Solar panels for dummies :)

elantan

Hi all, have been giving solar panels a thought for a while now and as time is going on I becoming more and more interested ... Have read the FAQ and like dreaming found most of it easy enough but some bits confusing. Like dreaming our main aim in getting the panels would be to reduce outgoings for our retirement ( ok we're still a good bit away from it but I want to think about these things just now )

A couple of q's if you don't mind, once the FIT deal finishes ( 20 years or so?) apart from the £100 ( roughly) saving per year what are the financial advantages of having a system? For example, is there a way in which we can store the energy gathered from the sun so that it will slowly feed back into consumption at night time etc?

I'm thinking of applying for the £2k interest free loan for it and paying the rest on a 0% finance credit card with 3% fee so if I borrowed £5k I would pay £150 in interest. Does that seem about a good way to go about it? Was reading the thread about children's savings for that idea ( great thread btw )

We currently average between 12-15 units per day of electricity consumption I work shifts so could effectively do the washing etc through the day to take advantage of the electricity, is there a system size that would be best for us for this consumption ?

We live in a two story bungalow ( I know it's a contradiction in terms ... It is a bungalow but the house is built into a hill and at the back we have a basement ... Which originally was used as a coal shed) so we would need scaffolding etc, I think we could have panels on the south wall but they would be vertical is that ok? We also have a slanted roof south west facing and also another part on the south east wall where we could have panels but like the south facing ones they would be vertical is it possible to have panels on three parts?

Are there any systems / makes more reliable/ value for money ( not necessarily the cheapest) than others ?

Thanks in advance for any help sorry I the questions seem a bit daft I am trying to learn honest

elantan

Also ... Any specific panels etc NOT to touch, I see in another thread the advice is to stay away from anything Chinese, any others I should avoid like the plague ?

Martyn1981

elantan wrote: »

Hi all, have been giving solar panels a thought for a while now and as time is going on I becoming more and more interested ... Have read the FAQ and like dreaming found most of it easy enough but some bits confusing. Like dreaming our main aim in getting the panels would be to reduce outgoings for our retirement ( ok we're still a good bit away from it but I want to think ahead)

Thanks in advance for any help sorry I the questions seem a bit daft I am trying to learn honest

Hiya elantan. I don't think any of those questions are daft, they are actually too good, so I'm going to have to start thinking about revising the FAQ thread.

Quick run through, then just ask for more detail:

1. After 20 years (hopefully panels will last much longer, maybe 40?), you'll still have the leccy savings, whether or not these will grow in real terms will depend on the difference between general inflation and fuel inflation. Probably best just to keep them proportional, though panel efficiency does drop (maybe 0.5% pa, hard to know) so in 20 years they may have 10% less output.

There will also be the export income. I don't know if this will be guaranteed, as leccy companies don't like dealing with very small export. Hopefully this will be forced upon them, and accurately monitored via smart meters.

2. Roofs and walls. S West roof is ok. Panels can be wall mounted but you'll need planning permission. The steeper the panels are, the more they will favour winter sun angles than summer.

Within reason (20deg to 50deg roof pitch) total annual generation will be similar, but monthly generation will be skewed. If you wall mounted at 90deg the drop off would be high. If planning permission were given to mount on wall brackets that tilted the panels down to say 70deg, then things improve a bit.

Guessing you are in Scotland (the mention of the 2k loan) I just stuck a pointer in the middle (on PVGIS) and for 1kWp I got:

35deg 744kWh's pa
90deg 502kWh's pa
70deg 636kWh's pa

3. System size, the bigger the better. There are a lot of fixed costs (scaffolding, paperwork, labour, travel etc) so, purely as an example, a 2kWp system might cost £4k, whilst a 4kWp system may cost £6k. You'll need to get quotes and see how it adds up. generally it's easier to stop at 4kWp, as the tariff rate then drops (for the whole install) and this also coincides with the DNO (district network operator) limit of needing prior approval for any system that can export more than 3.68kW (your inverter would be capped at this level).

4. Don't be too worried about Chinese panels, the vast majority are Chinese. But do try to review any systems once they are specified by an installer. People on here won't really be able to judge between panels, but may have info on companies in trouble etc. There are a lot of respected inverter manufacturers, always good to mention the make and model, as it's really easy to look at the tech sheets and spot obvious problems.

5. Panels on three parts, yes, but you'd need an inverter that can 'talk' to the three parts individually. This may be tricky. An alternative is micro-inverters (one per panel) or power optimisers (PO's) (one per panel), that do a similar job, but then 'talk' to one inverter. I have PO's on my WNW system.

I'll stop there, before I confuse you even more.

Mart.

elantan

Thanks for the info really helps


The FAQ is good honestly ... It just takes me a long long time to understand things ... Hence the reason I ask many questions


Yep on two of the walls they would be 90degrees as the walls are flat .... Hmmmm on the south west wall though I think the 35 degrees would be just about right... Would that be a viable alternative or would I be better to go for the 90degrees one and say a 35 degree one ... Will need to try and navigate my way around the website you mentioned ( putting in my postcode etc) that should be fun lol

I was reading last night about the equiemt that will heat the water as well ensuring you get the use of the generated electricity, this would be handy for us as we have a very old boiler system that we have to heat the water separately for an hour in order to have a bath etc ... Are these add ins worth it ?

Have a lot to think about but am very grateful for the help ... Really found the which guide of questions to ask before someone comes out and when they come out very helpful

Is there a way that the energy gathered can be stored so that it filters back for use throughout the night ... Ie the system manages to gather 14kwh and I use 6 kwh per day but the other 8 is stored somewhere so that I can use it at night ? Like a battery type thing? I imagine that would help cut the electricity costs right down

Fruit_and_Nut_Case

elantan wrote: »

Is there a way that the energy gathered can be stored so that it filters back for use throughout the night ... Ie the system manages to gather 14kwh and I use 6 kwh per day but the other 8 is stored somewhere so that I can use it at night ? Like a battery type thing? I imagine that would help cut the electricity costs right down

I think systems are being developed to do this but they are likely to be very expensive, due to the need for humungous banks of batteries, and thus of marginal use. As with all technology they are likely to become cheaper with time but who know over what time-scale.

You say you live on a hill; perhaps you could pump water to a pond at the top during the day and let it flow down overnight through a turbine.

dreaming

elantan wrote: »

Hi all, have been giving solar panels a thought for a while now and as time is going on I becoming more and more interested ... Have read the FAQ and like dreaming found most of it easy enough but some bits confusing. Like dreaming our main aim in getting the panels would be to reduce outgoings for our retirement ( ok we're still a good bit away from it but I want to think about these things just now )

Thanks in advance for any help sorry I the questions seem a bit daft I am trying to learn honest

Hi Elantan

Well 4 days of PV and have managed to read the generation meter which states 3520. Not bad as the weather hasn't been overly kind with really overcast afternoons. Right now I have the washing machine on (and the computer obviously) but have got to have my elec. meter changed as it is running backwards (at the moment it is standing still).
Realised today that although I learned a lot about PV from the kind cleverclogs;) on this site, I don't know too much about usage. I mean, I know that all electrical items have a Kw stated on them (e.g. kettle = 3Kw) but what does that mean in practical terms? I know I can't run all my electrical stuff in one go but what combinations could I use? Is there an optimum level of usage? Don't know about answers - sometimes I'm not sure what questions to ask!
Anyway good luck with your search.

tunnel

dreaming wrote: »

Hi Elantan

Well 4 days of PV and have managed to read the generation meter which states 3520. Not bad as the weather hasn't been overly kind with really overcast afternoons. Right now I have the washing machine on (and the computer obviously) but have got to have my elec. meter changed as it is running backwards (at the moment it is standing still).
Realised today that although I learned a lot about PV from the kind cleverclogs;) on this site, I don't know too much about usage. I mean, I know that all electrical items have a Kw stated on them (e.g. kettle = 3Kw) but what does that mean in practical terms? I know I can't run all my electrical stuff in one go but what combinations could I use? Is there an optimum level of usage? Don't know about answers - sometimes I'm not sure what questions to ask!
Anyway good luck with your search.

Might be an idea for you to look at a Wattson. It lets you know (by glowing green) when there's spare leccy from your PV system. Either that or the old fashioned way, look out the window and if its sunny then put a couple of things on. This depends though on how energy efficient your white goods are. If they're old may be better to stick with one at a time. I changed all mine to A rated or better and boy does it make a difference.

dreaming

tunnel wrote: »

Might be an idea for you to look at a Wattson. It lets you know (by glowing green) when there's spare leccy from your PV system. Either that or the old fashioned way, look out the window and if its sunny then put a couple of things on. This depends though on how energy efficient your white goods are. If they're old may be better to stick with one at a time. I changed all mine to A rated or better and boy does it make a difference.

Thanks - have been looking at how best to monitor it. Installer is coming this week to do handover etc. and might ask what they recommend. At moment working full time it is going to be guesswork based on weather forecast (or what is outside window) for when I set things to come on, but when I stop working I want to be able to be a bit more organised.
Luckily white goods have all been bought in last 3 years and are A+. The way I see it is that I have to do washing anyway so now trying to do it when I am generating (even a small amount) is better than nothing... just looked at elec. meter and with washing machine still on it is still running backwards.

[Deleted User]

dreaming wrote: »

Thanks - have been looking at how best to monitor it. Installer is coming this week to do handover etc. and might ask what they recommend. At moment working full time it is going to be guesswork based on weather forecast (or what is outside window) for when I set things to come on, but when I stop working I want to be able to be a bit more organised.
Luckily white goods have all been bought in last 3 years and are A+. The way I see it is that I have to do washing anyway so now trying to do it when I am generating (even a small amount) is better than nothing... just looked at elec. meter and with washing machine still on it is still running backwards.

With a backwards running meter the 'grid' is your battery so just use appliances anytime

Martyn1981

elantan wrote: »

Thanks for the info really helps


The FAQ is good honestly ... It just takes me a long long time to understand things ... Hence the reason I ask many questions


Yep on two of the walls they would be 90degrees as the walls are flat .... Hmmmm on the south west wall though I think the 35 degrees would be just about right... Would that be a viable alternative or would I be better to go for the 90degrees one and say a 35 degree one ... Will need to try and navigate my way around the website you mentioned ( putting in my postcode etc) that should be fun lol

I was reading last night about the equiemt that will heat the water as well ensuring you get the use of the generated electricity, this would be handy for us as we have a very old boiler system that we have to heat the water separately for an hour in order to have a bath etc ... Are these add ins worth it ?

Have a lot to think about but am very grateful for the help ... Really found the which guide of questions to ask before someone comes out and when they come out very helpful

Is there a way that the energy gathered can be stored so that it filters back for use throughout the night ... Ie the system manages to gather 14kwh and I use 6 kwh per day but the other 8 is stored somewhere so that I can use it at night ? Like a battery type thing? I imagine that would help cut the electricity costs right down

Hiya, don't worry about the questions, I was in exactly the same boat as you a few years ago, so started asking questions (and haven't stopped yet!).

Roof v's wall, just checking, you say south west wall. If you mean roof, then that's a very good location. Obviously we all get obsessed with south facing, but SE to SW is great. Even ESE is very good, but no comment on WNW.

With the walls, I gave an awful description of tilted down to 70 deg. Yes 70 is down from 90, but I really meant that the brackets would stick out more at the bottom than the top, tilting the panel up. I believe you'll need planning permission for wall mounted anyway, so worth checking if they can be 'tilted'.

In a similar vein, my ickle ESE system of 5 panels, has 3 on a low roof, and 2 acting as a replacement canopy over my backdoor. In a reversal of the above, I had the brackets made so that the canopy would match the low roof pitch of 20deg. Technically they are wall mounted, but the old canopy was original.

Storing leccy in batteries is gathering steam, but extremely expensive. Something for the future maybe. Here's an old article on such a system, it might possibly double the cost (check out the size of the battery box):

http://www.earthtechling.com/2012/02/japan-combines-solar-storage-to-beat-blackouts/2/

Storing leccy as hot water is a popular topic on here. Savings will vary, and consideration has to be given to when export is metered properly - losing 5p export to save 5p gas etc etc.

Try this thread, loads of info, it does get messy in the middle with some squabbling (me included ) but gets back on track later.

https://forums.moneysavingexpert.com/discussion/4152489

Mart.

tunnel

dreaming wrote: »

Thanks - have been looking at how best to monitor it. Installer is coming this week to do handover etc. and might ask what they recommend. At moment working full time it is going to be guesswork based on weather forecast (or what is outside window) for when I set things to come on, but when I stop working I want to be able to be a bit more organised.
Luckily white goods have all been bought in last 3 years and are A+. The way I see it is that I have to do washing anyway so now trying to do it when I am generating (even a small amount) is better than nothing... just looked at elec. meter and with washing machine still on it is still running backwards.

To give you an idea, when i'm generating between 2-3kWh per hour I can comfortably use my washer and dryer(heat pump condenser I think) together. With my base load(everything else) included i'm still only using my generated power. Dishwasher goes on separate though,thats my only really power hungry appliance.

It does get easier to understand as time goes by. As for the weather,when your home, stick your head out the door and check. Forecast for here today was rain and its been sunny all day so far