I used tigo optimisers on each of my 17 panels and it has been great to understand what is happening.

Great video, simply for garnering a wealth of informative answers in the comments! Thanks.

Very interesting. I too have been through this and have similar objectives. I mainly considered GivEnergy and Huawei. I've gone with a Huawei system 15kWh battery with 6kWh hybrid inverter from 8kWh PV powering a heat pump and also on Octopus Go with a Zappi and Eddie. The battery technology is the same Lithium iron phosphate (LiFePO4) but the Huawei is a high voltage battery at around 385V instead of GivEnergy 50V. The advantage with the Huawei inverter is that it can power the house with AC at 6kW max from solar whilst the battery simultaneously charges at 5kW (if there was enough solar!) and the battery can provide 5kW output. Whereas GivEnergy's hybrid shares it's 5kW maximum rating also it can only charge or discharge the battery at 2.5kW max. So if the house load was 4kW you'd only get 1kW into the battery. If your house load was 1kW you'd only get 2.5kW into the battery - so your solar goes to waste. I also found it was slow to ramp up, so every time you switch something on the first 16 seconds or so of extra demand is fed from the grid before the solar or battery ramps up to 100% of demand. All these spikes of grid energy add up during the day. That was when I enquired early in the year and they may have improved the spec as they recognised it was a disadvantage. The Huawei is much faster to respond so doesn't clock up all those initial load switches. The Huawei can provide grid tied mode which goes into standby when the grid fails, automatic backup (with an additional backup box) mode which is meant to keep critical circuits going, and a full off grid working mode. Theoretically the full off grid mode could power your house up to 5kW but as with any system primarily working grid tied it has to shut down or isolate when the grid fails otherwise it will attempt powering the grid which could be a safety issue down the line at a wire break that's expected to be dead. You are right to not be concerned about optimisers. As I was reminded only the other day, there are reverse biased connected diodes in solar panels to ensure that if a column of PV cells goes high impedance due to, say a leaf falling on a cell, the cell is protected from becoming reverse biased by the combined voltage of all the other panels in the string which could add to a high voltage. The diode becomes forward biased instead which limits the reversal and the current bypasses the affected column so the affected cell is only reverse biased by the other fewer cells in the column. So PV panels automatically optimise to an extent anyway. You may lose a couple of columns from a leaf but not the whole panel. If the shadow crosses all columns the panel output will be lost but the other diodes in that panel bypas the current so the whole string only losses the output of one panel and the impedance it's kept low allowing the inverter to maintain optimised power transfer. Where individual optimisers help is where there is partial shading of one or more panels, perhaps through a tree canopy or dirt film, not enough to switch off the cells completely but raising the impedance of the working panels. The cells don't become reverse biased and the diodes don't bypass the current but the raised impedance can cause the inverter to limit the power draw from the whole string as it starts to see the voltage collapse under load. Optimisers maintain some useful output from the affected panels but don't don't raise the impedance of that section and the whole series connected string, which would loose more power. Power is usually optimised in the inverter by taking increasing current from the string until the voltage voltage starts to fall so it finds the sweet spot for voltage x current = power maximum (MPPT maximum power point tracking). Optimisers can cost as much as the panels though. Anyway, It's just seen you have another video about a second battery and spreadsheet calculations - something else I've been through sizing mine.

I had similar requirements for myself and went with the following i) Solar is AC coupled using the cheapest Solis inverters ii) Battery is AC coupled with Victron Multiplus . This configuration keeps me lock in free from any brand ecosystem. Further Victron multiplus is fully open / programmable system and I am integrating it part by part to my homeassistant setup. Victron will also provide support for power outages if wired that way. Build quality of victron is like a tank ! and that's what I wanted for such a busy device in this mix. For battery , personally I built it myself ( 2 X 12kwh LFP) but commercial options such as Pylontech are economical enough.

Thanks - very early in the implementation process but support to date has been excellent. Fortunately asked questions concerning limits on the download process. Your podcast would also have helped!! Ended up selecting the maximum battery storage for the inverter. May well have over specified!! At the moment 55% capacity available at 1500. The combination is also working with the myenergi for our Hybrid.

SolarEdge Energy Bank does allow backup, you just need the right inverter and a backup module. Other advantage that makes a big difference is that any generation that would normally be clipped by the inverter is used to charge the battery so if your 6kW array is maxing out and you have a 5kW inverter the extra kW goes into the battery instead of being clipped and effectively wasted

Very interested in your excellent home storage presentation - Thanks. Just installed yesterday a Solarfast system with 8 Hanchu ESS LV batteries at 3.2 Kwh. (Total 25.6 Kwh) coupled with a Luxpower TEK Inverter. This is now linked to our existing 16 solar panels installed approx 11 years ago. We are hopefully downloading overnight at off peak rates at 3.5Kwh per hour (7 hours) with a maximum of 24.5 Kwh to cover daytime use including an electric Aga. We are using Octopus Energy. So far in 24 hours the system is doing what we expected without the benefit of much Solar input.

I have your option 3 being installed hopefully next month. I believe the hybrid inverters are also more efficient than AC systems as there isn't as many DC to AC conversions involved. The other consideration for me was that the Givenergy system can be completely controlled locally without internet through the modbus interface that in my case will be going to Home Assistant. I believe this is important not only for system longevity but for control during a blackout when the internet might also go down. Time will tell if I've chosen wisely.

Been through the same thought process and currently installing the GivEnergy 5kW hybrid inverter with 3 off 5 kWh GivEnergy batteries. This is for 14 panels on an unshaded South facing roof. Factors were cost, total capacity, peak current (I have some very power-hungry machines), and also the 2kW supply in a mains outage.

About optimizers: I had the same thought for our house, hardly any obstacles so why not make a 'bare' string and save on the optimizers (~70 euros per panel!). However, we decided to install them anyway based on advice from our installer, because these optimizers will *always* help when clouds come in play... after 3+ months now we can see that the amount of days with unobstructed full sunshine is very small, most of the time there is some (scattered) cloud cover.

Hybrid inverter without opttimister will be significantly less efficient. Though you might have little shading from trees, you will have significant shading early morning / late evening from the roof itself. Half the panels will generate very little, which without optimisation will drag the whole system down. SolarEdge also have a very powerful app, are firesafe, and their new home-hub inverter coming out within the next month will give great data. I'm planning to install int he spring.

I have just had a 6.2kwp system installed will solaredge inverter and battery. I haven’t got the backup system but I do believe that it is possible with solaredge. On the subject of optimisers, if it was me in your position I would get the system which allows them. When you do get shading it would essentially kill the power from that whole string. Your installer would be best placed to give you advice though.

Whilst the efficiencies you quoted for an air source heat pump are well known the actual energy use is affected by the heat losses in the house and the method you are using to transfer the heat eg. radiators, underfloor etc. We have a 4 bedroom house with underfloor heating upstairs and downstairs (EPC Rating A) and have used a heat pump for the last 12 years. In winter the worst case use is between 40Kw and 55Kw hours per day. Having said that we have replaced the old Worcester Bosch unit with an 11Kw Daikin this year so hopefully, that will be more efficient.

Givenergy Hybrid Inverter still limits you to a max charge (when charging solely from the Grid) of 3.6 KW. And max discharge of 3.6KW from your battery to your house. So even with two 9.5KW GivEnergy batteries you are still limited to 3.6kw limit when charging solely from grid. The Hybrid Inverter 5KW figure is when you combine that with solar generation. Battery is always limited to 3.6KW discharge and charge when using the 5KW Hybrid Inverter

I have option 2 SolarEdge Energy Bank with 3.68KW SE inverter and about 6KW of PV. Only had one issue so far, battery lost communication with the inverter for a few hours one day. We use about 9KWh a day and the Energy Bank should cover our usage 95% of the time. In the future I may add the back up module. I am currently waiting on Octopus to switch us over to the Go Faster tariff. I will add that so far the SolarEdge support has been excellent, they usually respond within 24 hours. The SE monitoring portal and app are also so very good, for me at least. At the moment you cannot set the battery to charge from the grid overnight via the Home Owner SE portal, you have to ask your installer to set it up. There is an update due later this year to allow home owners to do it via the portal and app.

Thanks for the video Tim, I am glad I found your channel. I too have an E/W facing roof, and for that reason not going for solar, but only a battery solution. I too want to cover both electricity and heating at some point, which is why I am looking at a modular battery solution for now. Using the smart meter data for the past year, I can see we use on average 13kWh per day for electricity throughout the the year. I am also on Octopus Go, currently charge the EV during the 4 hours, and want to also charge batteries. The solution I have been looking at consists of 5 x US3000 Pylontech 3.5kWh batteries (48v) and a Victron Inverter 48/5000 (5000va) 48 volts with a Victron Gx device for the smart connectivity, however I am being told by various shops that this type of setup is for off-the-grid and will be hard to get installed, as they are trying to push GivEnergy products. From what I have read and watched on GivEnergy solutions, a lot more mixed reviews regarding the software side of things, which is my concern. An alternative solution with less hassle is Powerwall 2 with the gateway. Slightly more expensive, although I hear there is a big delay in getting PW installed. I've subscribed as I am very keen to see what you do next.

Hi Tim. Regarding the optimisers. If you have an East and West panels as the sun moves around wont it cause shading issues on each set of panels at one point or another in a way that optimisers will be of some benefit as they are likely to prolong the generation period of the panels as they slowly become shaded?

I have recently had installed a 7.7Kw system almost identical to your option 1. However, I use excess solar to charge the batteries during the day up to about 80% at roughly mid day, then I "pause" the Givenergy battery so the excess solar charges my car. Once there is no excess solar, I restart the battery to supply our home. The solar panels have been in since May, but the battery system was only installed last week. During this last week, we have imported ZERO Kwh, so from that point of view, the system is doing what we expected so far.

I’m currently having option 3 on an east west two arrays. I have shading do we are using Tigo’s for optimisation, works out extra £50 a panel remember do on installation and no VAT. For you EPS read up on the Givenergy solutions, I’m trying to go full house manual switch, waiting for a quote but looks fairly straight forward. As for EV charger Givenergy currently have one out on beta I think which would talk to their hybrid inverter. There is also talk of a diverter in the pipeline that would do hot water .

If you go hybrid, the total output should be able to meet background house usage plus what the heat pump would require, plus cooking leaks etc. if you are not careful, you will still be pulling a lot for the grid, even if the sun is out. Look at your forecast demand profile through the day.

Check out the MyEnergi battery announcement this week, The Libbi. Its capable of multiple battery storage stacking and back up during a power cut on a single circuit (so plugs or lights etc). I think the batteries max is 20kwh.

Interesting to listen to your thought process Tim. I have just ordered a GivEnergy 3.6kW Hybrid Inverter, 9.6kW GivEnergy battery, Zappi, Eddi & 10 x 415watt solar panels. Like you I have no shading issues & all my panels are on one side of our roof facing 122 degrees SE. I could put a few more panels on the front of my roof to catch the late afternoon sun but I decided to keep the front of the house free of any solar accoutrements. Unlike you I have no plans to go down the Heat Pump route for home heating because our microbore heating pipework is far too small (10mm) & the cost & upheaval to rip it all out & replace it is prohibitive. I do have a small 4kW Air to Air Heat Pump in our conservatory which does a fine job of making it an all year round living space. So, on that basis I'm hoping that a combination of night rate electric & daytime solar should keep the battery & hot water topped up for most of what we use during the day & some free vehicle charging when needed - when we get an EV that is. As a retired couple we are at home most days which means we probably use more energy during the day than others who may be at work. That said there's only two of us now & we have started scheduling washing machine & Dishwasher etc to run over night instead of during the day. That may change when the solar system arrives. If I find we are using more energy than our battery & solar can deliver I guess an extra battery for more storage would be an option. However, as you pointed out, the max charge rate of our planned 3.6kW Hybrid Inverter would not be enough to charge anything much more than the planned 9.6kW battery during the 4hr night rate window. Do I need to go up to a 5.6kW Hybrid Inverter? I am also deliberating on where to put the Inverter & battery, in the garage or in the loft. My garage is small & is already rammed with stuff so a major clear out would be required to make some space. However, I've heard that a loft location for batteries & inverters is not the best for component reliability due to the high / low summer / winter temperature cycles. We also need a new consumer unit & our DNO needs to unloop our incoming mains electric supply from my neighbour before we can use the Zappi. I also need a new hot water cylinder because my 38 year old cylinder & immersion heater are well past their sell by date! I'm also in the process of installing a Tado smart system for our boiler, HW & radiators. This going green lark is starting to get a bit complicated & rather expensive.

This may be too expensive but I installed Solarege with optimisers on a E/W install with 2 x Tesla batteries with full offgrid back up. The advantage is that you can then go on the Octopus Tesla Tariff and buy AND sell at around 24.5p/kw/h 24/7. Thus you can put only one 13.5KW battery in and its note a concern if you are pulling from the grid or battery (other than conversation losses) Also if you have an E/W install, based on your graphic, you should also be able to install a few panels South. Remember on the 6kw solaredge invertor, you can over install upto 12KW of panels.

You can use tigo DC optimisers on any system

You are going to need two of either gen1 or gen2 Givenergy inverters, one for each of your batteries to meet off peak charging requirements. This could be set up with East on one set, West on the other. The only real difference of gen1 to gen2 would be the combined charge/discharge rate of 5.2kW Vs 7.2kW ( and ethernet/WiFi built in gen2). If you're wanting optimisers, go with Tigo optimisers and cloud monitoring if you want to see each panel. Source: my install!

Fabulous info ❤

Hey, Tim what did you go for in the end? I am having same decision problems.

Hello, great info and details. Question, I have been offered sunsynk 3.68 inverter and a sunsynk 5.32 battery with longi panels 12. Any views on the sunsynk against Givenergy equivalent please. Much appreciated for any comments. Thank you

Great Video I have two Electric cars and a ZAPPI charger Looking at option 3 mysel, butt is it compatible with the ZAPPI, ? Two 9.5 is what I want also with a 5 kW inverter

Hi Tim. Based on the Datasheet for Givenergy 5kw hybrid inverter, it seems the max battery charge rate is 3.3kw (same as 3.6kw inverter) so am I correct to assume that having a 5kw inverter is not going to help with fully charging 2 x 9.5kWh batteries in let’s say 4 hours? Thanks

Hello there, finding your videos very informative . My question to you would be: other than cost, why have you not considered the Solar Edge AC coupled 10kWh storage Battery, and have you considered Mains power failure back-up?

Very informative presentation

Fantastic video I'm installing a hybrid inverter with 13.5kw of pylontech batteries with no solar at this point. I'm interested to know how you plan to heat the house on batteries only thank you

Interesting video. I have a Givenergy 3.6 hybrid inverter as well as a Zappi and Havi controller. The Zappi is connected to a outside IP68 CU so the inverter cannot see it. A CT clap in the meter box tells the Myenergy software when we are exporting to the grid and takes that charge as needed. The GivEnergy system software says this is all export but the combination of these apps plus Octopus Energy app, gives me the complete data picture. Unlike you I have done this in stages which makes this a tad more challenging especially as I am now looking at removing the combi gas boiler and going all electric. The details matter and it is certainly far from easy with so many variables so our shared experiences hopefully save others from making mistakes. I have to say I have been very impressed with GivEnergy although I don't have experience of other systems as a reference. I was super impressed that a software update I suggested was implemented just 3 months later, so they clearly listen to feedback and their software both on your phone and PC is excellent.

Hi Great video and I like how you think. I am not a solar expert but I have a degree in Engineering Science and studied Electronics and Electrical Engineering and I am a Chartered Engineer. I have an AC coupled hybrid inverter system with solar pannels, battery storage , emergency circuits and sockets so that I can run off my batteries in the event of a power cut. I have a Zappi charger and an electric car. In my humble opinion and as I say I am no solar expert the best configuration is AC coupled. You can put CT clamps an the mains tails and that enables monitoring and fine control of the batteries charging discharging and charging of an electric car with solar divert using the Zappi. Having said that solar divert can still lead to excess solar less than 1.4kW being dumped to the grid. Essentially being wasted the best option in my humble opinion is using ct clamps on a AC coupled hybrid inverter system an eco + to maximise your own personal usage of solar and minimise grid exporting . A house earthing rod is required so that your house is independent of the grid earth so that in the event of a power cut you can use your own earth to get power out of the batteries Re optimisers if you have significant shading issues there maybe a benefit, however, pannels have an operating lifetime of circa 20 + years. Optimisers may fail after 5 years needing an expensive scaffolding deployment to replace a dodgy optimiser does rhe efficiency cover the cost of the scaffolding Moot point

Another informative video, have you posted anything regarding G98/G99/G100 DNO applications (Costs/time/pros & cons)? Does your 5kW inverter also result in supporting higher house loads and reduce probability of needing grid power (thinking of your kettle and toaster example)? Thanks 👍🏼

A very interesting video thank you. At the moment I am still in the process of trying to source a supplier for a solar system. However if I have interpreted your video correctly you aim to meet all of your electrical power needs by charging your battery at night using cheaper electricity. Using this model do you think there would be sufficient savings to negate the need for having solar panels installed and just having a battery system? Although I recognise that this would then attract a VAT charge. Many thanks.

Interesting video. I have just selected and am having installed tomorrow the GivEnergy 9.5 battery to compliment an existing solar array. I am also putting a second new array on the back of the house. A couple of thoughts on the issues you saw. Firstly - you could always add a second GivEnergy ac inverter into the mix to give you 6kw charge and discharge. (My plan is to add a second battery into the mix once I have seen how the second solar array performs - maybe adding a second ac inverter, maybe just daisy chaining) Second thought is have you considered going down the micro inverter route for you arrays. My second array is going to be an enphase microinverter solution. Shading issues don’t exist, ultimate flexibility and maximum efficiency (and lots of panel level data).

We have a 5.4kWp solar PV array, Tesla Powerwall 2, Myenergi Eddi & Zappi and ASHP. Our ASHP and EV were later additions. Consequently, the solar PV and battery are now undersized, even using Octopus Go overnight electricity to supplement the solar. Our DNO is blocking our application for additional solar PV so we are likely to purchase another Powerwall to cover our winter consumption.

What’s your guesstimate as to how much the solar panels will produce over winter (good days and bad days)?

Is thw ZAPPI char compatible with the givenergy system I am specing 2 9.5 using octopus GO like you

Check out the Fronius GEN24 Primo and the BYD battery modules.

I have option two. It has been great at saving me money but as you said in the video hard to track the data correctly with the DC coupled battery. If I could go back I would have spent the extra on a Powerwall. I got the same system installed for my mother and for her it is fine she is not interested in changing her battery settings. For anyone who is considering it the settings are hidden at installer level so you have to set up as business owner in order to configure storage profiles and then assign them to the system. As mentioned in another comment SolarEdge does have a backup option but it is not being released in the UK until 2023.

Great Video! I have an Air-Source Heat Pump and will hopefully soon get my solar and battery. Of course I don't know the size of your house and insulation status, but 15 kwH per day for heating in winter sounds too good to be true. Installers tend to mislead people about the actual usage of these pumps so I am really interested to see an update of this video once you have the pump, to see if your batteries cover all usage!

I believe the solaredge backup is only available on a 3Ph system. Without the opitimsers, when you have a little shadow on one panel, the whole string will default to that lower panel level, it could therefore have a bigger impact than you think. One other thing is that in the peak of summer both the east and west roofs will be generating so you may reach say 6.5kw/h rates. I assume you are limiting your export to 3.68kw or are you doing a G99 application?. If you are limiting to 3.68kw and your inverter can produce 6kw, the advantage of the solaredge system is that if you are only consuming 1.5kw/h in peak summer, the 5kw extra (including the 0.5kw clipping amount that is not being considered) will be diverted straight to the batteries.

Have you taken account of the 6kWh that you can deduct from the gas consumption and switch to your immersion heater (this would only drop the ASHP requirement by 1.5kWh due to its 400% efficiency). ALSO your ASHP could also be set to run during the 4hrs night time rates.

OK Tim, this is my system for comparison. 6.4kW solar, evenly split facing east and west, with optimisers for each panel. I have a Tesla 13.5kWh battery, which I've set to only 10% minimum for power outage backup. I have a Solar Energy inverter, 6kW output. Heating is via Ecodan 8.5kW ASHP with underfloor heating to ground floor, radiators in bedrooms. Live in a 4 bed house built 2021, ~2k sq ft. First, forget the claimed efficiencies for ASHP. In winter, when temperature is around 0° during the day and the atmosphere is very damp (say thin fog), the ASHP runs continuously and freezes. Before I installed battery and solar this year, last winter my worst day I had 84kWh usage, this did not include car charging, and probably averaged ~60kWh when daytime temperature

I've made a three part review on the SolarEdge Energy Bank. You can find them on my KZfaq channel. My opinion: Get a Pylontech AC coupled battery with a Solis/Solax inverter. Both SolarEdge and GivEnergy only allow configuration options to be accessed by the Installer. You have no access as a homeowner. In the case of GivEnergy, your warranty is also conditional of all work being done by a GivEnergy approved installer. Now at the moment, SolarEdge only allow installers access to Charge/Discharge battery profiling. That will change soon, but it is a demonstration of how little thought that they have put into how system owners want to use their batteries. Another problem with SolarEdge - your original installer has exclusive access privileges to carry out any further modifications to your system. So if you want to use another installer to add more solar panels, only the original installer can assign rights to your new installer. The new installer cannot adopt your inverter into their SolarEdge portfolio otherwise. That's a really poor philosophy. System owners, not installers should be the kings and queens of their system. Finally, there's no off grid backup option with the Energy Bank in the European single phase market. That's not a deal breaker, but if you're rural, or gas rationing starts to become a problem, it could be. As for roundtrip efficiency: They claim 94%. However when I aggregate charge/discharge throughput data, after a week I'm measuring 76% round trip. I'll be reporting on that in my next video, but I'll want to gather more data.

If you need optismers Solaredge is probably the one to go with but you can use tigo optimsers though I've heard they aren't great at the commissioning stage so installers don't mention them. I would probably look at Pylontech batteries as the cost per kwh is better than both givenergy and Solaredge, linked with a victron mulitplus 2 will give good data and the pylontech batteries are modular so can be added to if you need more.

Why can’t you use optimisers with GivEnergy DC charging? Surely they just bypass individual cells? Or do they have to communicate? What is the best solution then for 3 phases - as I am limited to 4kw on each phase

We use two inverters for each of the two givenergy 10kwh batteries. This gives you 6kw charge and discharge capacity.

I am looking to keep my UPS option open too, because I've replaced my lead acid batteries with 2 x Seplos Mason 10.5kWh LFP with an out limit of 200A DC, which giving me 18kWhs of useable storage. (80% helps to prolong the life of the pack) I too need to change my Inverter as a result. I have two strings coming into the house, I have to have a dual string input on the Inverter. So I am going with the Sofar HY 6000-EP Inverter. This has a 27A AC output which fall inline with the current Inverter, but can charger higher rate of a 100A DC, as opposed to 60A DC for the old Inverter. Currently on a sunny day I can get 14kWh (September) off my 4kw solar array. Mine operate without optimiser and there is little to gain from what I can see in your application to installed them. We have 2 batteries because we have a ASHP 9kw, Quin Sunamp 9kw, some Infrared panels, and 2 EV's to charge up. We to use the over night Octopus Go tariff to aid our charging use, and so far have achieve good results. In your case I would go with option 3. We have also uprated of house fuse to 80A, I don't know if you have taken this into consideration?

You can use tigo optimisers if you really need them due to shading with the GivEnergy Hybrid system. You can optionally install a tigo monitoring module into the string for viewing performance over the internet. I thought there is a GivEnergy portal for this already though? You’d need to get the GivEnergy EV charger for you to balance/manage supply between your EV and DC batteries. The Zappi can’t monitor DC. Heat pumps, look at daikin, specifically the solar pv/smart grid functionality. They can be triggered by your GivEnergy system when there is excess to heat the home or hot water. You’d need to get the GivEnergy smart plug and set the limit statically on the Daikin HP, say 1.5kW. Pretty much all Atherma 3 HP’s now have the solar PV/smart grid functionality. You can optionally install a smart meter with the Daikin HP to dynamically modulate it’s output to match PV generation, but I’ve found it jumps out of this window when heating hot water, a static limit is more deterministic and simpler to install/setup. I’m on intelligent octopus and heat the hot water tank at night with the HP. And I boost the house temp a couple of degrees.

So what about Puredrive 2 vs Givenergy? Which is better?

I wouldn't be hung up by the SolarEdge optimisers. Sure, monitoring is nice to have but if they go wrong then it's expensive to fix, unless you get them installed in the loft or don't require scaffolding to get to the roof. Plus people have made a few good points on KZfaq that they actually do very little to improve efficiency, as you've alluded to. Twin GivEnergy inverters seems to be your answer, but at present it's buggy but GE are apparently working on a fix. Some people already have this setup and it doubles the charge / discharge rate so would solve your problem. I'm going for 1 X 9.5 battery now to see how get on with the possibility of adding another battery /.inverter at a later date. Hoping the price of batteries drop as well so that might negate the 0% VAT loss. Plus with a bit of luck GE might bring out a Gen2 AC inverter next year with better charge rates.

Break even isn’t good enough. There needs to be a significant saving to off-set the risk of costs falling in the medium term.

Have you considered having a duplex system. 2x Givenergy AC inverters each with their own battery. Charge at 6Kw. bit more expensive but ...

Im looking at Growat, Give and SolarEdge, is there any reason you haven't looked at Growatt? Many thanks

Do you need an enclosed space to install storage battery? Sorry, if it is a stupid question...

What did you go for in the end?

All sounds about right to me, although I am only a newbie as well, but learning quick. As you have an East West split on your solar, does that mean you always have half your house in shade, thus needing optimizers, or if you have each side on a separate inverter, that does it not work like that? If you charge your battery and an EV overnight, will that stress your electrics, not sure if a constant 12kW for 4hrs could cause an issue? My guess is the most power hungry surprise will be your microwave. I was surprised how little each ring and oven used on our cooker. With 5kWs available, you should be able to run most things in your usual household routine. For us, running the house in a power cut is also essential, as it happens a couple of times a month.

AC coupled battery storage is a much better option imo. Firstly you can combine both the solar generation and the battery to output more power than a DC coupled sytem where you are restricted by the max AC discharge rate of the the inverter. Basically you get rid of that bottleneck in the system. Secondly an AC coupled battery is much more flexible in installation and when setting up with EV charge points, as you 'can't see' the DC coupled battery which is hidden behind the hybrid inverter. Thirdly the conversion losses compared to DC coupled system is nothing to lose sleep over, it's negligible. Cheers.

Great video, thank you. I think battery wont charge same rate last 20 %.

I placed my order today for a 4.6kw array with Givenergy 3.6kw Gen 2 hybrid inverter and 9.5kwh battery 🔋

Considering a second battery but I can’t make it make financial sense yet. Woudl be mainly for heating which means winter which means not much solar - so its off peak 7.5p vs 10p gas. Even with 400% COP the savings aren’t that high for that portion - Maybe £250 for gas for 6 months of heating vs £50 optimistically for a heat pump? I’ll definiltely add it if we have the spare money but it’ll be for ‘get off gas’ reasons rather than ‘saving money’ reasons

A lot of solar PV reciewers such as Gary does Solar etc, are now saying optimisers and micro inverters are not required on newer PV due to the inbuilt diodes effectively making the optimisers \ micro inverters obsolete. The diodes manage the panels so any shading issues doesnt drag down the whole string to the output of the affected panel.

What are the disadvantages with pylontech ? From what I know they are top notch batteries and they are modular .. £8k for 4 us5000 and then you când add to them ...

Switch to Intelligent Octopus for 6 hours (6x3=18)? or go faster 5 hours (but slightly higher off peak rate)? I’m going single Givenergy 9.5 but already have solar so will be effectively forced to go AC coupled.

Great Video. Very interesting discussion. Have you installed the system? If yes what is the final solution?

Solaredge DC-coupled + Eddi user here - all fine, it's just a case a configuring the Eddi correctly.

I noted that Soalx X1 -Hybrid G4, 6kw inveter has 6kw charge/discharge rate, please correct me. Thanks

SolarEdge optimised panels are fantastic, if you need them. I worry that your installer doesn't seem to be able to tell you things like "can I use this system as a backup in a power cut" - do check they are MCS accredited, as also you'll need that if you want to be paid for export. I also think both your battery sizes are too small if you want 20kwh usable a day (depth of discharge means you'll get less actual power in or out) and also you are betting a lot of money on tariffs like Octopus Go being around for 10 years +.

7kw exceeds the max dc input of givenergy 5kw hybrid inverter listed on the datasheet. This may or may not be a concern. Also the max current input is quite low on this inverter. We couldn't source any panels that would meet the listed max current rating. All this info is on the inverter datasheet.

From your bio, I see you're on the edge of the Cotswolds. Would you mind sharing the company you're using for your solar installation?

The 10kWh StorEdge battery and HD Wave inverter from SolarEdge cannot work off grid. New single phase models of battery and inverter will be released by SolarEdge next year with this capability. A three phase system already exists.

Gereat video, Tim. Option 3: The GE 5kW Hybrid will only alow you to charge at 3.6 kW (not 4.7), so your max capacity in four hours would be 14.4 kW. Out of interest, why can't you use optimisers on Option 3?

Sorry a bit late to the party here. A few very important things to note: The size of the inverter can impact how much electricity you can draw at any one time. These numbers ARE IMPORTANT. Giv-AC 3.0 - Max DC Power - N/A, Maximum Charge/Discharge 3kw Gen 1 Hybrid Giv-HY 3.6 - Max DC Power - 4.5kw, Max Battery Output 2.6kw, Max Solar + Battery 3.6kw Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 2.6kw, Max Solar + Battery 5kw Gen 2 Hybrid Giv-HY 3.6 - Max DC Power - 4.7kw, Max Battery Output 3.6kw, Max Solar + Battery 3.6kw Giv-HY 5.0 - Max DC Power - 6.5kw, Max Battery Output 5.0kw, Max Solar + Battery 5kw Option 1, your correct that the AC is limited to 3kw draw in either direction. Option 2 I suspect is MUCH more expensive than 1. Optimisers are a waste of money, adding a LOT of cost and added complexity of install and maintenance. Please watch these two videos for why. kzfaq.info/get/bejne/bLuTlZCXnb-0paM.html kzfaq.info/get/bejne/e59-ia9zxLW9g4k.html Option 3. For powercut protection you need to specifically have an "islanding" mode installation. This essentially would give you a few sockets that allow you to run essential devices. It DOES NOT run your house and would be limited to about 3kw (ie 13a fused plug) per socket. The only device, currenntly, that does this is the Tesla Powerwall, although I am sure there are more products coming from other suppliers (pretty certain that these are available in different countries already Australia and South Africa come to mind). For an easy answer I would probably go with an AC GIvEnergy & Battery system combined with a DC Coupled system & Battery

You're assuming cheap night time electricity is hear to stay! Who knows, probably, maybe? One thing is for sure it will also rise. Having a heating system providing efficiencies of 3/4/5 to 1 will limit your risk of a cheap tariff being removed. I'm not saying dash out and purchase a heat pump either. I'm also wondering what to replace my old gas boiler with that will heat my house efficiently. I have Solar and battery storage, a Sonnen unit which I had to wait more than 18 months for a repair on. If I relied on this for heating we would have been cold for 2 winters. Which ever one you choose consider asking what is the after sale service like. I would not recommend Sonnen.

Charging overnight will pull your average kwh unit rate down. We average 8pkwh ourselves. Our setup is slightly different, we have 2 solaredge se5000 and a pair of Lux 3.6 AC coupled inverters. This allows fully charging the batteries overnight in the four hour period. The setup means on a bright sunny day we can achieve over 10kw of discharge (solar+ac inverters). The Lux provides a 16 amp EPS system which work well, however if there is a power cut we loose the solar. Anything option is victron setup with a g100 rating. This allows completely off grid but victron is not cheap. Optimisers are down to shading, we have a bit of shading on our setup which helps and this shading is down to the seasons and the height of the sun. I can show you a couple figures etc on the setup. Ours is not the cheapest setup.

Great video and all very interesting. It is hard to gain concrete answers. I have the same idea as you except for not using solar panels. I am on GO and I thought a Givenergy 2 x 9.5kw on the 5kw Hybrid inverter would offer about 4.6kw output x 4 hours = just under 19kw but on speaking to Givenergy they told me that of the 5kw output 1.6kw is Solar only (hence Hybrid) leaving only app 3.4 kw to charge in 4 hours = 13.6kw of charge. I then said could I use 1 x 3kw AC for each 9.5 battery pack and they said; only if they are on separate phases as there is some kind of conflict with information I did ask would it work if each battery fed separate consumer units, answer no, so this brings into question if your neighbour had the same system on the same phase could this be an issue and I was told it would be an interesting point At the moment the option may be 1x 9.5 & 1 x 5.2 = 14.7 and the Hybrid 3.6 output x 4 hrs = 14.4 fully charged. My daily normal kWh is app 20kw so either I am not at present able to fully fund peak use or wait till they have got over the issues What do you or anyone else think?

Hello Tim, I would appreciate knowing who's doing your install and how good a job they do once you have figured out your system. Definitely worth an install video as follow up in due course. Just be careful with your ASHP , I've just had a quote that split the power consumption in three; heating mode 7944kWh/yr (SCOP 3.5 @ 50C), hot water 3082kWh/yr (SCOP 1.75 @ 50C) and Legionella cycle 7800kWh/yr (SCOP 1 @60C). So as you can see the Legionella cycle for the quoted 300l tank consumes nearly as much electricity as it does to heat the whole house. The rep went thru' the heating benefits but skirted around the water heating and Legionella cycle, it wasn't until I got the magnifying glass over the arithmetic that I spotted this. Needless to say I will not be purchasing an ASHP.

Personally I'd recommend a Victron inverter with pylontech batteries. They're modular, so you can add more at a later date if needed. You're very good at maths and spreadsheets, so I'm sure you've already considered this, but if you're getting solar installed, making sure you can supply the whole house electricity from batteries for the few days of the year where you have no solar at all and it's very cold is likely not the most efficient use of your money in terms of return on investment. I did some somewhat crude calculations looking at electrical demand each day vs number of pylontech 3.5kWh batteries needed to meet that demand: 4 batteries got me to something like 50% of days 5 got me to 80% 6 to 95% 7 to 98% But to get to 100% took 12 batteries. So there was definitely diminishing returns. and that 5% would never have paid for itself considering it took twice as many batteries to meet that demand. (This was batteries alone, no solar. It would have been a lot more complicated to calculate them combined.)

Use tigo optimisers only on the ones that get shade.

I’m not an expert but have done research like you. I have solar edge dc. It’s very easy to monitor and works well with Zappi in my experience. Re optimisers, I understand that it’s not just about shading. It’s also relevant if a single panel in a string fails or underperforms. I can see from the monitoring app that my panels facing in the same direction differ in their production by up to 10%. I think Octopus is brilliant but I wonder how sustainable their Go tariffs i.e. are they profitable for them. At 7.5p, do they even cover transmission costs? I’ve been using the Octopus Agile tariff (not available with Go) to benefit from up to 80p per kWh at certain times over the summer. I’ve been discharging my battery fully between 5pm and 7pm each day. Cost wise, I’ve seen 9.5kw GivEnergy quotes as little as £3k as part of a solar package. My Solar Edge was nearer £8k. May be not the best choice.

just to add an option 3 into the mix, you could have 2 give energy AC chargers, which gives you your requirements, and additionally you remove on option 2 & option 3 the single point of failure which the hybrid inverters, and more expandability on the batterys later should you need to store more, and instead of optimisers, you could go with micro inverters

You could look at using Intelligent tariff from Octopus which gives you 6 hours of off peak.

Have you considered the Intelligent Octopus tariff, same price as Go but gives you 6 hrs at cheap rate. The tradeoff is that you say by when you want your car charged and they control the actual timing of the charging. 3x6 is 18 kwh. Also, LFP is much better for deep cycle applications like a home battery. So id go AC coupled GivEnergy.

Get voltacon hybrid inverter, pylontech batterys were you can have 16 x 5kw batts on one data line x 4 on a hub....

Why don’t you change to intelligent octopus, you get the same 7.5p off peak rate but from 23.30 to 05.30 ?

People always say that they don't need Power Optimizers as they have no shading, but what is shading? Soiling, snow, clouds, birds on modules, trees (they grow) chimneys, aerials, telephone cables that are in front of the modules. What about the other benefits? You do need Power Optimizers due to module mismatch, as each module will differ +/- 3% regardless of azimuth or tilt. Safety, with the S series Power Optimizers, they have a thermal sensor that can detect the rise in tempertature and shut the inverter down to 1 volt per Power Optimizer (SafeDC), with AFCI, you can also stop an Arc at module level, and reduce the risk of fire. What about the monitoring, you want to see what each module is doing, you would'nt drive a car without a speedo, or fuel gauge. Maintenance, being about to power your inverter down, and removing the risk of electric shock to anyone working on the roof or near the modules. You can't do that with out SolarEdge Power Optimizers.

Octopus Go is only available if you have an electric vehicle (and it it has to be one of a few selected models & you have Octopus recommended charger unit).

Hi Tim , Octopus go faster is available for 5 hours @ 8.5p per kw . If there is no shading on the array dont worry about not having optimisers . The givenergy 9.5 can only charge / discharge at 2.8kw . a hybrid inverter can simultaneously feed into the AC and DC circuits , For example the 5kw givenergy hybrid inverter can push 5kw AC into the house whilst pushing 5kw into the batteries however if you are going to get a heat pump the pump can draw up to 5kw so i would suggest a hybrid inverter of 7kw Solis 7kw fox batteries solax 7kw solax batteries A Zappi will work with any system using its own ct clamp

what about using lg chem batteries

Look at switching to Octopus intelligent tariff. Same as Go but two extra hours off peak.

One thing you didn’t consider is that a DC coupled system are more efficient because in affect you have DC to AC and an AC to DC in an AC coupled system that you don’t have in a DC coupled system. You didn’t consider the Fox ESS hybrid system, two of these would give you what you need, I have one of these and a Zappi car charger and it doesn’t work very well when you are charging with solar but I can still use it in the summer and in the winter charge with overnight Go rates anyway and I’m talking with MyEnergy about a fix for this DC coupled problem what can happen is the charger turns on when the batteries are full and then keep charging until the batteries are empty. In most circumstances optimizers are not much use unless you have shading in the middle of the day. The other thing I like about the Fox ESS system is they use series connected batteries, minimum capacity is 5kWh, very easy to add additional storage not so easy when you are adding more batteries to a parallel connected system as you have to worry about balancing losses in the cable runs. FYI I have a 3k8 solar array and 10kWh of batteries, unlike you I'm not going for electric heating (at the moment).

I have DIY experience with power walls and solar. I use LFP batteries & Victron hardware. If the inverters you’re buying don’t contain automatic crossover switches for grid outages, Sterling sells them. Interesting you’re using Octopus Go & not Intelligent; Intelligent off-peak is 23:30 - 05:30. BTW Tesla has been using LFP batteries in their RWD cars since Sept. ‘21.

I just want to parse out a little arithmetic and accounting here, altho you could extract these points from T&K's excellent prez. Here goes. Typically (say Octopus; some others too) you pay /Kwh: nearly 40p peak + 10p off-peak. This single factor: off-peak vs peak - is the #1 ISSUE. It *OVERWHELMS* all else. The small print of your electric provider deal, and your home-insurance is *CRITICAL*. If your battery + heating system is correctly sized, off-peak covers nearly everything. So.. PV panels save you off-peak so under 10p/KWh. Typically, about 300 GBP/year. Batteries+inverter save you about half total single-rate spend: say 1500 GBP/year. So a battery+inverter spend of 7K5 GBP pays off in 5 years. Solar panels spend 5K GBP never pays off, if you take interest charges into account. Running your heat-pump off battery, is *CRITICAL*, and in fact, as in my case, it may not be possible to run a heat-pump at all without the battery!?! If you are forced to get 3-phase conversion, it can totally overwhelm all other costs. Still worse, provider might give you a 3-year lead time. You are at the mercy of your provider.

I’ll add my thoughts although I see this video is 6 months old so you’ve probably already chosen your solution. I have a 4kW existing FIT array and had a 10.4kW array (East and West facing) with 2x GivEnergy hybrid generation 1 5kW inverters, a 9.5 and a 5.2 battery, one on each inverter. Similar but larger than your option 3. I needed two inverters due to the number of panels, and it looked like your 3.6+3.6 arrays are actually slightly larger than a single inverter capacity. Worth noting that GE don’t officially support the twin-inverter setup I have although it does generally work ok. I think you have the overnight charge rate of option 3 wrong. My gen 1 inverter can only charge at 2.6kW, the gen 2 is better but it’s only 3.3kW. With multiple inverters each with their own battery you can get higher throughput with parallel charging. Agree batteries are important but the payback for 2nd and 3rd batteries is poor, so even though we have an ASHP we’ve not got more batteries. Do maximise the panels on your roof as the first option, cheaper add more when the scaffolding is up.

Hey Tim, how's life, it's been awhile! Firstly, ASHP isn't 400% efficient, that's very optimistic! GivEnergy are due to release a 5kW AC inverter for their batteries which would be much better. The inverters tend to charge more quickly than discharge I believe, so even on the AC3.0 you can charge them faster than 3kW check though! Have a look at Fully Charged latest video where they do a tour around Robert Llewellyn's house. Might give you some useful ideas. I'd definitely recommend some devices from MyEnergi, mixergy tank + Eddi would do you well!

Interesting video but I don't think you will be able to charge the 2 x 9.5 batteries in a 4 hour window if they are both empty. I have a Gen 1 5kWh inverter and a single 9.5kWh at the moment and this can charge off-peak at 2.42kWh (this is real life figures). I know the Gen 2 can do more but don't assume 3.6kWh as it does lose some in conversion so more likely 3.42kWh. If you take my Current single 9.5kWh battery then 4 hours at 2.42 is 9.68 so this just fits. I actually have a 5.2kWh battery still to be connected and have Go Faster so have 5 hours off-peak which means my combined system can only charge 12.1kWh on a capacity of around 14.3kWh so I can't actually fill a 9.5+5.2 in 5 hours. This is why I wanted a Gen 2 inverter but couldn't get one so had to compromise and lose the ability to fully charge my 2 batteries overnight. Time will tell if this is an issue or if solar makes up the difference for me. Certainly today it has with no problems. In your case you will have 19kWh and assuming 4% reserved thats is 18.24kWh to charge if totally empty, say in mid-winter when you want to use the heating, and to charge these in 4 hours you would need an effective rate of 4.56kWh. As far as I am aware the Gen 2 5kWh is capped at 3.6kWh official with a likely 3.42kWh reality. Assuming this is the case you can only get 13.68kWh of electricity in the 2 batteries in 4 hours. If you want to know more DM me on twitter, @sammoj2