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

ChrisJD · 1 February 2018 at 12:33PM

Frenchie67 wrote: »

It's called i boost and we are having it installed tomorrow with our 4Kw PV.

Whilst the numbers are very different with my older system, I am interested to know exactly how the payback calculation works for your installation.

Good luck, and let us know how it works out in practice.

zeupater · 1 February 2018 at 2:05PM

ChrisJD wrote: »

Whilst the numbers are very different with my older system, I am interested to know exactly how the payback calculation works for your installation.

Good luck, and let us know how it works out in practice.

Hi

There's already plenty of threads concerned with threshold switched or proportional diversion to DHW on the forum if you're interested ... an advanced search on thread titles including 'immersion' in the G&E board returns 17 threads, about half of which provide some information which should be useful!

HTH
Z

Steve_Riseley · 9 February 2018 at 10:04AM

Hi, I’m really glad to find this thread. I installed a 15KW system last year in October, in Southern Italy.
Since the installation which has 15KW of panels and 12.5KW of Batteries. The system cost around €35K, about 50% of that was the battery system. All Fronius Brand.
My question is, should I expect a better production than around 60% of the total installation of 15KW. So far even when we have had full sun, the maximum KW I have produced is about 8.5KW. I have yet to live through the mid summer, so I appreciate that my production should increase, but it is Southern Italy and even in February we have ful sun and temperatures are hovering around 18º C, today,
Also, my opinion so far is that the battery systems was a waste of money, even with only some lights etc and maybe the odd kettle boil, the battery will last at most one hour after no sun !
I have other questions but I will read through some other stuff here.
thanks,
Steve

zeupater · 9 February 2018 at 2:49PM

Steve_Riseley wrote: »

Hi, I'm really glad to find this thread. I installed a 15KW system last year in October, in Southern Italy.
Since the installation which has 15KW of panels and 12.5KW of Batteries. The system cost around 35K, about 50% of that was the battery system. All Fronius Brand.
My question is, should I expect a better production than around 60% of the total installation of 15KW. So far even when we have had full sun, the maximum KW I have produced is about 8.5KW. I have yet to live through the mid summer, so I appreciate that my production should increase, but it is Southern Italy and even in February we have ful sun and temperatures are hovering around 18º C, today,
Also, my opinion so far is that the battery systems was a waste of money, even with only some lights etc and maybe the odd kettle boil, the battery will last at most one hour after no sun !
I have other questions but I will read through some other stuff here.
thanks,
Steve

Hi & welcome to the forum ...

Probably best if you look to compare your system performance to a realistic target before going any further.

Have a look at PVGIS as the dataset covers Italy too ... there's information of how to use it & a links in the FAQ thread here (*section 5) on a useful blog site which shows an example of input here, or if you're happy to just jump in at the deep end, via direct access at http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php# ... most of us use the site to generate a monthly target/forecast to measure our own system performance against.

There's also the possibility that you'll be able to compare your daily generation to other similar orientation systems in your area using PVOutput (https://pvoutput.org) ... there are systems contributing to the dataset from all over the world, so it's worth having a look.

On the battery side, probably better to leave related questions to one side until the PV performance has been looked into!

HTH
Z

Steve_Riseley · 9 February 2018 at 3:20PM

Thank you, I will check that out !!!55357;!!!56833;

Sterlingtimes · 9 February 2018 at 3:53PM

Since Smart Metre Day, 15 June 2015, I have generated 9862 kWh and exported 1978 kWh. So I am using 80% of the power that I generate.

The cost of electricity is 13.66p per kilowatt hour and the export rate is 5.03p per kWh. So the opportunity lost over nearly 3 years is 1978 * 8.63/1000 = £170.

It is very difficult to micro manage a house of four adults but in financial terms our inefficiency is only wasting £56 a year.

I am not convinced that we could achieve 100% usage (with zero export) but it would take some inconvenience to save even another £20 a year.

philologus · 1 May 2019 at 1:46PM

I've just signed up for panels which will be installed a week on Thursday.
I started with a quote of £8750 for 16 x 280w panels and a 2.4kW battery. I got a few quotes and played one against the other for a week and ended with 20 x 300w panels and a 4.8kW battery for £8495.

My roof is east/west but is a 35 degree pitch so I'll get about 80% of the predicted 6kWh.

I used 650kWh during the three winter months Oct -Jan and I pay 14p per kWh until my fixed tariff with EDF runs out in August when it is likely to go up considerably.

I created a spreadsheet and I spent some time finding out what the average daily sun is for each month. I used an average from 2000-21010 even though this has risen a good bit since 2015. (Worst case scenario.)

Current selling price for any excess I produce is 6p per kWh but I expect this to rise as more energy suppliers start to bid for it.

Smart meters enable them to charge different amounts for different times so how much will they offer me for energy between 4pm and 8pm if they are charging 32p to their customers for this?

I have set up a spreadsheet to work it all out for me but I expect my estimated payback time to be considereably reduced once this all kicks in.

One for the admins here:-
1. I currently pay 18p a day for the privilege of being with EDF. Which company shall I switch to to reduce this overhead - or are they all the same?

2. Can we have a comparison thread in the near future for who currently pays the best price for our exported energy please?
George

Reed_Richards · 1 May 2019 at 2:36PM

Try to work out how much electricity you use between, say, 6 PM and 8 AM and make sure this is not more than 90% of 4.8 kWh or you need a bigger battery.

1961Nick · 1 May 2019 at 3:19PM

The DOD is likely to be limited by the inverter to 80% or possibly 85% on later models. 4.8 kWh will be more like 4 kWh which might not be enough to overcome the peak tariff period.

4.8 kWh sounds like 2 x Pylontech US2000 Plus batteries? If so, the maximum recommended current, at 50A combined, will give about 2.4kW charge/discharge. Is that enough to make best use of a 6 kWh array?

Bulb charge 13.232p/kWh so a saving could be made on the EDF tariff.

philologus · 1 May 2019 at 7:39PM

Thank you for your replies.
Yes the battery is a 2x 2.4k

I'm not sure if I understand what you mean about not being enough storage for a 6k system.
I understand DOD but surely I can store 4.8 for later use even if I can only draw 4k of it? Are you saying that it will not discharge at a rate that will run appliances?

George

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

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