Why is battery storage needed?
Grid connected solar PV systems do not work during a power cut. Unfortunately, the solar PV system will not work until the electricity supply to the property is restored. Grid connected solar PV systems are known as a battery less systems as the solar PV inverter requires a connection to the grid to function properly. If there is no grid voltage available then the solar PV will not work.
This does raise a question: if a solar PV system produces energy when the sun shines then why can't we use that energy even if the electricity supply is not available? The answer is not that simple. Solar PV system is a constant current source so it cannot increase or decrease the amount of energy it produces to handle normal, everyday, appliances and load demands. If the solar PV system produces 10A then it cannot produce more than that. Appliances that operate at 10A or less could run, but fridges and appliances with motors would not work as they require a higher current to turn their motor over. If you suffer from frequent power cuts or power cuts that last a long time, and assuming that you are grid connected, then you may want to consider having a battery storage system installed.
Why you should consume ALL the energy you produce
If you have paid for solar panels to be installed on your home, office, place of work, workshop or farm, you must be happy that not only is your electricity bill is being reduced, but that you're receiving feed-in-tariff payments for all the electricity generated, regardless of whether it is consumed or not. If you have had solar panels fitted for free you do not receive the FIT but you do reduce your electricity bill. In both cases you may be thinking about how to further reduce your electricity bill. All of the electricity generated by your solar PV system should be consumed and not exported if at all possible. If you are out at work all day and you discover that you are exporting more electricity that you would like then you can install a device to switch your immersion heater on & off depending on the power produced by the solar panels. This is simple and easy to achieve regardless of whether you receive the FIT payments or not. What if you cannot achieve 100% consumption and are still exporting? Exporting unused electricity really does not make financial sense whatsoever. If you can't use it then what else can you do with it? The simple answer is to store the electricity in deep-cycle batteries and use it when you want.
Demand for battery storage systems to compliment grid-connected solar PV systems will become increasingly popular in the UK.
Concern about ever increasing energy price rises. Ofgem have forecasted that energy prices will rise at by least 5% every year. Recent price hikes indicate that 5% is conservative; Concern over reliability of supply. The UK energy generation sector is in crisis with the lack of investment, coupled with aging power stations means that reliability of supply is in doubt. If you already live in a rural area, you will probably already have experienced power cuts. Indications are that the situation will continue to get worse. If you have installed a solar PV system then adding batteries to your solar system makes financial and practical sense. Practical because energy can be stored in batteries and used when required; financial because it is pointless to export any energy if it is not consumed. Why not use the energy generated to charge batteries?