Hello

[cmorewood]

Hi, We're renovating a 1966 semi in Aberdeenshire upgraging insulation and installing "green" technology. We've achieved an A 99 rating from D 64.

Currently 40 tube solar themal heating 300l water 5.6kw solar PV capped at 4kw supplying 4.4kw saltwater batteries, awaiting connection to 11kw. Running a Tesla Model 3 and a Samsung ASHP. Awaiting connection of our smart meter to take advantage of the Octopus Agile tariff. Also awaiting the tiles going on the dormer extension so the A99 doen't quite work at the moment.

[ProDave]

Hi and welcome

 

That sounds a really interesting project, please do tell us more.

[cmorewood]

What would you like to know?

UFH via gas initially in the kitchen extension installed in 2007 and UFH pipes running between joists in the suspended ground floor with a multi layer fopil insulation stapled in below.

2018 My brother and I renovated the ground floor, reorgainmed the sitting room, bathroom and doenstairs bedroom making better use of the space and installing a wetroom with decent bath. we installed new engineered flooring so we buried the pipes in sand which works well but doesn't have the response time that the old system had.

2019 first floor extension 2 large dormers and a porch with heat recovery installed but unfortunately got a bad builder..who promised stairs and doors that never turned and as we discovered recently, didn't tile the roof with enough cover. So since October, we've been doing what we can with whoever we can find to fix the problems. Still about 2-3 weeks work away from finishing the job  but with the virus, I think this might be about 5 or 6 months.

[MikeSharp01]

Sounds wonderful and Welcome to THE forum. 

[SteamyTea]

On 27/03/2020 at 21:26, cmorewood said:

4.4kw saltwater batteries,

How are you getting on with these batteries.

I shall assume that it is 4.4 kWh (storage capacity, kW is power)

[cmorewood]

? Correct 4.4Kwh. well spotted.

I think they're geat.. they need no looking after and no BMS just deplete and charge. I will be installing a BMS when I get the other 3 connected.. but that's going to be a while away.

I'm also considering the Blue Sky Greenrock EMS when they get a UK dealer.

Sounds wonderful and Welcome to THE forum. 

Thanks Mike

[SteamyTea]

10 hours ago, cmorewood said:

Correct 4.4Kwh. well spotted.

Some of us are a bit pedantic about units.

So what will be kWh, not Kwh.

 

If you select the text you wish to reply to, a small box will appear with 'Quote selection' in it.  This will notify the person that you have replied.

Same as using the @ sign before a username.

 

And welcome.

 

Now the important part, how much do the batteries cost and what it the volumetric energy density (how large are they).

[cmorewood]

38 minutes ago, SteamyTea said:

Now the important part, how much do the batteries cost and what it the volumetric energy density (how large are they).

They're Aquion S-line batteries. specifically the Aspen 48S 2.2 KWh. not the smallest (935H x 330W x 310D) or the lightest at 118kg  but when they're depleted you can tale them to the local tip as they're only plastic and aluminium. They take no looking after, just make sure they dont get too cold, no lower than -5c and you can use the full capacity, unlike the other types of battery which can only use a percentage of their capacity.

Unfortunately, they're no longer available new under the Aquion brand as Aquion in the US went bust due to cashflow problems. (you may be able to pick up one or two secondhand)

Blue Sky in Austria bought the rights and now produce an amazing range of batteries, BMS and EMS. Check out their YouTube channel. You can find them for sale in the UK but I don't think they have a UK dealer yet.

I have 2 new, well one year old now, and I managed to pick up 3 others from Kent in December which will give me 11KWh and I'm awaiting their connection.. but now that might be a while.

Aquion_Energy_Aspen_48S-2.2_Product_Specification_Sheet.pdf

[SteamyTea]

So around 23 Wh/litre and 19 Wh/kg.

 

Size and mass is not really a problem for domestic storage, so they have a place in load balancing.

 

Do you monitor your daily energy usage to see when the batteries are charging and discharging?

[cmorewood]

35 minutes ago, SteamyTea said:

 

Do you monitor your daily energy usage to see when the batteries are charging and discharging?

Yes, I can monitor via the VRM portal.. monitoring a bit more at the moment (the plans have gone awry with the virus changes.. 7KWh less as the new batteries aren't connected, no smart meter so I can't get on to the Octopus Agile Tariff and the arrival of the EV) as I'm trying to balance trickle charging the car and washing machine/dishwasher plus the recharge of the batteries from the solar during the day (not all at once obviously) Fortunately in the East of Scotland we get a good amount of sunshine, as long as the wind stays westerly.

I also have a daily and monthly Excel worksheet moitoring useage and production and cost. I've often had  the "we need to increase your DD" email and gone back to them chalenging their figures and they've backed down ?

[SteamyTea]

2 minutes ago, cmorewood said:

Yes, I can monitor via the VRM portal.

Does it save the data so you can look at it in fine detail.

I collect data about every 6 seconds.  Means I can easily pick up the kettle going on, or even if I have left a light on upstairs, and I only use 3W LEDs.

4 minutes ago, cmorewood said:

7KWh

It is 7 kWh, not upper case k (there is disagreement as to whether there is a space or not between number and unit).  A capital K is Kelvin, a temperature scale.

Units are really quite easy.  There are the SI ones i.e. metre, kilogram, second.

Then there are derived ones wish are normally named after a person so a watt is named after Watt, a j is named after Joule. as the k means kilo, or 1000, it is lower case, an hour is not named after a person, so it is lower case.

It gets odd only in that a watt or a joule is all lower case, but the abbreviation W or J is upper case.

And the kilogram is the odd one out, though it is now properly defined.

[MrMagic]

@cmorewood Keep the posts coming - I thought with Aquion going under this tech was dead but good to see it's still out there in places!

 

Would be good to see some graphs, cycles, charge rates etc... the more stats the merrier.

 

(and don't mind @SteamyTea, he means well ?)

[cmorewood]

Here's a few views for you

As you can see they're quite detailed.. You will notice the SOC graph isn't correct. We surmise thats because there's no BMS on the system.. there will be one when the new batteries get connected and possibly the Greenrock EMS next year

[cmorewood]

The graphs are for the past 2 days, I find that the most useful, however I can display from an hour to years.

[SteamyTea]

29 minutes ago, MrMagic said:

and don't mind @SteamyTea, he means well

Like herb immunity, eventually most will get it.

 

28 minutes ago, cmorewood said:

Here's a few views for you

 

That last chart collection is useful.  Does the Victron software allow you to grab the raw data for each element.

 

[Ferdinand]

29 minutes ago, SteamyTea said:

1 hour ago, MrMagic said:

and don't mind @SteamyTea, he means well

Like herb immunity, eventually most will get it.

 

I dig that, man. 

 

Give me those herbs ... then I won't even know if I have it.

Edited March 31, 2020 by Ferdinand

[cmorewood]

25 minutes ago, SteamyTea said:

That last chart collection is useful.  Does the Victron software allow you to grab the raw data for each element.

That I don't know I'm afraid. I don't think so, but I havent't gone that deep into it.

In fact yes it does! It allows you to download the raw data to the cloud in .csv and .xls format

Edited March 31, 2020 by cmorewood
new info

[SteamyTea]

17 minutes ago, cmorewood said:

In fact yes it does! It allows you to download the raw data to the cloud in .csv and .xls format

That's excellent.  It can tell you so much about when, on average, it is best to run heavy loads.

Link it into Gridwatch and you can work out the  best time to reduce CO₂, which is what it is all about anyway.

21 minutes ago, Ferdinand said:

I dig that, man. 

I think I am going to switch off the auto correct.  I had an ex offering a 'lick down' the other day, but I am sure it is not what she meant at all, especially considering what the conversation was about, quite inappropriate. 

[cmorewood]

29 minutes ago, SteamyTea said:

That's excellent.  It can tell you so much about when, on average, it is best to run heavy loads.

Link it into Gridwatch and you can work out the  best time to reduce CO₂, which is what it is all about anyway.

Shortly I hope, I'll be on the Octopus Agile tariff which is based on the wholesale grid price. A no brainer for those with batteries.

https://www.energy-stats.uk/octopus-agile/

Although you could use my referral code instead ?

Edited March 31, 2020 by cmorewood
sp

[Jeremy Harris]

I've been tracking Agile and Go for some time now, and so far neither are cheaper for us.  E7 is, for us, a slightly better option, with the main reason being that the Tesla will not accept control from a smart charge point (so must use the in-car charge timer) and the ASHP cannot be just ramped up and down to match the price, we need it to run for between 5 and 7 hours overnight in order to heat the slab.  We already store heat generated from excess PV generation in a Sunamp, so that delivers around 65% to 70% of our annual hot water needs for free, with the remainder being from an E7 boost (hot water only costs us around £50 or so a year).  I've been looking at installing batteries for a few years now, but cannot make the sums add up.  We would save so little money that capital investment in the batteries would never be recovered before they died of old age, even with me doing the installation in order to keep the price right down.

[SteamyTea]

7 minutes ago, Jeremy Harris said:

We would save so little money that capital investment in the batteries would never be recovered before they died of old age, even with me doing the installation in order to keep the price right down.

Yes, the initial installation has to be below £100/kWh really.

That is assuming no losses over the first 1000 charge cycles and power bought in at 10p/kWh (about current E7 price).

17 minutes ago, cmorewood said:

Shortly I hope, I'll be on the Octopus Agile tariff

That tracks wholesale price, not CO₂ intensity.  Would be interesting to look at the correlation between them.  Old nuclear is cheap, as is marginal natural gas generation.

Then biomass screws it all up, but in reality it is higher than coal.

[MrMagic]

Heres a very basic attempt at Agile Cost Vs Grid Carbon Vs Grid Generation Mix. It looks like demand 'swing' is probably the biggest cost contributor.

 

(Ignore the TZ in the top graph, need to update my code to handle BST)

 

[cmorewood]

3 hours ago, Jeremy Harris said:

I've been tracking Agile and Go for some time now, and so far neither are cheaper for us.  E7 is, for us, a slightly better option, with the main reason being that the Tesla will not accept control from a smart charge point (so must use the in-car charge timer) and the ASHP cannot be just ramped up and down to match the price, we need it to run for between 5 and 7 hours overnight in order to heat the slab.  We already store heat generated from excess PV generation in a Sunamp, so that delivers around 65% to 70% of our annual hot water needs for free, with the remainder being from an E7 boost (hot water only costs us around £50 or so a year).  I've been looking at installing batteries for a few years now, but cannot make the sums add up.  We would save so little money that capital investment in the batteries would never be recovered before they died of old age, even with me doing the installation in order to keep the price right down.

I'm Lucky in having solar thermal for 80% of our hot water needs.. It only really needs an assist in the 4 winter months and even then only a couple of times a week.. now the kids have gone and of course the obligatory 60C legionaires once a week. I've got 40 Navitron 58mm tubes heating 350 lit in 2 tanks. Its a little overkil for the summer but it means in the winter we can last a little longer without the HP.

We're planning, once we get the smart meter, on charging  the batteries, car and using the HP at night. I'm paying 15p per kWhour on the green fixed tariff at the moment so being able to run everything at about 6p is a massive saving for us despite the addition of the car.  But having all the batteries online will mean that we use them in the expensive periods during the day and so should see an H24 rate of about 5-7p.

I'm using an Ohme smart charger, again waiting for the smart meter to use it in anger, but still trickle charging off the excess solar at 6ah, 2kWh I just monitor the sunshine and stop it if it gets cloudy. and if I ever get to do a journey over 10 miles!! I'll use the local free charger in town although I'll sit and watch a movie for the time it takes !! at 20kWh I can't seem to get the 50 kWh ones to work with the Tesla.

 

Thats an interesting graph Mr Magic. You really can see where the windy days and the poor solar generation are interesting to see just how little coal generaton there is.

[Jeremy Harris]

Our PV system provides a fair chunk of our hot water for free, we really only need to boost it from off-peak for around 4 or 5 months of the year.  No need for any Legionaires stuff, as it's a sealed system, using a Sunamp thermal battery.

 

The problem I have with charging the Tesla is that it refuses to play nicely with a timed charge point.  There's a software glitch with the Model 3 that disables the charge port when the car goes to sleep, so if the charge point starts to advertise power when the car's asleep it refuses to accept it.  It's very, very annoying, as the only way around it is to take a massive security risk and allow a third party to have full control of both my car and Tesla account (both use the same security credentials).  There's no way that I'm going to do that, not least because Tesla haven't officially released their API to third parties, and giving my Tesla account login and password away to an unauthorised third party seems like madness, just like give a complete stranger the key to the car.

 

Other EVs are fine with charge control via the charge point; the BMW i3 I had would happily start and stop charging, and vary the charge rate, under charge point control, as did the Prius Plug-in I had before that.   This made it dead easy to charge the car up largely from excess PV generation for a large part of the year.

[Ferdinand]

15 minutes ago, cmorewood said:

I'm paying 15p per kWhour on the green fixed tariff at the moment so being able to run everything at about 6p is a massive saving for us despite the addition of the car. 

 

What is that potential saving in cash terms per annum?