Random Renewables Thread

ELM327

Because it's not necessary. There's a manual isolation switch for everything. If theres a grid power outage during the day, that shouldnt affect my generation.

DC999

Ah, I added the wrong info I think. I've 2 manual switches outside my house. I thought they were the fireman's switch. Or is that the automated one that turns off when the power goes of and back on when it's back on?

bullit_dodger

The fireman's switch is a box which has to be within 1.5m of where the DC power lines enters into your house. For most people, this is in the attic. It doesn't have to be accessible (easily) as it's function is really to remotely kill the solar power along the wires carrying the DC current from where it enters the house to your inverter.

In the scenario of where your inverter is right next to where the wires enter the abode, the firemans switch is somewhat useless as it's main function is to stop having 400-600V DC lines "live" in the house where you might have a fireman swinging an axe and the inverter is a good distance away from the entry point. When the power to the house gets cut the spring loaded switch opens the circuit and makes the lines safe.

The two isolators you have DC999 are probably one for each string, but I couldn't say for sure without seeing it.

slave1

https://www.boards.ie/discussion/comment/119848585#Comment_119848585

but those switches are manual, anyhow each to their own, in the grand scale of costs they were not going to bankrupt me and I couldn't be arsed removing after grant approval

ELM327

https://www.boards.ie/discussion/comment/119848657#Comment_119848657

Yes, fireman switch is automated. The manual switches are likely isolators and you need those for sure.

https://www.boards.ie/discussion/comment/119849077#Comment_119849077

I've already paid for it, part of the SEAI program, but I will be removing it as soon as the 2400 hits my bank and I know I'm not being inspected. A nonsense requirement, everything has an isolator switch on it and I don't want to cease generation just because the mains is off? When I'm off grid there won't be a mains at all so it has to be removed anyway.

slave1

I've so many manual switches at this stage, AC/DC I must have 6 of, one set for each PV inverter and another set for Battery Inverter, so much boxes and cabling, another one for the Zappi too actually

the_amazing_raisin

You could probably achieve the concept of bypassing the firefighter switch with a remotely operated transfer switch and some home automation

Basically the switch is normally on the firefighter switch output. Power cuts and solar panels are isolated, and the firefighters are safe. You still have backup power from your battery

In the case of a grid failure, after you've ensured the house is safe then you trigger the transfer switch to bypass the fireman switch and reconnect your PV

I hope it's a reasonable assumption that no-one is going to worry about their solar panels generating if the house is on fire, so you'd only trigger the bypass in the case that the house is safe

When the grid is restored then you have something which is watching the grid connection and resets the transfer switch to using the fireman switch

The transfer switch could also be wired to the smoke alarms, so if they trigger the solar is isolated as well

I see the merit in both arguments. It's a bit silly having solar and not being able to use it in a power cut. Similarly, firefighting is a difficult enough job without worrying about getting electrocuted

I think the current blanket statement of "no solar in a power cut" should be revisited and if there's a safe way to work around requirements then it should be allowed

con747

https://www.boards.ie/discussion/comment/119849358#Comment_119849358

Totally agree, I will be removing mine as well soon so I can generate during power cuts. My installer said it's not even a requirement in the north just down south.

slave1

Will you be able to consume that generated PV during a power cut or will it just charge batteries?

con747

https://www.boards.ie/discussion/comment/119850843#Comment_119850843

Should do both.

bullit_dodger

https://www.boards.ie/discussion/comment/119850362#Comment_119850362

I'd advise caution there. I'm not saying don't do it, but at the same time, I think removing it still might not enable you to achieve what you think you will be able to. All our inverters (well 99% of them) are grid tied-in, as in it's the grid power (220v ac) which powers the motherboard mostly and enables them to do their magic, barring of course the battery -> EPS route.

So in order for the inverter to work, you'd have to back-feed the EPS outlet as the inverter input. That would perhaps be "not a wise" thing to do. Different makes/models also will want to see how the grid CT clamp on the grid is working (so it can take excess). I think you could be a "test pilot" there with the route you'd have to go - possible invalidating your warranty on your inverter. Dunno - but it's likely.

I've somewhat the same feeling about the firemans's switch in general (especially if it's a short run of 1-2m anyway to the inverter, it's kind of pointless) but removing it from the loop may not solve the other issues.

Also, if you do go mucking about with the firemans switch - be super super careful. That's potentially close to 600V DC there going into it. (Do it at night would reduce risk as no solar output)

con747

https://www.boards.ie/discussion/comment/119850947#Comment_119850947

I'll leave that up to the installer! He has a few bits to do and said he would do that as well. I will post here if I get it done but he's up to his tonsils at the minute so I'm down the list.

irishchris

https://www.boards.ie/discussion/comment/119850947#Comment_119850947

No grid connection is needed for it to produce power during an outage but you do have to make sure to turn the AC isolator off to the inverter so it is not back fed it's own power.

Obviously need a generator switch to ensure no power fed back to grid also but my ground mount system works away producing power during day from panels whilst also charging up the batteries and running the house in a grid outage

ELM327

https://www.boards.ie/discussion/comment/119850843#Comment_119850843

It will do both. Everything will be the same except the inverter will not generate more than the house load + battery max input (You'll see this as an EPM), as there's nowhere to backfeed the excess to.

If you have a battery bank that can supply 100A or more and the inverter to do it, and you have wired most sockets and lights circuits to the EPS as opposed to the main grid connection, then you can continue as normal in a power outage.

(No one suggested backfeeding through the EPS. This may or may not work depending on the inverter but I woudlnt reccomend it!)

bullit_dodger

https://www.boards.ie/discussion/comment/119851282#Comment_119851282

Not 100% that all inverters support that. Sure, EPS power out yeah, but to my knowledge (and for sure I could be in error) I think they'll only do the battery ->EPS socket and not convert power from solar into usable power for battery etc.

ELM327

https://www.boards.ie/discussion/comment/119852710#Comment_119852710

I know Victrons do, and I'm pretty sure Solis do too. The 6kW inverter has a 5kW limit on the EPS output.

idc

Don't see why the default for all inverters would not be battery + Solar => EPS socket. It works like that by default in Ireland is due to the firemans switch disabling the panels. I expect in other countries where they don't have the same restriction hence it be more obvious that in EPS mode you can use both battery + solar. Why would inverter ignore power from panels in EPS mode if its available - makes no sense!

My AlphaESS definitiely works this way, in outage with change over switch moved to off grid/EPS mode i have solar+battery available

bullit_dodger

As I said, depends on the inverter. Just because you have one that works (and that's great), I wouldn't presume that every device will do the same. I'm not 100% sure that the GivEnergy one that I have will do the same.

Using a Home Battery in a Power Cut, Home Battery Backup - Joju Solar

WILL SOLAR PANELS CHARGE THE BATTERY WHEN THE GRID GOES DOWN?

You’d assume it would, right? Unfortunately, it’s not always the case. More “cost efficient” backup systems will just discharge their stored energy when the grid goes down and the solar will turn off. This is partly due to the fact that if the battery inverter is smaller than the solar inverter then the solar inverter could overload the battery system. More expensive battery systems can be charged by the solar when the grid goes down. To do this, the battery inverter will have a higher capacity than the solar. Once the battery is full, the solar will either turn off or, if the systems can talk to each other, the solar will ramp down to match the building’s load exactly.

irishchris

https://www.boards.ie/discussion/comment/119852871#Comment_119852871

possibly some dont alright but with the solis 4g and 5g inverters I can vouch it does allow use of solar panel power and batteries in backup mode as have unfortunately had couple grid outages over last two years

the_amazing_raisin

https://www.boards.ie/discussion/comment/119852762#Comment_119852762

Most Victron hybrids have 2 outputs. Interesting design feature is that the AC1 output is the critical loads and AC2 is the limited one. Typically seems to be 32A or 50A on the bigger ones

I think it comes from the off grid idea, so you'd put something power hungry like your immersion heaters on AC2, so they don't accidentally drain your battery in a power cut. And you still have full power from the inverter for critical loads

ELM327

https://www.boards.ie/discussion/comment/119854493#Comment_119854493

Yes I was talking about the Solis 6kW having 5kW peak limit on the EPS. I don't know what the victron has as an AC1/AC2 limit but I'm a real fan of them and probably will swap out my solis for a 10 or 15kva quattro next year. They are designed for great offgrid operation, expensive for what they are but they are the best out there.

unkel

If you want the best, get an SMA sunny boy.

ELM327

https://www.boards.ie/discussion/comment/119856488#Comment_119856488

Does any Irish based installer support this?

I had been having difficulties finding someone to do the Quattro install but there's someone in cork that I found that does it. I would much prefer getting someone in to do the install. I can add batteries or a couple of panels - not on a roof - myself but for an inverter I'd prefer to pay someone.

the_amazing_raisin

Okay, I'm going to harp on about the fireman switch a bit more. I'm trying to get my head around the SEAI requirements. There's the infamous section 4.7 on the fireman switch

Okay, seems fairly straightforward. You need an automatic isolation switch which cuts the output of the solar panels to the house. It has to happen upon "removal of the AC supply" to the house and can't be from a dedicated switch.

It has to be the same switch that disconnects the house also disconnects the solar

But then there's section 4.9 concerning off grid and backup power situations

So it says that section 4.7 can be achieved using the requirements under backup power

It's also important to note that backup power is defined here as PV and battery storage. This implies that the solar panels are included in the backup power supply and it isn't battery only

Here's the problem, I cannot see anything in that section which seems to clarify the requirements around the fireman switch. It all seems to be around grid isolation to prevent the system feeding power to the grid

The only part which seems relevant is the statement around moving the LOM protection to the meter box

So, if I'm reading that correctly (and I'm probably not) then you can have the fireman switch fed by the backup power supply, on the condition that there is a single switch in the meter cabinet which isolates the grid supply to the house and also isolates the PV array. That switch also needs to lock in the off position, so that it cannot be returned to the on position accidentally

Finally, there's the recent technical bulletin which seems to throw all of that out the window

So it seems that SEAI are contradicting their own code of practice

Personally I think this is something they need to address pretty soon as it's just going to lead to people removing the fireman switch in a power cut which completely defeats the purpose of one

Other countries are quite able to have solar panels providing backup power without electrocuting their firefighters, so I don't see why Ireland needs to be special

Jonathan

Most of us are pretty clued in as to the grid's greenest times anyway, but I see ESBN have launched their "Is this a good time" pilot.

https://www.esbnetworks.ie/who-we-are/beat-the-peak/is-this-a-good-time

I've signed up but haven't received any emails/SMS yet. If decent I'll recommend to family members.

unkel

Signed up too, but expecting just a load of spam from it.

graememk

https://www.boards.ie/discussion/comment/119858728#Comment_119858728

There was chat of being "rewarded" at the end of this earlier on in the year.

I'm an exception though. I have enough battery storage + power that I don't influence the peak at all.

Ubbquittious

https://www.boards.ie/discussion/comment/119857699#Comment_119857699

Its just that same really overcautious obsessed with insurance & liability attitude that you see from the same civil servants who give us all our signalised roundabouts. These lads don't ever have the ability to say "Ah, thats grand, horse away". They'll have to put some twisht in the tail to leave their mark and slow people down

the_amazing_raisin

https://www.boards.ie/discussion/comment/119859385#Comment_119859385

Yeah and I get SEAI's viewpoint, they want to ensure a safe solution for firefighters and the simplest answer is to just force the ultra conservative system of disconnecting the solar in a power cut

Okay, fine, I see their point

But, it really shouldn't be up to them. SEAI isn't a technical body, at least not in the way that they would be familiar with wiring up solar panels. The fireman switch should be described in IS 10101, or whatever the rules regarding fire safety are.

As far as I can tell, SEAI basically took those requirements and narrowed it down to a fixed solution for everyone

And then they seem to contradict themselves in the way I mentioned

My other issue is that this really shouldn't be in SEAI's authority to enforce, and I'm pretty sure it isn't beyond claiming the grant.

Safe electric are the body that enforces good practice among electricians, so it's really in their domain I think

ELM327

The only control SEAI have is the payment of the grant, nothing in legislation or on the DNO side. Once you get the grant, there's nothing wrong with removing the firemans switch installed per the grant requirements. This is what I will be doing. Long term, I'll be off grid anyway so there may not ever be a grid connection

silver_sky

So, I'm looking at moving the eddi from the attic downstairs into the hot press. Do I need an electrician for that?

bullit_dodger

Depends on the context of what you mean by "do I need an electrician". If you are talking about if it's a legal requirement, then no. If you are talking about do you (personally) need an electrician, then I guess it's down to how comfortable knowledable you are with electrics.

slave1

One of the advantages of the EDDI is its quiet operation because it has no fan, I would not position it in a hot press due to overheating. Could you drill a hole and mount it in a hallway perhaps?

silver_sky

https://www.boards.ie/discussion/comment/119872731#Comment_119872731

Yes, sorry I was querying the legal requirement. I'll have a look and see how things are up there.

https://www.boards.ie/discussion/comment/119872767#Comment_119872767

I could put it on the landing but it'll look a bit **** so I wouldn't, nor would the missus accept it either. I'll stick a thermometer in the hot press and see how it is but I don't think it's all that hot.

Jonathan

https://www.boards.ie/discussion/comment/119873076#Comment_119873076

I wasn't clear on the reason why you want to move it, but I have just seen another post elsewhere explaining. Your problem sounds identical to the issue I had with my data logging stick and poor signal in the attic. A RG58 SMA extension cable solved it for me. I think that would be the easiest and cheapest solution.

https://www.boards.ie/discussion/comment/119776157#Comment_119776157

silver_sky

https://www.boards.ie/discussion/comment/119873848#Comment_119873848

I actually tried that 🙁 3M extension and an external aerial. It worked far more frequently, but have had at least 2 dropouts in the past week. Stupidly there's no way to check the RF signal strength between ME devices. They can see something but wouldn't share what it is. Also it's not just a case of the Eddi dropping out, it takes the whole myenergi system with it so also impacts the Zappi.

Jonathan

https://www.boards.ie/discussion/comment/119873952#Comment_119873952

Is the antenna below the foil backed ceiling board? Or just closer to Zappi but still in attic?

the_amazing_raisin

https://www.boards.ie/discussion/comment/119873952#Comment_119873952

Instead of moving the Eddi, would it be easier to move the Hub? I'm guessing you've the older model which still requires the hub

Maybe a couple of homeplug ethernet adapters would let you move the Hub closer to the Eddi?

EDIT: Have you tried changing the channels on the Zappi and Eddi? I found I had to change channels a couple of times before I got good reception

silver_sky

https://www.boards.ie/discussion/comment/119874196#Comment_119874196

Still in the attic but closer to the Zappi.

https://www.boards.ie/discussion/comment/119874233#Comment_119874233

I've the Zappi V2 with the vhub. I had the Zappi V2 without the hub but it was having issues so myenergi swapped it out for the new one. All looked good after I swapped it out so I sold the old hub. 🙃

Jonathan

https://www.boards.ie/discussion/comment/119874253#Comment_119874253

The foil is the problem. Have you somewhere you can poke the antenna down through to the first floor to test?

the_amazing_raisin

https://www.boards.ie/discussion/comment/119874253#Comment_119874253

Darn, I'd definitely recommend trying different channels. Mine was very spotty signal at a distance of about 1 meter using the default channel. I think cycling through a couple of channels fixed it

I found it best to leave it for a day or so between testing channels to see if it stayed connected

It still drops every so often but for now doesn't seem to affect the system, although I don't have solar yet so we'll see how that goes

bullit_dodger

Just on the actual placement of the Eddi in the hotpress and the potential heat - I've mine in there a year now. No issues what-so-ever and yeah it does get a bit hot alright. I think the amount of heat that the Eddi generates internally is proporational to the current being pushed to the immersion, so one way of limiting the heat might be to allow a max usage of (say) 10A instead of the max inside the menu system.

Effectively you would be capping the immersion to 2200w (or there abouts), or lower if needed. Sure, heat is not good for it, but if the placement in the hot press was a requirement, I think you have a mitigation there anyway.

Aside: Inside my attic on a hot summers day with the sun beating down on the roof tiles could easily get to 35c-40c ambient.

silver_sky

https://www.boards.ie/discussion/comment/119874858#Comment_119874858

That's kinda what I was thinking. Attic temps got up quite a lot during the summer. I stuck a zigbee thermometer in the hot press earlier and the peak today was about 26C in there, so I think it'd be OK. As you mention, I could possibly scale back the amps slightly if needed.

https://www.boards.ie/discussion/comment/119874268#Comment_119874268

Sadly no, it's well sealed so I'd have to put a hole in.

the_amazing_raisin

Maybe just leave the attic door open for a while and see if the signal improves?

If your hot water cylinder is well insulated then it shouldn't get hot in your hot press. Mine doesn't seem to get any warmer than the rest of the house

silver_sky

https://www.boards.ie/discussion/comment/119877781#Comment_119877781

You can't actually see the signal strength. Myenergi devices don't show it.

Yeah the tank is insulated. I have a zigbee thermometer in there since yesterday and one outside on the landing also. It reads about 5-6 degrees higher inside. Peak around 26C which is fine. I'll scope things out at the weekend when I have time during the day. Too cold in the attic in the evenings after I finish work.

DC999

Wow, just did a check of my gas usage. Which I want to cut down on (primarily to reduce our household CO2). I never had a clue how much we used for cooking V heating before. Only using ~1kWh of gas a day for cooking, so costs us 13.5c per day (rate we pay for 1 kWh).

Used 1150kWh of gas overall for 2 months last winter (Jan to March) for both heating and cooking. So the 60kWh I’d use for cooking (over that 2 months) is a drop in the ocean - in a good way. 2 adults, 2 kids. But we tend to keep the house cool so our heating usage is low (house is small too but very leaky).

Now we’ve an EV and solar since earlier this year, we’re almost down to 1 energy bill from 3 – which is class. Petrol is gone, gas non existent at mo bar standing charges (until it gets colder and elec rads we’re using now won't cut it). So have just electricity and solar helps there of course.

We have an electric shower so not using gas for DHW tank. Will change to an electric cooker in the future (and our air fryer helps cuts down on usage).

unkel

And also there are gas plans out there that give you cash back. When I renewed in July, I got €220 cash back. This meant that if I used about 1100 kWh in gas for the year, I would have a zero bill, including standing charges! I won't make that, I will have to use gas central heating on very cold days (or use peak rate electricity) and we have a gas fireplace that's used too sometimes

I should be using at least 80% less gas than I used to, going forward though. Bigger inverter, even bigger battery and even more solar PV are going to be in place in the next couple of months.

DC999

Positive news story that France has passed a law that all carparks of more than 80 spaces need some amount of solar cover. I saw them in Portugal where a supermarket had rows of them. Everyone used them as it was really in summer. So in warmer climes, people will find them useful for shade. Once they become more common, people might start to want their own solar / renewables. Link: France to require all large car parks to be covered by solar panels | France | The Guardian

the_amazing_raisin

I've been trying to do some estimation of electricity usage of various cooking appliances

For standing appliances it seems to be much the same in terms of consumption. I guess you still need to put the same amount of thermal energy into the food

However, I've found a slow cooker only uses around 250W, so it would suit solar power really well as it can fit into your generation through most of the day, even on dim winters mornings

Air fryer is pretty frugal as well, only needs about 1.8kW. Compared to the 2-4kW used by the oven this is pretty good

DC999

https://www.boards.ie/discussion/comment/119882876#Comment_119882876

Slow cooker is a good idea. Low, slow heat into the kitchen too. I won't get a battery so am looking at lower watt devices like you. More likely they can use solar excess. I use a 400w electric heater at mo to easily heat the sitting room.

But even with a battery, an air fryer uses less power and finishes quicker than an oven.

Pretty much all devices have a lower energy setting. Dishwasher, washing machine. My tumble dryer has one that uses 1.4kw instead of around (so runs for longer).

Microwave has too. But would be a bridge too far for our family members :)