of the fancy stuff that I am seeing here on Navitron cost an arm and a leg to repair or replace and non of them provide any form of backup.When they are dead,they are really dead.
  We should be the ones who dictate the route to travel,We should not allow ourselves to be ripped off and forced to pay loadsa money for complicated boxs of tricks.
 The more complicated these companies make their product the more money you will pay and goodness,!! they are far from foolproof.
 But again, Is like I said at the start, I just don,t know.
                                                           Biff


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billt on October 17, 2014, 10:34:18 AM
All these expensive machines are like a trap,once you get sucked into them you have to keep buying them compatible toys,,for that year,,for that model.
  The whole idea of renewable energy is that life can be more simple,more compatible ,more renewable.

Absolutely.

The simplest, cheapest and most sensible option for the OP is a bigger generator. It's only to cover a couple of power outages a year, which could probably be coped with without standby power at all.

Trying to fully integrate the original PV system is silly. If you don't lose FIT entitlement altogether, the system output will be lower with so the FITs will be lower - and the cost will be totally disproportionate.

Having said that, I like expensive toys myself so when I have bought the batteries and built the room to house them I'll be going mainly off-grid with a non FITted 12kW SunnyBoy/Sunny Island system to replace the UPS. The original 3.8kW FIT system will be unmodified and export 100%.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: martin on October 17, 2014, 10:41:37 AM
I agree - things can just get so complicated, expensive, and completely out of the realm of "saving the planet" - as we've often seen (and it's a scenario I've oft quoted) - someone comes along full of good intentions to use solar power to give light to their remote lambing shed in winter - once you do the sums, the answer is "don't, use a generator or Tilley Lamps", as counter-intuitively, they're actually cheaper, and will do less overall damage to the environment (the moment "battery storage" is mentioned, the warning bells go off) - in the right circumstance, where there is no other pragmatic solution, perhaps, and think very hard about it and do some sensible sums (none of this "regularly discharge to 50% DOD" nonsense), THEN see if it's worth it - and as always, start at the other end first, minimise consumption, then look to provide for your needs............ :)

In this thread, another vote for a bigger (or 2nd) gennie, or just cut down on the power you're using!


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billi on October 17, 2014, 12:56:12 PM
Martin ,  i disagree 

because of the following  reasons

-In the UK  one is limited to  16 A   or under 4 kw PV , a battery based  idea  would provide  a much bigger PV solution  for many households ( depends on space )
- allowing people to invest in immersion  burning ideas  and get paid for it  per burnt kWh  is bad politics , instead of  providing a structure  balanced feed ing the grid
- with a battery based  idea the  Threadstarter can make  use of all his  PV   electricity , that he would otherwise have to import  from the coal and Nuclear Grid at night and get paid for it for his PV power at night  ( that  i  certainly support )
-buying another generator  ontop of the 1000 GBP  one he has  allready makse no sense to me .... cause seen with  a DIY  eye 2000 GBP  is 4000 watt of PV  and no fuel needed

Sorry for opening a  general court case here  :garden

Billi


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: biff on October 17, 2014, 01:34:18 PM
Hi Billi,
      I think, Martin means a second small geni that one could take out to the far flung sheds for lambing and then when the season is finished take it home again. One you can carry in one hand) Some of the little 2 stroke 750watt can be run very economically and then there are small inverter type geni,s that are very economical. The only the use the fuel that the load demands off them. So if you are only using it for lights they just putter along on fresh air almost, (so they tell us)
                                                         Biff


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: martin on October 17, 2014, 02:11:13 PM
As the op is "on grid", I'd think twice about a modicum of batteries just to fill the odd gap in supply (especially to run a microwave) - as I said, for that use I can't see batteries being particularly cost-effective. Just as a point of information, small modern 4-stroke inverter generators with eco-throttles run incredibly frugally  - they usually quote something like .45 litre per kilowatt hour, so certainly for the lambing house they've got to be a winner.
Having said that, if you're looking to go completely off grid, that's a different kettle of battery banks, and you'll be looking at serious money.........                               


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 17, 2014, 04:31:13 PM
Thank you for all the replies. I agree that the simplest and cheapest option would be to get a 2nd EU20i, but as I like the toys I'd like to explore the options a bit more!

I think all I am looking for now is a "better UPS" which is more suited to running from a small generator than the APC. Which is where the multiplus comes in.

I would then need some UPS type batteries. For primarily standby use, my thought was 4 of something like these Victron Gel batteries which seem safer and lower maintenance than the forklift batteries mentioned earlier. Any better value suggestions?

http://www.criticalpowersupplies.co.uk/12v-90ah-80ah-gel-deep-cycle-battery

(Hope the link is ok)

I'll not bother trying to integrate the existing PV as it looks like it will break the G83 rules.





Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: RIT on October 17, 2014, 05:16:42 PM

I'll not bother trying to integrate the existing PV as it looks like it will break the G83 rules.


You may want to move your PV to the grid side of the wiring. This way none of the work you do will effect its operation. It will be on when there is a grid service, and you can then do what you want on the generator/UPS side of the design.

Depending on when you plan to do all this you may want to watch the SMA Sunny Island product as it may at some point become UK G83 approved, so allowing everything to be intergrated, by the use of their power monitor and an indepedent control box.

As for the batteries, you may want to give Navitron a call and see if they can provide the duty cycle information for the Rolls batteries they supply. This will give you sometime to compair the Victron units against. From little info I have seen on the Rolls units, the duty cycle of the Victron unit seems rather low, as does its capacity.

On another site I have found the following publishes Rolls duty cycles

            Rolls 4000 Series     1280 cycles to 50% DOD      800 cycles to 80% DOD
            Rolls 5000 Series     3200 cycles to 50% DOD      2100 cycles to 80% DOD

The victon unit is quoted at  600 Cycles @ 50%

Navitron's battery page can be found at  http://www.navitron.org.uk/product.php?proID=157


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: biff on October 17, 2014, 05:48:01 PM
Hello Al,
         I have this thing about Ah claims.I don,t care what they say but a batt which weighs only 29kgs will not have 90ahs after a few discharges.
   I knackered a few AGMs in my time,great big brutes of 50kgs efforts, They start of ok but after a while they degrade and don,t hold the charge as well,
  I would put my money into the rolls or buy into good indestructible forklift jobs . A forklift battery will forgive you anything.
                                                                        Biff


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billi on October 17, 2014, 10:07:55 PM
All these expensive machines are like a trap,once you get sucked into them you have to keep buying them compatible toys,,for that year,,for that model.
  The whole idea of renewable energy is that life can be more simple,more compatible ,more renewable.

Absolutely.

The simplest, cheapest and most sensible option for the OP is a bigger generator. It's only to cover a couple of power outages a year, which could probably be coped with without standby power at all.

Trying to fully integrate the original PV system is silly. If you don't lose FIT entitlement altogether, the system output will be lower with so the FITs will be lower - and the cost will be totally disproportionate.

Having said that, I like expensive toys myself so when I have bought the batteries and built the room to house them I'll be going mainly off-grid with a non FITted 12kW SunnyBoy/Sunny Island system to replace the UPS. The original 3.8kW FIT system will be unmodified and export 100%.

Quote
Trying to fully integrate the original PV system is silly
 Why ?

Pretty easy    to store   electricity   from a FiT harvesting system and reuse  later  without  loosing FiT payments , but gaining  monney because of avoided imported units  from Grid  



Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 18, 2014, 12:02:29 AM
What maintenance do the Rolls batteries (or similar) need? Are they fit and forget?

My current UPS is in a small boiler room about 1m x 1m with a concrete floor and block walls, and not that much flammable stuff in it. Although it is part of the house, it is accessed only from outside. Would this be suitable for "proper" batteries, or should they be in a separate building?


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 18, 2014, 06:24:39 AM
What maintenance do the Rolls batteries (or similar) need? Are they fit and forget?

My current UPS is in a small boiler room about 1m x 1m with a concrete floor and block walls, and not that much flammable stuff in it. Although it is part of the house, it is accessed only from outside. Would this be suitable for "proper" batteries, or should they be in a separate building?

Your current location seems just fine and I guess if it has a boiler in it's well ventilated and not too cold, purrfect. I've just fitted Rolls batteries to my new 'off grid' build after years of using forklift cells. Not that there's anything wrong with fork lift batteries, as Biff says they're very forgiving and can stand lots of abuse. However I replaced a forklift bank for a mate with Rolls S530's a couple of years ago http://lifeattheendoftheroad.wordpress.com/2012/04/16/bouncing-batteries/ and was severely impressed with them. So much so that I spent £3K on a set for my new house

(http://i224.photobucket.com/albums/dd170/camillitech/032_zps03984b52.jpg)

I've mounted mine on a sturdy wooden frame to keep them warmer and make topping up easier, they are quite thirsty and float at a higher voltage than forklift cells. I religiously check SG's fortnightly and log them, my mates cells require topping up more often than mine as I have these fitted http://www.navitron.org.uk/product_detail.php?proID=808&catID=157

(http://www.barden-ukshop.com/ekmps/shops/bardenuk/images/rolls-water-miser-cap-2751-p%5Bekm%5D300x300%5Bekm%5D.jpg)

and I think that price is a miss print as mine were half that. Billy has had Rolls cells with hydro caps fitted in his barge and hasn't topped them up in seven years.

Sounds like a great project and great to see someone else doing something because they want to and not because it makes financial sense  8)

Good luck, Paul


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billt on October 18, 2014, 08:57:01 AM
Quote
Trying to fully integrate the original PV system is silly
 Why ?

Quote
Trying to fully integrate the original PV system is silly. If you don't lose FIT entitlement altogether, the system output will be lower with so the FITs will be lower - and the cost will be totally disproportionate.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 18, 2014, 09:08:28 AM
the system output will be lower with so the FITs will be lower - and the cost will be totally disproportionate.


How will the system output be lower? the generation meter is after the GTI and before the Mulitplus so the output kWh will be the same. Granted if the energy is not consumed via the AC bus and backfed into the batteries then the efficiency will be lower but then the OP will not be importing at night. Sure it probably makes no economic sense but then that's probably not the goal.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billt on October 18, 2014, 10:12:01 AM
That depends how the system is designed. Using a Sunny Island type system the PV output will be throttled when not consumed on site, hence less total generation. A SI system can't be grid connected AFAIK, hence there will be no export payments. Anything done to a FIT system needs to be approved by the relevant bureaucracies, so work done will need to get MCS approval. This will be expensive, which is the main point.

No doubt there are ways of doing it that don't involve changing the grid connected system, hence FITs won't be affected. I would expect that they will also be expensive to implement, just to avoid running a generator for a couple of days.

The OP wanted advice on implementing a super UPS system, without modifying the existing grid tied system. Billi then went on about using all the PV generation, by integrating the current PV system with the UPS system and then adding more PV. I'm just pointing out, along with Biff and Martin, that that isn't a sensible route.

I've got nothing against complicated, and even expensive, gadgets and systems, but to recommend an even more complex and expensive (and imaginary) system doesn't seem terribly good advice.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: martin on October 18, 2014, 10:34:59 AM
This does rather bring to mind the (now said to be untrue) story of how the Americans spent gazillions on building a "space pen" that could write in zero gravity (I remember when you could buy them, so it wasn't that much of a fib), the Russians scratched their heads for a bit when faced with the same problem, then used pencils........... :hysteria


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 18, 2014, 11:02:52 AM
I don't think it's a sensible route either and I've lost count of the number of times that I've said "a battery system 'on grid' is neither cost effective or green". I just didn't see how the generation would be less, having an 'off grid' head and having my meters on the outputs of both Sunny and Windy Boy's. My system is configured not to 'throttle' anything but of course it's not G83 compliant  wackoold

Cheers, Paul


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: Tinbum on October 18, 2014, 11:34:06 AM
The Sunny Island is G59/2 approved.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billt on October 18, 2014, 12:25:02 PM
I sit corrected.

However, for a backup system, that requires the addition of a G59 relay. So an over the top, expensive, system needs an extra costly component.

http://www.windandsun.co.uk/media/296773/SI60H-80H-G5921-Declaration.pdf


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: RIT on October 18, 2014, 01:31:06 PM
I sit corrected.

However, for a backup system, that requires the addition of a G59 relay. So an over the top, expensive, system needs an extra costly component.

http://www.windandsun.co.uk/media/296773/SI60H-80H-G5921-Declaration.pdf

The current G59 rating seems currently probamatic as SMA does not seem to have a switch in their product range and it you look at windandsun's web site its clear that there is not one currently available. My guess is no manufactor of a automatic transfer switch device has bothered to get the correct UK approval. After all with the FITs system in place there is a limited market for such a device.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: Tinbum on October 18, 2014, 01:38:01 PM
SMA used to make automatic transfer switches for the sunny backups but no longer do so. The Backup was basically the same as the Island, at that time, but with different software.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billi on October 18, 2014, 01:45:15 PM
Here it is for the Victron

Quote
Grid Connected Battery Back-up

With earth switching compliant with G59/2 the Victron Quattro and MultiPlus inverter/charges allow you to store excess generation from grid connected PV & wind systems during the day for use at night. As a bonus you will also have backup power should the grid go down.

See Victron G59 statement
http://www.windandsun.co.uk/media/289711/Victron_G59_statement_of_fact.pdf



I say it again , instead of buying   a Victron 3000 watt Multiplus and Batteries , just for the occasional  power failure ,  i would use it everyday and night instead ,  with that  , one can utilise    upto 100 % of homegrown PV   and the extra costs for better batteries  will be covert by avoiding the immesun and Co devices , and the  gain of  avoided imported units   ( even if only  1500 kWh per year at an guesstimated average  price of 20 p per kWh ,  that makes 3000 GBP  in 10 years )

A 15 kWh  Battery that lives more than 10 years   should be under 1500 GBP

Billi

Billi


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 19, 2014, 11:14:16 PM
Thank you all for the debate! Lots of food for thought, and I'm going to do some more research before coming back.

On a slight tangent, If I want to add more PV, then am I right in saying that I have the following options?

1. Call my DNO (SSE) to find out whether I can go beyond my existing 3.68kW install. If so, then standard MCS grid tied install of another approx 4kW.
2. If DNO says no, or wants to charge £££ to find out, then next best option (as per Nowty) is DIY. So, 2nd hand panels, into a GTI, then into a mini grid provided by a Multiplus/Sunny Island but synced with the main grid. Then to use the downstream power locally. Any excess power will be throttled back by the Multiplus. 

Am I correct in thinking that the Multiplus can be connected to the grid as a UPS (via 16A plug and socket) and G83/G59 does not apply. Therefore I need no notification to the DNO and no electrician EIC as long as the power is not exported back out to the AC1 input. However the moment I reconfigure the software to export back out to the AC1 input then G83/G59 applies?

I am confident I can use almost all the power locally from the diy "offgrid" system all year round.

Thanks again for all the comments.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 19, 2014, 11:16:16 PM
Hi Nowty, why did you go for Sunny Island rather than Multiplus? Cheers, Al


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billt on October 20, 2014, 08:25:28 AM
On a slight tangent, If I want to add more PV, then am I right in saying that I have the following options?

1. Call my DNO (SSE) to find out whether I can go beyond my existing 3.68kW install. If so, then standard MCS grid tied install of another approx 4kW.
2. If DNO says no, or wants to charge £££ to find out, then next best option (as per Nowty) is DIY. So, 2nd hand panels, into a GTI, then into a mini grid provided by a Multiplus/Sunny Island but synced with the main grid. Then to use the downstream power locally. Any excess power will be throttled back by the Multiplus. 

Sounds reasonable to me. I'm going the DIY off-grid route.

Am I correct in thinking that the Multiplus can be connected to the grid as a UPS (via 16A plug and socket) and G83/G59 does not apply. Therefore I need no notification to the DNO and no electrician EIC as long as the power is not exported back out to the AC1 input. However the moment I reconfigure the software to export back out to the AC1 input then G83/G59 applies?

That's a very interesting question, I'd expect the official answer to be that G83/G59 does apply, as the equipment is capable of back feeding the grid through that connection - hence it needs to be connected through some sort of automatic grid failure switch. It would be good to have  an reliable answer, but, given the silence in the documentation and the tiny number of people interested, I think there will be a long wait.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: RIT on October 20, 2014, 03:50:27 PM
Thank you all for the debate! Lots of food for thought, and I'm going to do some more research before coming back.

On a slight tangent, If I want to add more PV, then am I right in saying that I have the following options?

1. Call my DNO (SSE) to find out whether I can go beyond my existing 3.68kW install. If so, then standard MCS grid tied install of another approx 4kW.
2. If DNO says no, or wants to charge £££ to find out, then next best option (as per Nowty) is DIY. So, 2nd hand panels, into a GTI, then into a mini grid provided by a Multiplus/Sunny Island but synced with the main grid. Then to use the downstream power locally. Any excess power will be throttled back by the Multiplus. 

Am I correct in thinking that the Multiplus can be connected to the grid as a UPS (via 16A plug and socket) and G83/G59 does not apply. Therefore I need no notification to the DNO and no electrician EIC as long as the power is not exported back out to the AC1 input. However the moment I reconfigure the software to export back out to the AC1 input then G83/G59 applies?

I am confident I can use almost all the power locally from the diy "offgrid" system all year round.

Thanks again for all the comments.

If you can't get DNO approval and so need to install a standalone PV system, you may want to look at installing a system that charges the batteries directly rather than installing a PV mains inverter. The reasons behind this idea are

  - A battery charger is likely to be cheaper than a mains inverter.
  - You remove the limits of the 3000VA Victron Multiplus own charger which is only rated at 35A for a 48V battery pack. It seems a waste to have a total of 8KW PV install if you can only charge at about 1.7KW.
  - You can just forget about all the G83/G59 issues as you will have an "offgrid" solution with an "ongrid input".

If you can get DNO approval, you may want to look at using a Sunny Island rather than the 3000VA Victron Multiplus as

  - It will be possible to deploy a solution where the Sunny Island charges the batteries based on the available power from the PV system (you need extra SMA devices to allow this to happen)
  - The Sunny Island has a much larger charger built in. The 6.0H model can charge at 110A for a 48V battery pack.
  - The Sunny Island maybe better at powering your house as its rated at a much higher output, 4,600W rather than 2,500W.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: nowty on October 21, 2014, 06:13:59 PM
Hi Nowty, why did you go for Sunny Island rather than Multiplus? Cheers, Al

I have probably answered this several times on different threads but it is a very good question to answer.

First its worth stating my reason for having an off grid system when my house is on the grid. If you are grid tied, SMA gear (and other gear) cannot back off the generation but the excess simply flows into the grid. This obviously works as we all know from our standard 4kw (or 3.68kw) grid tie systems. But I cannot legally connect my 8.7kw of PV and multiple inverters to the grid without DNO permission which I have not got. So in order to add more PV capacity to my house I have made a separate off grid system so no DNO issues, its my mini grid and I can do what I like with it, in fact I am the DNO ! :police:

If you are off grid the biggest problem is there is nowhere for the power to go in your own mini grid except to your loads or to the batteries. If you have few loads on or the batteries are full there is nowhere for the power to go. Without anywhere for the power to go, the solar inverter AC ouptut will overvoltage and trip out, its all or nothing. sh*tfan:

The SMA kit is the only one AFAIK that beautifully self regulates off grid generation. As the batteries become full the Sunny Island changes the AC frequency proportionally from 50 Hz to 52 Hz to signal to the Sunny Boy feeding it to back off the generation by proportionally power limiting itself. The Sunny Boy does this by limiting the amount of DC current flowing from the panels into itself. If I then turn on a heavy load or the sun goes behind a cloud, the Sunny Island senses this as power will start coming out of the batteries to compensate and reduces the frequency back towards 50Hz. The Sunny Boy will then notice this and increase its generation back up to the full amount of power that is available from the panels. ralph:


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on October 21, 2014, 08:46:02 PM
Nowty, thank you for the detailed reply. For anyone else considering this route I just emailed Victron to find out what the Multiplus does - and it seems they've now added the throttling in the later versions. See below

Question to Victron:-
I am looking at 2.2. VE Storage Hub-2 in this document http://www.victronenergy.com/upload/documents/Whitepaper-Self-Consumption-and-Grid-independence-with-the-Victron-Energy-Storage-Hub-EN.pdf
In my case I do not want to export anything to the grid, but if the Solar PV is generating more than I am consuming then there is a problem.
Can the Multiplus be set up to vary the frequency so that no power is exported back through the AC1 input? If the Grid Tied Inverter is a SunnyBoy then these units can reduce its output proportionally if the mains frequency is varied between 50Hz and 52Hz.
Can you point me to a link to a section of the manual that explains this setting please?


Reply:- yes , there is a setting [ prevent to back feed ] in version hub2v3 which opens the backfeed relay when there is a surplus of energy
Then freq shift will reduce pv power to balance load/generation. Thatís not described in that manual but only in the software itself ( you can run this in demo mode using fake target full options

I'm also waiting for a call back from SSE to tell me whether a 2nd PV application is likely to succeed or whether I'll need to go through the full application process and pay a fee.

RIT, thank you for your comments on DC coupling rather than AC coupling - I shall investigate further, depending on what the DNO says. I did also ask Victron how the Multiplus compared with the Sunny Island, and they said it was more versatile, and the battery charging functionality was far more advanced...


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: nowty on October 21, 2014, 08:52:15 PM
I did also ask Victron how the Multiplus compared with the Sunny Island, and they said it was more versatile, and the battery charging functionality was far more advanced...

Well they would would'nt they ?

Interesting to note about the Victrons doing the throttling now, they certainly did not used to when I was looking at them, but with all things in this area, what will be available in another 5 years time, and probably from the Chinese who only knows.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 21, 2014, 09:05:37 PM
I did also ask Victron how the Multiplus compared with the Sunny Island, and they said it was more versatile, and the battery charging functionality was far more advanced...

It would need to be 'more advanced' even the 5000VA model only has a 70amp charger  :crossed Seriously though, the SI does have a bizarre logic to its battery charging that can defeat even its staunchest supporters, at least that's what I'm told.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: billi on October 21, 2014, 11:17:34 PM
Quote
If you can get DNO approval, you may want to look at using a Sunny Island rather than the 3000VA Victron Multiplus as

  - It will be possible to deploy a solution where the Sunny Island charges the batteries based on the available power from the PV system (you need extra SMA devices to allow this to happen)
  - The Sunny Island has a much larger charger built in. The 6.0H model can charge at 110A for a 48V battery pack.
  - The Sunny Island maybe better at powering your house as its rated at a much higher output, 4,600W rather than 2,500W.

Erhm ,    a Victron 3000 is half the price of     a Sunny Island  6.0       ....bigger Models are  available    like the Multiplus 5000     for lesser monney than the SI

As far as i know , is the  SI not as fast anymore  when it comes to switching over  to off grid in  case of a powerfailure

Billi




Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: heatherhopper on October 22, 2014, 10:03:59 AM
Quote
the SI does have a bizarre logic to its battery charging that can defeat even its staunchest supporters, at least that's what I'm told.

Paul - What is considered bizarre about it? Every time it's mentioned I panic and go back and look at mine, wondering where I may be doing something wrong!


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: RIT on October 22, 2014, 01:29:43 PM
Quote
If you can get DNO approval, you may want to look at using a Sunny Island rather than the 3000VA Victron Multiplus as

  - It will be possible to deploy a solution where the Sunny Island charges the batteries based on the available power from the PV system (you need extra SMA devices to allow this to happen)
  - The Sunny Island has a much larger charger built in. The 6.0H model can charge at 110A for a 48V battery pack.
  - The Sunny Island maybe better at powering your house as its rated at a much higher output, 4,600W rather than 2,500W.

Erhm ,    a Victron 3000 is half the price of     a Sunny Island  6.0       ....bigger Models are  available    like the Multiplus 5000     for lesser monney than the SI

Billi



Very true, but that's the reason why I gave some figures for the al_uk, the Victron Multiplus 3000 is half the price, but also has a much lower output rating and battery charger. As al_uk stated that he was considering an additional 4K of PV, it makes sense for him to take a look and consider some of the other options depending on the size of the battery pack he plans to install and his power usage patten.

The Multiplus 5000 is a lot nearer the specs of the the SI 6.0H as its output rating is 4,500W and the charger can support 70A for a 48V batter pack.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 22, 2014, 07:20:46 PM
Quote
the SI does have a bizarre logic to its battery charging that can defeat even its staunchest supporters, at least that's what I'm told.

Paul - What is considered bizarre about it? Every time it's mentioned I panic and go back and look at mine, wondering where I may be doing something wrong!

To be honest HH I don't really know but I've heard more than one person mention it and here's a quote from the supplier of mine, It's possible that the Sunny Island will decide to go to a float stage before the tristar at some point due to it's own byzantine logic.   :hysteria  :hysteria My only experience of this 'logic' is when I connected my new Rolls cells to it and the SI sat at 42% for two sunny days in succession as the batteries fizzed away at 60v  :o It seems to have sorted itself out now but it had me  banghead: for while.

Cheers, Paul


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: Tinbum on October 22, 2014, 08:51:30 PM

As far as i know , is the  SI not as fast anymore  when it comes to switching over  to off grid in  case of a powerfailure


I think there was a reference and link to that on here somewhere- its certainly not as fast as the sunny backup. I'll try and find the link or the printout I have.

EDIT found it:
http://www.navitron.org.uk/forum/index.php/topic,22034.msg255950.html#msg255950

and
http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CDYQFjAD&url=http%3A%2F%2Fwww.windandsun.co.uk%2Fmedia%2F304189%2FFlexible-Storage-Battery-Backup-Planning-Guide.pdf&ei=mh9IVL7-M7PG7AaAsoCgCA&usg=AFQjCNHxhliXZyhdSquL2KrYdI9Ul52GQA&bvm=bv.77880786,d.d2s


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: clockmanFR on October 23, 2014, 07:02:01 AM
AGGGHHH.

 It's possible that the Sunny Island will decide to go to a float stage before the tristar at some point due to it's own byzantine logic.    :hysteria :hysteria  My only experience of this 'logic' is when I connected my new Rolls cells to it and the SI sat at 42% for two sunny days in succession as the batteries fizzed away at 60v   :o  It seems to have sorted itself out now but it had me   banghead: for while.

Thanks Paul, nice to know.

Still trenching here........................... facepalm

Must get the hang of this Bluetooth communication thingy whatsit.  svengo


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: DaveSnafu on October 23, 2014, 10:37:20 AM
There are cheaper alternatives available, I have found a company based in britain that assembles components from greece and offers a five year warranty, the prices are very reasonable.
Being off grid and having broken versions of all the top brands, outback, victron and mastervolt, all beyond "economic" repair, I have decided that the only thing that makes any sense is to have a spare for everything, obviously this is very expensive to do. especially using the big brands, the big brand warranties are pretty much useless for off grid folks as by the time the replacement is here the freezer has defrosted.
So, I am going to flog my two big victrons,(one running, one as a spare), and with the dosh I am going to invest in a load of "british built" inverter chargers.
IF it is ok with the management,(navitron) then I will divulge the name of company, if not then PM me for details.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: heatherhopper on October 23, 2014, 11:42:11 AM
Quote
It's possible that the Sunny Island will decide to go to a float stage before the tristar at some point due to it's own byzantine logic.
I must emphasise I am no expert and my experience is with the 24v SI but it seems perfectly logical that the SI will float at a different point than the Tristar. The SI charge regime is based upon both voltage and ah exchange. This may be regarded as Byzantine (in this context I'm assuming "excessively complicated" as the meaning) but in my experience it works perfectly well provided the SI is, or is viewed as, the primary controller. If you have other controllers connected and want to view their SOC assessment as the valid one that is fine - depends on which you are most happy with I guess. I spent some considerable time adjusting the various charge voltages of both the SI and DC coupled Bergey controller when we had that connected and eventually managed to get them largely working in tandem. The SI really did not mind the Bergey charging to a higher voltage and simply idled along in float with an elevated frequency activating the AC dumps as required. Not sure the Bergey controller was happy but that is all an entirely different story. However the SI boost charge will always kick in out of synch with another controller.
There is (maybe was) an issue with the SI SOC recalibration routine when it will take some time to recover from a very high discharge at low SOC/voltage - essentially it resets to a very low SOC, takes a long charge and then resets to something reasonable. I have seen this a couple of times following some poor operation on my part and heard of similar experiences elsewhere. Simple answer to this is I don't repeat such foolish operation.
Quote
My only experience of this 'logic' is when I connected my new Rolls cells to it and the SI sat at 42% for two sunny days in succession as the batteries fizzed away at 60v  Shocked It seems to have sorted itself out now but it had me  banghead for while
Difficult to say without knowing what was coupled up and in what configuration but this does sound bizarre. Maybe just be a long winded recalibration? Why not send SMA the data for the period and ask for an explanation? I have found they respond very well to such requests although with typically stern tuetonic disapproval if the error is yours.
Don't despair CM - if a simpleton like me can get away with the SI anyone can.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 23, 2014, 12:02:07 PM
There are cheaper alternatives available, I have found a company based in britain that assembles components from greece and offers a five year warranty, the prices are very reasonable.
Being off grid and having broken versions of all the top brands, outback, victron and mastervolt, all beyond "economic" repair, I have decided that the only thing that makes any sense is to have a spare for everything, obviously this is very expensive to do. especially using the big brands, the big brand warranties are pretty much useless for off grid folks as by the time the replacement is here the freezer has defrosted.
So, I am going to flog my two big victrons,(one running, one as a spare), and with the dosh I am going to invest in a load of "british built" inverter chargers.
IF it is ok with the management,(navitron) then I will divulge the name of company, if not then PM me for details.


What are you doing to them Dave?? I've been 'off grid' 29 years, had one of the very first inverters ever made (a mechanical one crica WW2) and a solid state one dating back to the early eighties. That was the size of a microwave oven, hummed like a beehive and surged to an incredible 1kW  :o The only ones I've ever fecked was a Studer I fried when connecting up the wrong way round and the one off the Lancaster bomber that I cremated on a bonfire. Never had a power outage for more than a few minutes since 1985 and never carried a spare.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: DaveSnafu on October 23, 2014, 01:52:22 PM
We have been hit by lightning twice this year, once here in wales, (january) and in portugal, (july), other than that I just use this stuff till it fails and then get another, same as everyone else.
I would say that you have been very lucky to not need spares.
Back on topic................the price of some of the gear needed for a successfull long term back up to the grid (that may never be needed) is off putting, especially if you go with the big names.
There are far eastern and european assembled units with all the bells and whistles available at hobby or project prices, for instance a clone sunny island can be had for under a grand, a 5kva inverter charger for half that.
At prices like that more folk would be willing to take a punt at renewables.


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: Billy on October 23, 2014, 01:55:08 PM
Paul et al,

I have now topped up the Hydro Capped Rolls.  I found some data that told me how much the wet stuff should be above the perforated blue separator.  It was down a bit, maybe 20 - 25mm.  Took a few litres but considering the years they have been left.  Checked they were but not often, once they'd proved themselves not to drink.  ;D


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: biff on October 23, 2014, 02:04:33 PM
If you carry spares,
                   The chances are you will never need them. If you don,t carry spares,that,s the time you will get caught out. (Murphy,s law)The jam butty will always end up stuck to the floor.
         No disrespect aimed at the owners of these valuable boxs of kit but I find them way over the top money wise.
      My multiple Chinese controllers do the same job and if  had the most expensive box of tricks on the market,My short tail would still have scuppered our nice new wind turbine :'(.
                                                                                            Biff


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: DaveSnafu on October 23, 2014, 03:02:27 PM
Apparently the cure to lightning strikes is to get insured, once insured you'll never be hit again, (except by the insurance company once a year).


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: camillitech on October 23, 2014, 05:17:17 PM
Apparently the cure to lightning strikes is to get insured, once insured you'll never be hit again, (except by the insurance company once a year).

The cure for lightning strikes is 'Lucky Underpants'

(http://i224.photobucket.com/albums/dd170/camillitech/018Small_zpse7848682.jpg)


Title: Re: Victron Multiplus, SMA PV, Honda EU20i generator + On grid. What Batteries?
Post by: al_uk on December 28, 2014, 11:15:26 PM
Right. I'm back.

From the discussion in this thread I've given up on the battery and Multiplus/Sunny Island idea, until battery cost per kWH improves.

However I am now looking at adding more PV. I can use almost all of it on site through Immersun etc. I also have water pumps and heat pumps to run for a small pool.

Back in October I asked SSE how much extra PV I could add. I've now had the reply back as follows.


Option 1

The existing LV network will permit a maximum of 3kw plus existing 3.68kw = 6.68kw of generation connected into the existing single phase supply. - At a cost of £250.00 + VAT

Option 2

If you reduce the generation to 4kW on the existing single phase supply, as we do not currently charge for this size system you can connect without any charges. - However please me know if you wish to take this option up, as you will still require a connection offer issued for this - At a cost of £0.00

Option 3

To allow 6kw plus existing 3.68kw to be connected on a single phase supply, we would need to upgrade the overhead network. The cost to provide this option will not be less than £4000.0 + VAT 


I won't be doing option 3.

If I follow the full MCS route for option 1, what is the definition of the "3kW" these days. Is it panel rating, or Inverter rating - ie. if the Inverter was a 3kW but I had 4kW panel capacity, would that be acceptable?

Do I have a sensible DIY option? ie. buying 2nd hand panels and inverter and connecting via option 1? I know I won't get FITS. Or getting an Inverter that will prevent export, so I can ignore the DNO?