Solar + Zappi + MG4 = 😊

[tsedge]

Interesting. The system was commissioned on Thursday afternoon and it says we’ve consumed 64kWh of solar generation and exported 83kWh, so does that mean were we on Octopus we would have made £12.45p? That would certainly cover the standing charge.

Yeah, the worst is, if I import back that same energy, they’d (British Gas) charge me an arm and a leg.

Miles was talking on the Podcast about Octopus Flex which is a 3-level tariff paying up to 30p/kWh on exported electricity IIRC.

 

[Ayoull]

Interesting. The system was commissioned on Thursday afternoon and it says we’ve consumed 64kWh of solar generation and exported 83kWh, so does that mean were we on Octopus we would have made £12.45p? That would certainly cover the standing charge.

Yeah, the worst is, if I import back that same energy, they’d (British Gas) charge me an arm and a leg.

Yes if you were on the standard octopus tariff they do 15p export, my understanding is on go it's lower as they're saying you benefit from cheaper imports and could abuse the system by charging battery at night and exporting back during the day at a higher rate.

Miles was talking on the Podcast about Octopus Flex which is a 3-level tariff paying up to 30p/kWh on exported electricity IIRC.

That's between 16:00-19:00 which is the period of highest usage most folk unless out of the house would be using what their array was generating if they have electrical cooking appliances.

Unless you decide to discharge your home battery during this time to make some gains

 

[tsedge]

That's between 16:00-19:00 which is the period of highest usage most folk unless out of the house would be using what their array was generating if they have electrical cooking appliances.

Unless you decide to discharge your home battery during this time to make some gains

He has a big array.

 

[FiferMG4]

Miles was talking on the Podcast about Octopus Flex which is a 3-level tariff paying up to 30p/kWh on exported electricity IIRC.

I still have a decent tariff with British Gas until December, but I’ll be turning my attention to other energy companies’ tariffs towards the end of the year. The only interesting one British Gas offers at the moment is for off peak ev charging.

 

[IanMK]

could abuse the system by charging battery at night and exporting back during the day at a higher rate.

Is helping to smooth electricity generation demands 'abusing' the system? One of the problems electricity generators have is the varying demand and inability for them to store the electricity.

 

[Ayoull]

Is helping to smooth electricity generation demands 'abusing' the system? One of the problems electricity generators have is the varying demand and inability for them to store the electricity.

There's enough Ccgt reserve to supply the entire UK grid and have immediate ROCOF (rate of change of frequency) response which Nuclear and other generator types don't, even battery storage has issues under a ROCOF situation with changing demand as the inverters are stepped where as a turbine can be spun up and down to within an accuracy of 1rpm to maintain voltage and frequency,

Ccgt can handle the UK power demand without any other generators being online, just they're not the flavour of the month since Putin's foray into the Ukraine, but we're viewed as the saviour of the world against coal stations.

Even if we went 100% renewable you'd still need something like nuclear to provide base frequency support, and a small number of fuel burning stations or hydro storage that can be controlled to a granular level.

The abuse is where buying it in at circa 12p on octopus Go and then selling it back to octopus at 15p

Addendum:

Localised domestic battery storage and generation helps very little to the network in terms of demand, however large sites such as those circa 250MW of battery storage that are going up will make a difference but how the 275/400kV supergrid is built it's a problem as it was built for a small number of large generation sites such as Drax, Ferry Bridge, Thorpe Marsh, Eggborough, Radcliffe, not lots of medium sized generators, which cause big fault level issues on the EHV network, which is why alot of generators can't connect now until 2030+ as NG is having to reinforce their network for something that it wasn't originally designed to handle.

But it's important to clarify the NG supergrid is capable of handling around 60GW+ of demand but it's how it's distributed that is the problem now and where the power is coming from.

 

[tsedge]

There's enough Ccgt reserve to supply the entire UK grid and have immediate ROCOF (rate of change of frequency) response which Nuclear and other generator types don't, even battery storage has issues under a ROCOF situation with changing demand as the inverters are stepped where as a turbine can be spun up and down to within an accuracy of 1rpm to maintain voltage and frequency,

Ccgt can handle the UK power demand without any other generators being online, just they're not the flavour of the month since Putin's foray into the Ukraine, but we're viewed as the saviour of the world against coal stations.

Even if we went 100% renewable you'd still need something like nuclear to provide base frequency support, and a small number of fuel burning stations or hydro storage that can be controlled to a granular level.

The abuse is where buying it in at circa 12p on octopus Go and then selling it back to octopus at 15p

I don't see that as abuse, more a smart move

 

[Ayoull]

I don't see that as abuse, more a smart move

There is a distinction in the DCODE that you can't sell back energy bought at a reduced rate for a profit unless it has been used to undertake a mechanical work, or you're a registered Elexon exporter

Essentially unless you've say utilised the energy like how hydro storage does to pump water from a lake at the bottom of a hill at a cheap rate to then store at the top of the hill and spin a turbine to generate at time of high demand or you hold an Elexon license you can't buy cheap and sell back for profit.

 

[tsedge]

There is a distinction in the DCODE that you can't sell back energy bought at a reduced rate for a profit unless it has been used to undertake a mechanical work, or you're a registered Elexon exporter

Essentially unless you've say utilised the energy like how hydro storage does to pump water from a lake at the bottom of a hill at a cheap rate to then store at the top of the hill and spin a turbine to generate at time of high demand or you hold an Elexon license you can't buy cheap and sell back for profit.

That's something I see as a clause to protect the big guys, so I am all in favour of battery time shifting to save money.

 

[charlie bravo]

My trouble is that I'm arguing with myself about solar,and a home battery or just a home battery or leave it as the technology improves. Unfortunately I'm loosing...

Use solar to charge, or go EV and your car battery for home

 

[Brianlescargot]

If you have Solar and Battery you get the VAT removed. If you only go with a Battery install only, you have to pay VAT. I've got a Givenergy battery and inverter which has a SoC issue which they can't seem to resolve. Been going on for 12 months and they ignored it until everyone kicked off on the community pages. Wouldn't recommend them at the moment.

I'm about to have my solar array increased from 3.2kwh to 6.7kwh in the next few weeks. Excellent return on the investment when you include all the free charging in the summer!

Also worth looking at a solar hot water diverter if you have a hot water tank. I've got a Solar iBoost as I managed to get one brand new for £100 just over a year ago. They go for about £400 now. The My energi Eddi is excellent and integrates well. They go for quite a bit now so you need to heat a lot of hot water to justify it!

I paid no VAT on battery install alone.

 

[adiel]

Bear in mind when you do your 'business case' calculations any solar generated energy you use to charge your car is saving you money at the tariff you would normally use to charge your EV. In my case that is the off-peak 4-hour rate on Octopus Go. I found the green energy arguments, given the obvious impact of climate change we all are starting to feel, seemed to resonate with my wife.

I do agree with the OP that it is satisfying to charge your EV using electric your solar panels have generated.

 

[cbowen]

I paid no VAT on battery install alone.

Better not tell the tax man

 

[Oakland]

I’ve finally been able to convince my wife that the initial outlay for a Zappi, solar PV and battery storage installation has been worth it. I showed her our solar being diverted to the car (instead of British Gas) via the Zappi app and I got a big smile and thumbs up, which coming from my wife is a big win.

Feels great to be charging the MG4 with solar energy. 3kWh is not too shabby for Fife. View attachment 17059View attachment 17060

I have a similar set-up. MG4 Trophy with 3phase Zappi, 5.8kW solar and 11.6kWh battery. I'm also on Octopus FLUX for the summer. I might change to an different tariff in the winter when there's not so much sun but I'll be staying with Octopus.
I'm generating 5.3kW at the moment today and the batteries have been full since about 9:30am (2pm now) so I've stuck the car into the Zappi to squeeze a few miles out of the sun.
The house is only taking about 300w at the moment - freezers, fridges etc.
Flux allows me to charge the batteries for three hours at night for 19.4p per kWh and then I can export for three hours in the afternoon at 34.36p per kWh if I have some to spare.
I also have an air-source heat pump so I make sure it's converting the cheap (19p) power in the middle of the night into hot water or heating. I have a couple of other power-hungry devices which I've set to take advantage of the cheap power or the solar or the batteries, and also set them to avoid drawing any power during the peak period as that would cost me 45p per kWh
Since going onto FLUX at the beginning of April we've only used mains power during the cheapest period (2am - 5am) and the rest of the time it's been solar and/or batteries. So as long as we get a few hours of sun our bills are going to be very cheap (we're all electric)

 

[NigelMK]

If you have Solar and Battery you get the VAT removed. If you only go with a Battery install only, you have to pay VAT. I've got a Givenergy battery and inverter which has a SoC issue which they can't seem to resolve. Been going on for 12 months and they ignored it until everyone kicked off on the community pages. Wouldn't recommend them at the moment.

I'm about to have my solar array increased from 3.2kwh to 6.7kwh in the next few weeks. Excellent return on the investment when you include all the free charging in the summer!

Also worth looking at a solar hot water diverter if you have a hot water tank. I've got a Solar iBoost as I managed to get one brand new for £100 just over a year ago. They go for about £400 now. The My energi Eddi is excellent and integrates well. They go for quite a bit now so you need to heat a lot of hot water to justify it!

I have just upgraded my 4kW solar with additional panels 3.7kW and solax 12.4kW battery. Really pleased. I also have Myenergi Zappi EV charger and Eddi hot water diverter and would strongly recommend both.

 

[ianwlk]

Is the V2L limited to about 2.5 kW? Great if it was fully bi-directional.

 

[dawson2099]

I’ve finally been able to convince my wife that the initial outlay for a Zappi, solar PV and battery storage installation has been worth it. I showed her our solar being diverted to the car (instead of British Gas) via the Zappi app and I got a big smile and thumbs up, which coming from my wife is a big win.

Feels great to be charging the MG4 with solar energy. 3kWh is not too shabby for Fife. View attachment 17059View attachment 17060

You have the same set up as I do - works well - I leave the car plugged in all the time and it absorbs all surplus energy (along with my immersion heater). I have an inverter from GivEnergy which shows up as an unknown device - I prefer your approach - but I guess you have a myenergi invertor too?

 

[dawson2099]

I have a similar set-up. MG4 Trophy with 3phase Zappi, 5.8kW solar and 11.6kWh battery. I'm also on Octopus FLUX for the summer. I might change to an different tariff in the winter when there's not so much sun but I'll be staying with Octopus.
I'm generating 5.3kW at the moment today and the batteries have been full since about 9:30am (2pm now) so I've stuck the car into the Zappi to squeeze a few miles out of the sun.
The house is only taking about 300w at the moment - freezers, fridges etc.
Flux allows me to charge the batteries for three hours at night for 19.4p per kWh and then I can export for three hours in the afternoon at 34.36p per kWh if I have some to spare.
I also have an air-source heat pump so I make sure it's converting the cheap (19p) power in the middle of the night into hot water or heating. I have a couple of other power-hungry devices which I've set to take advantage of the cheap power or the solar or the batteries, and also set them to avoid drawing any power during the peak period as that would cost me 45p per kWh
Since going onto FLUX at the beginning of April we've only used mains power during the cheapest period (2am - 5am) and the rest of the time it's been solar and/or batteries. So as long as we get a few hours of sun our bills are going to be very cheap (we're all electric)

Are you able to charge your storage batteries directly from the grid? I have a hybrid invertor which I don't think allows that - although there is a continual very low flow back in - maybe a setting somewhere that needs to be tweaked? I like your approach.

Footnote: I found an option on the Givenergy app to enable the battery to charge either Solar only or Solar plus Grid. Not sure if this would enable me to charge it at a cheap night rate unless I can find a scheduling option

 

[MGJimmy]

I took early retirement a couple of years ago and spent some of my inheritance on the MG4 so now I'm veering towards leaving it for another 2.5 years until I reach 66 and can maximise my pension pots.
Hopefully the technology will have improved and be easier to integrate as I'd be looking at solar, battery and some form of heat pump as my central heating is on it's last legs.
But nothing is written in stone and I'm just starting on the whole EV solar journey.

The pension pot argument kinda makes sense, but don’t wait for the tech to evolve as you’ll always be 2 years away from making the leap. The efficiency of batteries, solar and heat pumps make sense now, yea they will be better in 5 years but that’ll be 5 years of paying for fossil fuel premium priced electricity and gas. It’ll be even better in 10 years, or 20 years! Get the work done before the boiler packs up.
Hope that helps the argument with yourself.

 

[siteguru]

Is the V2L limited to about 2.5 kW? Great if it was fully bi-directional.

Search this board ... I'm sure someone tested V2L and got ~7kW export. (The V2L cable needs a specific resistor value to tell the car to increase the export capacity).