Electricity isn't just expensive

[harm_less]

Be independent, get lots of panels.  Do your own daylight saving!

That's our plan. I'm sure if we suck enough energy out of that sun we can counter global warming.

[R2x1]

Be independent, get lots of panels.  Do your own daylight saving!

That's our plan. I'm sure if we suck enough energy out of that sun we can counter global warming.

Working pretty well here for the last few weeks. Well done!

[nzoomed]

Yeah i suspected that, im happy to wait and save up a bit anyways, since I dont have ridiculous power bills currently, but should I get an EV, I would like to make use of the solar to charge my vehicle in the future.

Welcome to the PV/EV wormhole   In our case we got PV first and then when Meridian slashed the rate they paid for our excess we got a Leaf to be able to better self consume our generation. It worked to a degree but now with a different property and a second EV purchased we upgraded our PV to better cope with charging 2 EVs. The feeling of being able to run a vehicle on your own generation, rather than being beholden to the oil or electricity industries is great, especially when your home's energy costs also benefit.

The next phase for us is to be able to justify the cost of storage of our excess electricity, hopefully by putting our Leaf to service in a V2H/V2G capacity.

How much capacity of panels do you have?  I would imagine you would need about an extra 10kW to charge your vehicle?
I wonder how much RuCs will stack up going forward?

[harm_less]

Welcome to the PV/EV wormhole   In our case we got PV first and then when Meridian slashed the rate they paid for our excess we got a Leaf to be able to better self consume our generation. It worked to a degree but now with a different property and a second EV purchased we upgraded our PV to better cope with charging 2 EVs. The feeling of being able to run a vehicle on your own generation, rather than being beholden to the oil or electricity industries is great, especially when your home's energy costs also benefit.

The next phase for us is to be able to justify the cost of storage of our excess electricity, hopefully by putting our Leaf to service in a V2H/V2G capacity.

How much capacity of panels do you have?  I would imagine you would need about an extra 10kW to charge your vehicle?
I wonder how much RuCs will stack up going forward?

The installation mounted on top of a shed that is in the Solar One link I posted above is us. 9.5kW of panels feeding a 8.2kW inverter. The excess of panels is to boost generation during off peak sunlight times. We upgraded for 5kW of panel capacity so that we had sufficient to fully supply our 7kW EV charger and combined with a Paladin diverter which controls our HWC we are able to limit the amount of 'excess' generation that needs to be exported/sold to the grid. There's quite a bit more detail than that but suffice to say our PV is more than enough to charge both our EVs. We have actually been caught with our EVs (3 ATM as we're still to sell an older Leaf) and the HWC max'd out over the past week and been left with no choice but to export.

10kW is the largest PV capacity that can be connected to the grid without having to export at wholesale electricity rates, and 5kW is as much as most lines companies will allow to be exported per phase. Due to the relatively low export tariffs offered by most electricity retailers maximising your self consumption is key to economic return and this situation results in designing PV systems to absolutely minimise contributing to public supply which is a negative outcome in what is a country that is hunting for additional generating capacity as we increasingly all electrify our lives. We are currently considering a change of electricity provider due to the significant changes our PV upgrade has made to our consumption and export habits.

The whole RUC thing is a hot topic in EV circles and Simeon Brown's recent statement sounds like it is essentially a leak of information from the governmental discussions currently going on over this issue. A distance based RUC system for all road vehicles seems like the most likely outcome. This captures hybrids, and particularly PHEVs, which currently enjoy a discounted if not free ride on RUCs. A distance system, like diesels currently have, would need to include removal of the Road Tax portion of the Fuel Excise Tax (essentially the RUC component) to balance things up and would have the advantage of removing road taxation for boats, power tools and off road vehicles. The NZTA RUC system is already struggling to administer RUC monitoring and collection so some sort of electronic vehicle monitoring system is on the cards, as hinted to by Simeon.

The likely RUC rate for all <3.5T vehicles, including EVs, is most likely to be similar to the 7.c/km rate that diesels pay, and petrol FET equates to for the average petrol consuming vehicle. The fact that this system would be counterproductive on an emissions basis, as a Mini would be paying the same as a V8 is most easily addressed by adusting the carbon tax component of various fossil fuels.

One comment in support of a GPS monitored (similar to ERoad) system for all vehicles is that this would be a powerful tool for collection of congestion charges, traffic control systems and would allow off road use of vehicles to be deducted from their RUC account.

Plenty of vigourous discussion in some circles as you can well imagine but come April 2024 we should have a better idea where this is going, if not full details of a new RUC system. We just have the minor inconvenience of an election between now and then.

Most EV owners aren't too concerned about the arrival of RUCs as it has been long expected and for those that home charge their EV energy costs are typically ~5c/km (or as low as 2c based on lost PV export opportunity) an extra 7c/km is hardly a deal breaker. For those that rely on public charging at up to 85c/kWh an extra 7c/km will bring their energy costs per km up to that of a petrol vehicle (~25c/km) as petrol prices rise through the $3 mark. The 'fuel' economics of hybrids aren't so low as EVs so expect some squawking from that quarter.

[king1]

I read somewhere meridian? are going to start charging 50c kwh at their charging stations, does that seem reasonable given domestic charges are around 30c kwh?

[harm_less]

I read somewhere meridian? are going to start charging 50c kwh at their charging stations, does that seem reasonable given domestic charges are around 30c kwh?

Cheap compared to Chargenet's facilities, but in most cases slower. Someone has to pay for all that investment in infrastructure, IT and admin. Around 90% of EV owners in NZ charge at home at offpeak rates or from solar so public charging isn't as important for most except when we go on a road trip. At 50c/kWh it still equates to ~10c/km so still way cheaper than putting petrol in your car.

[Praktica]

The capital costs has to be taken into account - I saw 3 EVs on display at the mall in Dunedin, today. They were all priced at just under $50,000 plus orc. I paid a quarter of that for a small economical petrol car (used) some years ago, We don't use it much - I've spent less than $100 on fuel since the 1st of June, and the tank is 3/4 full. An EV would be no use to me. Having to go through the RUC rigmarole is, for me, a gross waste of time.

[harm_less]

The capital costs has to be taken into account - I saw 3 EVs on display at the mall in Dunedin, today. They were all priced at just under $50,000 plus orc. I paid a quarter of that for a small economical petrol car (used) some years ago, We don't use it much - I've spent less than $100 on fuel since the 1st of June, and the tank is 3/4 full. An EV would be no use to me. Having to go through the RUC rigmarole is, for me, a gross waste of time.

Comparing new EVs with secondhand petrol cars is fairly irrelevant. We are currently selling an older Leaf (which still has ~70km of usable battery range) for $6,000. We're rural so the range has become challenging for us but for an urban dweller it will provide a shopping and school run vehicle that will probably cost the new owner <$3/day in home charging. EVs are no longer the domain of just the rich and their new prices are now reaching parity with their petrol equivalents.

As for the RUC "rigmarole" it will most likely be able to be done online and it's looking very probable that all road vehicles will be drawn into this system next year.

[Praktica]

The capital costs has to be taken into account - I saw 3 EVs on display at the mall in Dunedin, today. They were all priced at just under $50,000 plus orc. I paid a quarter of that for a small economical petrol car (used) some years ago, We don't use it much - I've spent less than $100 on fuel since the 1st of June, and the tank is 3/4 full. An EV would be no use to me. Having to go through the RUC rigmarole is, for me, a gross waste of time.

Comparing new EVs with secondhand petrol cars is fairly irrelevant. We are currently selling an older Leaf (which still has ~70km of usable battery range) for $6,000. We're rural so the range has become challenging for us but for an urban dweller it will provide a shopping and school run vehicle that will probably cost the new owner <$3/day in home charging. EVs are no longer the domain of just the rich and their new prices are now reaching parity with their petrol equivalents.

As for the RUC "rigmarole" it will most likely be able to be done online and it's looking very probable that all road vehicles will be drawn into this system next year.

It's not irrelevant if the money is not there to pay.

[Zurdo]

Pay in advance...I guess the road you pay to repair is finally repaired by the time you get to drive on it.

[nzoomed]

How much capacity of panels do you have?  I would imagine you would need about an extra 10kW to charge your vehicle?
I wonder how much RuCs will stack up going forward?

The installation mounted on top of a shed that is in the Solar One link I posted above is us. 9.5kW of panels feeding a 8.2kW inverter. The excess of panels is to boost generation during off peak sunlight times. We upgraded for 5kW of panel capacity so that we had sufficient to fully supply our 7kW EV charger and combined with a Paladin diverter which controls our HWC we are able to limit the amount of 'excess' generation that needs to be exported/sold to the grid. There's quite a bit more detail than that but suffice to say our PV is more than enough to charge both our EVs. We have actually been caught with our EVs (3 ATM as we're still to sell an older Leaf) and the HWC max'd out over the past week and been left with no choice but to export.

10kW is the largest PV capacity that can be connected to the grid without having to export at wholesale electricity rates, and 5kW is as much as most lines companies will allow to be exported per phase. Due to the relatively low export tariffs offered by most electricity retailers maximising your self consumption is key to economic return and this situation results in designing PV systems to absolutely minimise contributing to public supply which is a negative outcome in what is a country that is hunting for additional generating capacity as we increasingly all electrify our lives. We are currently considering a change of electricity provider due to the significant changes our PV upgrade has made to our consumption and export habits.

The whole RUC thing is a hot topic in EV circles and Simeon Brown's recent statement sounds like it is essentially a leak of information from the governmental discussions currently going on over this issue. A distance based RUC system for all road vehicles seems like the most likely outcome. This captures hybrids, and particularly PHEVs, which currently enjoy a discounted if not free ride on RUCs. A distance system, like diesels currently have, would need to include removal of the Road Tax portion of the Fuel Excise Tax (essentially the RUC component) to balance things up and would have the advantage of removing road taxation for boats, power tools and off road vehicles. The NZTA RUC system is already struggling to administer RUC monitoring and collection so some sort of electronic vehicle monitoring system is on the cards, as hinted to by Simeon.

The likely RUC rate for all <3.5T vehicles, including EVs, is most likely to be similar to the 7.c/km rate that diesels pay, and petrol FET equates to for the average petrol consuming vehicle. The fact that this system would be counterproductive on an emissions basis, as a Mini would be paying the same as a V8 is most easily addressed by adusting the carbon tax component of various fossil fuels.

One comment in support of a GPS monitored (similar to ERoad) system for all vehicles is that this would be a powerful tool for collection of congestion charges, traffic control systems and would allow off road use of vehicles to be deducted from their RUC account.

Plenty of vigourous discussion in some circles as you can well imagine but come April 2024 we should have a better idea where this is going, if not full details of a new RUC system. We just have the minor inconvenience of an election between now and then.

Most EV owners aren't too concerned about the arrival of RUCs as it has been long expected and for those that home charge their EV energy costs are typically ~5c/km (or as low as 2c based on lost PV export opportunity) an extra 7c/km is hardly a deal breaker. For those that rely on public charging at up to 85c/kWh an extra 7c/km will bring their energy costs per km up to that of a petrol vehicle (~25c/km) as petrol prices rise through the $3 mark. The 'fuel' economics of hybrids aren't so low as EVs so expect some squawking from that quarter.

Sounds like you have a pretty good system, I would probably need about 15kW on total if I were to get an EV.
I worked out I could just squeeze 10kW of panels on the north side of my home and garage.
I think the RUC system does need reform, I think it would be a great outcome to have all cars pay a fair amount per km rather than your fuel amount.

[harm_less]

Sounds like you have a pretty good system, I would probably need about 15kW on total if I were to get an EV.
I worked out I could just squeeze 10kW of panels on the north side of my home and garage.
I think the RUC system does need reform, I think it would be a great outcome to have all cars pay a fair amount per km rather than your fuel amount.

15kW of solar is huge by domestic standards. As you can see on Solar One's gallery of domestic installations they have done most top out at 10kW. There are reasons for this:

• In most homes the self consumption (which is their best ROI) max's out at around 5kW.
  
• Most electricity retailers have a 10kW limit to PV installations before they have to revert to selling on the variable wholesale market rates rather than at a fixed FIT (Feed In Tariff). More complex back charging situation and highly variable return complicated by PV generation happening during daylight hours which may present a glut as PV increases in NZ. In AU where around 1/3 of homes have PV the lines companies have the ability to throttle, or even disable, PV installations at peak times to protect their infrastructure. We're a long way from that situation but if PV gains incentives here it may well happen.
  
• Many lines companies have a 5kW/phase export limit on their PV customers so 10kW requires three phase supply to your property, or throttling ability on your inverter/s to ensure a 5kW cap. Don't know where this goes beyond 10kW but balancing export between phases would be necessary.
  
• It is unlikely that ownership of an EV would require a 15kW installation. Domestic EV chargers have a 7kW capacity for single phase, or 11kW for a three phase charger. Most EVs return around 5km/kWh so best to estimate your daily driving distances and work back from there. Also bear in mind that if you are driving big kms/day you will more likely be using public charging by necessity rather than being able to gain 35km/hour on a 7kW home charger, or 55km/hour on a 11kW one. Also some EVs have a cap on their AC (home) charging rate (e.g. ex-Japan Leafs are 3.3kW max)
  
• Also there are PV panels now capable of 500W (or more if bifacial) so roof space is becoming less of a restricting factor.
  
• Battery prices are still too high to be viable in most cases and definitely it doesn't make sense to charge an EV from home batteries. Personally we're waiting for V2G/V2H to find its way here so we can use our Leaf in a home storage/supply capacity.
  
• Prices continue to drop on a $/kW basis but 10kW or beyond is still a significant investment so crunch your numbers carefully.
  

If you are serious about going down the PV route get some advice from a reputable installer in your area. This is a rapidly evolving space and the guys that are involved in doing it on a daily basis are best qualified to guide you.

[nzoomed]

Sounds like you have a pretty good system, I would probably need about 15kW on total if I were to get an EV.
I worked out I could just squeeze 10kW of panels on the north side of my home and garage.
I think the RUC system does need reform, I think it would be a great outcome to have all cars pay a fair amount per km rather than your fuel amount.

15kW of solar is huge by domestic standards. As you can see on Solar One's gallery of domestic installations they have done most top out at 10kW. There are reasons for this:

• In most homes the self consumption (which is their best ROI) max's out at around 5kW.
  
• Most electricity retailers have a 10kW limit to PV installations before they have to revert to selling on the variable wholesale market rates rather than at a fixed FIT (Feed In Tariff). More complex back charging situation and highly variable return complicated by PV generation happening during daylight hours which may present a glut as PV increases in NZ. In AU where around 1/3 of homes have PV the lines companies have the ability to throttle, or even disable, PV installations at peak times to protect their infrastructure. We're a long way from that situation but if PV gains incentives here it may well happen.
  
• Many lines companies have a 5kW/phase export limit on their PV customers so 10kW requires three phase supply to your property, or throttling ability on your inverter/s to ensure a 5kW cap. Don't know where this goes beyond 10kW but balancing export between phases would be necessary.
  
• It is unlikely that ownership of an EV would require a 15kW installation. Domestic EV chargers have a 7kW capacity for single phase, or 11kW for a three phase charger. Most EVs return around 5km/kWh so best to estimate your daily driving distances and work back from there. Also bear in mind that if you are driving big kms/day you will more likely be using public charging by necessity rather than being able to gain 35km/hour on a 7kW home charger, or 55km/hour on a 11kW one. Also some EVs have a cap on their AC (home) charging rate (e.g. ex-Japan Leafs are 3.3kW max)
  
• Also there are PV panels now capable of 500W (or more if bifacial) so roof space is becoming less of a restricting factor.
  
• Battery prices are still too high to be viable in most cases and definitely it doesn't make sense to charge an EV from home batteries. Personally we're waiting for V2G/V2H to find its way here so we can use our Leaf in a home storage/supply capacity.
  
• Prices continue to drop on a $/kW basis but 10kW or beyond is still a significant investment so crunch your numbers carefully.
  

If you are serious about going down the PV route get some advice from a reputable installer in your area. This is a rapidly evolving space and the guys that are involved in doing it on a daily basis are best qualified to guide you.

OK, I was looking at roughly doube the capacity (~7kW for the home and another 7kW to charge the EV) I probably dont need the extra power unless I was using that load while charging the vehicle, but if I already have a battery bank, I could just use that  power anyway to minimize taking power off the grid.
Would also mean I would need to charge during the day to maximise the savings?

[harm_less]

OK, I was looking at roughly doube the capacity (~7kW for the home and another 7kW to charge the EV) I probably dont need the extra power unless I was using that load while charging the vehicle, but if I already have a battery bank, I could just use that  power anyway to minimize taking power off the grid.
Would also mean I would need to charge during the day to maximise the savings?

You're best to calculate your home's electricity consumption as this will be a deciding factor in how much PV generation you can consume instantaneously, which is where the real value of PV lies. Our inverter provides us with real time generation and consumption data. e.g.

As you can see our 'background' consumption is around 0.5kW and for us that relates to lighting (LED), two 700L chest freezers, 2 fridges, a heated towel rail and a few appliances on standby. The consumption peak that evening was probably oven use.

The morning consumption (in yellow) was our diverter heating the HWC, and the afternoon was our Evnex EV charger charging our EV. Both these units monitor export to the grid and tailor their consumption to suit (avoiding drawing from the grid). And yes, having an EV at home during daylight generating periods is key to matching their charging to your otherwise exported electricity. Most EVs have batteries larger than 50kWh and to discharge a home battery for EV charging is bad economics. It will prematurely degrade the home battery and most home batteries are in the 10-15kWh size. The price of 50+kWh of home battery is close to that of an EV, hence why I'm holding out for V2G.

We have recently changed to Octopus as our supplier whose off peak rate of 18c/kWh which is so similar to the 17c export rate they pay us that it makes very little sense to be charging a home battery as the only time we would gain from drawing down on the battery would be the dawn and evening peak periods. The payback on a battery would be so extremely long that it's not worth considering.

[nzoomed]

OK, I was looking at roughly doube the capacity (~7kW for the home and another 7kW to charge the EV) I probably dont need the extra power unless I was using that load while charging the vehicle, but if I already have a battery bank, I could just use that  power anyway to minimize taking power off the grid.
Would also mean I would need to charge during the day to maximise the savings?

You're best to calculate your home's electricity consumption as this will be a deciding factor in how much PV generation you can consume instantaneously, which is where the real value of PV lies. Our inverter provides us with real time generation and consumption data. e.g.

As you can see our 'background' consumption is around 0.5kW and for us that relates to lighting (LED), two 700L chest freezers, 2 fridges, a heated towel rail and a few appliances on standby. The consumption peak that evening was probably oven use.

The morning consumption (in yellow) was our diverter heating the HWC, and the afternoon was our Evnex EV charger charging our EV. Both these units monitor export to the grid and tailor their consumption to suit (avoiding drawing from the grid). And yes, having an EV at home during daylight generating periods is key to matching their charging to your otherwise exported electricity. Most EVs have batteries larger than 50kWh and to discharge a home battery for EV charging is bad economics. It will prematurely degrade the home battery and most home batteries are in the 10-15kWh size. The price of 50+kWh of home battery is close to that of an EV, hence why I'm holding out for V2G.

We have recently changed to Octopus as our supplier whose off peak rate of 18c/kWh which is so similar to the 17c export rate they pay us that it makes very little sense to be charging a home battery as the only time we would gain from drawing down on the battery would be the dawn and evening peak periods. The payback on a battery would be so extremely long that it's not worth considering.

I know people who are using banks of 18650 or 21700 cells in home made battery banks that work well, bit of work assembling them, but if can be cost effective, there is a plentiful supply of the things from e-scooters, etc.
I dont think I would build myself a bank much bigger than 5kWh if I went down that path.
Im definitely doing alot of research on the subject, I have a friend who has also learned a great deal, so any mistakes he made, I will be aware of. There are probably some things I would do different to him already, notably around the batteries used, but he got a one off good deal on the components. He is assembling his battery bank and installing the BMS himself, he is using CATL cells, but I have learned that the EVE cells are actually better and have less issues with them swelling up and the need for clamping properly compared to CATL.
I think I would be best to charge an EV during daylight hours and use off peak hours the rest of the time.

[harm_less]

I know people who are using banks of 18650 or 21700 cells in home made battery banks that work well, bit of work assembling them, but if can be cost effective, there is a plentiful supply of the things from e-scooters, etc.
I dont think I would build myself a bank much bigger than 5kWh if I went down that path.
Im definitely doing alot of research on the subject, I have a friend who has also learned a great deal, so any mistakes he made, I will be aware of. There are probably some things I would do different to him already, notably around the batteries used, but he got a one off good deal on the components. He is assembling his battery bank and installing the BMS himself, he is using CATL cells, but I have learned that the EVE cells are actually better and have less issues with them swelling up and the need for clamping properly compared to CATL.
I think I would be best to charge an EV during daylight hours and use off peak hours the rest of the time.

There's plenty of DIY home battery installs on YouTube with many using ex-EV battery packs, particularly from Leafs. Even a ~60%SoH 24kWh Leaf battery has more capacity than a Tesla Powerwall and older Leafs in that sort of SoH can be had for <$6K. If TPTB got V2G cranked up all it would take would be to park up an old Leaf connected to your home's grid and you're good to go with very little effort. The hurdle at present is the price of bidirectional EV chargers and the regulatory hoops involved in doing so.

[nzoomed]

I know people who are using banks of 18650 or 21700 cells in home made battery banks that work well, bit of work assembling them, but if can be cost effective, there is a plentiful supply of the things from e-scooters, etc.
I dont think I would build myself a bank much bigger than 5kWh if I went down that path.
Im definitely doing alot of research on the subject, I have a friend who has also learned a great deal, so any mistakes he made, I will be aware of. There are probably some things I would do different to him already, notably around the batteries used, but he got a one off good deal on the components. He is assembling his battery bank and installing the BMS himself, he is using CATL cells, but I have learned that the EVE cells are actually better and have less issues with them swelling up and the need for clamping properly compared to CATL.
I think I would be best to charge an EV during daylight hours and use off peak hours the rest of the time.

There's plenty of DIY home battery installs on YouTube with many using ex-EV battery packs, particularly from Leafs. Even a ~60%SoH 24kWh Leaf battery has more capacity than a Tesla Powerwall and older Leafs in that sort of SoH can be had for <$6K. If TPTB got V2G cranked up all it would take would be to park up an old Leaf connected to your home's grid and you're good to go with very little effort. The hurdle at present is the price of bidirectional EV chargers and the regulatory hoops involved in doing so.

Yeah there is a ton of information out there on leaf batteries. Ive got a friend thats installing a leaf battery, not just the modules, but the whole battery pack straight out of the car!
Edit: looks like that guy in the link you provided is using the same project on github.
Turns out an open source community has figured out how to hack the leaf BMS and reverse engineer it so they can communicate with the Nissan system meaning no expensive hardware to be installed.
Its pretty awesome what you can do with this sort of stuff, this is where real savings can be made, as you say even with a tired old leaf battery, they still have plenty of capacity remaining for a solar installation.

This guy also has a wealth of information here, no doubt you are probably aware of him.
https://www.youtube.com/@WillProwse

[harm_less]

I've watched Will's video on drilling through a LiFePO4 battery but hadn't gone deeper into his content as I consider going fully off grid a step too far, particularly with 2 EVs to charge, and with Octopus's night rate being so close to their FIT it makes for using the grid a reasonably efficient storage medium.

Being able to buy and sell electricity at almost the same rate pretty much kills the viability of investing in enough storage to make an off-grid existence work for us, and that's how our national electricity system should function if TPTB are really serious about incentivising the masses into contributing to the nation's total generating capacity while ensuring their own long term relevance.