PV- real world figures

macgabhs · 18-12-2017 10:37PM

I got an open energy monitor earlier this year for this very reason. Wasn't too hard to install but it helps if you have some room around the fuse board area as the current clamps are large enough. Gives you loads of info. I've a 2kW array installed and turns out I'm using 66% of what I generate. That's without any divertor but I've MHRV, septic tank etc running 24/7 and a heat pump. Although heat pump use doesn't really overlap with the PV generation.

Gumbo · 19-12-2017 12:03AM

5.11 kWh generates today.
3.54kwh diverted to the inmersion, the test powered the house base and diverted to the grid.

But I came home to a full cylinder of hot water.

TomOnBoard · 19-12-2017 12:14AM

air wrote: »

If he's into technology / DIY get an open energy monitor, otherwise something like an Owl Intuition PV will give him the info he's looking for.

Thanks for those suggestions. I reckon they're worth pursuing.

unkel · 19-12-2017 12:43AM

kceire wrote: »

5.11 kWh generates today.

Very nice. The hot water heating I get from my solar tubes on a cold, but sunny winters day, is also much better than I expected

kceire wrote: »

3.54kwh diverted to the inmersion, the test powered the house base and diverted to the grid.

How is some lost to the grid when you have an immersion diverter?

You should consider crypto currency mining. Then you get your full day rate for every kWh generated, rather than the fairly miserably 2c or so per kWh (after depreciation) for diverting to immersion. When my fixed price electricity contract comes to an end, I can finally put PV on my roof - and do it with financial justification

Gumbo · 19-12-2017 01:53AM

unkel wrote: »

Very nice. The hot water heating I get from my solar tubes on a cold, but sunny winters day, is also much better than I expected

How is some lost to the grid when you have an immersion diverter?

You should consider crypto currency mining. Then you get your full day rate for every kWh generated, rather than the fairly miserably 2c or so per kWh (after depreciation) for diverting to immersion. When my fixed price electricity contract comes to an end, I can finally put PV on my roof - and do it with financial justification

Once the cylinder is heated to capacity then the power generated is sent back to the grid (if we are not home and using it).

I would mine for bitcoin if I knew how

unkel · 19-12-2017 02:03AM

Oh wow, I didn't assume your cylinder was fully heated by the diverter!

Maybe we can help each other out here. You arrange for me to have as good a value PV install as you got (minus the diverter

) and I will upgrade your 16A EVSE to a 32A and help set you up solar powered crypto mining?

rolion · 19-12-2017 10:33AM

A 200l cylinder fully heated to 60 degrees by a 3.5Wh !???
That is a really beating physics' performance !
Can't do it with 40 solar tubes AND 5 KW PVs.

Gumbo · 19-12-2017 12:09PM

rolion wrote: »

A 200l cylinder fully heated to 60 degrees by a 3.5Wh !???
That is a really beating physics' performance !
Can't do it with 40 solar tubes AND 5 KW PVs.

Don’t forget it’s not heating from 0, as t would be still warm from the day before. It’s a brand new fully insukated cylinder.

The Eddi unit displays ‘max temp reached’
I’ve also seen it hit max temp with less input, so I guess it depends on whether it gets the full power diverted in one go or drop fed throughout the day.

I find it hard that your 5kw system didn’t produce anything to match, and the solar tubes?
I have a 3kw array on a due south facing roof in north dublin.

I’ve posted the graphs from my invertor so I’m hiding nothing. Unless the invertor is telling me
Porkies???

a148pro · 29-12-2017 02:49PM

Going to move my meter for aesthetic reasons - have hooks on roof for future PV - anything I should think about now in terms of monitors and the like or in terms of what meter to put in?

Also - on the diverter - is there not a cheaper way to do that? I have the cylinder wired for immersion already. Is there not some kind of electric switch that works over wireless that I could use to link in to an energy monitor with the functionality to turn on when the system is generating excess? I'm surprised that costs 500

Was thinking similar for smart thermostats - really I only want them to turn on my heat or water when I'm out, I know someone posted here about just getting a switch you could turn on or off over wifi to do that

Gumbo · 29-12-2017 11:31PM

Great sun shine this week in the morning and up to around lunch time give or take.

Generated 5.17 kWh today alone.
Fill cylinder of hot water before lunch again today. The washing machine used any surplus in the early hours.

Calahonda52 · 30-12-2017 05:52PM

kceire wrote: »

Once the cylinder is heated to capacity then the power generated is sent back to the grid (if we are not home and using it).

I would mine for bitcoin if I knew how

Are you being paid for the "sent to grid bit"?

Gumbo · 30-12-2017 05:57PM

Calahonda52 wrote: »

Are you being paid for the "sent to grid bit"?

No, nothing:(

I do my best to use it by running the dishwasher and timing the washing machine when we leave for work in the morning. Anything after that powers the immersion and base load of the house.

Calahonda52 · 30-12-2017 06:00PM

kceire wrote: »

No, nothing:(

I do my best to use it by running the dishwasher and timing the washing machine when we leave for work in the morning. Anything after that powers the immersion and base load of the house.

Thanks, best for 2018

Capt'n Midnight · 30-12-2017 08:44PM

Can farmers put PV on land they are claiming biodiversity grants on ?

Effects · 09-01-2018 01:20PM

My 1.7 Kw system is generating about 1 Kwhr a day, if I'm lucky.

Effects · 09-01-2018 01:21PM

kceire wrote: »

5.11 kWh generates today.

What size is your system again?

Gumbo · 09-01-2018 03:23PM

Effects wrote: »

What size is your system again?

3kw

Effects · 09-01-2018 04:29PM

I'm just going to redo my system when the weather is better. It was installed by cowboys and suppliers weren't much help.

Gumbo · 09-01-2018 11:22PM

Effects wrote: »

I'm just going to redo my system when the weather is better. It was installed by cowboys and suppliers weren't much help.

Who done it?
I got mine from Solar Team ireland.

I have no complaints about them at present.

Sleeper12 · 09-01-2018 11:28PM

I don't know what the rest of the country is like but it seems every new house in Dublin is going pv instead of solar for the last 18 months or so. I'm only seeing solar going into older homes.

rolion · 10-01-2018 12:42AM

Sleeper12 wrote: »

I don't know what the rest of the country is like but it seems every new house in Dublin is going pv instead of solar for the last 18 months or so. I'm only seeing solar going into older homes.

Easy way to get past standards... but lets appreciate the effort and the volume,large volume of the systems / houses that will create awareness and not lastly,increase the interest and the installations.
Today,my PVs barely made 4 hundreds while the solar tubes warmed the water above 25ish,just enough for the boiler to take it and UP-it to 40ish.

unkel · 10-01-2018 01:26AM

I'll contact your company, kceire. I will for sure plaster all of my roof with PV hopefully before the summer, if I can get a very good value quote

rolion wrote: »

Today,my PVs barely made 4 hundreds while the solar tubes warmed the water above 25ish,just enough for the boiler to take it and UP-it to 40ish.

The performance of the tubes on freezing, but sunny winter days is far exceeding my expectation. A few days ago my whole cylinder (360l) was heated to well over 30C. Upping the top of it to about 50C would not have cost me much in gas. Can't wait for my next gas bill anyway as half the house is heated for free now through mining

Effects · 10-01-2018 10:11AM

kceire wrote: »

Who done it?

Builders labourers and a lazy electrician.

I tried to pay the PV equipment suppliers to come out and inspect but they weren't interested.

rolion · 10-01-2018 10:48AM

Effects wrote: »

Builders labourers and a lazy electrician.

I tried to pay the PV equipment suppliers to come out and inspect but they weren't interested.

Why do you think is lazy cowboys work !? Can you list your concerns ?!
I DIY my both systems and i dont think im better or worse than anyone out there.

Effects · 10-01-2018 12:15PM

rolion wrote: »

Why do you think is lazy cowboys work !? Can you list your concerns ?!
I DIY my both systems and i dont think im better or worse than anyone out there.

The panels were stacked on the roof, pre installation, where they were meant to be installed.
Rather than move the panels to fit the mounting system in the correct place they just installed the mounting system and panels elsewhere, behind an up stand which blocks the sunlight hitting them. Had a hard fight to get them moved but they didn't bother moving the cabling or isolator so they are still in the shade as they weren't moved where they were asked to.
They put in a mounting system that wasn't recommended and I'm in breach of my planning as a result.
The builders also did a lot of bad chasing in the house and the electrician just mounted the back boxes anyway. They were all over the place, not centred, varying heights and crooked. Light points in the ceiling weren't correctly measured and installed. I fixed them myself and he hit the roof.

I'd rather just do the job properly on the PV myself when I have more time. I'm sick of dealing with builders at this stage.

googled eyes · 22-02-2018 08:01PM

Lads who have Pv installed.

Could you please say how big your system is and roughly ( on average ) the reduction to electricity bills, how much you bills have dropped since the installation.

Talking it through with Mrs googledeyes and it would be nice to say 'this is how much the bills could reduce by' ( not worried by pay back time etc)

Thanks

fclauson · 22-02-2018 08:10PM

real world figures - Wexford - https://www.facebook.com/Passive.House.Wexford

4kpw system
Delivers circa 4000kwh/annum
I am on the old ESB program and get paid 9c per exported unit
I typically export 1400Kwh
No clever diversion technology but SWMBO will put washer etc on "if its sunny" - otherwise we do this at night rate

being a passive house - my PV covers all my heating/h/w costs (roughly)

Payback calculated at around 8 years @ 18.5c saved for every unit used during the day and the 9c for the 1400kwh exported

Things I would change ?
as you see on the FB page - it might have made more sense to have two strings - one on the SE roof and one on the SW roof - currently they are all on the S facing roof

Would I add more panels - Yes - as the price has dropped a lot in 5 years

I am allowed to export 3500Kwh (I think)

vincenzolorenzo · 12-03-2018 02:56PM

unkel wrote: »

Your sums are not realistic, don't fool yourself.

1. 5370 is extremely optimistic of the midlands

2. if you can use the 5370 units? Almost certainly not. How are you going to use 4kW coming into your house on a sunny day? A lot of it will be lost (go to the grid for free). If you have an EV that's always parked at home during the day, than maybe you will get close

3. it is not EUR0.16/kWh. Most of your production is competing with night rate, which is EUR0.0665/kWh

So your savings are probably more like 4000 units production. Half lost (this is already optimistic), other half at 6.65c, so about EUR250 per year (unless you have the EV parked at home during the day)

I'd agree entirely with your first two points but how would solar production be competing with night rate when there is no generation at night?

unkel · 12-03-2018 03:59PM

Because running washing machines, dish washers, dryers etc. during the cay (on solar) doesn't save you the full day rate. All these appliances could have been scheduled to run at night at the night rate. So your real savings for these appliances are just 6.65c / kWh. Only the base load of the house and what you have to run during the day, you save the full day rate on (like your fridge / freezer, running your kettle for a cuppa, hoovering, etc.)

Gumbo · 12-03-2018 04:04PM

unkel wrote: »

Because running washing machines, dish washers, dryers etc. during the cay (on solar) doesn't save you the full day rate. All these appliances could have been scheduled to run at night at the night rate. So your real savings for these appliances are just 6.65c / kWh. Only the base load of the house and what you have to run during the day, you save the full day rate on (like your fridge / freezer, running your kettle for a cuppa, hoovering, etc.)

Technically you are correct, but I know I wouldn't run the washing machine and dishwasher at night due to the noise they make etc

The kids bedrooms are directly over the kitchen, so for me, even if I was on night rate, I wouldn't do it.

PV- real world figures

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