Our first installed TESLA POWERWALL! Fitted in June 2016

‘Self consumption has increased from 54% to 93%, representing staggering savings.’
Dr Sharma, Cheshire

Technical Information
(that you may find a bit dull but want to know)

What are they?

It literally does as its name suggests; it stores any surplus energy that your solar PV system has generated that you have not used. You can even use the stored energy if you are using more energy than your PV system is generating. Certain types of batteries can even be used during a power cut, as long as there is enough energy stored in the battery.

Types
There are two different types of battery storage systems: AC (alternating current) and DC (direct current).

Benefits of an AC current :

1. modular battery storage size
2. superior monitoring
3. high load appliance bypass possible
4. can work with any PV array size
5. can be retro fitted to any array: single or three phase
6. AC systems will continue to run in a power cut as standard
7. AC system has a 10 yr LG battery warranty to 90% discharge with a 5 yr charge controller warranty too

Benefits of a DC current :

1. Fixed battery storage size
2. can work with pre-determined PV array sizes: 2KW to 4KW , 3KW to 6KW with either 2.7KW or 5KW storage
3. can be retro fitted to any single phase array
4. It is more cost effective, however it must be kept indoors and adjacent to the existing PV inverter
5. DC systems will continue to generate even when its dark
6. DC system has a 5 year warranty on all parts and equipment

Dimensions
There are several factors to take into account when dimensioning the battery:
Small batteries will be more cost effective: all available storage capacity is used every day.
Small batteries will be charged and discharged with high currents: especially with lead batteries this will reduce battery life time.
Larger batteries, combined with a relatively large PV installation, can store excess power during good days, which can then be used during several consecutive days of bad weather.
Larger batteries provide longer autonomy during a power outage (requires using the UPS output)

Remember that battery storage systems can be used during the day when you are using more electricity than you are generating!