This is my November 2020 solar PV and Tesla Powerwall 2 performance here in the UK.
Along with our Tesla Model 3 and Kona electric costs and usage. So stay tuned.
Hi John here and welcome in this video. I will take you through our solar PV and Tesla Powerwall
2 performance for the month of November 2020 plus the usual stats and usage information for the
Tesla Model 3 the Hyundai Kona electric and the my energy eddi and zappi. In the description down
below is a list of all of our components for our system so please have a look down there if you're
not familiar with our setup and our system. So dive straight into it. In November we produced
a total of 289kWh from our 2 separate PV arrays. We had an average daily solar generation of 9.6kWh
for the month which as you can see is actually identical to October's average.
Although putting that into perspective October was our worst month since
records began dating back to 2011 for our solar installation. So perhaps not a great comparison!
We scroll down and have a look at both charts to look at what each one
contributed. Our 4kW array produced 181kWh and our newer 2.34kW array produced 108kWh.
As you can see really close to October's totals. And you can see how October 2020 compares to the
previous Novembers in a minute when we look at the year-on-year chart. So let me know in
the comments section down below how you got on with your generation. I'd love to hear
what your totals were and what your system is. Plus as I've said before other people like to
read the comments and see how everyone got on. So it's a really useful sort of community sharing.
So thank you in advance to those that you who do that. Do comment and drop in your
details, it is very much appreciated by everyone. So let's have a look at the percentage
contribution of the Powerwall and solar to our overall house self-power. Bring up that chart.
Our Powerwall is in cost-saving mode we swapped that to self from self-powered mode
in the middle of August. We're with Octopus Energy and we're on the Agile tariff. Often
the unit price of electricity during peak is around 25 - 30 pence per kilowatt.
In cost-saving mode the battery provides the power to the house for the peak period from 4pm to
7pm and it can provide a 5kW constant load or continuous load. During November 2020 we were
50% self-powered from the Powerwall and solar contributions. As you can see from the stack
chart there 18% of that came from solar generation and the remainder of 32% came from the Powerwall.
If we scroll down and have a look at the peak and off-peak for self-power. The Powerwall did
a really good job of supplying the home's power needs during the peak periods between 4pm and 7pm.
During the month I actually extended the peak period time slot in the Tesla app right through to
8pm, so 4 pm to 8pm as the electricity unit price can still be a little high at that time of night.
So the percentages on this chart represent the performance of the Powerwall's ability
to supply the house rather than us pulling from the grid. The months along the bottom are only
populated with data when we're in cost-saving mode so the blanks, basically we weren't on cost-saving
we'd have been on self-power. The red column represents the 4 hour peak period at 4pm to 8pm.
So for 98% of that time we were on battery power and no pull from the grid. Just 2%
of our total energy was grid energy during that peak time. I don't actually have the exact figures
as my electricity bill hasn't arrived yet. But I've extracted the data from the OctopusWatch
app which I use and it shows 12kWh of usage for a cost of £2.88 for that 2% peak grid pull over the
course of the month. Which I don't think is too bad. I suspect that would be less now as we've
had our old smart meters removed and the new one installed which has stopped the phantom draw issue
that was adding erroneous power usage readings onto our meter when we were running purely on
battery. So probably find that 12kWh will actually be less from next month, from this month December.
The green in the chart represents the remaining 20 hours of the day and during that time we were on
battery power for 10% of that time so within the 20-hour off-peak period slot there are times the
day when the electricity is much cheaper and to cater for this I have the Tesla Powerwall app set
with an off-peak time slot of 12:30 through to 7:30am in the morning each day.
And in the winter this cheaper block of time becomes an almost daily ritual
where we pull from the grid to charge up the Powerwall this is done automatically by the
algorithm in the Tesla Gateway, but we also run our glass kilns we've got three of them.
Charge our EVs if they need it, run our dishwasher and any other appliances that we need to.
Unless we are forecast sunshine for the following day then we hold off and run them on access solar.
Let's move along have a look at the PV year on year. Here's the month of November
solar generation going back to November 2011. The totals for years 2011 to 2018
will be for the original 4kW system and the 2019 and 2020 figures are for both
arrays. If you recall the original 4kW array produced 181kWh hours for November
2020 making it in the middle of a pack in terms of performance over those past 10 years of data.
And the new array managed 108 kWh giving us the 289kWh total that you've already seen.
So this November's total was better than last November's total
for a like-for-like system. So 289 versus 289kWh for the month.
Powerwall in and out chart. So the Powerwall had a 88% around trip efficiency for the month.
And during that month we managed to store, what we store yeah, 324kWh and we were able to get
out of that 284kWh. The figures are spookily so close to last month's I did actually have
to double check them to make sure that I've pulled the figures from the correct place.
But yeah they they are correct. So very bizarre it's so strange that it's bang on the on the money
for one of those figures. Day-by-day chart. This chart gives you more detail on basically what's
happened on a day-b- day basis. I don't go through this on a day-by-day basis but feel free to pause
the video if that's of interest to you. The legend that you're looking at is blue is house usage.
Yellow is solar generation. Orange is export to the grid and red is pulled from the grid.
A quick visual at the graph shows you there's lots of blue and lots of red. So yeah solar wasn't
great for us. Overall we only had 2 days where our solar production was above 20kWh in a day that was
on the 2nd and the 4th. And I thought we're in for a good month this month because it was early
on. But no that wasn't the case. I actually had to adjust the Y-axis, the vertical axis,
to show 5kWh increments rather than the normal 10 that it previously shown. Just to show the data in
a bit more granularity because it was difficult to see otherwise. There are 11 days where we
generated less than 5kWh in a day which is over a third of the month. However, if we were to compare
it to last month which should have been better in terms of the amount of solar generation. Um
spoiler alert it wasn't! November as it turned out wasn't that bad. And as you'll see when we look at
the grid usage as well what impact that's had in terms of what we exported and what we pulled in.
So we made about the same amount of solar as last month so you know not too bad really
for the time of year when daylight is still shortening and we're less than three weeks away,
basically we're heading towards the shortest day. At least it goes the other way from then.
Let's have a look at our overall totals chart. Overall totals tracks total for the four
data sources that we've just looked at on the day-by-day. House usage is the key one I guess.
949kWh compare that against 1090kWh in October. So slightly less usage over the month by 141kWh.
We've already looked at the solar production and we're about to
look in more detail at the grid import and export figures so I shall skip on to those.
This chart looks at our daily average grid and house usage as you can see there our average
daily house uses were down in November to 31.6kWh from 35.6kWh in October.
And on average each day we pull 22.8kWh from the grid again down from October's figure of 28.2kWh.
In terms of what we sent to the grid we sent 26.3kWh of excess solar generation
back to the grid in November which is less than October's. Which again is a positive.
As ever it's sort of made up of small bits and bobs, dribs and drabs, which tot up over the
course of the month. I'm not really too worried about it. It happens, stuff that we can't use.
Scroll down and we'll have a look at what we pulled from the grid. This chart tracks what
we pulled from the grid each month. And this month is total last month November
it's a total of 685kWh from the grid again it's down from October's total which is good to see.
Let's move on have a look at our eddi. This table is for our eddi and it heats the hot water by
diverting excess solar. Once the Tesla Powerwall is full then the eddi takes over and fills up.
November is a repeat of October in terms of monthly totals. Another 17kWh
this gives us a year to date total of 389kWh and a from installation of 462kWh.
The 17kWh amount is low again this month which you know means we would have used grid energy and or
natural gas to heat our hot water. So just be a heads up on that. In terms of cost savings I've
taken the £1.00 cost savings based on a 5p/kWh which is probably a little low because the average
Agile price we're paying is around 7p to 8p/kWh overall. But I've left it as is.
Talk about the cars. The Tesla Model 3 has covered 319 miles during the month of November bringing
its total mileage to 7,990 miles. All the charging for the Model 3 was done at home on the zappi.
We added 156.98kWh of which just 17% was from solar, 27.9kWh of green energy.
The remainder from the grid would all have been off-peak rates or during some negative pricing.
Because we had some negative pricing during November as well. And to work out the costs
on that because again we haven't got the bill through yet I've used an average of 6p/kWh to
calculate the costs which is probably about right. But either or be a penny one way or the other.
The 319 miles covered in the Tesla during the month cost us £0.02 pounds per mile. So
pretty good. The Kona covered just 79 miles in the month and now has a total mileage of 10,482 miles.
The Kona hasn't been charged for the month as we did very little mileage
and I'm sort of tending not to use it at the moment in case it bursts
into flames! Yeah it's on the recall list it's actually been booked in with Hyundai
for the battery recall fault check on the 14th of December. So I'll update you on that once I know
the outcome of that and then hopefully I'll get my confidence back restored in it that it's okay
to charge and it won't burst into flames and obviously then start to use it more.
Down below please Comment, please Like, please Share. As ever that all of those
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Thank you for watching. And I will see you on the next video. All right. Take care. Bye.