Solar panels and Total Heat Total Control (THTC)- How do they work together?

Welcome @Hels24 ,

I’m one of the Forum Volunteers here.

Right now might not be the best time to install solar panels if you’ve got THTC. With the RTS Shutdown round the corner and the need to get you upgraded to THTC capable Smart Meters being high priority, you may want to wait a bit longer and do the meter upgrade first.

I’ll ask @BPLightlog to stop by though - he might be able to advise a bit more than I can.

I’m getting them through funding…and when I spoke to someone at OVO about the shutdown they had no idea when it was likely to happen because and what she said is they have literally nothing to replace them with at the moment…

Thank you…I’m just so confused at the minute..

An upgrade path for the meters is close to being ready. :)

Watch this space.

Hi @Hels24 , you should be able to have the solar PV system set up but it probably won’t be able to give you any export tariff (SEG).

You will need a separate monitor to look at solar feed but that is often provided as a link via the inverter. Failing that your installer could fit a generation meter but that is not really needed. 
 

Ok…thank you for that…it’s tricky getting your head round it all :-)

Just one thing to reiterate @Hels24 , with your meter set up it’s doubtful you would be able to get an export tariff despite some of the info above. You would still benefit from the solar feed during decent generating days of course and if these have some additional funding for you it’s probably still worth going for. 

We are in the same boat - funding for solar panels added to an existing THTC system. We’ve been advised that we can’t use the solar electricity generated ourselves and must export it all at 4p/kWh! Then we buy it back at 23p/kWh. Surely this can’t be right?

Can anyone confirm?

You’d probably be able to use it yourself but I can’t be 100% certain.

However, if you are on THTC then it’s possible that constraints from the DNO may prevent you from having Solar Exports at all.

With that being said, some THTC Meters can’t cope with exports very well. Proceed with caution.

Proceed with caution is good advice but too late unfortunately. Not really concerned about exporting - with storage heaters there won’t be anything left to export. This was all recommended as part of the ECO scheme. Guess we’ll find out soon enough😬

Hey @ToSH67,

Keep us updated on your findings; you have a more complex setup than most. I have added a couple of badges to your profile to let others know you have solar panels and heat storage. 

It would be great to hear your feedback and thoughts on your journey!

I’ll be sure to let you know how it goes!

Our solar panels provide power for our storage heaters, panel heaters, hot water and charge our car. Unfortunately we can't use the electricity for the rest of the household appliances.  They work very well and save a considerable amount of money. We try to use most of our production because we don't get anything when we send it to the grid. In the summer we do have to put a lot to the grid and it's painful to see how much we are giving away to OVO for nothing. They get it free and then sell itl!!  We had hoped to have a smart meter ages ago but the RTS switch off keeps being postponed. Hopefully we will be paid for exporting electricity when we eventually get a smart meter.

Actually, in this situation OVO gets nothing for it either. They cannot buy the power from you nor sell it to anyone else without a FiT/SEG Contract in place, so you’re basically sending super green eco juice to the National Grid for free - no-one is explicitly buying it.

Given that the FiT/SEG Contract and Export Supplier doesn’t have to be with your Import Supplier, you DO NOT automatically get Export Accounts created just because you’re with OVO - you must manually set one up with whoever you choose to Export with.

If anything, someone else on the National Grid is probably gobbling up the generated power for free and raking in profits - but I doubt it’s OVO.

Thanks, Cassie511, that’s actually really encouraging as I doubt there’ll much for us to export and just charging the storage heaters would be good enough. Feeling more optimistic!🤞 

Dear All

Thought I’d give you an update. The solar panels are in and working well. We haven’t got them talking to the storage heaters properly yet because the latter were installed to operate with the switched off peak electricity we no longer have. I think it should be possible to change this so that we can programme them to charge during daylight (solar) hours.

The more interesting thing is that when the sun shines and we aren’t consuming our old analogue meter goes backwards! Given that OVO still haven’t figured out how to give us a smart meter one could argue this is fair enough since it effectively gives us full credit for the solar generation that we should be able to export. We’ll see what OVO’s view on the matter is.  

That’s not actually a good thing i.e. the meter going backwards. I’m concerned it’ll mess the bills up so I’d probably suggest reporting that as a meter fault if you’re able to.

Hi

Yes, we reported it straight away and await a response. It would be ironic though if OVO rushed to change our old meter for one that can’t go backwards thereby preventing us from getting full credit for our solar exports while continuing to delay and vacillate with regard to a smart meter solution that would allow us (and others) to get proper control of our electricity supply and exploit opportunities presented by, for instance, switching supplier. 

Don’t expect to be able to quit that easily. OVO never created this problem, but merely inherited it from SSE - OVO is in fact one of only two major UK suppliers that never had anything to do with it in the first place, the other being Octopus.

I maintain my stance regarding your specific meter however. If you continue to let it run backwards, you WILL run the risk of messing up your bills and it could lead to a shockingly high bill down the road. Please don’t take that risk. It’s often associated with something known as Reverse Run Fraud, a type of meter tampering where the customer deliberately tries to make the meter run backwards to cut the bills. OVO has ways to detect that and iirc this stuff gets investigated every time. Please don’t run the risk of being flagged up.

They do however, have spare THTC Meters that can be swapped in for cases like this one. Not a huge stockpile, but a few still kicking around the inventory. They’re not exactly… Brand new… However, so you’ll still suffer from the same issue of their Certifications having already ticked down pretty hard even if it’s never been used before - the timer starts from the date of manufacture, not the date of (re)install.

Also, even on a Smart Meter, don’t expect to be able to nuke THTC immediately - there’s no guarantee of that. And given that 99% of suppliers won’t touch THTC accounts with a 100 foot bargepole, your options may well still be limited either way. And that really is a matter beyond OVO’s control.

For the avoidance of doubt, once again, we reported the reversing meter at the first opportunity and await a response. Moreover, how can one ‘let it run backwards’ ? We have no control over the meter and to try and influence it surely then would be tampering!

Apologies if it confused you. My writing style is designed for a wide audience, since this stuff often stays up for several years after you’ve moved on. Given the wide range of folks who’ll likely read these things, I write it as a warning to those who might get tempted - it’s not intended to target any specific individual.

Got ya!

Hi @ToSH67 

Sorry to hear about the issues you’re having at the moment surrounding the meter set up.

I did reach out to one of our specialists to double check if a replacement meter would be possible at the moment but we’re currently unable to replace the meter as we don’t have an appropriate replacement for THTC just yet - this is due to be available in the next few months.

It’s fairly common with traditional meters to clock backwards when there’s a solar export systems connected, more so when there’s more energy being generated than imported, so this isn’t something the team haven’t seen or dealt with before, unfortunately the twin element (THTC setup) makes replacing the meter and fixing the issue more tricky than normal.

We’ll be in touch directly when we have meter replacements available.