Poll

Do you keep records of your solar production

No I dont have solar
24 (55.8%)
No I don't care
3 (7%)
I look at the GTI LCD occasionally
5 (11.6%)
I look at the GTI display often
4 (9.3%)
I look at the GTI display even after dark
4 (9.3%)
I have solar, no GTI and I keep records (like Mike)
3 (7%)

Total Members Voted: 43

Author Topic: UK solar doldrums  (Read 13709 times)

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Offline woody

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Re: UK solar doldrums
« Reply #225 on: May 01, 2018, 07:55:45 pm »
Spring 2018 in NL. Yesterday I made 0.879 kWh. In a day. With 7kWP on the roof. The day before that 1.05 kWh. The entire month of April was 86kWh behind April 2017.

On the up side, the rain just stopped, the sun shines a bit and forecasts for the next week are not bad. And the boat floats again after spending the winter on the shore  8)
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #226 on: May 02, 2018, 02:53:15 am »
Just plotted mine till the end of April, spring came, the plums and damsons all flowered and immediatly we were hit by a cold washout! 1C last night :( Apples are just starting now so I hope the weather improves for the bees in time!

Y axis is weekly average Kwh/day, X axis is hours.

House was in danger of floating away a while ago, who needs a boat  :-DD
 

Offline G7PSK

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Re: UK solar doldrums
« Reply #227 on: May 02, 2018, 06:27:35 pm »
I am looking at getting solar, but I think wind might be better here in Norfolk so am looking at that as well. I built a wind system for my father twenty years ago and although he no longer is there last time I went past the turbine was still up.
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #228 on: May 02, 2018, 09:05:15 pm »
I am looking at getting solar, but I think wind might be better here in Norfolk so am looking at that as well. I built a wind system for my father twenty years ago and although he no longer is there last time I went past the turbine was still up.
I live in Norfolk too :) I have also tried wind but if you only have a small plot it's very very fussy and the planning regs get in the way hence I gave that up and moved to solar. There are still problems with the planning regs (not enough room to fit tracking gear on a roof) but I am getting a lot more output than I ever managed from wind. Depends entirely upon your circumstances and I guess you already know about the problems with turbulent flow and obstacles to close!
 

Offline woody

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Re: UK solar doldrums
« Reply #229 on: May 04, 2018, 03:34:58 am »
I just GOT to replace that inverter to get this to 40k...

Scratch that. Today, not too hot and very very sunny, we made 40.920 kWh / 5683kWh/kW. That is an all time high for this installation.  8)
 

Offline paulca

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Re: UK solar doldrums
« Reply #230 on: May 04, 2018, 05:29:25 pm »
My mini 50W system has been running with full battery now for a week.  With a few blue sky days I got all my batteries charged and the broken sunshine since is just enough to keep up with demand of my phone, electronics PSU and USB devices.

I bought a 22400mAh power bank to try and capture some more of the energy for when it becomes miserable and dark again.  So that came at 70% charge so didn't really dent the solar battery that much charging it. 13.1V down to 12.6V.  Today will probably put that back to 13V

If only it was this easy in winter.

"What could possibly go wrong?"
Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 
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Offline woody

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Re: UK solar doldrums
« Reply #231 on: May 24, 2018, 04:49:22 pm »
Got the yearly settlement from my power company yesterday. Used 3753 kWh from the grid and put back in 4193 kWh. That leaves me with 440 kWh * €0,11 * 1.21 (VAT) = €58,56 in cash.

Total electricity use over the last year (including the energy generated by the panels and directly used) was 5367 kWh. Up 1.9% from the year before. Which fuels my pet peeve that LED lamps do not save energy  >:D

Oh, and May 2018 is looking to be a very good month for solar over here  8)
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #232 on: May 25, 2018, 03:19:04 am »
Woww Woody good figures indeed :) So adding your saved electric bill to your rebate have you worked out how many years the system will take to break even on present performance ?

Last week was great here averaging over 3Kwh/day/Kw but as usual I lost quite a bit through not having completely converted the household to not using electricity unless the sun is shining and the water is hot already  ;D

IMOP the CCFL's are/were far more efficient till someone discovered they had a drop of mercury in them and outlawed them, I wonder what poison they will decide exists in LEDs meaning the get the same treatment in years to come!!
 

Offline metrologist

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Re: UK solar doldrums
« Reply #233 on: May 25, 2018, 03:38:48 am »
I've been very happy with all my LED lights, and the W numbers printed in them are much lower than the CCFL's they replaced.

In two rooms, however, there are remote 4-pin CCFL supplies where I used compatible LED bulbs - so I am sure some efficiency is lost.

My lowly panel just keeps my battery topped up. It would be much better if I set up my aquariums to run off solar, and just during sun time too. That's only 12W.  :-\
 

Offline woody

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Re: UK solar doldrums
« Reply #234 on: May 25, 2018, 05:52:56 pm »
So adding your saved electric bill to your rebate have you worked out how many years the system will take to break even on present performance?
I find that a very difficult discussion. If you look at it from the sunny side break even is maybe 7 years. But I could argue for 15 years as well. It is the same with my car; I never managed to work out the break-even for that.

My take is that since 2013 we produced 25,8MWh of clean energy and thereby avoided between 5 and 12 tons of CO2 (depending on the fuel mix used in the power plant). That at a cost that is cheaper than getting it out of the grid. How much cheaper? I don't know. Time will tell. But cheaper, that is for sure.

And when I take into account the foot-between-the-door effect that decentralized solar systems like mine have on how the grid is run by those big power companies, for me break even is already reached  ;D
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #235 on: May 26, 2018, 12:32:37 am »
Since asking the question I have tried to calculate mine, given its upgrading, early failures and weather changes from year to year it's hard to grab the figures as most of the output is converted into oil fuel savings. My initial small 500W system would have had an estimated payback of 6 years but that was before the oil price shot up recently. The extended 1kw system with a gti but no subsidy has a calculated payback of 4 years, this is in part due to the rising oil price but also because the incremental cost of extending a system is not as high as the initial. My costs are much reduced as a lot of the electronics came from my junkbox (recycling at it's best), the only things directly purchased were the panels themselves and there mounting hardware.

I am also concerned for the environment and this is one way I can contribute, in my case directly by burning less oil for heating :) The contribution via the gti to reduced grid consumption is minimal as unless it's a hot day in summer water heating takes most if not all of the available energy.

I will continue to monitor the results to see if a further extension is worthwile but presently it is large enough to provide all the summer hot water so a larger system would simply spend more time idle! Of course the real nut to crack is energy in the winter, already tried wind and that was no good, I have a small stream but no fall (3 inches on my land at most) and hydro has it's own problems in winter (freezing) leaving heat pumps. I was fortunate enough to experience air source HP's at someone else's expense and they were completely hopeless in freezing weather (spent all there time going into reverse to de-ice the external unit). My trusty woodburner helps out but they are now under threat from PC! I still say the best solution is for mankind to copy the sensible part of the animal kingdom and hibernate for the duration  :-DD
« Last Edit: May 26, 2018, 12:48:56 am by fourtytwo42 »
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #236 on: June 01, 2018, 01:48:54 am »
End of this month weekly averages, definetly getting out of the doldrums :) Vertical scale is Kwh/day horizontal is hours so the droop in the middle is Dec/Jan/Feb
 

Offline woody

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Re: UK solar doldrums
« Reply #237 on: June 01, 2018, 11:07:08 pm »
Nice figures!

For our panels it turns out that May 2018 was the best ever; May always is the top month of the year. The previous record was May 2015 with 761 kWh. May 2018 broke that easily: 905 kWh. +19%, with one inverter still broken.

Now what am I going to do with all that power  :-//
 

Offline ahbushnell

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Re: UK solar doldrums
« Reply #238 on: June 23, 2018, 10:30:57 pm »
Updates on energy generation?
 

Offline paulca

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Re: UK solar doldrums
« Reply #239 on: July 08, 2018, 07:53:38 pm »
Updates on energy generation?

It's been unseasonally sunny here in Northern Ireland.  We are into our third or forth week of actual summer weather.  25*C+ blue skies all day.

My 50W panel, in a window has been generating much more than my original demands, so I have taken to charging large LiPos and using them via a laptop car charger to run my laptop in the evenings.

I expect those with large systems will be doing rather well in the UK this last month.
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Current Open Projects:  3 Channel Audio mixer with DAC, BT, pre-amps and h/phone amp, WS281x LED controller Version 2 5V/5A w/Atmega328, FY6600 Power supply, 5A DC Load (Still!)
 

Offline Bassman59

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Re: UK solar doldrums
« Reply #240 on: July 16, 2018, 01:26:41 pm »
I live in sunny Tucson, Arizona.
A solar power paradise, payback very fast I should imagine...
Yeah, but you use a lot of that power just running the air cons.  :)
Like I said, we were running the swamp cooler through May. (OK, I realize that the whole concept of an evaporative cooler makes no sense in the UK.) We turned it on in late May because, well, why not, it was hot.

We were sending back to the grid between 400 and 500 kWh for the months up to May. For the May bill we sent back 216 kWh. The bill ending June 25 we used 422 kWh in excess of what we generated; that is, that month was the first month since the panels were installed (started up beginning of last September) that our use exceeded our generation. We used about the same amount of power this June as last June, about 1600 kWh, which cost almost $250 last year.

Even though May and June are hotter than July (June has many days over 110 degrees F), July is typically the month with the most energy usage here. That's because the humidity becomes unbearably high, as our monsoon season starts. We don't get monsoons in the tropical sense; the native word for the storms is "chubasca," but basically every day starts out hot and dry and as the day progresses, moisture in the air builds up and in the late afternoon we get thunderstorms and a lot of rain, and an hour later both the temperature and the humidity drop significantly. But during the day, before the storms, it's hot and sticky so we run the A/C, and that's our energy use.

Monsoon "season" lasts from July to the middle of September, and its start is defined as when the dew point exceeds 54 degrees F for three consecutive days.

Of course, today it was rainy and the temperature never got above 80 degrees and we opened the windows.

ANYWAY, we have nearly 1300 kWh in credit (what we've generated in excess of what we've used) and my guess is that even with another month of high-ish humidity and temperature, we will end up not paying anything to the utility for our electricity usage.

I really think that in the desert southwest, not having solar panel installations for both residences and businesses is a mistake. The problem is that the incumbent utilities are wholly against residential solar power and probably don't want businesses to have solar power, either.  But rather than invest in solar farms and even installing the panels for customers, they'd rather continue to push the natural-gas-fired turbines as the only source for electricity.
 
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Offline fourtytwo42

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Re: UK solar doldrums
« Reply #241 on: October 04, 2018, 04:48:11 am »
I sooo wish I lived in a hot country and needed aircon, it would be so simple to solar power it per the last post. Interestingly I have spent time near the equator in several countries where aircon is an expensive luxury but PV is almost unheard of. Anyway back to the UK and the doldrums are beginning to return, this is my last 15 months data (rolling averaged over a week) vertical axis in Kwh/day and horizontal in hours so you can see Autumn beginning to have its effect in shorter days and more cloud. The glitch around 9600 hours coincides with downtime caused by equipment experimentation. Ohh I should mention this system is controlled to prevent export so sometimes energy production is limited by what can be consumed locally by water heating or electricity use.
« Last Edit: October 06, 2018, 01:29:06 am by fourtytwo42 »
 

Offline Kibi

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Re: UK solar doldrums
« Reply #242 on: October 10, 2018, 06:49:18 am »
Alas, the doldrums are returning rapidly. However, after a recent upgrade of 1.1KW of additional PV atop my garage, my system reached a record of 10.03KWh today here in sunny Norfolk :)
2.78KWh went into the battery, 0.35KWh was used directly. 6.89KWh left the shed and went towards the house, of which 3.4KWh went into my hot water cylinder.
Quite a good day.
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #243 on: October 11, 2018, 05:03:58 am »
Hi Kibi, I knew there was a Norfolk also in the USA but not one in Zimbabwe  :-// So perhaps you have a home in both countries :) Your results are very good, what is the installed power of your solar panels, mine is 4*265W poly ?
BTW according to the weather forecast today was the hottest in October since 2011 BUT tomorrow the rain comes (some say at last!!).
 

Offline Kibi

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Re: UK solar doldrums
« Reply #244 on: October 11, 2018, 07:47:46 am »
Yes, I'm from Zimbabwe, patriotism sometimes gets the better of me when selecting the location settings. No solar doldrums in Zimbabwe, winter time is the best because it is not the rainy season and it's often fine weather for days on end. Alas I don't live there or even visit anymore.
I have a mixture of PV. The modules you buy at any one time are never available the next time you have more pocket money.
Several years ago, I started out with 4x 250W Renesola poly modules followed later on by two Trina Honey 265W poly modules. The latest addition is a set of 4x JA Solar 275W mono modules. A total of 2.63KV nominal. Like a conventional grid tied system, this assortment of PV arrays operates at the maximum power available all day. My system is rather unconventional though. Its mainly Victron components tied together in an ESS system.
1KW Renesola array is DC coupled via a Victron 35A MPPT charge controller. Same for the JA Solar array via its own Victron 35A MPPT controller. These are on a 24V DC system which means they are charging at just about 1KW each at the top end of the charge.
The two Trina modules are in parallel feeding a Enphase Energy M215 micro GTI. This array is over powered for the GTI, but it's fine and only really a waste on sunny days when I have excess anyway. I get about 229 Watts out of the Enphase at full chat. I might get another GTI one day and get more out of those two modules.The Enphase GTI is connected to the AC-OUT of my Victron MultiPlus Inverter / Charger which enables that energy to charge the battery and also to work off grid if necessary. If the grid fails, the MultiPlus will frequency-shift to control the output of the Enphase GTI when the battery is full.
I have configured my MultiPlus with the G83-2 grid code so that it can back feed via its AC-IN when the battery is full and the power has nowhere else to go. Therefore both the DC coupled and AC coupled arrays will go full blast all day without rest. This excess energy then goes back into the house. This is what helps bolster my output figures. I have a Solar iBoost immersion heater controller which ensures that any energy not consumed by house loads goes into the hot water cylinder.
My batttery bank is an old worn out LiFePO4 set that spent the first 8 years of it's life in a motorcycle, where it got hammered, often. The battery bank has a nameplate capacity of about 7KWh, but I'm lucky if I get 4KWh out of it. This is usually enough energy for the electronics lab, workshop and observatory.
The battery's BMS is an OpenReVolt design (from the EV community) but with 4springs firmware instead. This is quite basic and simply signals the MultiPlus with two signals, 1) charging allowed, 2)discharging allowed.
The ESS system is designed to run on Victron's (expensive) CCGX unit which ties the charge controllers, MultiPlus, battery monitors, fuel tanks, GPS (for mobile applications) etc. all together. It performs the data gathering and publishes the data to their (free to use) portal. They have opened up the code (Venus) for the CCGX, so people are running it on RaspberryPi and other machines. I am running Venus on a BeagleBone Black. The portal is still free to use even if you use a RaspberryPi.
It's taken me several years to cobble this lot together, but it's ever so rewarding.
 

Offline fourtytwo42

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Re: UK solar doldrums
« Reply #245 on: October 11, 2018, 07:03:14 pm »
Good morning Kibi thank you very much for your excellent system description! The problem of mismatched panels can be severe indeed, I was lucky when upgrading from ~500W to ~1Kw to get two more panels of the same make and type. I am sticking at 1Kw for the time being as that is enough to serve the primary purpose of water heating. Unlike just about everybody else as my system was designed from scratch primarily as a water heater it uses a combined buck/boost converter to drive the 3Kw/240Vrms element directly from the panels.  The GTI was added later merely to soak up the excess but is controlled to prevent export. If/when I eventually move house the whole system is up for re-design as I would like to add wind to the mix to provide more winter energy. Your system has the advantage of being able to store excess energy though at 1Kw I really have very little and not enough to amortize the cost of the equipment.
 

Offline Kibi

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Re: UK solar doldrums
« Reply #246 on: October 11, 2018, 11:51:02 pm »
The GTI was added later merely to soak up the excess but is controlled to prevent export.

This is another feature that the ESS system supports. Certain MODBUS energy meters can be included in the system. If one of these energy meters were to be placed directly after your main switch, then any loads downstream of the meter will be supplied by back-fed energy from the MultiPlus. The MultiPlus will do everything it can to ensure that the energy meter reads 0 Watts (or whatever offset you choose). If a 3KVA MultiPlus is runnung at full capacity because a 10KW shower is on, then the remaining 7KW will simply come from the grid.
Of course in the event of a grid failure, the MultiPlus disconnects it's AC-IN, so no loads on that side are supplied.
My dream is to have such an energy meter connected in the Consumer Unit beyond the shower and cooker circuits so that these are never supplied by the system. "Luxury" circuits (ringmains, welders, EV charging) can then sit between the energy meter and MultiPlus' AC-IN to be supplied by Grid Tied renewable energy. Then "critical" circuits like lights, fridge, boiler and security systems can be fed by MultiPlus' AC-OUT and always be supplied by renewable energy until the battery runs down.
I just need to talk to an electrician who understands my needs and is willing to try something different.
 

Offline Kibi

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Re: UK solar doldrums
« Reply #247 on: October 15, 2018, 04:49:29 am »
It's days like today which are really depressing, a start contrast in weather from just a few days ago.

Today my 2.6KW of PV harvested just 300Wh. :( This is one of the worst harvests that I can remember.

This is a snapshot of the pwer levels when the weather was at its most miserable:
 
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Offline fourtytwo42

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Re: UK solar doldrums
« Reply #248 on: October 15, 2018, 05:46:01 am »
Me too, peak today was just 30W and less then 100Wh for the day, means I have to burn expensive oil fuel to heat the water tomorrow morning :( However I must say the garden was in need of a drink and still very dry, maybe a bit more rain tomorrow too. As you can tell as a gardener I am torn hahaha Altogether I collected around 100Ltrs that will be used for all sorts of things including wine & beer making :)
 

Offline HB9EVI

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Re: UK solar doldrums
« Reply #249 on: October 15, 2018, 05:56:58 am »
seems to be quite a grey weather up in the UK, guys

my small 200Wp system fed 500Wh in the batteries today; so far we're just running the house lighting over the system and got along with the capacities of batteries and panels for our needs, but I guess it'll get tight with different weather and the upcoming shorter days.
I'll add soon a 400Wp windmill to back up for the poorer weather days
 
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