Is it spring yet?

This is more like it, but is only one day!

Most of our import (and today it is likely all of our import) was 2am to 5am at 14.71p.

Most export was during the day at 15.08p.

A lot of export, around 15kWh (54MJ) was 4pm to 7pm (actually 5:30pm to 7pm so we save some for evening) at 24.93p

Doing the sums I think...

• Import 34.1kWh (122.8MJ), assume 14.71p, £5.02
• Export sunshine, 26.7kWh (96.1MJ) at 15.08p, £4.02
• Export battery, 15kWh (54MJ) at 24.93p, £3.74

Total electricity bill (excluding standing charge) -£2.74, and that left some in the battery still.

Without solar and battery? House used 31.4kWh (113MJ) and would have been mostly 24.51p, so £7.70.

If only every day was like this.

Save power to avoid blackouts

Article on the BBC, here... "Households will be offered discounts on their electricity bills if they cut peak-time use on a handful of days over the winter, as part of National Grid's efforts to avoid blackouts."

These sorts of things are incredibly difficult to get right.

Punished for being proactive?

Some of us have already been proactive. I am a high user, but now have solar and battery. The hot tub (a big chunk of usage) is now on a timer so largely heating in the middle of the night, and easy to avoid the 4-7pm peak. I am also on a special battery tariff, so for example, my usage 4pm-7pm is actually about -30% of my daily usage (yes MINUS 30%, i.e. I export around 30% of my net daily usage 4-7pm).

Now, this means it would be physically impossible for me to use less 4pm-7pm, whether net (i.e. allowing for export) or just import (i.e. currently 0kWh usage).

So no way I can benefit from the Octopus scheme as I see it, unless I have misunderstood, as I cannot "improve" my peak usage.

Had I *not* been proactive. Had I left the hot tub on 4-7pm. Had I not run the battery like this. I could be easily making that extra £100 on offer. I am being punished for my being considerate and proactive - or so it seems. That feels wrong, somehow.

Other approaches

My understanding is that some providers are working on getting people to make their 4-7pm usage a lower percentage of their net 24/7 usage. That would work for me, as I already do that, assuming they would even cope with a negative percentage, maybe I would get more than £100, LOL.

Encouraging bad behaviour

I need to work out the "reference" period for saving. Even on the tariff I am on, it would not be hard to make my 4-7pm usage really high. It would not be hard for anyone to do that by running the washing mashing, and tumble drier (and I know most people don't have one, a hot tub), even electric water heating as many have that as a backup for gas. And, of course, if you have one (we don't) charging your EV.

If doing that for a few days before, then during the key days you move the power usage away from 4-7pm, you can get that bonus. For a lot of people "moving" the power usage has not extra cost, so why not.

This is a problem with any system that is "relative improvement". Make it absolute, e.g. usage below X kWh for the period per hours, or even less than % of net 24/7 household usage, and that may work, no need to force a high "reference" against which you are saving.

Not in the spirit of the scheme

One criticism of anyone adjusting their usage before these saving sessions to get a better reduction is that it would not be in the spirit of the scheme. Not "the right thing to do". Even Octopus said that on twitter.

Well yes, that is true, but the whole scheme is based on people doing "what makes them money" not "what is the right thing". There would be no need for any financial reward if people would "do the right thing", so yeh, you kind of have to expect that people, as a whole, will do what makes/saves them the most money - that is how people as a whole tend to work, even if individuals do sometimes do the right thing - it's the very basis of economics (from what I remember).

Getting data out of smart meters

For the tariff I am on, I needed a smart meter - there are various concerns about smart meters, but having actually got them, I want to be able to make use of them for the one thing they are good at. That is accurate usage data in real time.

Yes, for electricity a current clamp also works, but how "calibrated" is that exactly? Getting the data from the actual smart meter is much nicer.

But how?

Well, it turns out that there is an in home display you can buy which links to your smart meter and also to your wifi, and will send data via MQTT!

Slightly redacted MQTT smart meter data

It seems I can get electricity updates every 10 seconds, and gas every half an hour. It even includes electricity export data (although only a cumulative figure).

Next step will be putting data in to an SQL database.

And yes, it shows export real time as well :-

What is this marvel?

It is the Glow from Hilderbrand. They have been quite good sorting it out - it was to be an SMETS1 unit, but with new smart meters it is the SMETS2 that I have.

So far, I am impressed.

Power line signalling thoughts (demand power management)

There are ways that things can communicate over power lines, notably Ethernet over power, which, IMHO, is crap. I am sure it has its place, but I would avoid like the plague.

However, I can see one area where some simple signalling would be very cool, and ideally in a really standardised way. Indeed, the idea that this could even signal incoming on your mains feed is not at all daft.

It actually sort of exists, it is frequency - when under 50Hz (UK) the power grid is struggling to meet demand, and when over 50Hz it has extra capacity. At present, few, if any, devices can detect or use that. Just using that could be useful, but I am thinking only a simple signal of 5 possible values.

What I am talking about is some signal that can tell a device :-

• Right now power is effectively negative, please consume some power now even if it is going to waste
• Power is cheap now, if you have a choice, now is the time to use it
• Normal - use power as needed
• Power is expensive now, if you have a choice, now is the time not to use it
• Please shut down usage if at all possible right now

Not suggesting a complex set of signals by any means.

Now, if this was inherent in the mains supply, that could be useful of a lot of devices in the home. Ideally you need some signally (i.e. not frequency, really) so that you can isolate and run your own in the house. So for a house with solar and not a sane feed in rate, you can set this based on your solar/battery status in the home. But for most people not having this, the grid can set it.

I guess, it could be a standard that is frequency as the primary key and a secondary power signally for home override, maybe.

The point is that lots of kit really has a choice. At the simplest level, things like electric emersion heater, but in my case things like my hot tub. At present my hot tub heats based solely on temperature. With a very slight bias it could target that heating when we have spare solar. Just adjust target temp by say 0.5C depending on the signal on cost of power right now. Same for water heater. Same for heating or cooling a home, e.g. even aircon. Especially true for charging anything from a mobile phone, right up to a car.

It would need to be a simple standard and somehow in the chipsets for power supplies on any and every device. A world wide standard for this would be great.

Let the juice flow

Well, the nice man from British Gas came round and did a very neat job, and we are all 100A now. Cool.

Unfortunately there was another side effect of having everything re done that has added a lot to the cost! A new washing machine.

Turns out the old one had an earth leakage issue but was not tripping the old circuits (may have been one of the non RCD circuits), and so as soon as we put in RCBOs, we find it is duff.

All good fun.

P.S. the geek in me that passed A-level physics can't help feeling there should be something more fun and youtube worthy to do with a 100A power feed than just charge a car and run a tumble dryer at the same time. Shame.

Power to the people: Stage 1

Upgrading the power in the house is not something I really expected, but seems like a good idea.

The main driver is the fact my son has a Tesla, and now has a 32A Tesla charger on the wall. It is quite nice technically, can take one or three phase, and can be configured to tell the car how much current it is allowed to draw. Mostly James uses the free supercharger on his way to/from work, but he tops up over night at the house. It makes it very cheap to run (for him, at any rate).

So, having installed the Tesla charger, we can be using 32A extra. That is a lot for a domestic installation, even for a large(ish) house like this one. The first time it was charging at the same time as the tumble dryer it tripped the 80A RCB on one half of the consumer unit. Now, we were not up to 80A, I can be pretty sure of that, and it is an RCB, so it is likely just all of that load from various sources led to just enough leakage current somewhere. Hard to be sure to be honest. Moving off the RCB worked.

There are therefore a couple of concerns. One is the nuisance caused by an RCB that trips half the house. We have computers with disks, a wax printer with melted wax in it, sudden power losses are a nuisance. To be fair, computers are way better at this these days (journalling file systems, etc), but if you are in the middle of something time consuming you can end up starting again. And then there is the possibility that you are playing some on-line game, which, by total fluke, my son and I were doing at the time (I rarely play anything, this was AoE on steam!).

The other concern is the overall current usage, with one device that can draw 32A, and a "commercial" tumble dryer on a 30A circuit, and five air-con units on 16A circuits. One can see this adding up.

So, yesterday was stage 1.

I have had the consumer unit replaced. As per that picture it is all RCBOs. This means each individual breaker is an RCB, rather than a breaker for each half. They are on 100A switches on each half. This is not cheap, and took many hours to do. But now, each circuit will trip independently of the others, which is much cleaner. I also isolated my "Internet" stuff (connection, switches, PoE for WiFi, and security cameras) on to their own circuit. The alarm is already battery backed up. So this means less chance of tripping something taking out the Internet as well.

Also, the tails to the meter were upgraded from 16mm to 25mm to allow for 100A feed.

Also, a separate meter was installed on the Tesla circuit so I know how much James is costing exactly.

Stage 2: The next stage is upgrading the tails from fuse to meter - next week. They are also adding an isolation switch, which is nice. All that for £44 from British Gas.

Stage 3: We checked the fuse, and it is marked 100A on the carrier, but is in fact only 60A. Wow, we are way closer to hitting that than we realised. So we need that upgraded. That cannot happen until the tails are upgraded, and they checked the meter is 100A, which it is. So we are good to go for 100A installation...

Frozen!

No, not the film, my feet, and other parts of me.

I am glad to be back home in the warm as I have spent all day from early hours at the office with no power (and hence no heat). The alarm system can only run on batteries for so long...

In spite of the cold, it was fascinating watching the guys from SSEN diagnose and work on the fault outside the A&A offices today. The power went off, well, mostly, last night. Actually all three phases (we only use one) went to around 40V, so some things still managed to blink the odd light.

They dug a hole by the road last night, and confirmed the power was fine there...

So this morning they dug a hole in our car park...

They took out one of the water mains...

Which caused a lot of delay as they had to stop the water and empty the hole full of water before exposing some of the electricity...

They also found our fibre connection, but managed to do so without breaking it, phew... (the grey pipe)

The dismantling of the cable was interesting, and they were slightly shocked to find the aluminium sheath was live :-) The rubber gloves came out quite quickly.

They checked the cable and found it was faulty, meaning the fault is between the two holes. However, this means they can isolate it and connect us to a big generator truck...

So now we have power, and they even fixed the water...

Yes, Sandra got them all coffee.

So we can look forward to them finding the fault next week, and then jointing us back on to mains power at some point, which I am guessing is going to take an hour or so. Time to order a UPS.

Obviously we set up calls to go to mobiles so staff could handle customer enquiries for normal hours of operation today.