the ROI on removing a working system boiler and tank to fit a combi will buy alot of gas.
if the tank has an immersion - you could rig that up to solar - but at current rates your better off just selling the solar and buying the gas. Gas is about 1/3 the price per kw than you can get paid from octopus.
But either way if the roof points south id spend the money on solar over putting a combi in place of a working system boiler. .
my biggest regret in my house refurb was fitting a combi tbh ( we had a non working system boiler though)
Retrofitting a solar thermal coil is a non starter and using a standard coil with solar thermal is inefficient. heat transfer isnt quick enough to pull a good Delta T
I have a Gledhill 250l direct solar tank in situ waiting to be plumbed in + a grant sahara two panel system on order. - ill advised likely on costs and projected life spans but its about self sufficiency and minimising ongoing costs in out future - that said the majority of the kit is benign and its only the moving parts that wear out in given time as oppose the whole system
My simplistic notion was that the PV could run the immersion heater somehow (I’m assuming its got one)?
it can - but its cheaper to use the gas and sell the power to the grid.....
Okay, thats the info i was after - brilliant stuff guys!
@rockhopper - if it's got one then yes you could do that.
IF the tank is pressurised (i.e. there's no header tank in the loft and the hot water system is main pressure) then it could be relatively simple to have the cylinder swapped for a double coil one and you could go for solar thermal - I installed my own a year ago and it produces plenty of hot water over the summer months.
However I have a feeling that the previous owners will have put the electric show in because it's a gravity fed hot water system with little pressure.
Trying to work out if I should cough up for another battery, as they’re back in stock at the moment. £1000 for another 2.4kWh is a lot though, and I doubt I’d ever make it back. But it would mean the house would never draw from the grid outside of off-peak times. At the moment cooking hammers the 5.2kWh setup I’ve got in the winter months.
On the other hand £1,000 buys a lot of air fryers and the electricity to run them.
Buying a battery still feels a bit of a gamble, who knows what the export tariffs will look like over the next 5 yearsish...? 😏
Having said that, we just turned on our setup for the first time yesterday with a 15KW battery, so we'll see how it works out in the short term. 😁
At the moment, you’ll have an indirect cylinder and for PV heating, you’d want direct, or better still, both.
That's not really correct .... I have an indirect cylinder with an immersion and the PV heats it up splendidly - there's no need to change. In fact I've just look at the immersion switch light in the utility room and it's glowing a solid red meaning the tank is up to about 63c just from diverted PV today.
My simplistic notion was that the PV could run the immersion heater somehow
Yes it can.... just fit a diverter system - there's a number out there.
That’s not really correct …. I have an indirect cylinder with an immersion and the PV heats it up splendidly – there’s no need to change. In fact I’ve just look at the immersion switch light in the utility room and it’s glowing a solid red meaning the tank is up to about 63c just from diverted PV today.
Only if the tank has an immersion backup and even then, it's not efficient.
Buying a battery still feels a bit of a gamble, who knows what the export tariffs will look like over the next 5 yearsish…?
If anything the battery makes more sense than solar panels - costs of electric long term as demand grows and our country does the square root of sod all to secure our energy. Will go up.
Being able to load shift will be a godsend.
One week into having Flux export live here in South Leeds. Broadly we are generating 2x what we are using (69kW exported in a week). Taking into account import costs and standing charge, Flux has still MADE US over £19 last week.
If you want more info then pics are on twitter: @chb_leeds
I've just started the switch to Flux today. We have a large array (good) but an EV to charge (bad) and use electric heating (bad). I think it'll work out well in summer when the high export tariff and lots of generation compensate for charging the car being more expensive than a normal overnight tariff, but as soon as it starts getting colder next winter we'll be back on Go.
Only if the tank has an immersion backup and even then, it’s not efficient.
Sorry I didn't know that direct tanks ever came without an immersion.
Re "efficiency" why, because the element isn't at the bottom of the tank?
Frankly I couldn't GAS about efficiency if I'm getting free hot water - no way would I buy another tank just to get the immersion a few inches lower.
I changed to Flux about a month ago but I'm still waiting to get paid for exports. Chased Octopus on Thursday and they told me they are still waiting on Mpan from the DNO.
Anyone else had to wait this long? I'm exporting 20 Kw most days at the minute.
Sadly it can take a while as many of the DNOs are a complete shambles when it comes to doing this. We’ve been waiting months from SSEN.
Chased Octopus on Thursday and they told me they are still waiting on Mpan from the DNO.
That appears to be the script.
When I pushed them on the fact they were provided with an existing export mpan they hung up.
They also won't respond to Twitter on the same question.
I think they are just overwhelmed with integrating all the bulb customers
Anyone know the limitation of obtaining an export tariff on a system associated with the old Feed in Tariff schemes?
My system was installed in 2014, and has a generation meter recording PV inverter output. The FiT payments go to the supplier of the system, as it was a free install.
Confused by this statement on octopus website, "If you have started receiving FiT payments in the last 12 months, the FiT rules mean you won't be able to switch to Outgoing Octopus just yet". I thought the FiT subsidies for new installs stopped several years ago.
My system was installed in 2014, and has a generation meter recording PV inverter output. The FiT payments go to the supplier of the system, as it was a free install.
It's not yours to move the payments.
Yep, I'm doubtful it's even your system at all.
You get as much generation as you can use and the suppliers get the FIT.
You can't change any of the system either i.e. change the inverter to fit batteries.
(And no-one in their right mind would change from an existing FIT from that era to anything else.)
Frankly I couldn’t GAS about efficiency if I’m getting free hot water
Its not quite free (i have the same system by the way) as you could send that excess back to the grid.
I don't need to.
The old FIT system assumes 50% of your production goes to the grid and that's what we get paid [an insane amount of money per kWh] for regardless of what actually goes back.
The benefit of being an early adopter!
I'm on Flux and my fag packet calculations tell me I am saving around £10 per day as per this week. Obvs solar dependent etc. Ironically I am drawing more from the grid as I force charge my batteries overnight. Previously I didn't always do this. I dont draw any from the grid outside this window and export solar until the sun sets.
The benefit of being an early adopter!
Forgot about that... Lucky ****** 🙂
@surfer are you force charging all year? Is that so you get the most export?
@nixie We have only had our PV and battery since November 2022 so not a full years experience yet. Also we have changed tariffs a couple of times since then, from a Flexi tariff to Eco7 then to Flux so the circumstances have changed as have the seasons.
In the most part though yes one way or another I have used lower price energy overnight to either protect us from higher prices during the day or more recently to be able to be self sufficient and feed back to the grid to make us money/offset bills.
Sounds good.
I've just this morning got an email confirming access to the solaredge battery control beta. Not had a chance to play yet but a quick scan of the documents looks promising. Seems like you can configure different cost periods to charge cheap and avoid grid usage as well as having a monthly plan. I think there is an element of smart learning in their system based on usage and perhaps expected generation so the battery will only force charge enough to cover usage (i.e. so you'll get the most from any production).
Is there much to tell between the different manufacturers of inverters and batteries? Around where we are the two main suppliers are SolarEdge and Huwawei and I think I would lean towards SolarEdge but happy to be educated
There’s a good spreadsheet here which helps judge whether Go / Flux etc is better for you.
https://protonsforbreakfast.wordpress.com/2023/03/05/tariff-calculation-spreadsheet/
I’m still on Go at the moment. Over the last eight months my average unit price has been 9p/kWh.
I’m still on Go at the moment
Assume you have an EV? We dont yet so I should imagine that would change things for us.
Re FiT system, yes I'm fully aware the system is not "mine" and the solar company get the FiT payment. I'd actaully forgotten about the 50% deemed export rule, I imagine they claim that as well, with an account tied to the MPAN of the generation meter. Do FiT payments and deemed export payments come from same source?
Fair enough. Reality is of course I export very little, most of the free to me energy gets used or diverted to water heating. Really sunny days when the whole 300 litres reaches max temperature there will be more exported, but not often.
I'm thinking along the lines if I had installed a second independent system with batteries how that would work, no doubt its now got complicated, if not impossible, to get any export credit.
BTW, the rules regarding modifications / replacement parts in FiT systems has changed, any "improvement" gained is factored out from the payments. Something like this had to be done, as inverters or panels could fail in the 25 year contract period.
You could replace broken kit like for like but not replace a broken panel with one with a higher output.
General rule is not to mess with anything!
I imagine they claim that as well, with an account tied to the MPAN of the generation meter.
That's all there is basically.... But it is significant.
You could replace broken kit like for like but not replace a broken panel with one with a higher output.
On panels I didn't own ... I wouldn't even be doing that.
If nothing else it would be convenient if the birds were to peck away at all the wiring and the inverter was to no longer operate. Doubtful the rentaroofers would be back to replace it in a hurry
@leffeboy I suspect not all animals are equal.
I thought about starting a thread on this as the set up I have has many flaws. However, I’ve no experience of others so can’t compare.
My inverter often imports a small amount even if my battery is charged or solar generated which adds up over the day to maybe a kWh.
When I set my inverter to charge the battery to any percentage it ceases to discharge during that period regardless of the level set which makes the feature a bit rubbish as you can’t leave it set e.g. to charge to 50pct in the early hours of the morning from 2am to 3am if the battery is at 70 say, it still draws from the grid for any load between 2 and 3.
The battery and inverter don’t talk to each other properly such that the battery Can overnight fall below 10pct which I don’t think is good for it. Time will tell if it fails- I suspect it will just become less efficient more quickly which will be difficult to prove as faulty unless it fails completely.
Fox system perchance? I can answer some questions.
It has to import a little bit of power to make sure you’re definitely connected to the grid. You can’t avoid this really as the only reliable way is to put a load on it. Not going to change.
You can actually do what you want to do in your second paragraph but you need to either connect your inverter to Home Assistant via RS485, or delve into the settings on the inverter itself.
Third point - it’s really difficult to measure the capacity of LFP batteries. The voltage doesn’t vary linearly with charge level so the only way to know what’s going on is to count electricity in and out. The available capacity does vary with temperature so as that falls (overnight), the percentage available also drops. The inverter will trigger a charge regardless of how it’s configured in order to protect the battery.
They all have decent warranty cover and I wouldn’t be bothered by this at all.
Thanks. It’s a lux and uhome system. The concern I have re the battery is that the inverter doesn’t always kick in.
So the battery can drop to say 1pct- according to the inverter software and battery app. Sometimes the battery software records a low voltage warning. At some point the inverter then realises there is a problem and charges back up to 10pct. They were all logged- I complained and it looks as if they’ve done something to erase the log. Battery still performing the same way albeit less times crashing over night, I guess because there’s now more solar charge in it and it’s warmer.
Re the charging I contacted lux and they seemed to think that operation was correct.
Re warranty- unless something stops working completely I think most solar warranties are going to be difficult to apply, since for example even if the battery takes 3kwh and only gives back 1kwh, how can I prove its not working.
First full week on Flux tariff. Paying roughly £9-£10 per day so this is a circa £10 per day saving which is pretty impressive.
Is there much to tell between the different manufacturers of inverters and batteries? Around where we are the two main suppliers are SolarEdge and Huwawei and I think I would lean towards SolarEdge but happy to be educated
Can't comment on Solar Edge, but we have Huawei and these are the things which annoy me about it.
It does work fine and a nice phone app and web interface, but there is a big PITA:
Only the installer can change the operating mode eg from max self consumption to scheduled charging. You can get round this by resetting the system and over riding the installation password fairly easily, but it's still a stupid design feature.
However, once you've done this you have to connect locally with the unit via it's own Wifi network to change the mode (another massive PITA). The next PITA is that the phone App won't let you change any settings until it has updated the firmware and they seem to release new firmware almost daily.
You then hit the next issue, immediately after an update and for several hours later, the system never seems to behave properly. At first I thought the SW was duff but have just come to realise that after every update it basically stops working for a few hours and it back to normal by the next day - this is another PITA as you end up thinking you've broken it. If you try a reset it switches everything off and then only bits switch back on e.g last time I had to manually power back up the BMS as only the inverter came back after the reset.
However, if you leave it alone, it just works, so can't really complain too much.
I do also notice that the speed at which the battery kicks in to power stuff seems quite random. If I switch the kettle on, sometimes it's instant and our energy meter just says zero, other times it basically doesn't seem to notice the kettle has swicthed on and by the time it's boiled, it's too late. Our smart meter claims we use about 0.2 kWh a day when running on battery, so the 'leakage' isn't too bad..
Another thing, it's a closed Huawei system, so no hooks / API for any IFTTT integration (that I know of). The inverter and BMS talk to Huawei central and your app connects to that server to find out what's going on. No local interface.
Around where we are the two main suppliers are SolarEdge and Huwawei and I think I would lean towards SolarEdge but happy to be educated
We have two Solaredge inverters. One failed after about three months use and was replaced under warranty quickly and with no hassle so I can recommend Solaredge's warranty service. Other than that the operation of the two inverters has been faultless and the dashboard software is simple but effective.
@nixie Its from an app called "Octopus Watch" its £1.99 for Android. I have the data already but it saves me a lot of spreadsheet work. Its challenging even with Home Assistant to work out when exactly power is exported and with 3 different tariffs over 24 hours it would be quite difficult.
Thanks surfer. I'll look that one up.
Only the installer can change the operating mode eg from max self consumption to scheduled charging.
The normal app operation for solaredge is the same. However you can get around it by registering as an installer and taking full control of your site. Alternatively solaredge are working on owner control via the app. I got access to this beta yesterday but not had the time to explore yet.
I'm with Foxees and fortunately I can do that from the app, although unlike others I cant force discharge my battery. Having said that I cant see a situation when I would. I need the battery close to full in the evenings anyway to be sure of getting to the 2am cheap charge window. I find I am doing that with lots to spare at the moment but I would still only be messing around trying to discharge up to around 30-40% of my battery (about 4kw) so its hardly worth it. Same with the diverting. My battery is usually full by 4pm so its feeding any solar in then already so not really worth changing. If I had a much larger battery and array, maybe.
The normal app operation for solaredge is the same. However you can get around it by registering as an installer and taking full control of your site.
I've done the same with Huawei, but it wasn't necessary to change the operating mode.
thanks for the info uponthedowns and footflaps, it all helps.
I'd suggest joining the Facebook group for what ever inverter system your thinking.
See what the common issues are. Identify which are issues for you as opposed to gripes.
We landed with a solid hybrid mainly as id had a solis string inverter previous and I wanted puredrive batteries so had a choice of brands of inverter -and the solis offered the better control.
Ours is a givenergy system; I like the app, it gives you absolutely loads of data to look at in shiny graphs, you get pretty good control over how you want the battery to work and what times you want it to charge and discharge, it updates every five minutes when you're away from home but every ten seconds when you're on the local network. It is occasionally a bit temperamental about whether it can find the inverter on the local network, but most of the time it's fine. You can talk to the inverter using modbus from something like Home Assistant if you want (but I haven't). I like it a lot.
Hmm first real look at the solaredge changes and they seem limited. Can set multiple high cost bands but no way of setting a low period or any kind of ranking/weighting to the different periods. Still no way to force charge when you want.
Another point re Huawei.
A rather minor gripe...
When you program force charge you have two options, you can just specify a period, eg 3-5am, and say charge during this period. Or you can also specify a maximum charge state and say charge up to, say, 60% between 3 and 5am.
However, if the battery is over 60% at the start, or at any point during the charging period, it just sits there doing nothing ie not powering the house off the battery. Admittedly, we don't draw much power between 3 and 5am but even if we have a fully charged battery, we end up using power from the grid.
Just seems a bit of an oversight in how they've implemented it.
I've switched back to max self consumption for the summer, but was running force charge up to 60% over the winter to make sure we always had enough to make it till after peak evening pricing.
Is there such a thing as an AC buffer/capacitor that can be installed to fill the gap between demand and the battery kicking in? My system has a very small draw from the grid before the battery kicks in and this usually isn't aproblem, but say you’re cooking something for a long period in the oven, the heating element switches on and off with quite some regularity. Even at only 80deg over maybe 4 hours, over half that power use is from the grid due to the latency.
Is there such a thing as an AC buffer/capacitor that can be installed to fill the gap between demand and the battery kicking in?
Nope, all batteries are DC, so require inverter circuitry which has to be switched on etc. No reason why this can't be very responsive though. My guess is they wait a bit to stop over reacting as that probably improves the longevity of the batteries (just a guess).
Depending on the install, it might help a tiny bit to swap the grid CT for a meter which transmits power through RS485, which will be more accurate. But to be honest I don't think there's much you can do without changing the inverter. Mine is pretty quick (eg maybe 2-3 seconds lag).
Don't forget that it has to sense you drawing power from the grid before it can ramp up to match.
Finally got faith my flux is hooked up right. All the reading are live in the app and it's showing my meter details correctly.
It's all been backdated to April 19th and my net bill for the 28 days Lecky including standing charge is £2.68
Numbers looking great now even on slighlty dull days bringing in high 20's with a high of 40Kw and lots around 35Kw+
The last 7 days (on Flux) Octopus has paid me £29.39. Including fixed charge our daily usage was around (this is an average based on our annual daily usage and on the basic tariff) £6. Thats a weekly saving of around £70. Obvs there is a big payback required for the installation but that is now looking to be around 6 years...
Octopus are taking ages to sort out export. They have all the paperwork and the MPAN but for some reason turning Flux on requires weeks of waiting.
I removed the export block on our system last week and for the first time I'm seeing the full generation potential. We hit a new record on saturday of 60.4 KWh and have averaged about 45/ day for the week.
However, it's all being donated to the grid... fingers crossed they will back date it like trail_rat.
(10KWp array, 6.5 limit on inverter, 40:60 EW split, oxfordshire, 10kwh battery)
Octopuses. Where do you see your export information? I can see export amounts in the app now but only from the point they set it up (no historic ones) and nothing for export on my last bill.
Octo aid doesn’t seem to pick export data up for me either.
I use octopus watch..... But if they have not committed to back dating they don't automatically and even even it's wurh the caveat they can retrieve the historical data
Just got estimate through for this years Solar Together scheme… £8.5k for 12 panels + 3.2kWh battery, £10.5k for 9.6 kWh battery. Price seems reasonable, need to do some research on the installer now!
Flux up and running properly now. Last week up until today has been great - averaging £9/day net income.
I have been onto Solar Edge to tweak the battery profile so now it's going to charge between 2 and 5am and then maximise self-consumption between 4 and 7pm so any solar is exported. I'd like to be able to tell it to discharge a few units at peak time too but that didn't seem to be an option. It was all or nothing. That might mean getting to the evening with an empty battery and needing to import anyway.
The relatively similar prices for the off peak import and export means that this is probably not worth too much effort but i thought i'd try it out. With wholesale prices dropping, it will be interesting to see if these levels stay the same. I guess the best outcome for me is selling high this summer and buying cheap(er) in the winter when the import prices drop.
Price seems reasonable, need to do some research on the installer now!
They telling you ? Usually goes to reverse auction after your all signed up.
Also getting about £15/day net with Flux too.
Albeit it’s somewhat exaggerated because there appears to be an issue with the way their system interrogates my meter but they say they’ll honour the overpayments. Quietly hoping that it takes as long to fix as everything else related to smart meters usually goes on for.
Missing the 5p overnight rate for car charging but will go back to Intelligent Octopus for the winter.
Getting about £5 a day currently (22kwh export). Clipping for around 4/5 hours by about 1.6 KWh. I used the hardware throttle on our car charger over the weekend so it charged at 3Kwh. By starting this before the sun hit the side properly I pull 70% of the house battery into the car then got a good period of 5Kwh production with 3 going to the car, a bit to house usage and the rest to the battery but slower.
Not exported anything as I am "off-grid", but I have only bought 34 KwH fromthe grid while using 521 Kwh for the month. At the 60p a unit I currently pay that means I have saved £290 for the month. I'll take that.
Well, May’s numbers are in. 5.4kWp array, South facing, in the SW, 19kWh of storage.
841kWh generated! 562kWh used, 21kWh imported, over 300kWh exported (and not paid for). Electricity bill for the month is £6.79. Standing charge £15.75. So less than £30 inc vat.
Appointment for final issuance of export certificate tomorrow. Had we been able to export, we’d have earned a net profit of ~£50.
731kWh produced, 382kWh consumed and 364kWh exported. £21 income for the month despite payment only starting on the 20th.
So, I've signed up for Flux and the tariff has registered as Flux Import and I can't see any export data at all - it this what happened to others when they first signed up?
My kit is all signed off with DNO approval and I have my MCS certificate, all of which have been given to Octopus.
@Daffy, yes exactly that. It took weeks and weeks after Flux import showed up before Flux export came online. Once it is up and running you can see export data in both the app and website. You'll also not get paid for anything exported until setup is complete.
itll be 4-6 weeks most likely before you see the export data.
They will backdate it till the date they can find - i signed up april 4th , flux import went live on the 7th and flux export went live on may 17th but they backdated to april 19th as thats when flux had data for my export.
That was moving from an existing SEG provider .
the previous 68 days of billable use inc standing charge have cost me £2.54 - including 12 days of no flux export.
over the time exports been live I'm on £-11.316
The month of may which was pretty dire for sun its £-6.95 - in may we only generated 444kwh - of which we consumed 309kwh
Hopefully we will start getting some sustained sun for the summer. -But flux has boosted my business case for some north facing panels to take advantage of their 31p rate.
Ah - okay, I'll stop fretting about it, but will try to record my export meter readings in the hope of some form of reclaim.
Today is crunch day (final day I can accept my Solar Together quote)! I am minded to go for it, with 12 panels & the smallest battery option (3.2 kw) as they are modular units (Pylontech) and I gather you can just add more yourself if you like later (assuming you can source them)?
One thing I've just thought of which might tip the balance - we have a massive issue of overheating in the bedroom of our chalet bungalow, as (I guess) there's no loft-space above to act as a buffer... would solar panels on the (south facing) roof absorb enough energy to make a significant difference? 🤔
After much to-ing and fro-ing with our provider, our order (placed Oct last year with a verbal installation date of March this year) has been scheduled for Week 32-36 this year. Maybe, probably.
This is a relatively small installation (12-16 panels and a 5 KWh battery) and their excuses have pissed us off enough to look at cancelling and re-ordering elsewhere. This installation promise date was the result of us getting very annoyed with them.
Fingers crossed they actually manage to keep to a date this time.
Wilard, I think I landed lucky… ordered Jan 2023, fitted end of feb 2023.
Battery size is a funny one. We have 12.8kWh of Greenlinx batteries and with Octopus Flux we fully charge and discharge them each day to max the peak/offpeak price gap. I guess if we had a smaller battery then would still use flux tarif and charge to 100% overnight which is easier (and pretty cost neutral) on set up/management than charging batteries from solar I think. At the moment the solar is making 37-40kWh per day and domestic usage is c10kWh (though doubled this week with portable AC!). So battery usage is low.
Will be curious to see how batteries help in winter. I expect they will just help keep us on the 19p per unit overnight leccy.
Very impressed with solar so far. P4Solar in Ilkley, recommended from this forum.
I’d look very hard at the cost vs benefit of adding extra cycles to your battery by doing a full charge/discharge cycle on a daily basis. Given that the net income is about 85% of 35p/kWh at best, it must be pretty marginal in the long run if you need to replace the batteries (and probably the inverter) halfway through the predicted life cycle.
The manufacturer almost certainly publishes degradation data and yours will be at the bottom end if you’re discharging and charging at the full load of the inverter. Certainly for mine (Fox ESS) it wasn’t worth it in the long run and I just take the solar output which is already generating £10/day.
I’ve done the same calculation as flaperon and have decided not to force discharge my batteries on a regular basis. My paired batteries did discharge down to 13% during the winter, but in spring that had disappeared and late spring summer, we rarely get below 60% no matter what is happening.
An extra few ££ a day for at most 6months a year isn’t going move the needle much. At most, it might cover 50% of the battery cost over 10y.
Edit: 85% of 15p/kWh if you charge from the grid.
<p style="text-align: right;">Flaperon and Daffy, you are probably right from a profit/loss perspective. However I like the idea with helping with national load shifting (combined with solar if its sunny my system pushes 6-7kW continuously to the grid 4pm-7pm), if we have enough of that nationally then thats fewer gas powerstations revved up. Based on c£1.50 a day extra from having the charge/discharge cycles its c£5000 extra over 10 years. Payback on whole system is c6 years and then £2000+ profit per annum. If I have to spend a few £k in 7-10 years on replacement kit then thats not disastrous. The wear on inverters is a funny one. As its an AC coupled system I have three inverters (one dumb one for panels and twin Lux Squirrel pods that give 7kW flow between them). The panels inverter runs at 3.5-3.6 kw for large parts of the day when sunny, so if any will fail its this. The Squirrel Pods charge at full rate for two hours each night, then sit there doing not much if its sunny till 4pm when they are set to discharge at 45% rate (c1800w) so they get down to 15% DOD by 7pm. The 15% covers us till 2am when they charge up again.So the squirrel pod inverters have a fairly easy life most of the year as the are dormant whenever the sun is out. Will report back over the years as batteries age, but right now cant see why I would have the capacity and not use it.</p>
I have been discharging some of our battery capacity for a couple of hours some days for similar reasons as above in that we have the capability to do so so we may as well use it. In terms of load on the inverter an extra few kwh at a low rate is negligible compared with what the system will push through on a long sunny day; in terms of battery cycles it does not cycle anywhere near as much as the full charge / full discharge every day over winter. I discharge ours so by 2am they're still at at least 30% so it's not doing a very deep discharge. I wonder about the opposite, actually; if it weren't for doing this the battery would spend the summer over 90% pretty much all of the time and 100% for most of that, which isn't good for the battery in itself.
What I wonder about is recharging the batteries again; even though the overnight rate is very slightly cheaper, doing it from solar is currently lower carbon (overnight grid power isn't particularly low emission at the moment), solar tends to recharge it slower which I assume is better for the battery, and on a good day we can charge the battery with DC power above the AC rating of the hybrid inverter so it's "free" power that we couldn't export anyway.
I'm happy that we're essentially off grid and fully green for 97% of our energy requirements at the moment, even if there's a rainy day or two, there's enough reserve capacity and generation capacity that we're still off-grid. That, in my opinion is the best thing I can do. Charge the house, charge the car, export the extra. It's enough for the moment. I wanted to do more this year, but I need to save the pennies for the impending mortgage hammer that will happen next year. £5-7k extra a year is a tough pill to swallow.
Octopus have told me that the export will go live tomorrow morning. Really good given we only switch to Octopus on the 8th and then onto Flux on the 10th. Whoop!
Octopus have told me that the export will go live tomorrow morning. Really good given we only switch to Octopus on the 8th and then onto Flux on the 10th. Whoop!
have you asked them if you can backdate ?
I do have readings, so assume that they could, but it's not the end of the world as we're talking £25-£30 from the point of transfer, but I will ask once its live.
