So now I have a solar PV system how do I make the most of it???

orrery

cannonballdaze wrote: »

Use a low wattage electric kettle.
We boil quite a lot of tea, fruit tea and coffee. I bought a 1 kW Travel Kettle to replace my large 2 kW kettle.

Agreed. We bought a Kenwood 600W travel kettle, but the kettle itself turned out to cheap tat and lasted about a year. It then started tripping out the earth leakage trip.

Can anyone recommend a good quality low power kettle?

EricMears

orrery wrote: »

Can anyone recommend a good quality low power kettle?

I don't think there's a lot to choose between different brands. Even the apparently well known brands are probably re-badged items from the Far East !

But a good place to view a selection of them would be a caravan dealers. caravan pitches are usually restricted to a 16A supply (often less) and of course a 2.5kW kettle is going to use 10A leaving very little power to run everything else so caravanners tend to use low power kettles.

John_Pierpoint

The cheapest ones (< £10) tend to be make of plastic with a "sole" plate to heat the water what can go rusty, however the drawback is that they rely on the steam operated latent heat switch to turn off. So pay the extra few pounds to for one with a manual off switch for those occasions where you want more than one kettle full at a time.
The cheapest kettle will tend to be half a litre and the one costing half as much again one whole litre. [These sizes roughly a pint and quart for those thinking in imperial measurements].

Beware of the kettle where the lid can flop shut just as you are trying to fill it from a jug.

John_Pierpoint

orrery wrote: »

But the questions are: Does everyone have two elements? Does the OP have two elements?

Most dryers have two elements, when set at "high heat" both elements are switched on. Obviously "low heat" will take almost twice as long to dry the load.

There is a "no heat" option, but that is pegs and a clothes line, which probably takes an extra 15 minutes of your time on a nice sunny day, over just bundling the load from the washer to the adjacent dryer.

Some posters on here swear by a dehumidifier and at least one has a dryer incorporating a heat pump (ie you dump cold air into the garden).

My experience of sold called condensing dryers is that they still push a lot of humidity into the home, not a good idea in a modern, low air change building..

Helen18

Hi I'm new to MSE forums but have been reading this thread (up to March 13 so far). Apologies if I'm posting this in the wrong place as I haven't actually got panels yet but I do have questions about getting the best from them as about to get them.

We have an electric aga (please don't hate me!) It is my luxury (a big one yes I know) but we have a disabled daughter who needs the house warm, loads of washing to dry and well no other excuses really, I just love it. We have put it right in the middle of a very open plan house and it contributes to the heating a lot. Ok, questions:

We have some south facing roof (enough for 12 panels) and some east and west facing if we want to go up to 16 panels.

Aga seems to use about 2kw max. At mo it's on most of the time and we're using about 2 units per hour.

One company have quoted for inverter with optimiser - anyone know anything about these and whether they're any good?

Another company have suggested an immersun on the hot water tank. Anyone know if these are any good?

We also have a thermal store and a pellet stove and ufh through whole house so in colder weather use a lot of hot water. No mains gas here so pellet stove, aga and sometimes log burner (also connected to thermal store). Aga is just a space heater, no boiler or anything.

Am in a dilemma whether to stick with 12 panels and aga use a lot of the free electricity or if it's worth going for full 16 (which will cost more and be less efficient as on east and/or west) so we can then hopefully run washing machine etc for free or nearly more often and also use spare to heat water with something like immersun.

Have more questions and more info but as it's first post, will stop there.

Anyone got any thoughts/advise on best solution?

Thanks
Hx

Martyn1981

Hiya Helen and welcome. Loads of suggestions, but will need more info, but here's a start:-

Firstly general info on PV can be found on this thread:

https://forums.moneysavingexpert.com/discussion/3872445

Next, how many panels, and how big should you go. It's pretty much a numbers game, you need to see how much each option will cost, and what sort of income they will bring. Generally the larger you go, the cheaper the cost per kWp. By 12 panels I'm assuming we're looking at about 3kWp. Going bigger will cost more, but should be less per kWp.

However, if you go onto additional roofs, possibly more scaffolding, more complex inverter(s), lower generation etc, then you will need to compare and contrast the costs/incomes of each option.

Option 1, stick with 12 panels, about 3kWp.
Option 2, try for more powerful panels such as YingLi 275W (or similar), only a bit more expensive.
Option 3, go for hybrid panels, which have higher efficiency. They will be physically smaller (about 20%) than a comparative 'regular' panel so you might be able to fit 4kWp, but they will be a lot more expensive.
Option 4, put additional panels on one of the other roofs. If they are exactly E/W and you can't decide which, I'd suggest the west roof, as teatime consumption is harder to avoid/move than morning consumption.
Option 5, go supersize, put extra panels on both E & W (if big enough) as well as south. Possibly 5kWp (or even more) then run all the systems through a single inverter capped at 3.68kW (for DNO compliance). This will give you great all day long generation, with some 'capping' on really good days. But will attract a 10% lower FiT rate - 13.5p/kWh (4-10kWp) v's 14.9p (upto 4kWp).
Option 6, as 5, but seek permission from the DNO for approval without capping, to maximise generation.

Happy to go through any or all of these with you, and help work out the various income figures. Have a good play with section 5 of the FAQ thread, and try to get a guesstimate of generation for your location. Again, happy to help walk you through this if it doesn't make sense.

Regarding optimisers, I have a SolarEdge system on the WNW roof that uses PO's (power optimisers). These help minimise the effects of shade, but if you don't have shade, probably not worth bothering. However, they also allow a mix and match approach to panels, so might suit you if you have panels on differing roofs, pitches, shade etc, and also if the panel split is unsuitable for some inverters minimum and maximum voltage range. A 12 and 4 panel split might be tricky for a lot of dual inverters, hence why this might work for you options 4, 5 and 6.

Best stop now before it gets too much (too late?).

Mart.

Helen18

Hi Mart,

Thanks so much for all this. Just making a start on exploring what you've said. Had a look at the thread of FAQs and went to the europa site for predicting generation. This is what I think is our situation...(brain slightly exploding but beginning to get the idea).

Our south facing roof is at two angles 40 degrees and 22 degrees. The quotes we've had for 3KWp and 12 panels I think split them evenly. They are also split into two groups of 6 at either side of the house. Actually the house is a bit off south (25 degrees). So according to the site, we get an average per month of 226 kWh on the 40 degrees and 220 on 22 degrees - surprisingly not much difference. So can average out to 223 I presume.

If we were to add an extra kw on to either the west (well 115 degrees) or the east (-65 degrees) then we would get either 50.7 kwh average per month or 67.1 kwh so this makes putting panels on the east sound a better option. (Although maybe half and half might be better?)

If I use 50 units @ 12p per unit that would be £6 per month saving (or £72 per year) although that assumes using everything generated I think so it would be less I think. Doesn't sound very much! But then the FIT helps. According to one quote we would get £430.90 for a 3kwp system or £557.99 for a 4KWp system. So £127.09 for the extra 1kwp.

At best that would give us £200 ish per year? I've had two quotes and both are about £8000 for a 3kwp system (more than I'd hoped to be honest, but then we have to split the panels on two levels and across two sides of the house so I suppose that adds up?). One quote has inverter with optimiser(s), the other includes the immersun. One company have also quoted for the extra 1kw using 10 panels on the south ish facing and a further 6 panels on the east facing. This comes in at just under £10000 so £2000 for the extra 1kwp and payback at best of 10 years.

Am I getting it or have I gone wrong anywhere? Not too bothered about absolute accuracy of figures as long as I'm roughly on track.

Thanks so much
Helen
ps will take me a while to reply sometimes as children do seem to get in the way of investigations from time to time!

Martyn1981

Hiya Helen. Everything you've posted, suggests to me that you are indeed 'getting it'.

If I'm reading those numbers correct, with 3kWp on the south(ish) and 1kWp on the east(ish) then that looks like roughly 800kWh/kWp E and 900kWh/kWp S. Without knowing your specific location, that still sounds very likely, so I think you're on the ball.

25 degrees off south is significant enough to go for extra on the East (if you want extra). I'm in a similar boat, but without the SSW roof. My ESE roofs work out at about 810kWh/kWp and my WNW at around 680.

Pitches - my ESE's are 30d and 20d, this will make a difference, and with yours varying more it'll be essential that they aren't all wired on a single string. That's not a problem and the installer will use a dual MPPT inverter placing the 6 40d panels on one MPPT and the 6 22d panels on the other. But .....

if you want more panels on the East, then you've run out of MPPT's unless you have multiple inverters (I do, but it gets more complicated and expensive). At this point micro-inverters (one on each panels) or PO's make sense. You could have panels on the two roof orientations (all 3 E, S & W if you really get the bug!) and on the differing S pitches and this won't be detrimental to overall generation. You could even have different types, or sizes of panels if this allows a better fit.

Apologies if this is confusing, but for a normal string inverter, you need all panels to match each other, orientation, pitch, shading etc in order to maximise generation, by minimising any drag one panel has on the others.

Am I there yet ... nope .. income. Roughly, and based on your 3kWp south numbers of 223pm, that would give:
FiT 2676 * 14.9p = £400
Export (deemed 50%) 1338 * 4.64p = £62
Leccy savings, I'd suggest a guess at £120 (£80 to £160)
Total £582pa

4kWp, perhaps 3480, equals £520 + £80 + £120 = £720pa

Please note, these are only guesstimates.

Cost, well really a nice target price for a normal/simple system would probably be £6k for 4kWp and maybe £5k for the 3kWp, but, with multiple roofs, and perhaps a SolarEdge system, and maybe a diversionary switch too ... guessing here at perhaps £1k to £1.5k more for either of them. Tough targets, but hopefully a starting point.

Mart.

legoman62

Have a look at Sunpower 335 panels.
You may be able to fit 12 of these, and get 4kW output.
If I was buying solar panels today, I would be pricing them up:D

Helen18

Gosh, so much to consider...

Looking back at the figures you've suggested Mart, they are just a bit more conservative than those suggested on one of our quotes (I guess they're bound to make it sound as rosey as possible) but not far different so that all seems in order.

I'm worried about the overall price though - you're suggesting we ought to get a system for substantially less. The companies we've gone for are based on recommendations from a friend who does SAP calcs etc so gets feed back from her customers. One is a big national company and one is a local one who do all the work for the council and have been going for 30 odd years and have a good reputation.

I don't want to pay over the odds at all but I also want to make sure I go with a reputable company. My friend said to be careful of smaller companies as a lot have gone bust in recent years. Anyone any advise on this aspect.

I will investigate more powerful panels as legoman62 suggested. I didn't realise there were big differences.

We do have a possible shading situation and with the panels needing to be split at two ends of the house (we extended and put two east/west gables out the back leaving only either end with more south roof). I think just by nature of the fact that they are about 9 metres apart will probably make slight differences when the sun is coming up? Also, one end is right up to next door which has a higher roof so there will be a bit of shading as the sun moves round from that. I don't think it will be massive as it's not much higher, but nevertheless it is very inconsiderate of the panels to function at the lowest performing panel level! I guess the optimisers would help with all that.

We did discuss all the business of needing the panels at different angles on different strings and then running out of strings and needing more inverters if we want to add panels on east and or west with the local company. That's why for the 4Kwp system they have quoted for just south and east panels rather than west as well I presume. They've also suggested only 10 on the south and 6 on east rather than 12 on south (as in the 3kwp quote). Not too sure I understand why that is, perhaps to keep away from the shady end, but I don't think 10 would fit all on the other end, or all on the same angle so will have to ask them about that.

Feel a bit down now about the prices. Do I try and bash them down by about £1.5k or look at other companies? Don't really know where to start finding ones with good reputation/after sales etc. Last thing I want is a cheaper system that causes loads of problems (joint equal last thing I want as don't want to pay load more than I need to either!)

Going back to Mart's first reply, I think at this stage I'm going to rule out the options of adding more panels to go above 4kwp. From the calculations we did last night, adding an extra kw onto east or west roof would probably generate an average of about £6 per month. FIT obviously helps a lot but if that is less above 4kwp then I think it's a step too far for us. If the 4kwp is being quoted so far at £10k then that's over what we were hoping our max spend would be. Although I do feel we need to try and do better with that. Anyone else recently installed a similar system willing to share rough costs and what we ought to be aiming for?

If we have an inverter with a power optimiser, can they cope with any number of panels in different orientations/pitches? Or is there a limit. I've asked this of the company quoting for one but haven't had a response yet. They have only so far quoted for a 3kwp system with 12 panels on the south ish roofs but I'm wondering if we can add either east or east and west panels without the need for extra inverters/strings if we have an inverter with an optimiser. Just hoping that might keep the cost of upgrading from 3kwp to 4kwp down as it makes £2k difference on the other quote.

Have also been reading through the threads that mention hybrid panels. There sounds to be a lot of controversy and very different opinions about these so at a complete loss to know whether to consider this option.

Looking out of the window today at the greyness makes me think that without the FIT this whole thing would be a non starter. I do hope future governments don't scrap the scheme before we get our money back. 20 years seems a long time to expect them to honour a scheme. My knowledge of politics is virtually zero, anyone think this might be a problem?

Enough for my brain just now!
Thanks everyone again