We'd like to remind Forumites to please avoid political debate on the Forum... Read More »
📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!
So now I have a solar PV system how do I make the most of it???
Options
Comments
-
sly_dog_jonah wrote: »I'll ask the inlaws about it, since they have their own plumbing business (and fitted our PV). I've just checked and it doesn't appear we have such a valve in our airing cupboard - which was to what I expected since lowering the thermostat last year stopped us scalding ourselves!
According to the manufacturer of our tank/cylinder, our particular model has a standing heat loss of 1.85kWh/24hrs. I think that defines 'how much energy would I have to pump into the cylinder to top up the temperature after 24hours of it cooling down (without drawing any water)'. Considering 1.85kWh costs less than 6.5p of gas (ignoring inefficiencies) or less than 2hrs of heating with a 1kW immersion element, it looks like a very good proportion of any heat should be retained overnight, and certainly between daytime and evening bathtime.
That appears to be the BSI spec which is a 24 hour test with water @ 65C.
The very low heat loss from a well insulated HW tank is something I have been stressing for a long time on MSE. Many people justify getting a Combi on the grounds that they save the 'huge losses' from a HW tank*.
In the 'real world' when a tank isn't at 65C all the time, the daily loss is probably < 1kWh; and that heat isn't 'lost' as it warms the fabric of the house. Indeed I suspect that, depending on length of pipe runs, a HW tank could work out cheaper than a Combi in some properties.
* I do appreciate there are other advantages of a combi, space saved etc.0 -
Martyn1981 wrote: »No probs Ed. Sly Dogs' post is excellent at explaining shading and panel strings. That's what you and hubbie need to try to ascertain.
Also, just to remind you, check both roofs are IDENTICAL slope. Do you mean full height extension to side / directly next to main roof, or extension out, ie a single story roof lower down? If the roofs are a different angle, (mine are 20deg and 30deg) then they will operate differently as the relative angle of the sun to the panel will always be different. If I'm being really pedantic, there will be a brief sweet spot when the sun angle is equally wrong to both roofs, but now I'm just trying to confuse you, sorry.
Mart.
Hello Mart
The make and model of the inverter is a SunnyBoy SB2500
The solar panels are Ultima Solar US 660
All the panel are on the back of the house. 6 on the main roof of the house and the other 4 on the back extension (also south facing).
Not sure of the pitch but hubbie reckons 30degrees for main roof and 20 for lower roof. Obviously not identical
Right now to the wiring of the inverter:-
Coming from the inverter there are 3 cables, one black coming from 1 point, another black coming from another point. These go to box 2 and 1 white cable coming from the inverter goes to the on/off box.
First on the left is the inverter.
Next to this is the on/off box. (box 1)
Next to this is a similar box.(box 2)
Lets call them the inverter, box 1 & box 2 to make this easier
The 2 black cables from the inverter go to box 2.
The white cable from the inverter goes to box 1.
FOLLOWING??????
From box 1 coming out the top is a grey mains cable which goes to the meter.
From box 2 coming out the top is 4 black cables in 2 single ports. From what it looks like to us is 2 of the cables go to the top 6 panels and the other 2 cables go the the lower 4 panels.
I have made a drawing of it but it is hard to explain. Briefly the black cable coming from the left hand side of the inverter goes to box 2 at the bottom and box 2 has 2 black cables coming out the top. The 2nd black cable coming from the inverter goes to box 2 also at the bottom and has 2 cables coming from the top. Total 4 cables in al coming out of box 2l!!!
Hope this is not too confusing and complicated. I hope you can cope. So sorry!!!
Will keep an eye out for your reply tonight if you are available . Please let me know if you need to know anything else. Have gone through you list of questions and answered the best I can. Thanks again!!!!*3.36 kWp solar panel system,10 x Ultima & 4 x Panasonic solar panels, Solaredge Inverter *Biomass boiler stove for cooking, hot water & heating *2000ltr Rainwater harvesting system for loo flushing *Hybrid Toyota Auris car *RIP Pingu, Hoppy, Ginger & Biscuit *Hens & Ducks* chat thread. http://forums.moneysavingexpert.com/showthread.php?t=52822090 -
Hello Mart
The make and model of the inverter is a SunnyBoy SB2500
The solar panels are Ultima Solar US 660
All the panel are on the back of the house. 6 on the main roof of the house and the other 4 on the back extension (also south facing).
Not sure of the pitch but hubbie reckons 30degrees for main roof and 20 for lower roof. Obviously not identical
Hiya Ed.
Good news, I've also got a SMA SB2500. Mine is a 2500HF-30 model. Any chance you can trouble hubbie to look at the full model number, should be on the id sticker on the side of the inverter.
Mine is (for want of a better description) tall and thin, there is also the SB2500 model which is short and fat. Mine can take 2 strings, the other model can, I believe take 3 strings.
Bad news, as far as I'm aware, no SB2500 model has dual MPPT, meaning that all inputs (strings) should be closely matched / identical.
Hopefully someone with 'real' knowledge can help us out here, but I'm concerned that the different roof angles of 20 and 30 degree (coincidentally, the same as mine) may mean that this is a problem. Anyone?
Can you just post the exact model specs (if you haven't already) and I'll do some more digging.
Mart.Mart. Cardiff. 8.72 kWp PV systems (2.12 SSW 4.6 ESE & 2.0 WNW). 20kWh battery storage. Two A2A units for cleaner heating. Two BEV's for cleaner driving.
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
Martyn1981 wrote: »Hiya Ed.
Good news, I've also got a SMA SB2500. Mine is a 2500HF-30 model. Any chance you can trouble hubbie to look at the full model number, should be on the id sticker on the side of the inverter.
Mine is (for want of a better description) tall and thin, there is also the SB2500 model which is short and fat. Mine can take 2 strings, the other model can, I believe take 3 strings.
Bad news, as far as I'm aware, no SB2500 model has dual MPPT, meaning that all inputs (strings) should be closely matched / identical.
Hopefully someone with 'real' knowledge can help us out here, but I'm concerned that the different roof angles of 20 and 30 degree (coincidentally, the same as mine) may mean that this is a problem. Anyone?
Can you just post the exact model specs (if you haven't already) and I'll do some more digging.
Mart.
Hello again
The model is - SB2500
The side sticker reads:-
VDC max 600v
VDC MPP 224-480v
IDC max 12a
VAC nom 230v
FAC nom 50/60 H2
PAC nom 2300W
IPAC nom 10a
COS 1
I hope this helps!!! Oh and it is short and fat!!!
Thanks!!*3.36 kWp solar panel system,10 x Ultima & 4 x Panasonic solar panels, Solaredge Inverter *Biomass boiler stove for cooking, hot water & heating *2000ltr Rainwater harvesting system for loo flushing *Hybrid Toyota Auris car *RIP Pingu, Hoppy, Ginger & Biscuit *Hens & Ducks* chat thread. http://forums.moneysavingexpert.com/showthread.php?t=52822090 -
Hello again
The model is - SB2500
I hope this helps!!! Oh and it is short and fat!!!
Bit like me then!
No probs Ed, I'll do some digging. It may be absolutely fine, but your numbers do look a little on the low side.
Back later, or tomorrow hopefully.
Mart.Mart. Cardiff. 8.72 kWp PV systems (2.12 SSW 4.6 ESE & 2.0 WNW). 20kWh battery storage. Two A2A units for cleaner heating. Two BEV's for cleaner driving.
For general PV advice please see the PV FAQ thread on the Green & Ethical Board.0 -
Martyn1981 wrote: »Bit like me then!
No probs Ed, I'll do some digging. It may be absolutely fine, but your numbers do look a little on the low side.
Back later, or tomorrow hopefully.
Mart.
Thank you so much for all of your help!!! I'll wait to hear from you!! I hope it is good news!!*3.36 kWp solar panel system,10 x Ultima & 4 x Panasonic solar panels, Solaredge Inverter *Biomass boiler stove for cooking, hot water & heating *2000ltr Rainwater harvesting system for loo flushing *Hybrid Toyota Auris car *RIP Pingu, Hoppy, Ginger & Biscuit *Hens & Ducks* chat thread. http://forums.moneysavingexpert.com/showthread.php?t=52822090 -
sly_dog_jonah wrote: »The lack of manual override is a pretty big limitation though.
Would the relay switch get upset if it turned on the electricity to the immersion only to discover that the immersion was already "live" via another feed all together?
I can hear howls of protest from professional electricians already, because the immersion could be or become live when someone thinks they have switched it off.
But it must be possible to buy a switch that offers On via ordinary switch/on via relay/on via ordinary switch and via relay/both off?
In fact I've got one of those security lights and have wired into it 2 bulkheads too and that can be off, on via simple switch, on via movement detector.
Methinks it must be doable.0 -
Of the two approaches (current sensing and light sensing), I think the latter is the more elegant as it doesn't involve fiddling around at the fuse box.
For me the situation is more straightforward as I don't have gas. The difference between oil heating and peak imported electricity is much less than with gas. So I think I'll just (!) get a 1kw immersion and run a time to have it come on during daylight hours in summer. That system will only be on when the CH boiler is off.0 -
John_Pierpoint wrote: »Would the relay switch get upset if it turned on the electricity to the immersion only to discover that the immersion was already "live" via another feed all together?
I can hear howls of protest from professional electricians already, because the immersion could be or become live when someone thinks they have switched it off.
Certainly - it's possible to wire another switch across the relay.
It would be prudent to find an illuminated switch that could indicate the heater circuit was live, even when 'off' of course.
And you need to make sure that any electrician is informed of this, otherwise it may be dangerous.0 -
Of the two approaches (current sensing and light sensing), I think the latter is the more elegant as it doesn't involve fiddling around at the fuse box.
It may be 'elegant', but relying upon light sensing can make it more difficult to use your 'free' electricity for something else. For instance, boil a kettle for a drink and you could be paying to do so unless you remember to go and turn off the automatic immersion heater connection.NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50
Confirm your email address to Create Threads and Reply

Categories
- All Categories
- 351.1K Banking & Borrowing
- 253.2K Reduce Debt & Boost Income
- 453.7K Spending & Discounts
- 244.1K Work, Benefits & Business
- 599.2K Mortgages, Homes & Bills
- 177K Life & Family
- 257.5K Travel & Transport
- 1.5M Hobbies & Leisure
- 16.1K Discuss & Feedback
- 37.6K Read-Only Boards