From beginning of March to the end of October should be a considerable increase.
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Solar panels and battery - any real world reccomendations?
- Thread starter GinG
- Start date
I have a quote for 20 panels (415w) plus battery 9.5kwh on south facing roof. Could add another 2 panels for £750 and/or increase the battery to 11.9kwh for £1,200. Just trying to work out how to calculate whether these increases makes sense. I think probably yes to the panels but maybe not for the battery? Our current usage is c3,600kwh. Thanks in advance for any advice.
@viking3
2 panels for £750 seems very dear, same with an extra 2.4kwh battery for £1200
for comparison the company that i used for my pv installation 3 weeks ago quoted £210 per panel (jinko neo 440w) installed, and £1450 per 5.12kwh battery (sunsynk L5.1)
just out of interest what is your current full quote?
2 panels for £750 seems very dear, same with an extra 2.4kwh battery for £1200
for comparison the company that i used for my pv installation 3 weeks ago quoted £210 per panel (jinko neo 440w) installed, and £1450 per 5.12kwh battery (sunsynk L5.1)
just out of interest what is your current full quote?
@viking3 that's a pretty high capacity inverter for a 8.3kw system, have they overspecced your inverter by mistake?
either way, that quote appears on the higher end of reasonable, mostly because the scaffolding works and installation costs are fixed, regardless of the size of system you're installing
in perspective, mine was 10x 440w, 3.6kw hybrid inverter, 5.1kwh battery for £6885 all included
i would've expected that yours would come under £11k tbh, £12k at a push
either way, that quote appears on the higher end of reasonable, mostly because the scaffolding works and installation costs are fixed, regardless of the size of system you're installing
in perspective, mine was 10x 440w, 3.6kw hybrid inverter, 5.1kwh battery for £6885 all included
i would've expected that yours would come under £11k tbh, £12k at a push
They can do a GivEnergy 5kw hybrid & 9.5kw battery for £511 extra instead of the Luxpower/Hanchu. Lower battery charge/discharge and lower overall PV output but I wonder if the GivEnergy support and software (Octopus integrations) are worth it?It's alright, not sure what the long term support will be like with Lux and Hanchu though. Hardware costs (at retail ex. VAT) with better 415w panels and a 15kWh Fogstar battery are ~£4200, using a Solis Hybris inverter. If I were you i'd ask for them to up the panels to 435w, you can never have enough kWp.
Shropshire
Associate
That's a Fox KH10.5 inverter with four PV strings. I'm guessing the 20 panels are over several different roofs? That's the only reason I can think why they've specced it over a smaller inverter.
Soldato
Hi Guys, just wanted to get your input. We've building a house and it's looking unlikely we'll be connected to mains power. This is fine with us as long as we have enough capacity to run everything we need, we work from home, but it's only 2 of us and we're usually together so i don't think our consumption would be massive. The house should also be pretty efficient to minimise needs for heating/AC
Here's the spec pulled from the builder. It seems hefty enough from what reading i've done, but i'll admit to not being an expert. Is it Enough/too much?
For background info, we'll be based in Spain so likely to get sun even during the winter. However there can be times where it might rain/be cloudy for a few days and i imagine that's where the high capacity batteries come in. The last thing we need is to run out. Although we'll likely have a diesel generator to provide backup if ever needed.
Any improvements/changes you guys would make?
Here's the spec pulled from the builder. It seems hefty enough from what reading i've done, but i'll admit to not being an expert. Is it Enough/too much?
For background info, we'll be based in Spain so likely to get sun even during the winter. However there can be times where it might rain/be cloudy for a few days and i imagine that's where the high capacity batteries come in. The last thing we need is to run out. Although we'll likely have a diesel generator to provide backup if ever needed.
Any improvements/changes you guys would make?
Soldato
Thats a lot of generation potential.
20kwh is quite a lot of storage, 2-3 days I would guess unless you cook a lot etc
You really need to understand your usage pattern.
I haven't converted to English, but I cannot see an obvious backup to solar. I wouldnt go off grid even in high production areas without one.
Something could fail on panels and you have no backup. Inverters can also fail, you would be without power. I would look into costs of have 2 inverter based system personally.
I would be asking to have a small generator installed. Doesnt need to be high, something like 2kwh diesel, if your batteries were getting very low due to say low solar for a week, then you would fire that up for a few hours to recharge you batteries a bit.
Your correct spain will generate a lot more and with 11kwp thats some power to kick in, although looks like the inverter is 8kwh many will accept higher, but not all so you may be capped at 8kwh.
Is your pool going to be heated at all.
When solar is doing well its can massively over generate, I could imagine you could be well into high xx kwh, maybe even touch xxx kwh per day range at peak times, which will mean you will significantly under produce compared to potential since you will have no where to send it.
Thought was could you divert to pool maybe?
Ev would also obviously be ideal, but depends on local charging for when solar isn't super strong.
Do you plan on a hot water tank, excess solar with no where else to go is also very suited to going to hot water.
20kwh is quite a lot of storage, 2-3 days I would guess unless you cook a lot etc
You really need to understand your usage pattern.
I haven't converted to English, but I cannot see an obvious backup to solar. I wouldnt go off grid even in high production areas without one.
Something could fail on panels and you have no backup. Inverters can also fail, you would be without power. I would look into costs of have 2 inverter based system personally.
I would be asking to have a small generator installed. Doesnt need to be high, something like 2kwh diesel, if your batteries were getting very low due to say low solar for a week, then you would fire that up for a few hours to recharge you batteries a bit.
Your correct spain will generate a lot more and with 11kwp thats some power to kick in, although looks like the inverter is 8kwh many will accept higher, but not all so you may be capped at 8kwh.
Is your pool going to be heated at all.
When solar is doing well its can massively over generate, I could imagine you could be well into high xx kwh, maybe even touch xxx kwh per day range at peak times, which will mean you will significantly under produce compared to potential since you will have no where to send it.
Thought was could you divert to pool maybe?
Ev would also obviously be ideal, but depends on local charging for when solar isn't super strong.
Do you plan on a hot water tank, excess solar with no where else to go is also very suited to going to hot water.
Ah that makes sense
Soldato
@Martynt74
I'd go for a Quattro over a Multiplus, the Quattro has secondary input for a generator (which is a must for off-grid), the Multiplus may have the option, but I'm pretty sure that was the major benefit of the Quatro. I'd also go for different batteries, you could get 30 kWh for similar money, it is also easy to add more.
Edit. Just checked Multiplus doesn't have two inputs, so you need the Quattro. It will also be able to automatically start the generator. If you can afford it, get the largest version, it's a big investment and you don't want to find you're underpowered in a few years time.
www.fogstar.co.uk
You can also buy similar direct from China.
I'd go for a Quattro over a Multiplus, the Quattro has secondary input for a generator (which is a must for off-grid), the Multiplus may have the option, but I'm pretty sure that was the major benefit of the Quatro. I'd also go for different batteries, you could get 30 kWh for similar money, it is also easy to add more.
Edit. Just checked Multiplus doesn't have two inputs, so you need the Quattro. It will also be able to automatically start the generator. If you can afford it, get the largest version, it's a big investment and you don't want to find you're underpowered in a few years time.
Solar Battery Storage | Fogstar UK
When it comes to solar battery storage, we understand that choosing the right storage solution for your solar energy is crucial, which is why we offer a range of options to suit your installation.
www.fogstar.co.uk
You can also buy similar direct from China.
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No - It's on one long south facing roof - but they just seem to use the same inverter as a quote I'd had from them for a smaller number of panels. Our local council have done a bulk purchase deal and are recommending it to residents and therefore I was hoping that the £s and the equipment used would make more sense and £s would be more competitive. I'll ask them about the inverter but sounds like I may need to get some more quotes
Soldato
@Martynt74
I'd go for a Quattro over a Multiplus, the Quattro has secondary input for a generator (which is a must for off-grid), the Multiplus may have the option, but I'm pretty sure that was the major benefit of the Quatro. I'd also go for different batteries, you could get 30 kWh for similar money, it is also easy to add more.
Edit. Just checked Multiplus doesn't have two inputs, so you need the Quattro. It will also be able to automatically start the generator. If you can afford it, get the largest version, it's a big investment and you don't want to find you're underpowered in a few years time.
Solar Battery Storage | Fogstar UK
When it comes to solar battery storage, we understand that choosing the right storage solution for your solar energy is crucial, which is why we offer a range of options to suit your installation.
You can also buy similar direct from China.
Awesome thanks guys. I'll make sure they upgrade to the Quattro as the ability to add in a diesel generator is crucial as you say.
We did consider a pool heater but sacked off the idea, mainly due to cost of the heater and also the lack of ability to get above a 5C differential, so if it's 7C outside we were told we'd only really hit 12C water temp and that's still too cold to be enjoyable. I do plan on adding a hot tub though. Would've loved a log powered one, but given we'll likely have lots of spare capacity then it makes sense to use electric.
We'll have a hot water tank though.
On the panels, i assume the 11kwp is at peak capacity, so overspeccing on panels but only having an 8kw inverter means we're more likely to hit the 8kw level even in sub optimal conditions.
Do you guys have any thoughts on the arrays which track the sunlight and adjust? Not sure whether it's needed as much in somewhere like Spain vs further north where you may get much more lower sun day.
Associate
In all honesty that inverter will serve you well. It'll never clip regardless of generation and you'll be able to charge and discharge the batteries at a very high rate (up to 48A) The batteries are modular so you can have up to 7 aswell at about £600 each.
It's a good quote.
Soldato
I will leave anything Victron to ronski as hes the forum expert on that one I think (well without doubt amongst the active posters)
I would if I was you however also look at a second inverter. Are you roof mounting, or tracker mounting, or still unsure.
The tracking systems either work on fixed alignment (ie the just rotate) or some also tilt, so they perfectly track the sun from low to high and back to low as they rotate.
Ronski would need to say how easily victron inverters play in serial/parallel, but you could maybe do roof mounted for one inverter with maybe the backup gen as well, and another smaller inverter with a tracking system.
The highest failure rate amongst solar is inverters. They typically have a lifespan not much over 10 years average. So bear that in mind.
Two systems based on sep panels with sep inverters will give you far more backup in case of a failure.
Ofc the inverters can be purchased fairly quickly but your not going to want to mess about if you have a failure with no grid to fall back upon.
Will cost more to double up for sure, but if it was me I would.
The hot water tank diverter is a cheap unit but not sure how it would or if it could work based on they normally look for export happening and divert if the water isn't hot.
Again I think ronski is likely to know potential in regards Victron, but in general they have a lot of flexibility and are the go to for large especially offgrid installs. (the origin iirc was more canal boats etc)
They are simply a smart diverter that uses the normal heating coil to divert excess electricity.
I mention pool heating since if you have solar potential and no other way to use it, then it seems to be a waste.
You dont need to worry about efficiency if its literally generation that would go to waste. So you could just go with a simple inline water heater and have it in the pump "house".
A hot tub though may be perfect using the same theory as a hot water tank diverter.
Just send excess energy to the hot tub to run that heating coil. It should cut itself off if the hut tub is at max.
Edit tracking are supposed to produce about 30% more than pure south facing which itself is about 25% more efficient then pure east or west.
There is some advantage to having multiple facings if the weather is variable. Rotating gets round this perfectly.
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Soldato
There are a couple of others on here that are very knowledgeable when it comes to Victron. It is a very flexible system, and a highly configurable system. You can parallel multiple Victron inverters, but it adds complexity, but if you wanted redundancy it would be a good idea
With most Victron inverters the PV is not connected to the inverter, it's connected to solar charge controllers (MPPT), these are connected to a 48v busbar system, which the inverter is also connected to, and via a shunt to the batteries. You could have 16kW of solar connected, and the full 16kW would be used to charge the batteries presuming that side of the system was up to handling the current and the inverter wasn't drawing anything.
@reef think you might be muddled with 48A, when I grid charge I'm sending 130 Amps to the batteries, this is restricted by my 8kW inverter, when I discharge I'm often pulling 180 amps from the batteries. I would certainly not go with Pylon tech batteries, there are much better options now.
With most Victron inverters the PV is not connected to the inverter, it's connected to solar charge controllers (MPPT), these are connected to a 48v busbar system, which the inverter is also connected to, and via a shunt to the batteries. You could have 16kW of solar connected, and the full 16kW would be used to charge the batteries presuming that side of the system was up to handling the current and the inverter wasn't drawing anything.
@reef think you might be muddled with 48A, when I grid charge I'm sending 130 Amps to the batteries, this is restricted by my 8kW inverter, when I discharge I'm often pulling 180 amps from the batteries. I would certainly not go with Pylon tech batteries, there are much better options now.
Soldato
Awesome thanks again. I think i need to spend some more time doing actual research into this. Realistically it's many months away, i'm also debating whether it makes sense to try and integrate some of the home wind generators as a backup option for periods of bad weather. I guess the main thing is to leave myself open to upgrades in the future.
I think i'd risk a single inverter given the cost at the moment. I could likely pick one up the same day if it came down to it and could make do without power. Especially with a diesel generator to run as backup. The plan is for the house to be pretty efficient, and so power consumption should be able to run pretty minimally if needed.
I think i'd risk a single inverter given the cost at the moment. I could likely pick one up the same day if it came down to it and could make do without power. Especially with a diesel generator to run as backup. The plan is for the house to be pretty efficient, and so power consumption should be able to run pretty minimally if needed.
Soldato
@Martynt74 from what I've seen most the home wind turbines are useless especially if they come from China. In case you haven't noticed there's some links on my signature for my build thread, and also to my Victron VRM.
Associate
The HV25s are high voltage. My five run at about 260v so in theory at 48A they can charge/discharge up to 12kW if warm enough.
When I'm charging at 5kW they are pulling about 20A.
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