Car (or bike) Chat!

[CageyH]

My charger plugs into to a standard socket, so I have a suitably rated smart plug that controls the charger, as a back up solution.
I don't want to overcharge the battery.

My electricity costs the same during off peaks hours, as there are no interesting tariffs available here. I did the calculation for peak/off peak, and we were better staying on a standard rate.

[dave2010]

My charger plugs into to a standard socket, so I have a suitably rated smart plug that controls the charger, as a back up solution.
I don't want to overcharge the battery.

My electricity costs the same during off peaks hours, as there are no interesting tariffs available here. I did the calculation for peak/off peak, and we were better staying on a standard rate.

Yes, but aren't you using a plug-in hybrid - IIRC? They probably don't store as much energy, or take as long to charge, so can (perhaps) run off a simple plug-in charger. We do have a plug-in charger for the M3 - but hardly ever use it - and the recommendation is to never use it on a extension cable or other accessary. Perhaps it's OK with some very low power, low rate chargers.

I guess if I was "forced" (by circumstances) to use one on an extension cable I would, but otherwise I'm not trying that. In the UK the ratio between some off-peak tariffs and max rate is over 6:1. Definitely worth keeping control over the timing. Even 5 minutes on a 7 kW charger daily can mount up considerably, so I always try to avoid having any accidental overlaps.

If we ever fit a storage battery system [possible, but quite expensive] then we might adopt slightly different approaches. My guess then is that a few minutes leeway with tarriffs would be less critical, as the battery system would already have saved quite a lot of energy for use with cars, though note that most battery systems for home use are typically between 1/4-1/8 the size of a large car battery.

[AJSki2fly]

Yes, but aren't you using a plug-in hybrid - IIRC? They probably don't store as much energy, or take as long to charge, so can (perhaps) run off a simple plug-in charger. We do have a plug-in charger for the M3 - but hardly ever use it - and the recommendation is to never use it on a extension cable or other accessary. Perhaps it's OK with some very low power, low rate chargers.

I guess if I was "forced" (by circumstances) to use one on an extension cable I would, but otherwise I'm not trying that. In the UK the ratio between some off-peak tariffs and max rate is over 6:1. Definitely worth keeping control over the timing. Even 5 minutes on a 7 kW charger daily can mount up considerably, so I always try to avoid having any accidental overlaps.

If we ever fit a storage battery system [possible, but quite expensive] then we might adopt slightly different approaches. My guess then is that a few minutes leeway with tarriffs would be less critical, as the battery system would already have saved quite a lot of energy for use with cars, though note that most battery systems for home use are typically between 1/4-1/8 the size of a large car battery.

We have a Tesla M3, a myenergi Zappi charger for it, 2 SolarEdge 9.7Kwh batteries hooked to a SolarEdge 8Kwh hybrid inverter, the Inverter is also fed with 22 Trina 390Kw solar panels.

Electricity supplier is Octopus on the Intelligent Octopus tariff, 41p outside cheap rate and 7.5p from 23:30 to 05:30, and 51p/day standing charge, we switched to Octopus 2 weeks before they put up the EV/off peak rate to the current 10p/Kwh. We only get the SEG payment for export power at 4.3p/Kwh.

So this is how we use our system.

Winter mid Oct to mid March

The Solaredge batteries charge to full every night during off peak, and so does the Tesla if it is below 90%. The 19.4Kwh from the batteries on most winter days Dec, Jan and March gets us through the peak charging period, without out any grid import for the house. Beer in mind our house is totally electric, NO gas supply, we have a 9Kw Air Source Heat Pump for heating and hot water and all cooking is electric. In days when it goes down to 0- 5C then we can expect to import during peak charge rate around 0-5Kwh, and if down below 0c the 5-10Kwh.

Summer mid March to mis Oct

As we get more sunshine, and it does not mean blue skies days, but brighter days, so for example today, last night we only imported 10.54 kWh at cheap rate to charge the Solaredge batteries to full, today is overcast but we have so far generated 6.02 kWh and exported 450 Wh, so this is either being use by the house or topping up the batteries, the batteries at 9:15 had dropped to 64.5% capacity and now are at 68.8%. Based on yesterdays electricity usage(and current temperatures) by 23:30 I would expect the batteries to drop no lower than 50%.

For those interested, our daily heating profile is 5:45 to 9:00 - 20.5C, 9:00 to 16:00 21:30 - 21C and 21:30 to 5:45 - 17.5C. if the temperature drops 0.5C below the lowest setting at any time it will cut in and return it to the temperature set. For example yesterday our heating was on for 7hrs 44mins, with two pre-heats period one at 4:02 slowly raising the temperature from 19C to 20C and the second pre-heat from 15:00 to 16:00 raise the temperature to the 2C set at 16:00. The pre-heat is down by the system and it determines the necessary power on time based on outside and indoor temperatures for it to see the set requirements. it can be modified as you wish, but it self learns and optimises the systems to minimise power usage.

I recently found a very useful software modelling tool from the National Renewable Energy Laboratory(NREL in USA) called System Advisor Model(SAM), and it is FREE. SAM is very sophisticated you can select the actual inverter(s), solar panels, batteries that is in your system, or planned, enter the exact electricity rates for export and import down to half hourly, and import the actual solar radiance figures captured for where you live. I used the SOLCAST data which is an EU solar monitoring organisation, and downloaded the data for the our grid reference for the past 20 years into SAM. You can also enter costs for the hardware and a host of other data. The data for manufacturers kit gives all the operational AC/DC Voltage ratings, Kwh ratings, maximum/minimum power, losses due to temperature impact and other stuff.

What was very interesting is I plugged in everything for our system and ran the simulation and the figures are within a £50 electricity cost of what the system is doing for its first year of operation, I did my own estimates and am pleased that I was within £100. If you look at the electricity cost it shows $703, (substitute £ for $), £180 of this is the standing charge, so the SAM modelled electricity cost is £523 for the year. Based on our bills to date I believe we may be slightly below this, around £450.

Immediately below are the SAM figures and graphs for predicted usage and below them is the actual usage from our SolarEdge system. As you can see our actual figures are very close the SAM model figures.

So if any are interested in Solar/Batteries, costs/savings you can model it and get a very good idea of how it may work for you. One word of advise, to maximise benefit you need to understand what your average peak usage is in a day in the middle of winter, this will give you a base to work from. So for example if you use 20Kwh in a day then it would be sensible to have the ability to store that amount, but also you need to establish what the maximum you can capture is, this will be determined by number of solar panels, which way they face and what the total watt rating is. You can plug the basics into SAM and then play around to get the best you can for your needs. I hope some might find this useful.

[CageyH]

Yes, but aren't you using a plug-in hybrid - IIRC? They probably don't store as much energy, or take as long to charge, so can (perhaps) run off a simple plug-in charger. We do have a plug-in charger for the M3 - but hardly ever use it - and the recommendation is to never use it on a extension cable or other accessary. Perhaps it's OK with some very low power, low rate chargers.

I guess if I was "forced" (by circumstances) to use one on an extension cable I would, but otherwise I'm not trying that. In the UK the ratio between some off-peak tariffs and max rate is over 6:1. Definitely worth keeping control over the timing. Even 5 minutes on a 7 kW charger daily can mount up considerably, so I always try to avoid having any accidental overlaps.

If we ever fit a storage battery system [possible, but quite expensive] then we might adopt slightly different approaches. My guess then is that a few minutes leeway with tarriffs would be less critical, as the battery system would already have saved quite a lot of energy for use with cars, though note that most battery systems for home use are typically between 1/4-1/8 the size of a large car battery.

Yes, A Skoda Superb IV. I can charge using 10A or 16A. Probably not enough for an EV but suits my PHEV fine.

[dave2010]

We have a Tesla M3, a myenergi Zappi charger for it, 2 SolarEdge 9.7Kwh batteries hooked to a SolarEdge 8Kwh hybrid inverter, the Inverter is also fed with 22 Trina 390Kw solar panels.

Should that be 22 Trina 390 W solar panels? 22*390 W comes to around 8.5 Kw.

Currently we are waiting to see if we can get an ASHP installed, so batteries - if we go for them - will come later - or not!

How big are the batteries?

Possibly we are now too old to worry about payback times - sadly! I tried to persuade our neighbour to have PV panels put on the roof of her house - said it would probably save her some dosh, but she's older than us, and she suggested it wouldn't give a return in sufficient time to be worthwhile.

Don't really blame her for that.

[AJSki2fly]

Yes it is 22*390w = 8.5kw

We are limited to 7.6kwh out to the grid, by Western Power. A lot of PV installer will try and tell you it can be no more than 3.6kwh for domestic. That is rubbish it’s down to the sub station capacity and current draw that your property is within, although getting more than 10kwh at the moment unless you feed out 3 phase is not likely.

Personally we did not look at from a payback view, for us it is more about insulation from rising power prices over the next 20 years or so, and doing our little bit for the planet, we are not well off, but comfortable I would say. I am 65 and Sue is 62, we don’t have hardly any savings now, it went in the bungalow refurb, the EV, Solar, batteries and heat pump.

Power (however and whatever it’s produced from)costs will go up over the long term, anyone who thinks otherwise is the poroverbial Ostrich IMO. There are many factors that will cause this, as burning stuff becomes more restricted, green energy generation will have to take over, infrastructure costs are not small and do not last forever. Whether people like it or not Nuclear will be needed at some level to support heavy draw periods and when green production is low. We all know building nuclear is very costly and energy companies will want their money back.

No one has heavily invested in tidal generation of electricity yet, there are a few small test plants that show this to be a very good prospect, it is possible that very large tidal station could generate megawatts of power and would operate 24*7, and daily low generation periods could be managed.

By the way if you think you will be able to heat your home with a log burner and limit the power costs, think again. I have been told installation of wooden burner will be legislated against within 2-3 years in a domestic environment, and then burning wood or coal will follow.

The so called renewable energy plant that burns wood pellet in the midlands is scheduled to be shutdown by the end of 2025. It has been realised that burning wood in any form is not ECO friendly, and chopping vast swaths of Canadian timber down to support it and shipping it to the UK does nothing for the planet in any form. All it does it make a few people very rich.

As most know being green or doing the right thing for the future of the planet is not easy, anything any of us do to make it better will help. If you don’t believe that just look at the improvement in air quality when we all went through the sad time of Covid lock down. It improved within weeks and got back to extremely high air quality levels in months, all because we were burning less pollutants.

We won’t be here in 20-30 years, and we don’t have children, so why should we care? Well IMO we have had the free gift of life on a rather beautiful planet, sadly we and our forbears have done a good job of getting close to trashing it, some purely driven by greed. Surely it’s time we made an effort to change that as much as we can?

By the way I and Sue knowvwe are not perfect in the ECO way, we still run a 20 year old Honda Jazz that does about 5k a year, but it will be replaced within 2 years with a small used EV or if it is not cost effective to repair. Also we do fly once a year, and this is not great, the only alternative I can see in the future will be holidays in the UK or EU countries and going by EV and enjoying getting there. I think flying will become too expensive for us in the next 5 years anyway.

I did not intend writing this but thought it worth saying. I make no apologies to the proverbial Ostriches out the.[emoji1]

[struth]

dont fly; have ev. use what power im connected to. it used to be supposedly green, but it probably wasnt...dont go hols either. gas heating and unless someone changes it it will stay that way. be surprised if im still around at time to change to those exchangers

[dave2010]

Adrian - I believe 2nd hand Nissan Leafs are considered a good buy. Early models are not very good, but the more recent ones have batteries which will still have some life in them. OK - Nissan use that Chadomo plug thing, but I don't think that's an insuperable problem.

The point is that if you don't do many miles, then the outlay is low with a 2nd hand Leaf, and you already know about the costs of running EVs. Trying to do long journeys in a Leaf - and I've met people who do - seems a total pain, but for everyday use - short distances - really OK.

Here is a YT video showing a view on PV panels from the US - https://youtu.be/jxt3v7kTlvw but most of the details are not currently relevant in the UK.
Interesting that this guy is using 1 MwH per month!

We use logs occasionally, and will be able to continue to do so since the burner is fairly new. It really is useful as a backup in case of grid failures. Re the wood - we have had a lot of locally sourced wood, which we're still working through.
I also bought wood [quite good] but sadly on checking, most of it comes from Lithuania. Really BAD! That's chopping down trees somewhere else, then moving it by road and sea at some expense and environmental damage until it eventually ends up in our wood pile.
We'll try to avoid doing that in the future, or at least moderate/minimise our use of such timber.

[struth]

cant convert the chademo either sadly. still you may find more of them free and available.

edit... ive got 309mls in tank after charging car the other day pretty decent for time of year.

[AJSki2fly]

Adrian - I believe 2nd hand Nissan Leafs are considered a good buy. Early models are not very good, but the more recent ones have batteries which will still have some life in them. OK - Nissan use that Chadomo plug thing, but I don't think that's an insuperable problem.

The point is that if you don't do many miles, then the outlay is low with a 2nd hand Leaf, and you already know about the costs of running EVs. Trying to do long journeys in a Leaf - and I've met people who do - seems a total pain, but for everyday use - short distances - really OK.

Here is a YT video showing a view on PV panels from the US - https://youtu.be/jxt3v7kTlvw but most of the details are not currently relevant in the UK.
Interesting that this guy is using 1 MwH per month!

We use logs occasionally, and will be able to continue to do so since the burner is fairly new. It really is useful as a backup in case of grid failures. Re the wood - we have had a lot of locally sourced wood, which we're still working through.
I also bought wood [quite good] but sadly on checking, most of it comes from Lithuania. Really BAD! That's chopping down trees somewhere else, then moving it by road and sea at some expense and environmental damage until it eventually ends up in our wood pile.
We'll try to avoid doing that in the future, or at least moderate/minimise our use of such timber.

Hi Dave,

Yes, we had the Nissan Leaf high up the list of possible replacements for the Jazz, it will be used mainly for local journeys. The Cha-Cha-demon plug is a bit of a put off, I will see if there are sensibly priced adapters, I don't understand why Nissan continue to use them, they are not exactly popular or maybe that's just here.

Thanks for the video I will take a look.