Newbie with a lot of questions

[frozengiblet]

Hi All.

I stumbled across this very useful forum while trying to do some research on my first Solar PV system and am hoping you would be able to help what is quickly becoming a very complex process for something I thought to be very simple e.g. buy panels, inverter decide if I want batteries and get it all installed.

Now I have gone to a couple of companies that provide the whole process and based on giving them the same simple requirements I was shocked to see that one was nearly double the price of the other. This has lead me to believe that the main factor comes down to the components being selected and that if I want to get the best value for money and the functionality and benefits I'm looking for.

So to that end, heres a bit of info on my situation:

Annual house usage is ~7500 KWh which will likely go up as looking to move to an EV
The house has space for 5-6KWp system with high output panels and is 10 degrees off south with a pitch of 38 degrees so near ideal orientation I have been told and being in the south west will help generation too.
I am also considering putting some panels on the East and West roof space that would help manage the typical morning and evening peaks of usage and this could see the total size go up to 8-9KWp system.
Battery backup is desirable to ensure I use as much of the electric I generate rather than exporting but this seems very costly and we suffer on average a couple of small outages a year and would like to be able to maintain supply in a power cut.
Single Phase supply with 100A fuse.

So my questions are:

• What is a good inverter and size for this arrangement (both south only and with E/W panels) that can also support the batteries and not cause me issues with getting DNO approval?

• Battery wise I am looking at Pylontech (how I found the forum) as these seem the perfect solution for a modular system to be ran in series and parallel and not break the bank. How easy are these to incorporate into the system and will they require any specific equipment or dictate the type of inverter I need?

• If I am going for an South with East and West panels will this require any additional equipment e.g an additional inverter, optimisers etc

• If using batteries will I need a certain number based on the size of inverter(s) I choose?

• I am also keen to ensure that I use any excess before exporting and looking to use incorporate the Myenergi Eddi is this a suitable choice or are there better alternatives.

I dont know if I am overthinking this and as long as I give these details someone that can do the whole process from start to beginning then there wont be much difference between the final solutions but the range of prices I have received so far has confused what I thought would be a simple process. Any recommendations of design and kit for this system or good companies that can help me through this would be appreciated.

[Countrypaul]

Welcome.

It would be worth you posting some details of the quotes you have had , number and model of panels, model of inverter.
If you are getting an EV the it is worth making sure any PV diverter can work with both the EV charger and the resistive load diversion - in that regard the Eddi along with a Zappi might have benefits.

If you have 3 sets of panels (E, S, & W) then you have 3 different inputs to your inverter(s) - that may make things a little more complex.

[frozengiblet]

Hi Paul,

To provide details of my quotes.

The cheaper of the two is:

14 x Jinko 360W Tiger N-Type All Black Mono Panels
Givenergy 5kw Hybrid Inverter including Givenergy breakers, wifi dongle and CT clamps
Givenergy 8.2kWh LiFePO4 Battery (ideally I would be looking for more so would affect the price)
Fastensol mounting kit
labour
excludes scaffolding

The more expensive is:

15 x Sunpower Maxeon 3 400w panels
Fronius Primo 5kW (With WLAN)
Tesla Powerwall 2 with Gateway
Schletter mounting system
Labour
Includes Scaffolding

I have found that there is a big difference in price in some of the components e.g. the batteries and panels themselves but this leads to part of my question, is the higher price for the premium products actually value for money. Can I scale back some of these specs and add other bits like Pylontech batteries at a later date for less and still have the functionality I want?

[Stinsy]

Hi All.

I stumbled across this very useful forum while trying to do some research on my first Solar PV system and am hoping you would be able to help what is quickly becoming a very complex process for something I thought to be very simple e.g. buy panels, inverter decide if I want batteries and get it all installed.

Now I have gone to a couple of companies that provide the whole process and based on giving them the same simple requirements I was shocked to see that one was nearly double the price of the other. This has lead me to believe that the main factor comes down to the components being selected and that if I want to get the best value for money and the functionality and benefits I'm looking for.

So to that end, heres a bit of info on my situation:

Annual house usage is ~7500 KWh which will likely go up as looking to move to an EV
The house has space for 5-6KWp system with high output panels and is 10 degrees off south with a pitch of 38 degrees so near ideal orientation I have been told and being in the south west will help generation too.
I am also considering putting some panels on the East and West roof space that would help manage the typical morning and evening peaks of usage and this could see the total size go up to 8-9KWp system.
Battery backup is desirable to ensure I use as much of the electric I generate rather than exporting but this seems very costly and we suffer on average a couple of small outages a year and would like to be able to maintain supply in a power cut.
Single Phase supply with 100A fuse.

So my questions are:

• What is a good inverter and size for this arrangement (both south only and with E/W panels) that can also support the batteries and not cause me issues with getting DNO approval?

• Battery wise I am looking at Pylontech (how I found the forum) as these seem the perfect solution for a modular system to be ran in series and parallel and not break the bank. How easy are these to incorporate into the system and will they require any specific equipment or dictate the type of inverter I need?

• If I am going for an South with East and West panels will this require any additional equipment e.g an additional inverter, optimisers etc

• If using batteries will I need a certain number based on the size of inverter(s) I choose?

• I am also keen to ensure that I use any excess before exporting and looking to use incorporate the Myenergi Eddi is this a suitable choice or are there better alternatives.

I dont know if I am overthinking this and as long as I give these details someone that can do the whole process from start to beginning then there wont be much difference between the final solutions but the range of prices I have received so far has confused what I thought would be a simple process. Any recommendations of design and kit for this system or good companies that can help me through this would be appreciated.

There is a lot to digest in this post. Often in life there isn't one "best" solution, there are several ways to go allofwhich are perfectly sensible. I'll address your questions:

What is a good inverter and size for this arrangement (both south only and with E/W panels) that can also support the batteries and not cause me issues with getting DNO approval?

Inverters are reliable these days. There are plenty of good brands and few to avoid. You have two routes:

• A 16A inverter. This doesn't need "permission" from the DNO, you just need to inform them afterwards. While your array can be as big as you like, the maximum power is 3.6kW (any generated above that goes to batteries or is wasted).

• A bigger-than-16A inverter (eg 6kW). If you're getting a professional install you shouldn't be shy away from having the company doing the install do an application for 5or-6kW, it is just a form nothing arduous. Given you're considering a 9kW array this is probably the best route.

Battery wise I am looking at Pylontech (how I found the forum) as these seem the perfect solution for a modular system to be ran in series and parallel and not break the bank. How easy are these to incorporate into the system and will they require any specific equipment or dictate the type of inverter I need?

The easiest solution is a "Hybrid inverter" this is a single device that connects to your solar panels, the grid, and your batteries and does all the hard work. I too have Pylontech batteries they're the best around for price/performance/upgradability/reliability. However: batteries are expensive, there is no way around it. Get what you can afford now and add more later...

If I am going for an South with East and West panels will this require any additional equipment e.g an additional inverter, optimisers etc

More than one way to skin a cat! I'd suggest plugging your main south-facing array directly in to your inverter and having the other two arrays charging the batteries via a charge-controller. However some inverters have inputs for 3x arrays.

If using batteries will I need a certain number based on the size of inverter(s) I choose?

No "ideal" it depends on your lifestyle (how much power can you use while the sun is shining?), and whether you want to timeshift from the day to the evening or you want to cover a sunny day running in to a cloudy day. 2x or 2x your kWp of solar in usable kWh of battery capacity is a good starting point.

I am also keen to ensure that I use any excess before exporting and looking to use incorporate the Myenergi Eddi is this a suitable choice or are there better alternatives.


Yes the Eddi is probably the best of its kind in the market. Particularly as it works with the Zappi EV charging point.