Effective Smart Tariff Strategies (Part 2: Template Tariffs) 

This is where the beauty of the Tesla solution comes in. Programme in your Tarif, and it handles all of the import/export based on your Tarif, use and the weather.

Very nice and helpful content. Well worth watching

Hi Gary, I'm glad that you came to agree with my views on sunk costs. It's standard business economics, but a fallacy that many fall prey to.

Another very detailed and comprehensive explanation Gary. I agree with the position that once you’ve paid for the battery you might as well use it, the investment Is sunk and you should get best usage out of the asset. Your analysis of flux pretty much matches my own modelling and experience of using Flux through the summer, I force discharged in the evening peak but not too much that I had to rely on grid draw later on at night. I personally didn’t force charge overnight as long as I had enough battery to see me through to the solar start next day: the overnight Flux import rate is so close to the daytime Flux export rate, and by the time you include battery losses I felt it was very marginal. I’m lucky that I have a large array and the roof is East West aligned so we get a long solar day. Some of the summer I was solar charging the battery at 5am and exporting at 8:30pm!

Hi Gary, another excellent video. I did what I think you hoped people would do, I listened to the first part of the video and thought about it and made my own assumption. Then watched the rest of your video and was very surprised on your conclusions. I will now go away and think about what I could do in the future. Well done. One thing I have been considering for a while now is the clocks going back and forward, I understand why we did it, but looking to the future, should we keep to GMT all year round now? How would this affect your calculation. I would think in the summer I can discharge during the peak period and it might still be sunny to charge the battery up for an hour. As more and more people get solar there maybe an advantage in keeping to GMT. I am happy if it is proven to start a gov initiative to see if we can get 100,000 votes to get it discussed in parliament 😀👍

Your videos are very helpful Gary! Many thanks for all the useful information. Is it worth it to program home appliances to operate when the battery is charging at the same time?

One thing I don't think you covered is the difference between forced-charging and load-support. Load-support tends to be more efficient because it only supports the loads on the system when the battery is below a certain level, and does not try to actually charge the battery. Thus load-support completely avoids the battery round-trip. It essentially prevents the battery from depleting past a certain point (in order to ensure proper battery reserves are available in case of a power outage and for other reasons). Load-support can also be used to ensure that the battery has enough suds to load-shift the evening peak, though this sort of automation is somewhat more difficult to setup. You load-support at (battery) voltage level A through 4pm, then drop the load-support to voltage level B from 4pm overnight to the next morning, thus allowing the battery to provide the energy at least through the evening. Then you set it back to level A around noon the next day so, presumably, you can avoid charging from the grid if there is sufficient solar to have recovered back to level A the next day. That's load-support vs forced-charging. It is basically just a programmable battery charger where you set the voltage level near the bottom of the battery rather than at the top. It kicks in and provides energy support once the battery has gotten low. And one other nice thing about load-support is that it doesn't kick in instantly. The battery voltage will tend to recover a little as the load is shifted (fewer amps being pulled from the battery), so the load-support mechanism gradually imposes itself. This has the effect of shifting some of the burden to the next day where it might potentially be able to recover from solar. -- Another problem not well mentioned is the need for weather prediction when deciding whether to export during the evening peak or not. Exporting during the evening peak will begin to deplete the battery, since the sun is heading down at that point. This by itself is not a problem but if poor weather develops in successive days it can cause the battery to get behind the curve and force charging to occur on later days. Usually you only want to export during the evening peak if you know the battery will be able to complete recover the next day. Which requires a weather prediction to be incorporated. -Matt

If the battery is your insurance against blackouts, then ignore the sunk costs of the battery, as it is part of a different benefit cost problem. 😊

I have an East+West system with a 6.5KW battery. I'm on the Economy 7 tariff with Octopus, current rate paying 14.84p per unit cheap rate import, 15p per unit for export. For the past month I've been force charging the battery to "time shift" my daytime use. If the battery is at a high state of charge and I get excess solar generation, I basically sell it back to Octopus for what I paid 12 hours earlier. The same logic applies all year round unless the rates change.

Great videos Gary. Personally I prefer agile Octopus, using force charging (5.8Kw Battery) early hours or during price plunge events. My daily use is on average 12Kw a day. I have managed to keep My monthly bill at £60 during November and December.

I have just come across your channel and you have some fantastic videos and insights. One thing that I do that I have not seen mentioned (and is now giving me concerns) is that I also force charge my battery between 1pm and 4,00pm(over the winter months) so that I do not have to buy from the grid during the peak 4pm to 7pm period (regardless of whether on Agile or Flux). We have high usage and the battery won't have enough energy and will be depleted by the the time of the cheap rate the following early morning. I am also hammering the battery with 2 force charges per day over these dark winter months! Any thoughts please?

Haaa hhaa, I like the fact your "solar array" is in the Horse Guards Parade. Seriously though, trying to get your head around what gives you the very best ROI can be totally mind numbing to try and work out. Thanks for the pointers.

This is very useful as we are about to have a solar and battery system installed, we already have Octopus and a smart meter installed in preparation. From this video it looks like there is quite a bit of data gathering and learning to be done once we have the system installed. I wonder how much automation can be implemented in the various control software for the inverter/ battery system. Can you set up perameters like " if battery is below X charge at Y time then force charge until a certain value is reached" or the reverse for force export at peak times etc. ? If this level of control is not available in the standard software is there a 3rd party control system that can be used ? It looks like we will have 3 different data points, the inverter, the battery which seems to have a second inverter and the tigo optimisers, will this data be consolidated through one software? Thanks for these videos, the expanations are clear and understandable for non electricians like me.

I've come to the conclusion that the best overall Flux strategy is to import and export in the appropriate tariff windows only what is necessary to maintain a change buffer of (in my case) 2-3 kwh. This covers the most profitable actions that you outline, because we still import cheap and export peak, but also by focusing on the buffer maintenance we have spare to cover the variable British weather, or a big unexpected load. It also has the side effect of avoiding wear on the battery.

It’s all getting a bit too sophisticated for me and when I look at the figures, for me, the real issue is can I substitute a 30+ pence rate to a 7.5p which makes a 22.5p saving for 18 hours of the day. In my case that is 20kWh x 22.5p = £1,642 saving p.a. Plus any Solar benefit set against an installation cost of £17k which together with Solar is 10%+ TAX FREE It is nice to be able to export Solar at zero cost for 15p return, but in my short experience that only seems possible in the sunny months if your battery is sized for winter needs I have never at age 69 seen any relevance in pay back time. My focus has always been; is the tax free saving greater than the return on other types of investments whatever they are, which are taxed

Gary, You are making an interesting and thought-provoking series and I look forwards to the next 2 videos. I also support your efforts as a patreon. I know that you cannot export and import at the same time. Here are some scenarios to make my query clearer. Let's say that an inverter is capable of exporting at 3 kW. Please tell me if I am correct. I am ignoring any bonus from solar energy and also efficiency.. 1. I try to export 3kW to the grid but I have a house load of 1 kW. Will 2 kW be exported with the remaining 1 kW used for the house load? 2. I try to export 3kW to the grid but I have a house load of 4 kW. Will nothing be exported with 3 kW being used for the house load and the remaining 1 kW being imported from the grid? (i.e. the inverter cancels my export request). 3. I try to import 3 kW into the battery. All 3 kW go into the battery, and house load is also taken care of by the grid (i.e. Charging makes no difference.) I agree with Tim that the battery cost only becomes relevant when considering ROI. If I have purchase the battery anyway, I wouldn't include this in my immediate day-to-costs. Importing in the night flux 'cheap' period makes sense to me. After all, I get the cost back anyway when exporting excess solar during the day. I have an E/S/W grid. In spring-autumn, the E and W panels perform nearly as well as the S panels over the day. But in Winter, the S panels do much better with the reduced direct E and W direction of the sun. Rob

Thanks Gary. I’m pleased that you’ve confirmed with the maths the instinct I had that force charging in the 2-5am window, even in Summer, is the right thing to do. My reasoning was along the lines that, if you don’t need it (and you probably won’t), you can simply get your money back by exporting it. So I do that all year round and it makes things simple. However, I don’t force discharge, and my reason for that was to do with battery life. I heard on the ‘rumour mill’ that it’s not good for the battery. Is that a valid concern?

Thanks very helpful. Do you know how to force discharge an alphaESS smile B3 plus?

I was wondering how I was going to do this in the summer with Agile and I know you have a video to come on this. In the past I have turned off force charging in the summer, but you bring up some interesting points. I then realised that my inverter has the options to set an import cost option. I could set it to say, charge if the slots are below a certain figure. I was thinking 10p as the export is 15p. If not then don’t force change and I will take the imported solar to charge the battery and start to export later.

One thing I don't think you have covered is the control of the battery. I have recently installed a Tesla Powerwall and (although I'm on a fixed rate tarif) I can model Octopus flux in the Tesla app and see the effect of the off-peak periods etc. The app automatically charges the battery 100% in the off peak period and discharges throughout the day - but I have very little control otherwise.

I have tested the efficiency of my GivEnergy 8.2 a few times, when forced charged and forced discharged and consistently it needs 10kwh to charge to 100% and exports only 6.7kwh. The readings are from our smart meter and the efficiency is only 67%. The efficiency increases significantly when the battery is charged and discharged at lower power. I only discharge the battery to the grid during the octopus saving sessions. Would be interesting to see similar tests from other owners

Silly question from someone new to this: what happens during forced discharge? Does it go toward usage during that time with excess discharge (for lack of a better word) going to the grid?

Gary, I've become a Patreon. I've tried using your Solarazma. Are you certain that the calculations are correct? I don't have a battery yet but I'm planning on getting one next year and would like to use your tool to decide if I want a bigger capacity then my home needs. My daily needs are about 15 - 20 kWh in the Winter (all electric heat pump) but nothing in the Summer (PV). Maybe I'm using the tool wrong but tried several scenarios and never get a revenue.

You have moved to the battery being a sunk cost, but surely we should account for needing to replace it. Hopefully the replacement cost will be lower and will buy increased capacity with a longer life so the price per kWh on a replacement basis could be a lot less than the price that someone about to buy tomorrow should use. But still very much not zero.

This is excellent work to provide an income. But what if you are more concerned with UPS?

If you force discharge your battery to the grid in stage 3 to maximise income then what power are you left with for your own use until the cheap rate? Is it not better to save your battery for use in stage 3 and 4? I can’t get my head around that one.

Excellent Gary and I have just split the £100 Octopus referral with your account. Enjoy the £50.

How would I force discharge a foxess battery and inverter during peak times on octopus flux?

Have you allowed for the efficiency loss between putting energy into the battery and taking it out. For my Tesla battery this appears to be a loss of apx 12.5%.

Really enjoy your videos Gary. Shame Agile is performing poorly currently. I'm monitoring but sticking with flux for the moment. it's all pointless if Octopus fail to retrieve any half hour period from the meter, you get shunted onto standard as happened in October for me.

Did you take into account the 10% loss for force charging the battery?

The UK is not in a situation (for 99% of the population) where blackout redundency is a need. It is so rare, it is not a issue.

Abit heavy going towards the end. if I had battery it would be Tesla and I would just leave it to learn and do its thing. This is like an “Home Energy Stock market” scheme. The end user has paid up front for all this equipment, plays his game to make the best of his investment whilst the energy companies play their game on the back of the end user.

If your EVs battery is free with the vehicle and has the V2G feature. Then again, the battery costs are zero. The vehicle is normally parked 23hrs every day and can still day trade electricity and grid stability, then you should still get benefits. 😊😊😊😊😊😊

Say EV big battery is 100kwh, and the daily drive is only 7kwh, and daily top-up is std operating procedure. Then, smart weather forecasting and you weekly use profile programed into the vehicles computer, ezi pezi backup as needed. 😊😊😊 With V2G. And selfparking plugin to the grid. Edit. Just saw your software. Excellent. My example is the 100kwh big battery, but only a 7kwh daily drive. Compared to your 10kwh fixed home battery in your example. V2G looks very interesting. Can you do the V2G example please. Because that is the future I believe. If I am right a little bit of fossil fueled generation in the worst of winter will have little climate impact and avoid worldwide nuclear proliferation. And be the cheapest for the economy and climate as the national grid expansion is stupendously expensive and CO2 emissions from metal production.

Gary, what you have exposed is a few very interesting facts: 1. The battery takes on a much more significant role for both the VPP and the utility. If force charge makes sense in every case with Flux (as proven) as proven, then moving to say even four days battery supply as a black out strategy (as recommended by Tony Saba of RethinkX - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7eJKTYc_v-I.html), makes even more sense 2. The EV charging overnight is no different from battery charging as long as your inverters are properly sized. 3. Electrical options when upgrading one's home are much more viable and industry experts need to be monitored carefully, as many still don't appreciate the significance of our solar systems. Many thanks

Unfortunately this video is geared to selling your software package.. Such a shame as I have no interest in buying it and 👋

Hi Gary ive just joined your patreon, how do i message you directly as i have a couple of questions 😀

Used your referral code when signing up for Octopus. Let me know if you get the credit!