In this video IU'm going to take you through our solar pv
and Tesla Powerwall 2 performance for September 2020 here in the UK, along with our Tesla Model 3
and Kona electric costs and usage. So stay tuned!
Hi John here and welcome. As I said in the intro in this video I'm going to take you through our
solar pv and Tesla Powerwall 2 performance for the month of September 2020. Plus the usual
stats and usage information for the Tesla Model 3 the Hyundai Kona and our myenergi eddi and zappi
components. Incidentally I've recorded a separate video on 12 months ownership of the Tesla Model 3.
It turned a year old on the 28th September and I'll put a link to that up here. And also down
in the video description. If you recall in our August video I told you that comms hub on
our electric SMETS2 smart meter had died. And it's was having a power cycle on the 6th of October
which is next week. I'm recording this on Friday the 2nd of October so hopefully that will fix it,
but I'll do you an update in due course on that. So yeah both gas and electric now aren't reading
data through to Octopus. If you're not familiar with our setup we're based in the UK but again
all the details are down below in the description so have a look down there to all the component
parts the sizes the specs all of that kind of thing. So on to September's performance. Let's
have a look at our monthly pv generation totals. So in September we produced a total of 69kWh
from our two separate arrays. We had a daily average generation of 23.2kWh for the month
which is almost identical to August total. Which it's actually good for this time of year because
often September trails behind August in terms of the totals. As well as the way the months run!
So let me know in the comment section down below how you got on with your solar generation
because I really like to hear what your totals were, and your system, and your components.
Plus everyone else likes to have a look as well so you're sharing with
the wilder... wilder! community it might be wild but it's also wider!
Let's have a look at our split of our both arrays so our 4kW array original solar array produced
434kWh and our newer 2.3kW array produced 262kWh. And those figures are within a nats whisker of
August totals as you can see there from the chart. If we look at the percentage contribution of the
Powerwall 2 and our solar to our overall self power bring that chart up for you.
Our Powerwall is in Cost Saving Mode it's kept in there from when we swapped it in August. It
was on self-powered mode and in the middle of August we moved it across to Cost Saving
and as I mentioned in that last video in the August video is that it's probably going to
stay on that mode until the early summer of 2021. We are with Octopus energy on the Agile tariff
and often the unit of electricity during peak is around 25 to 30 pence per unit of electricity
so in the cost saving mode the battery provides the power to the house during that peak period
from 4pm to 7pm the power wall can provide a 5kW continuous load or up to 7kW for a quick burst.
So for the month of September we were 64% self-powered from the Powerwall and solar
combined with both contributions. Which is about the same as September 2019 when we
were 66% percent self-powered for the month. In September 2020 41% came from solar and 23%
came from the Powerwall. And looking at the figures you can certainly see the drop in
solar production here against last month when if you look at August last month. And also if
you compare it to September 2019 to September 2020 you will see a difference in solar contribution,
so less solar contribution in 2019 but more battery usage to supply the house demand. Let's
have a look at the peak and off-peak for that self power see how that split out. And the Powerwall
did a good job of managing our power usage at peak period so let me show you that chart.
This is the monthly figures for the Powerwall supplying the house
rather than the house pulling from the grid. The months along the bottom are only populated
with data when we are you when we are in cost saving mode with the Powerwall 2. This allows
me to track how effective it was at powering the house during that peak and off-peak period.
As you can see we were 9% self-powered during that peak time of 4pm to 7pm and off-peak the power
was able to supply a home usage for 29% of the total amount of time over the month. The reason
for the lower figure compared to the August's 49% during off peak will become apparent when we have
a look at the day by day chart in a minute. If we move on to have a look on the year on year chart
here is September's solar generation and that goes back to 2011. The totals for 2011 through
2019 our original 4kW system the 2020 figure is for both arrays.
If you recall our original array produced 434kWh in September of this year,
making it actually our third best September over the 10 years that we've been recording the data.
Let's move on have a look at our Powerwall in and out.
Powerwall did well this month it had a round-trip efficiency of 92%
based on what it managed to store versus what it was able to supply. So we stored 248kWh
into the battery and it supplied 229kWh and the input was the same as August but we managed to
pull just slightly more out another 12kWh over the course of the month comparing it to August. So
let's look at that day by day chart so this chart gives you a certainly a lot more detail of what
happened day by day through our usage. The key or the legend is blue is our house usage, yellow is
solar production, red is what's been pulled from the grid and orange is excess exported back to the
grid. You'll see there's a lot of blue there! We used lots of power this month basically the house
used lots of power. We charged the Tesla Model 3 much more in September compared to previous months
with most of it coming from the grid. And we certainly use the car much more which
you'll see in a bit when we have a look at the Model 3 stats which is coming up. But I guess
also not being able to make the most of the sunshine as we were out during the day in the car
and this meant we exported perhaps a little bit more solar production than we wanted to because
we were away well we couldn't use it. So for me the takeaway is never leave the house
or if you do leave the house when it's dark! So let's have a look at those days let's pick out
some of the key ones if you look at the these the 1st, 8th, 17th, 18th the 24th and the 26th.
All those days we charged the car from grid power typically that would have been in the early hours
of the morning when the electricity prices were cheap because our smart meter is no longer smart
I can't actually give you the exact costs of those charging activities. However the unit rates vary
between 2p per kilowatt hour to 7p per kilowatt hour when we were actually charging the car.
I made sure that I did charge it, it was no more than 7p per kilowatt hour for our unit rate.
We've also been running at least one of our kilns almost every day be that each night or during the
day and that's again for most of the month. So I guess depending on the program that the kilns
are actually running they typically consume about 5kWh of electricity for each firing from start to
finish. This works out on average based on the price of electricity when we actually run in
the cut the kilns at about 7p per kilowatt hour so it's 35 pence to run the kiln basically. So
it's only not clearing out our bank account when we're running the kilns, which is good to know.
I guess in summary of that day-to-day we had very high house usage more reliance on the grid
and in some cases we were less effective in using the solar energy, mainly because we were out.
Let's have a look at the overall totals quickly for September
with this chart here. So that shows you the four data sources and we'll look at
some more in a little bit more detail in a second. So the house usage is the key one,
1090kWh for the month which compare that to August which was 860kWh.
And we've already looked at the solar production and we're about to look in more detail about the
grid import and export so they're there but I'm just not going to dwell on them. Which leads me
neatly on to talk about our daily average grid usage and house usage chart. This chart tracks our
average daily house usage and our average daily grid usage as you can see here our average daily
house usage is up at 36.3kWh and this ties in what I've already told you about our increase in usage
our average daily pull from the grid was also higher at 15.kWh. Double what we did in August.
What we sent to the grid let's have a look at that so we sent 79.3kWh of excess solar generated back
to the grid in September which actually is less than August. So you know that is a positive.
The export total is really made up of very small amounts of surplus each day that we
were unable to make use of. What I found is once the hot water was heated up by
excess solar, once the battery was 100% state of charge then two to three kilowatt hours would
trickle back to the grid over the day unless we were at home and the car was plugged in
and charging. The Kona, because we didn't use it much in the month, had 80%
state of charge for the month so there was pointless trying to push more juice into that.
It sort of goes back to my earlier point about never leaving the house during the daytime!
If we go down have a look at the monthly totals from the grid chart so in September we pulled a
total of 455kWh from the grid. It's almost twice as much as we did in August. And I've
always mentioned already mentioned the reasons for extra grid usage so I won't repeat myself here.
In terms of the eddi for the month of September. The eddi diverted 4kWh of excess solar energy
to heat our hot water and that's all we use to heat our hot water we don't use any additional
gas or anything like that. So this gives us a yearly day year-to-date total of 353kWh.
We have an accumulative total since installation on the 22nd of July 2019 of 426kWh.
I've taken the cost savings of £2.66 that I've listed there based on 5p per kilowatt hour. Which
I think I said before last month was probably a little on the low side because the average agile
price is around 8p per kilowatt hour over 24 hour period. Anyway leave it at that. Onto the zappi
and the cars. The Tesla Model 3 basically doubled our last month's total of 731 miles covered during
the month and we did a very credible 1433 miles and that brings its overall total to 6,583 miles.
The Kona covered just 134 miles in a month and now has a total of 10,322 miles.
The Kona hasn't been charged at all during the month because
we didn't use it was very much, 130 miles. So it didn't have much impact at all on its charge.
The Model 3 has been the one, the backbone I guess for the month. The Model 3 has had 5 supercharging
sessions much of that was down to an issue we had of being unable to supercharge which meant there
was a bit of post-fix testing. And there's a link to that video up there if you want to know all
about that and there's also one that follows it was which is the fix to what the problem was. Yeah
they're up there if you want to go and have a look at those. So the 5 supercharging sessions added
182.07kWh to the Tesla at no cost because of our referral miles for our Tesla. It is a real thank
you to those of you who have used our referral code as we both benefit from a 1,000, three....
a thousand three... free! oh I struggle with that. A thousand, a lot, a thousand supercharging miles
each. Yeah the codes coming up down there so if you're thinking of getting aTesla then
perhaps consider using my code that would be much appreciated. It'll benefit us both.
On the zappi point of view from charging at home we added 397.87kWh to the Model 3.
As you can see from this picture the split between the grid and energy was 42% green and
the remaining was 58% which came from the grid. This cost us £13.76 to use the grid for those
22kWh which is how much we pushed in. And this is based on our 6p per kilowatt hour
on the Agile tariff which was when we would have charged the Tesla overnight.
Again I've had to sort of guesstimate this on our smart meter as as it's broken. So
I know we only charged in the early hours when the price was around 6p to 7p per kilowatt hour.
So it's fairly accurate but it's not bob on the money, but you get the flavour.
So if we push that into our 1,433 miles covered during the month it's cost us £0.01
pounds per mile. So that's it. Please comment and like as those actions means that the video
gets shown to more people. It's all about engagement on Youtube. Thanks for watching
and I will see you on the next video. All right take care. Bye.