2 5hp motors, and the load for them 2 or 3 hours would be 60amps or so.
With water, on average 250l a day to 60deg, I was actually only looking at a2w heat pumps the other day, they are actually surprisingly cheap and would be a no brainer with the cop of 3 or 4, however my biggest problem here is we have very hard water, that burns out elements regularly. A salt based water softener helps but I still only get 2yrs out of elements (using coated elements). What i read up was those a2w heat pump systems for say 2 or 3grand would only last afew years, so how short a life would they have with my hard water.
In terms of temperature, that's an interesting one. Ideally I'd have more control of temperature, at the minute all I can do is use a screwdriver to adjust the temperature on the element (which is factory set to 60deg), I remember once bumping it up to 70, and the water started coming out cloudy which probably meant it was burning the limescale in the water (or maybe Stripping the coating on the element or something?), so I decided to quickly drop back the temperature. 65 or 70degree water would be useful and would allow me to get away with less chemicals and/or less frequent hot washes for the milking machine, but obviously not worth wrecking elements or cylinders for.
I can run into milk quality problems if I don't hot wash frequently enough or temperature isn't high enough (which usually happens when one element burns out and the other one can't get all the water to temperature, which you might not spot till you have a problem), the fines for poor milk quality can run into the thousands so not something to mess with ha. However if I could find an a2w system that can sustain my water type, and gives me some better control on the temperature, and maybe say set it to run a 65 or 70degree wash once a week I'd be interested, but for now the simple solution is just stick with my 60degrees and throw in a new incoloy element every 2 or 3yrs.
Edit, just looking at the specs here, 5kw ac output for the inverter, so that's only 22amps of the 60amps that I'd use, I'm a long way off there so.
You could safely push them to 15-10% of the advertised amount.
Should easily be able to charge on night rate, and no issue at all charging up again on solar for the evening.
What is the power draw of the plant when milking? The size of your hybrid inverter could limit how much can come from batteries. Can't say without getting specifics.
Re hot water.
How much do you use every day and what temperature would you normally heat to?
You possibly could look into an air source heatpump just to heat the water! Yes the outlay could be a few grand, for a 6kw one(same output as 2 immersions) but if your only heating to 50c it would be about a third of the running cost.(COP of 3), using 2kw instead of 6kw!
If the tank goes cold, you'll gain even more efficiency.
Rising main is say about 10c. You heat to 60.
Every time you empty that tank it's 15kWh.
Heatpump could heat it for 5. At a cop of 3.
This milder weather I'm heating a 500L buffer tank to 50 and getting 4x.
If you really want to get into the details, start a new thread!
How many kWh can you generally get out of a Solar battery? I've got a price on a 15kwp system with a 15kwh battery, I'm a dairyfarmer with a reasonably steady 90kwh daily load from say March to October and dropping back to 30 or 40kwh this time of the year. Main 2 times of the day I need power are at milking , 8 till 10am and 5 to 7pm, when I probably use 20kwh, and then other big draw is water heater using 250l a day which is ran off 2 3kw electric elements (which has proven horribly expensive last 2 yrs).
Anyways the above is the maximum size system the ESBN will let me get with my current MIC (16kva single phase supply that I wouldn't mind upgrading, but tidy grand on the solar system I've priced up and closing date soon), my aim is that I'll utilize most the solar I generate on the farm, and use the battery to supply a good part of the morning and evening peaks. How realistic is it to expect to charge the battery at night rate, and have a full 15kwh for the morning, then do the same again with daytime solar for the evening?
I'd be of the same opinion as Graeme here. If your getting a grant, they won't pass it without having a fireman's switch installed, but it's not an actual requirement I believe (if sans grant). Originally I thought it a waste of money, but for some houses who might have a long run of High voltage DC cables inside the house from the roof to where the inverter sits - it makes sense.
It's main function is to stop having those high voltage DC lines running "live" through the house when the main power is cut. That's why they specify "must be installed within 1.5m of where the wires enter the house". Nothing really to do with anti-islanding directly although it's a related insofar as the solenoid will break the connection to the inverter when the grid is cut, but yeah, a badly wired inverter back feeding the emergency power to the consumer unit and then out to the grid could happen with/without a firemans switch.
Aside: It's not a requirement in the north or the UK to have a fireman's switch.
Get clarity immediately IN WRITING that the guys you PAID are the responsible party
I wouldn't be happy with the arrangement to be honest. You research your companies, get quotes, make an informed decision and then you end up getting someone else?
Sorry if this is the wrong thread for this question. But I have an install going in as we speak. Got a quote/paid a deposit from *company A*. But an different company(*company B*) is doing the install. I assume they've have just been sub contracted and is fairly standard?
Mod:removed names
Yeah, still it's still not a must.
As for the emergency/backup output. If improperly connected, a fireman switch won't effect it as it will still be running from batteries.
Straight inverters don't have a backup output.
The fireman switch is not for anti-islanding. It is for disconnection of the panels.
I'd have one if I had everything in the attic.
Dictionary definition of SHOULD. past tense of shall. [modal verb] 1. a — used to say or suggest that something is the proper, reasonable, or best thing to do.
Makes sense to put the warnings everywhere. It’s not like you don’t get enough stickers on the sheet.
The answer would have to be yes; many inverters have a “emergency” AC output that is always live; and would remain live in a situation where the grid power is down (and no projoy automatic dc isolation switch is installed). It’s possible that this emergency output is connected into the household electrical system in an improper manner which would result in backfeed.
I’ve read of several potentially poor implementations that believe they are mitigating all the risks of backfeed; but then later figure out that they are still sharing a neutral or PE route back to grid.
Big difference between should and must.
Regarding off grid use/changeover switch - The changeover switch is an interlocked device that will isolate the grid from the inverter. same if you were running a generator.
Argument could be made that in attics the DC isolators are not accessible vs if they were on an outside wall. The fireman switch is not for anti islanding, but is for the fire regulation as you have said. Its still a should, not a must.
The way I read it...
provision should be made for the isolation
...is not definitive, so it's recommended but optional.
EN50549 (superseded by I.S. EN50549-1) and requires that each generator have "Means to detect island situation" as detailed in part 3.8. So if fire-safety is the concern then the meter box needs to be marked with the regulatory stickers as per part 3.14 (Labeling).
At the ESB Networks metering position of a location where a Micro-Generator is installed
Can a solar inverter can feed back to the grid if it has no AC supply ?
@graememk how are you suggesting one should comply with this reg?
Backup operation is permitted so long as the below conditions are met;
- The backup supply from the PV and battery energy storage system must be on the load side of the ESB meter and cannot feed any other premises.
- The requirements of I.S. 10101 must be met, particularly relating to the requirements of ‘standby supply’ and break-before-make changeover switch, and the requirements for neutral treatment in island mode and impacts on protection operation.
- There can be no circumstances where the PV and battery system will feed energy into the grid during backup operation.
- Ensure that, by design, loss of mains (LOM) protection is not compromised. This could be either by relocating LOM to ESBN-Customer interface or by interlocking LOM changeover switch.
Section 5.4.5 of Building Regulation TGD B - Fire Safety (2017) states that “where Photovoltaic (P.V.) panels are provided on buildings, provision should be made for the isolation of the panel array externally and in accordance with ET101, 2008” which has been replaced by I.S. 10101.
For all live conductors where a risk of electric shock is involved
Must act as directly as possible on the appropriate supply conductors
Accessible, readily identifiable and convenient for intended use
The inverter does that. It's built into every grid tied inverter, it's how grid tied inverters work.
That’s not true. It’s part of building regs / electrical regs unless there is some other means of isolating the DC strings externally or automatically preventing your inverter from feeding back to the grid.
I see, then yes two of them. I was lucky the installer used 2 of these so can use 4 strings in total.
Will end up with 3 strings in total, 2 x 6 ( x360w) in the 3.5kw and 1 x 8 (x360) in the 2.5
No need for the fireman if you are not getting a grant.
Looks the same as mine so yeah it should have another input, projoy, I have 2 strings of 12 connected to it no problem.
If you look underneath you will see the - and + labelled there.
Check the model of the fireman switch. It might have a second pair of unused inputs/outputs.. Though with 12 panels you might be looking to go with two strings, in which case, your original idea sounds fine.
Adding a second inverter, 12 more panels so I will have a 3.5kw & 2.5kw inverters, current inverter is hybrid, wired to fireman switch. Is there any reason I cant just connect a second fireman switch off this wiring as per image
Thanks for the reply, appreciate it.
I really rate the Fogstar stuff and the customer service responses when I had questions.
I was intending to get 6 of their rack batteries myself but when I discovered they would not physically fit in my loft I decided instead to build a couple of Seplos 280L kits.
If you can, I would get a rack cabinet for them as well, keeps everything nice and neat.
Nothing fancy. Just converts the 1000imp/kWh LED pulses into instantaneous power. Works with non-smart digital meters too.
How exactly does that app work? You need the smart meter but do you also need a smart tariff? Can you add multiple meters?
Hey, I'm looking for some battery advice, please. I am getting my solar PV installed on December 5th. System 5.66KW E/W split with a hybrid inverter, no battery. I have been reading through this thread and found it very informative, so thanks for that. Many of ye have built your own batterys and have very impressive systems. Im looking for a pre-built battery that I can hook up to the system myself. I dont have time at the moment to attempt to build a battery. I have seen Fogstar mentioned previously in the thread; at the moment, they have a black friday sale and have a 5kw battery for £999.
Specs are as folows:
Any thoughts on this, any advice appreciated. Thanks
