Battery New Pv Install Looking What Battery Storage & Monitoring To Look At.

[marc8]

Hi All

just got the panels up today on my own house install went fairly well, 8 on 8, 2 strings, south facing, Seraphim 250 watts.

Just looking for battery storage & monitoring of the system so I can log in & show potential savings, unsure if this is possible or not, never installed battery unit before.

any preferences or help appreciated ?

 

[TJ Anderson]

This baby will get you sorted out.

https://www.google.co.uk/aclk?sa=L&ai=C6NDMMYljVsXEJJTMbfylsbAFuvqlrgfaj87ivAHC7OKT6wMIBBABIPT06BgoCmC7hoCA0ArIAQepAgQZUTdoWLk-qgQnT9DFh3DiI2W62SHECaIqTVn88F_H8g_nTB6HXh34NIje2CBYkuaGgAWz-P4YwAUFoAYm2AYEgAfipeMciAcBkAcCqAemvhvYBwHgEsbFrNrzjNqf_AE&sig=AOD64_0jimEM4HSaObSFZPAngsmBSatU-g&ctype=5&clui=5&q=&ved=0ahUKEwi2v6HhhMbJAhWHSRoKHVWoAHMQwg8IHA&adurl=http://rover.ebay.com/rover/1/710-134428-41853-0/2%3Fipn%3Dicep%26icep_id%3D67%26mtid%3D1673%26kwid%3D1%26crlp%3D50600204586_563391%26icep_item_id%3D161836343339%26itemid%3D161836343339%26icep_meta_categ_id%3D293%26icep_etrs%3DN%26icep_epid%3D-999%26icep_ctlg%3D-999%26icep_cond%3DNew%26targetid%3D131843274306%26rlsatarget%3Daud-133395220866la-131843274306%26rpc%3D0.19%26rpc_upld_id%3D59814%26device%3Dt%26icep_msku_flag%3Dn%26icep_cbt%3Dn%26adtype%3Dpla%26loc%3D1006664%26poi%3D1006676%26campaignid%3D207297426%26adgroupid%3D13585920426

 

[marc8]

Hi TJ Anderson

looking maybe slightly more than charging a couple of AA's, nice link though.
thanks

 

[Worcester]

Storage is about 3 years away from economic viability, unless you just want to spend some money to boast about it...

Monitoring:
eco eye
elios 4 you
immersun with montoring

 

[marc8]

Hi Worcester
as a contractor with feet in both camps solar & electrics the system has not cost me a great deal, looking at putting in as a selling tool with monitoring so can show customers potential savings.

 

[Worcester]

Hi Worcester
as a contractor with feet in both camps solar & electrics the system has not cost me a great deal, looking at putting in as a selling tool with monitoring so can show customers potential savings.

No difference, batterry back up systems still make no financial sense (yet) even in the US, where there is a lot of interest in products such as the Tesla Powerwall, they acknowledge the greater cost of batteries than power purchase.

 

[Gavin A]

I'll contradict Worcester to say that there are some niche situations where battery storage makes financial sense, but only with big lead acid systems with 6-7p / kWh lifetime storage costs vs 10-12p/kWh for the Li-Ion battery packs.

We have half a dozen systems out there at the moment that made economic sense, in part though it's because we're using them to enable us to install bigger pv systems onto restricted grid capacities.

 

[Worcester]

I'll contradict Worcester to say that there are some niche situations where battery storage makes financial sense, but only with big lead acid systems with 6-7p / kWh lifetime storage costs vs 10-12p/kWh for the Li-Ion battery packs.

We have half a dozen systems out there at the moment that made economic sense, in part though it's because we're using them to enable us to install bigger pv systems onto restricted grid capacities.

I don't disagree

The OP is looking at a 4kW system and battery storage of probably 4-10kWh; different economics.

Here's the original discussion: http://www.electriciansforums.co.uk/photovoltaic-solar-panels-forum/101768-storage-way-forward.html

and a useful document: http://www.bre.co.uk/filelibrary/events/BRE Events/Jonny Williams/9-Martin-Cotterell.pdf

 

[marc8]

Hi All thanks for response will let u know what i go for, as the system installed did not run me a lot well nothing really apart from time, scaffold & a roofer, that was about it.

 

[marc8]

Hi All

got the set up on the 24th, bought SolaX Hybrid SK-SU3700C, with Battery unit.

lucky I can say it's going in my loft. the unit is around 850mm x 724mm, without the rack unit for the batteries spent most of yesterday building an IT rack to install the battery units.

any how will get some pictures up when installed.


Just having a quick look at the energy advisory service uk, using the calculations given on the battery & the BRE guidelines.

This battery has a total capacity of xxxkWh (at the C20 rate). However, toensure a good battery life, the system is designed to cycle the battery down tono more than xx% discharged – this means an effective usable capacity ofxxxkWh – this equates to a 100W light bulb operating for xxhours

Cost of Battery storage £2000.00 this is less the cost of the Inverter (800.00) not taken into account rack
cost of electric taken average 13p per unit
20% in battery after discharge 5KW battery unit total 4.166KW

100W lamp running for 10 hours uses 1KW hour of electric (1KWH)

10 x 4.16 = 41.6 hours

41.6 x 0.13p £5.40

to break even on my battery storage system I will need it to fully charge & discharge 370 times to break even. simple calculations used & information provided in the earlier responses to my post.
the above is just saying if the battery unit fully charges & discharges to 20% I would save £5.40 each cycle.

unless I have missed something.

 

[Worcester]

Using your figures:

100W x 10Hrs = 1000Wh = 1kWh
4.16 kWh @ 0.13p = 0.5408 £ (you are a factor of 10 out)

So you'll cave 54p each cycle

so so break even you need to do that FULL cycle 3700 times.

Now in practice there are a very large number of days when you won't have 5.2kWh (5200Wh) 'spare' that you would have exported. Let me be generous and say that on a 4kWp system you could do that for 6 months of the year (some days you'll get zero, some days you may still be exporting) so on an average year you'll achieve 185 fce's (Full cycle equivalents)

That gives you a 20 year pay back assuming zero maintenance costs, and no additional costs over the £2000.

 

[marc8]

sorry decimal place LOL, I see your point but i think 6 months of the year is probably a bit low judging by today I would easily fill the battery storage.
probably shave of 2-3 years off that but as you say 17 -20 year pay back with no maintenance, bought more for me to see what will happen & monitor the system see what is really produced & I will happily post my findings on a monthly basis. (after all personally has not cost me a lot of money)

 

[Worcester]

sorry decimal place LOL, I see your point but i think 6 months of the year is probably a bit low judging by today I would easily fill the battery storage.

Did you have 'spare' capacity over today's production then? Or does the system charge the batteries first.

I'd be really interested to see in kWh your daily generation, energy to batteries, energy imported, and energy produced from batteris

I would suspect that unless you have a super efficient house / lifestyle, you base load will have consumed almost all the output.

Here's the actual generation for a 4kWp south facing 37° pitch system in Warwick for November and December:

Date kWh Peak KW
28/12/2015 1.149 1.390
27/12/2015 0.745 0.228
26/12/2015 1.344 0.783
25/12/2015 0.833 0.250
24/12/2015 1.897 1.329
23/12/2015 3.789 1.627
22/12/2015 0.892 0.363
21/12/2015 1.171 0.466
20/12/2015 3.282 1.739
19/12/2015 0.791 0.395
18/12/2015 1.430 0.345
17/12/2015 1.043 0.468
16/12/2015 1.510 0.573
15/12/2015 0.847 0.244
14/12/2015 1.115 0.278
13/12/2015 0.719 0.139
12/12/2015 0.770 0.238
11/12/2015 2.053 0.548
10/12/2015 0.665 0.161
09/12/2015 5.049 1.587
08/12/2015 3.524 1.423
07/12/2015 3.189 1.551
06/12/2015 1.261 0.645
05/12/2015 1.329 0.337
04/12/2015 4.748 1.637
03/12/2015 0.816 0.307
02/12/2015 2.350 1.106
01/12/2015 3.315 1.521
30/11/2015 1.260 0.493
29/11/2015 1.120 0.439
28/11/2015 1.529 0.439
27/11/2015 2.292 1.406
26/11/2015 1.087 0.328
25/11/2015 2.033 0.773
24/11/2015 1.710 1.351
23/11/2015 3.592 1.440
22/11/2015 4.237 2.287
21/11/2015 7.806 2.126
20/11/2015 4.653 2.022
19/11/2015 1.460 0.574
18/11/2015 2.253 0.935
17/11/2015 1.293 0.520
16/11/2015 2.977 1.506
15/11/2015 2.156 1.467
14/11/2015 1.463 0.517
13/11/2015 5.594 2.378
12/11/2015 5.836 2.135
11/11/2015 2.525 0.870
10/11/2015 3.049 1.985
09/11/2015 1.293 0.417
08/11/2015 1.428 0.896
07/11/2015 2.865 1.707
06/11/2015 1.307 0.361
05/11/2015 0.768 0.384
04/11/2015 3.654 2.228
03/11/2015 1.183 0.433
02/11/2015 2.119 0.410
01/11/2015 8.035 2.054

And another system with a MyImmersun device that logs generation, consumption and diverted power:
December
Diverted 0 kWh
Exported 0.3 kWh
Generated 187.1 kWh
Imported 188.5 kWh
House 375.3 kWh

November
Diverted 0 kWh
Exported 0.2 kWh
Generated 155.4 kWh
Imported 156.5 kWh
House 311.7 kWh

i.e. NO spare energy to charge the batteries.

What happens to the batteries in that case if for 2 months they aren't used / cycled?

 

[matthunt]

Did you have 'spare' capacity over today's production then? Or does the system charge the batteries first.

I'd be really interested to see in kWh your daily generation, energy to batteries, energy imported, and energy produced from batteris

I would suspect that unless you have a super efficient house / lifestyle, you base load will have consumed almost all the output.

Here's the actual generation for a 4kWp south facing 37° pitch system in Warwick for November and December:


i.e. NO spare energy to charge the batteries.

What happens to the batteries in that case if for 2 months they aren't used / cycled?

Hi Worcester, have you actually looked at how the SOLAX hybrid works? you cant use examples over a full day, lets say for example that you are generating 500watts at 11am but only using 300 watts, the 200 watts will go into the battery at that given time, you can also set to '0' export so all excess will go to battery and not grid etc etc but still ultimately through your meter. The technology is actually really good! I hear what you are saying on paybacks on the units but take a look at PV and how long the paybacks are without FIT!! my opinion is hats off to the guy for trying and investing in it and lets stop being derogatory

 

[Worcester]

@matthunt. I'm not being derogatory. I'm trying to get to the bottom of the technology.

I've got very detailed generation, consumption, power diversion and export of my own systems and a number of others for the last 3 years (there are 18 different environmental and energy monitors on my property), and know how difficult it is to use what you generate and store.

I understand the principles of most of the storage systems, even with the SolaX if you do configure it into 'force time use' mode (so it charges the batteries before self consumption) you're still not likely to be in a net gain situation over a considerable number of days in the year - just look at the generation figures above, and even the average household can use 35% of their annual generation by tweaking their usage habits. Even if you could use 4kW/day over a whole year = 1460kWh that is still only represents 44% of most homes annual usage. So in practice in most instances you'll still want to prioritise self consumption over generation, so that the benefits are cumulative not replacement. Even so you'll struggle to get above 75% when only having 4kWh of storage available. You need to look closely at consumption and generation profiles to work out the actual optimum storage capacity (see here https://www.elexon.co.uk/reference/technical-operations/profiling/ ) Just in case you didn't know it your profile is part of the information displayed above your MPAN on your leccy bill

I was NOT criticising marc8, or the Solax system, as I mentioned earlier marc8 is clearly an innovator (see Geoffrey Moore, Crossing the chasm) and the industry needs those guys

What we need for the next group - the early adopters is some good factual information on the real life performance of storage systems, and we need it as soon as possible, so that they can relate themselves as to how to use it and the benefits that they will get from it. - They will put their own value on the technology, they will however expect it to work and perform as stated - and that's the current issue we don't have that data - the price is not such an issue for this group (think people that always by the latest iPhone / Galaxy phone as soon as it comes out)

The big market place is the early majority, and these guys want well established references and tests and for it to be an established technology so they are at least 2 years away, that ties in nicely with battery development and costs