Solar Panel Guide Discussion

Martyn1981

Sirlaughalot wrote: »

EST quote eleccy savings of £100 per annum so i don`t think an extra £50 per annum for the immersun looks rediculously high.

So i`m comfortable with the calculations i`ve made the only reservations i have is the nuclear power/ fracking debate which if the industries prosper in the uk then energy prices could well fall like they have in the worlds biggest economy USA!

SL

Morning SL. Just to avoid any confusion, I suggested a low £80 leccy saving for you, as originally, you were very unsure how much daytime generation you could use. TBH with a little common sense, and the application of some simple timer switches (as you suggested) £100+ should be very easy.

My original system, the 3.58kWp ESE generates about 2,800 units per year, and cut my bill by about £140. The extension boosted this to about £180. [The WNW £40 might appear low, but remember, it was 'after' the ESE, so if we were already meeting or exceeding demand, then the WNW would be 'spare'.] The more you add the less (proportionately) you'll be able to use.

Wins & losses for me.
Split system - win, I get long generation, so able to meet demand over a longer daytime period.
E/W orientation & shallow pitch - lose, this makes my system a summer specialist, so I export lots in the BST months, but generate less in the GMT months than say a steep pitched south system.
Average to low consumption - lose(?), our demand was about 2,700 units before PV, possibly 3,000 now as we switched to an induction hob, and a few other bits and bobs. Pretty obvious, but the more you use, the more you can save. If demand is very low, then savings will be lower.

A SW system is possibly 'perfect' since it will only generate a little less than a due south, but shifts the generation curve slightly in favour of the afternoon and evening, when it's easier to use leccy, or should that be, harder to avoid using leccy.

I'd suggest you pop onto the generation thread (very friendly and helpful bunch) introduce yourself, and ask them for info on savings:

https://forums.moneysavingexpert.com/discussion/3853851


Regarding the future, it's all a guess, but your thoughts are perfectly reasonable in the short term.

I wouldn't worry about nuclear 'cheapening' our leccy. The latest proposed subsidy (via a CfD) is to guarantee a strike price of £100/MWh. With current average market prices of about £45/£50 that's a 'subsidy' of £50/MWh (5p/kWh) equivalent to an increase of around 100% on grid prices, and around 33% on socket prices.

Fracking, who knows? The gas may (or may not) be cheaper, but if carbon taxing is applied or CCS (carbon capture and sequestration) is required, then this may not push prices down at all. No CfD figures yet for CCS but that might give us a clue when they are announced.

Mart.

John_Pierpoint

Cardew wrote: »

WHICH agreed with the EST, IIRC they talked about £70 pa savings.

Bear in mind that the preferred method of maximising in-house consumption is to divert electricity to an immersion heater.

If you have a hot water tank(and many have combis these days) you saving if you have gas will be at gas price per kWh + boiler efficiency - say around 5p/kWh.

.

Economy 7 heats up a whole (well insulated ???) tank of water per night.
If consumption and tank size valance that is it.

Most fas systems turn on and off to maintain the hot water requirement and in summer having to heat up the equipment each time means that the efficiency is likely to be a whole lot lower than the theoretical performance of the equipment receiving nice low temperature water to heat.

Cardew wrote: »

IMO £150 in-house savings from a predicted generation of 2,649kWh is far too optimistic.

Electricity tariffs nearly all have a daily standing charge and electricity is available for between 11p/kWh and 12pkWh.

As explained above any electricity diverted by the immersun will need to be priced at the cost of gas/oil/economy 7 (so between 5p to 7p/kWh)

Fuel inflation at 10% I hope not!

My practical experience is that most of my electricity saving is from the economy 7 meter's night time reading.
Hot water, Washing machine, Dryer and Dish washer all used to run on night rates and now run on day rates if the "free" electricty can cover 2/3 rds of the load.

There is also the human factor to be considered - this tends to catch out the engineers responsible for installing green technology.
I don't know if this is a female thing, but I have noticed an attitude encouraged by the utilities advertising that their supplies obey the user.
My wife is far from stupid, in fact she is better qualified than I am on paper.
I have just about got to the stage where the rule of thumb that if the sun is shining then it is cheaper to use the above facilities. However a deeper understanding of the interaction between equipment power ratings and the free power being generated seems to be impossible as it crosses the line between the machine obeying the person and the person obeying the machine.

Sirlaughalot

Just a quick technical question chaps if anyone is upto date with the immersat concept. What`s the effect of leaving the 3kw element in the tank as opposed to a replacement 1kw element. Can the immersat settings be tweeked so that any negatives, if there are any can be overcome?

SL

Sirlaughalot

Even more questions after one of the salesman suggested mono systems are n`t designed for the uk?

Another area of debate now as one salesman has said that mono systems are best avoided in the uk in preference to a poly system due to the cloud/climate of the uk weather.
The Netherlands which has a similar climate to our selves only use poly systems according to the salesman from company D!

So Mono or Poly whats best for Birmingham MSE solar panelists? Research here could be crucial as Company D are by far the best price!

SL

zeupater

Sirlaughalot wrote: »

Even more questions after one of the salesman suggested mono systems are n`t designed for the uk?

Another area of debate now as one salesman has said that mono systems are best avoided in the uk in preference to a poly system due to the cloud/climate of the uk weather.
The Netherlands which has a similar climate to our selves only use poly systems according to the salesman from company D!

So Mono or Poly whats best for Birmingham MSE solar panelists? Research here could be crucial as Company D are by far the best price!

SL

Hi

Technically, mono-crystalline cells should be physically stronger than poly-crystalline due to there being no crystal boundaries in the wafers, whether this makes a difference to long-term 'real world' structural failure rates only time will tell ...

Depending on individual manufacturer specs, there is usually a small performance gain in hot weather for mono-crystalline, but this would have very little overall effect in the UK (there should be a difference at the moment though). What needs to be considered is that there is normally a price difference between the two, this being caused by the way that the crystals are grown/manufactured, therefore the decision revolves around whether the price differential is worth it, or whether some installers quote for cheaper product at an inflated margin ....

We have mono and are very happy with their performance considering the orientation is well 'off-South' ...

HTH
Z

Sirlaughalot

zeupater wrote: »

Hi

Technically, mono-crystalline cells should be physically stronger than poly-crystalline due to there being no crystal boundaries in the wafers, whether this makes a difference to long-term 'real world' structural failure rates only time will tell ...

Depending on individual manufacturer specs, there is usually a small performance gain in hot weather for mono-crystalline, but this would have very little overall effect in the UK (there should be a difference at the moment though). What needs to be considered is that there is normally a price difference between the two, this being caused by the way that the crystals are grown/manufactured, therefore the decision revolves around whether the price differential is worth it, or whether some installers quote for cheaper product at an inflated margin ....

We have mono and are very happy with their performance considering the orientation is well 'off-South' ...

HTH
Z

Thanks Z that`s very informative and i`m sure like you it comes down to a quality/value issue!

SL

Sirlaughalot

Just had another 3 surveys today but only 1 written quote so far from company 4.

Must say it has been the most impressive one so far but is right at the top of our budget!

Company 4 is a nationwide established company offering a two week turn around from order placement. From what i can research It has good reviews.

Here`s the cost figures.

£6500 for a 4KW - 12 panel mono system with a industry leading high performance panel. with standard fittings and a monitor thrown in for free i have tried to drive a hard bargain which has basically seen me given a special £500 discount but even without the special discount it still looks good to me.

Any way here`s the sap figures for the first year

[FONT=&quot]Feed in Tariff[/FONT]

[FONT=&quot](FIT)14.9P[/FONT]

[FONT=&quot]SAP 2013 3600[/FONT]

[FONT=&quot]Savings on Electric Bill @ £0.14p Based on saving 70%[/FONT]

[FONT=&quot]Export[/FONT]

[FONT=&quot]@ £0.045p[/FONT]

[FONT=&quot]Yearly Total[/FONT]

[FONT=&quot]Qu1 [/FONT][FONT=&quot]£536.40[/FONT]
[FONT=&quot]£352.80[/FONT]
[FONT=&quot]£83.52[/FONT]
[FONT=&quot]£972.72[/FONT]


· [FONT=&quot]And here`s the detail.[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]10 years on the parts, materials and Labour[/FONT]

· [FONT=&quot]20 years on the inverter[/FONT]

· [FONT=&quot]10 year REIGA insurance backed guarantee. (Not applicable for commercial)[/FONT]

· [FONT=&quot]25 year performance Guarantee on the panels[/FONT]

· [FONT=&quot]Guaranteed return on the SAP calculation: If you panels do not achieve SAP in the first 60 months we will refund the difference[/FONT]

· [FONT=&quot]7 Day Price Promise[/FONT]

· [FONT=&quot]Anti-Theft device[/FONT]

· [FONT=&quot]48 Hour repair response, with dedicated customer care[/FONT]

· [FONT=&quot]Free weekly performance check by our Technical team.[/FONT]

Also no VAT if bought in the next 2 weeks

Looks a good deal to me any comments good or bad?

This is the bit i like

[FONT=&quot]Guaranteed return on the SAP calculation: If you panels do not achieve SAP in the first 60 months we will refund the difference[/FONT]

SL

Fruit_and_Nut_Case

Sirlaughalot wrote: »

[FONT=&quot]Guaranteed return on the SAP calculation: If you panels do not achieve SAP in the first 60 months we will refund the difference[/FONT]

I'm not sure if you have mentioned your location but as long as you're south of Sheffield you're pretty much guaranteed to achieve it.

zeupater

Hi

Almost everyone gets involved with the detail of the inverter & panels completely missing the importance of a quality mounting system and the potential consequences of having a poor mounting system, or poorly installed mounting system.

Probably a good idea to anyone looking into having a new system to question the installer on what they're considering using and how they fit the system ... there's a considerable difference in quality/cost/reliability between simply drilling through tiles installing with roof hooks and lead flashing !

HTH
Z

EricMears

Fruit_and_Nut_Case wrote: »

I'm not sure if you have mentioned your location but as long as you're south of Sheffield you're pretty much guaranteed to achieve it.

I'm about 10 miles South of Sheffield and have been well ahead of SAP forecasts. My guess would be that anyone South of Newcastle would probably meet that forecast