If there is a power cut will I be OK since I have a battery installed? Keeping the lights on.
To cut a long story short here batteries can potentially be used to run completely independently from Grid electricity, or to ride through short power cuts so that if there is a power cut in your street then you will still have power available to your home.
This is not true of all battery systems however, some do not offer this functionality at all or some do in a very limited way. This service may
be available with your chosen battery but at additional cost.
Essentially you need to be clear if you want it and that it is included in your quote if so. Furthermore, just to confuse the issue, you can go from an Emergency Power Supply plug at one end of the scale to full household support at the other end whereby everything that is connected to your homes main consumer unit is supported and will stay on.
“Be clear about the difference!” I hear you ask. Simply put money talks – a simpler system, if it comes with EPS most likely is offering a cable with a twin socket at the end of it coming out from the inverter wherever that may be. If this was in the garage or the loft then I am unsure how much use this is to you but could be used to keep fridges & freezers, or boilers powered up in the event of a power cut.
Also, if it is a more budget size battery then the amount of power it can supply – even under Emergency Power Supply – will be most likely small, around the 1-2kW capacity. As such even if you COULD connect to it then it still does not necessarily give you enough capacity to do much of use.
On the other side of the scale you can request that you whole home will be backed and would continue to work if the street supply went off. This is not necessarily a large increase in cost but you would want a decent size battery system to be able to supply enough power over enough time to be of use, hence probably a higher cost system. Therefore, if this is important to you make sure to ask, yet again a decent surveyor/design engineer would discuss this with you when discussing a battery in general.
You should consider though, how often do I actually get power cuts?
You may also wonder why don’t all systems do this?
Simply put, the battery is connected to your house which is of course connected to the grid. If the local Electricity Board sent an engineer out to fix the supply to your street and your live solar panels and battery were connected then you have a real potential that he could get electrocuted whilst working on the supply to your house when reasonably expecting everything to be safe. Electricity boards tend to frown on this… you would have lots of Health and Safety men muttering to themselves and walking around with clipboards.
For this to be done safely then you need additional equipment which costs a bit extra so particularly lower cost options don’t always offer this option.
Written by John Rowlatt