Solar panels

[Ian Smeeton]

Pondering the Smart (!) Meter readout, and the info from my solar App.

 

According to the app. I have imported 1kWh today.

 

 

 

 

 

 

According to the Smart Meter, I have used 3.39kWh

 

 

I wonder which is the more accurate, and how to check.

 

Regards

 

Ian

[Kris]

Monday to Thursday this week we have exported over 74kWh of Solar to the grid. 

[hayfield]

I must stress than my system was brought on a budget, I was looking for the biggest bang for my buck as the americans would say. A recap of my system which is 2.66 years old, 7 panels costing £2688 to install

 

Wednesday it generated a surplus of 70p, Thursday 91p yesterday will be much the same and the outlook for today wont be far off yesterdays. Admittedly Tuesday only gave a surplus of 19p and monday our net cost was 98p. There is a standing charge of 48p per day, certainly the past few days have actually made a net profit, all from a budget system !!  OK its been sunnier than normal, but it shows the potential, the last 6 days of electricity usage has cost us a net £1.22, the value of the electricity we have used has been £13.16 (included the standing charge).  

 

Whilst the cost of energy is expected to fall next quarter, we are now in my opinion about back at the non inflated energy prices.

 

I have at the moment nearly 2 years worth of actual figures, I could try and get an approximation of the first 8/9 months but it will be interesting to see my actual returns as my third anniversary approaches. The energy crisis will perhaps distort the figures when comparing to the initial sale projections, but in the end its hard cash that has saved. And now I am approaching the 4 year of paying the same DDI amount.

[Metr0Land]

13 hours ago, Ian Smeeton said:

Pondering the Smart (!) Meter readout, and the info from my solar App.

 

According to the app. I have imported 1kWh today.

 

 

 

 

 

 

According to the Smart Meter, I have used 3.39kWh

 

 

I wonder which is the more accurate, and how to check.

 

Regards

 

Ian

 

Ignire the detail on the desktop thingy.  It's not a smart meter.  When I had one it couldn't cope with peak/off peak pricing etc.  Just use it a s a general guide as to when you're pulling a lot of power from the grid and try to juggle things to avoid drawing too much.

[Metr0Land]

I had a great day Thursday which may never be repeated?  I imported 24kWh from solar and managed to use all of it without dropping any excess to the grid.

[eldavo]

I love my batteries.  3 days and we haven't taken any power from the grid and the batteries were still at 70% capacity this morning.   :-) 

 

Cheers

Dave

 

[Metr0Land]

22 minutes ago, eldavo said:

I love my batteries.  3 days and we haven't taken any power from the grid and the batteries were still at 70% capacity this morning.   :-) 

 

Cheers

Dave

 

 

Similar but not quite the same here.  Only used ~18.5KWh/£1.40 of imported electricity 6-10May and hoping today and tomorrow will be zero imports but from Monday it may change.  (Tesla Powerwall with notional 13.6kWh storage capacity)

[hayfield]

56 minutes ago, Metr0Land said:

 

Ignire the detail on the desktop thingy.  It's not a smart meter.  When I had one it couldn't cope with peak/off peak pricing etc.  Just use it a s a general guide as to when you're pulling a lot of power from the grid and try to juggle things to avoid drawing too much.

 

I use it as a guide for importing both gas and electricity, the electric seems to be within 0.1 kwh of electricity when compared with Octopus daily figures, having said this I hardly compare figures but sometimes just look at how we are doing during the day

 

The best guide is looking out of the window

[hayfield]

Despite the wash out on Monday the past 7 days has been the best May weekly production for the last 3 years, My exports after deductions for imported power created a surplus of £2.37 reducing my net cost after £5.38 worth of standing charge to £3.01 for the week

 

My weekly benefit (value of power used and exports to £14.38 for the week, OK its an exceptional week for May, but so far its been a bit of a disappointing start to the year when compared to the past 2 years. On the other hand we were told to expect an average weekly yield of £4.30,  

[hayfield]

Best day of the year so far 16.1kwh produced. On Sundays we tend to use about 8 kwh (roast then dishwasher).  By 7:30 we have imported 2.4kwh ,

 

Interesting to see tomorrow the final figures, but the weather forecast is down hill for the next week. Still the first 12 days has produced 131 kwh. Good for early May 

[black and decker boy]

In the last 7 days our solar has generated 116kwh. Most of it exported to the grid (15p/kwh)

 

we have then imported 86kwh overnight for my EV and to top up the solar batteries (7.5p/kwh)

 

so a pretty good week.

[hayfield]

In preparation for my third anniversary of installing my system I thought it would be a useful to see how I have benefitted year on year from having them installed

 

My original illustration had projected my total benefit in year 1 would be £204.59, the combined benefits after 5 years would be £1118.01

 

What has happened is that year 1 actual benefit was £283.74, pleased it was above expectations

 

Year 2 ended up with a total benefit of £470.47. Mainly down to the energy crisis

 

With 8 months of the 3rd year in my benefit has been £218.13 , above initial expectations with the best 4 months to come

 

I am projecting a benefit for the year of £400  projecting a total for the first 3 years of £1154. which is 43% of what I paid for the system. seven not ten + years to get my money back

 

Now even when the big discounts have disappeared it still is a good time to buy a system, but rather than a luxury item its turning into a necessary item   

Edited May 13 by hayfield

[hayfield]

Now I have had time to mull over the figgures, my rational in buying a system was simply to cushion the effect of ever rising energy prices. At that time discounts were available, mine apparently was worth about 40% , so it seemed a good time at least to explore buying a system

 

I decided to look at all the alternatives, very soon I realised batteries were not necessarily be a profitable investment for me, simply would I need to replace them before I recouped their cost ?

 

Should I fill my roofs with panels (12 maximum) or go for a smaller but optimum number. Based on the rates at the time, 7 panels in my case on one roof proved the most cost effective

 

We had some cash in the bank earning us very little, being retired I came to the conclusion that if we did nothing at some point we would have to supplement our income from our savings to pay for our ever rising energy cost. So taking decisive action seemed the sensible course of action, and I am still paying the same DDI payment as I was paying 3 years ago, even after the energy crisis

 

A few of my piers say they are too old to benefit, but still renew their double glazing or new kitchens, stating it will add to the value of their property, which they end up giving to others. Thankfully home buyers are wising up on the benefits of solar power and having them must reflect in the house's value.  With nearly 3 years of usage my first years return was 10.5%. the second rose to 17.5% and this year seems not far behind, yet the bank interest rate has increased little and the spendable value of my £2688 investment nearly 3 years ago would have reduced greatly by inflation.

[stewartingram]

I have to admit I became more interested in solar when you started posting. I tried to sign up with the local council scheme, like yourself, but was too late for that year. I've signed up (as interested) but there has been no more council schemes since. I'd like to think there would be, given the advantages, but who knows?

[hayfield]

3 hours ago, stewartingram said:

I have to admit I became more interested in solar when you started posting. I tried to sign up with the local council scheme, like yourself, but was too late for that year. I've signed up (as interested) but there has been no more council schemes since. I'd like to think there would be, given the advantages, but who knows?

 

Stewart

 

They are still going, I had a quote for batteries I think earlier this year

 

The problem is they do an area once a year, Essex is not showing anything at the moment

 

What I would suggest is tif not already registered, register an interest, when it opens aging they will mail you, or just give them a call.

If registered and not received anything yet give them a call and enquire, perhaps piggy back on the nearest

 

https://solartogether.co.uk/landing

[stewartingram]

Thanks for that. Yes I am registered with them, good idea about contacting them and trying to piggy-back. I'm loath to go with anyone elso, and not get the back-up guarantees.

[hayfield]

13 hours ago, stewartingram said:

Thanks for that. Yes I am registered with them, good idea about contacting them and trying to piggy-back. I'm loath to go with anyone elso, and not get the back-up guarantees.

 

 

My son-in -law has done his own research and is having his system fitted this week. Sadly his apex is facing north to south so his panels will be facing both east and west on a much steeper angle than normal (design of the house) plus he is getting quite a large battery.

 

At the moment he has a hybrid car and charges it at night on cheap rates, part of his plan is to buy cheap electricity (Charging the panels up) at night after discharging his battery during peak hours for best export rates. Exactly how the balance works on when and where to charge and discharge works I assume is controlled by an application based on weather forecasts. But he likes all types of electric gadgets etc

[stewartingram]

I'm a tad concerned, as in the early days I contacted a company who said the roof was in the wrong direction. But nowadays others do seem to cope it. I have a bungalow, apex roughly N-S, with a roof angle about 45 degrees. And a separate garage, S facing.

[hayfield]

We have a medium size CooP near us, they have the same roof orientation (north/south) Both east and west elevations are covered in panels

 

Our roof is 2 degrees off dead due south, plus on a single story roof on a shallow pitch, also prone to partial shading in the 3 winter months

 

I guess when both energy was cheap, technology less advanced and equipment more expensive, this was the case

 

Now there is a plethora of both import and export rates/schemes, energy costs rising. I assume the viability equations are changing

 

As for having panels on east west alignment, whilst you maximise early and late generation times plus much steeper rake  of the panels, but loose middle of the day efficiency, then add the high cost of a larger battery package.

 

But with the latter you both store more of your own production, but with both peak and off peak tariffs again for import and export usage, you have the energy providers paying you to store their power/help maintain/meet peak time demand

 

I guess we all were sceptics when early panels came on the market, but the early birds are raking it in with very generous FIT payments, Domestic solar production and storage will continue and in the end be the norm

[sjp23480]

We have a ESE/WNW orientation and the panels are partially shaded by dormers on the ESE aspect of the house.  Production is great in the morning, but falls away substantially in the afternoon.

 

When we had ours fitted the surveyor told me that the optimisers were a game changer when they came along. 

 

Previously, the output of the whole array of panels was limited to the least efficient panel, so if one panel was in shade production of each of the other panels was limited to the output of the shaded one.  Apparently.

 

The optimisers (one per panel) mitigates this limitation and makes partially shaded arrays more viable.

 

Happy to be corrected on this.

[Ian Morgan]

Having panels split between east and west facing roofs, the maximum power generated is lower, but power will be generated over a longer part of the day than a south facing array.

 

I don't know how the overall figures compare though.

 

[hayfield]

58 minutes ago, sjp23480 said:

We have a ESE/WNW orientation and the panels are partially shaded by dormers on the ESE aspect of the house.  Production is great in the morning, but falls away substantially in the afternoon.

 

When we had ours fitted the surveyor told me that the optimisers were a game changer when they came along. 

 

Previously, the output of the whole array of panels was limited to the least efficient panel, so if one panel was in shade production of each of the other panels was limited to the output of the shaded one.  Apparently.

 

The optimisers (one per panel) mitigates this limitation and makes partially shaded arrays more viable.

 

Happy to be corrected on this.

 

 

Thanks for this information, we have partial shade (3 periods) during the day from mid November to early Feb, thankfully this happens during the most inefficient period as far as production is concerned, but confirms my thoughts about the worst panel controlling the output of others. I doubt if the cost of retro fitting optimizers is worthwhile and I guess always affects first and last production periods  

[Phil Himsworth]

A system on a north facing roof will generate iirc 60% of what it would on a south facing roof. It makes more sense to install on a south facing roof if you've got the choice, but even on a north facing roof it would be worthwhile. Maybe back when panels were much less efficient this meant a north facing install was pointless, but it's not now.

 

Without a battery an east-west split system is arguably better; the peak and total power are lower, but it's spread more evenly throughout the day and is more likely to still be generating into the evening when you are likely to use it most.

 

With a battery it doesn't really matter as much, as you can use the power whenever you like to some extent. The capacity and charge rate of the battery matters more.

 

4 hours ago, hayfield said:

part of his plan is to buy cheap electricity (Charging the panels up) at night after discharging his battery during peak hours for best export rates.

 

There are a few tariffs now where overnight imported electricity is cheaper than exported daytime electricity, so (especially if you have a battery) it makes sense to use as much of the overnight power as you can and export as much of your generation as you can. Octopus Intelligent has 7.5p/kwh overnight import but 16p/kwh daytime export; Eon have a similar rate.  This turns things about a bit; clever EV chargers or solar hot water diverters become unnecessary as it's cheaper to use power overnight and use as little of your own generation as possible, the opposite from a few years ago when maximising your own self consumption was the big thing.

[hayfield]

17 minutes ago, Phil Himsworth said:

A system on a north facing roof will generate iirc 60% of what it would on a south facing roof. It makes more sense to install on a south facing roof if you've got the choice, but even on a north facing roof it would be worthwhile. Maybe back when panels were much less efficient this meant a north facing install was pointless, but it's not now.

 

Without a battery an east-west split system is arguably better; the peak and total power are lower, but it's spread more evenly throughout the day and is more likely to still be generating into the evening when you are likely to use it most.

 

With a battery it doesn't really matter as much, as you can use the power whenever you like to some extent. The capacity and charge rate of the battery matters more.

 

 

There are a few tariffs now where overnight imported electricity is cheaper than exported daytime electricity, so (especially if you have a battery) it makes sense to use as much of the overnight power as you can and export as much of your generation as you can. Octopus Intelligent has 7.5p/kwh overnight import but 16p/kwh daytime export; Eon have a similar rate.  This turns things about a bit; clever EV chargers or solar hot water diverters become unnecessary as it's cheaper to use power overnight and use as little of your own generation as possible, the opposite from a few years ago when maximising your own self consumption was the big thing.

 

Phil

 

Thanks for the information regarding the information about differing roof directions.

 

My son in law has found information on high export tariffs during the peak evening period and unless the battery is full only exporting during that time, I think this has been mentioned on this or other threads before

[hayfield]

Just finished 20 of the 30 days of this months billing period. Net cost of imports £10.06 of which £9.57 is standing charges, for May a super result providing we don't have a very wet end to the period.

 

The past 2 days an empty bucket now has 2" of water in it !!