Storage

[TedM]

Thanks Ted. Can you add an energy inflation feature for the Grid supply?

The model is not really amenable to it unfortunately, as the number of years is only included as the result of the calculation. You could alter the 15p and 7p for other figures to account for a higher averaged cost over future years.

 

[The Solar King]

I might have this wrong, and happy for someone else to come up with a better formula, using their published figures (believe them or not..)

Trade List Prices, ignoring VAT and Installation costs

Aquion:
Price £875.00
Capacity 2 kWh
DoD 90%
Cycles 6000
Total Lifetime Capacity = Ca*DoD*Cy = 10800 kWh
Cost / kWh £8.10 p/kWh

LG Chem
Price £2,780.00
Capacity 6.4 kWh
DoD 90%
Cycles 6000
Total Lifetime Capacity = Ca*DoD*Cy = 34560 kWh
Cost / kWh £8.04 p/kWh

Should you not include deduction of the round trip charge/discharge losses (cdL) into this calculation? If these were 15% should formula not then be Ca*DoD*Cy*cdL where cdL in this example would be 85%. This would give a figure of 29376kWh and a cost of £0.0946.

In reality you need a full DCF to take into account the value of money (hurdle rate) and inflation rates (background and fuel).

Other thought. If it is 6000 cycles, how many usable cycles per year will be utilised? May only be 250 if thing is put into winter mode. Haven't yet got near what the energy take for this latter state is. If battery life is only ten years number of available cycles would not be utilised.

 

[Gavin A]

I might have this wrong, and happy for someone else to come up with a better formula, using their published figures (believe them or not..)

Trade List Prices, ignoring VAT and Installation costs

Aquion:
Price £875.00
Capacity 2 kWh
DoD 90%
Cycles 6000
Total Lifetime Capacity = Ca*DoD*Cy = 10800 kWh
Cost / kWh £8.10 p/kWh

LG Chem
Price £2,780.00
Capacity 6.4 kWh
DoD 90%
Cycles 6000
Total Lifetime Capacity = Ca*DoD*Cy = 34560 kWh
Cost / kWh £8.04 p/kWh

yep, that's basically it.

Calculated that way allows a proper comparison between different battery options.

 

[whinmoor]

Do you also have to factor in the warrantied degradation (which can be up to 20%)?

Also, the rate at which the battery is going to be discharged will affect its capacity and life span (Peukert's Law).

 

[The Solar King]

For information, here is the wording from ENA Engineering Recommendation G83, on the last page 53:


C1.6 Energy Storage Device
Energy Storage Devices can be connected to the DNO’s Distribution System directly or using Inverters.
For those connected via Inverters, the type verification testing and interface protection requirements shall be as specified in Annex A.

For those connected directly to the DNO’s Distribution System, the type verification testing and interface protection requirements shall be as specified in Annex B.






For reference Annex A is Common Inverter Requirements, and Annex B is Common Directly Coupled Requirements.

 

[whinmoor]

Cardiff installer claims to install UK?s first Tesla Powerwall | Solar Power Portal

 

[solarfred]

Hopefully they checked their facts this time and the system is actually working - unlike the Aquion "first" installation claim last month.:icon10:

 

[TedM]

Welsh home installs UK's first Tesla Powerwall storage battery | Environment | The Guardian

 

[solarfred]

This was from the Guardian last year Tesla's new batteries may be harder on the environment than you think | Vital Signs | The Guardian
I wonder what the customer was told about disposal after maybe 10 years. By then it could be a major issue and potential cost for any customers to dispose of the power packs if regulations are tightened further.

 

[infinity]

Has anyone been accepted as a Tesla partner as of yet? Or know if anyone has been?

 

[The Solar King]

Has anyone been accepted as a Tesla partner as of yet? Or know if anyone has been?

I know of two companies. One based in the East Midlands and the other in Morayshire. Plus there must be the one in Wales that is all over the press.

 

[SibertSolar]

http://www.out-law.com/en/articles/...ers-to-energy-storage-innovation-says-expert/

 

[The Solar King]

Finished reading the BRE guide by Martin Cotterell over the weekend. Hoped it would be more illuminating with more content. As soon as it gets anywhere near serious technical in section 7 it simply refers to the IET Solar CoP. Feel I should have bought that instead.

All a bit disappointing.

 

[SibertSolar]

It's a very broad overview isn't it....

Are you saying you didn't buy the IET PV CoP yet?!...tut tut

 

[The Solar King]

There is work going on in MCS to produce a new version of the PV Guide covering IET changes (eg earthing) which would mean installers didn't need the IET CoP as well. Original thought had been to produce a version of the PV Guide that covered all aspects not in IET CoP, eg output estimation, civils, wind loading etc.