Understanding the benefits of battery storage

Solar and battery energy storage systems

There is no doubt that with the technological improvements and the decreasing cost of battery storage, it is becoming an attractive proposition when it comes to Commercial & Industrial solar systems. Whilst this technology has been employed to a significant extent in the residential market, the high CAPEX requirement related to the application of batteries in the C&I space has limited it’s adoption in this segment of the market.

However, this is changing as the cost of large BESS comes down and the economics of including them in systems become more feasible.

A BESS can provide the following benefits
in a Renewable Energy system:

  • Off-Grid – a Solar PV System with BESS and generator integration provides the option of going completely off-grid or can provide a solution to businesses that have no choice but to come up with an independent energy solution. The batteries are charged either by Solar power or generators and then the stored energy is discharged or utilised during the evening or when there is a limited amount of solar production.
  • Backup – Batteries can provide backup during load shedding. The amount of time that the battery bank can provide backup will depend on a number of factors including size of the BESS and the amount of energy being drawn from the BESS. On sunny days when there is excess solar power being generated by the PV array, this power can be used to recharge or top-up the battery bank, reducing the amount that the bank is cycled and prolonging the backup time available. Generators can also be used to recharge the batteries.
  • Energy Arbitrage – this involves charging batteries either using solar power or grid utility power (when it is cheapest) and then discharging the stored power during periods such as the early morning and evening when peak utility energy tariffs are charged. The difference between the cost of the stored energy and peak utility tariff per kWh is a saving.
  • Peak Shaving/ Demand Reduction – The aim of this exercise is to use a BESS to discharge power during peak consumption periods or spikes to reduce a businesses Notified Maximum Demand Charge or NMD. The BESS can also be used to reduce the total demand from a business’s electricity utility.
  • Reducing Solar Energy Wastage – Certain pure grid-tie systems will result in a certain amount of throttled or wasted solar energy. This is energy which could be produced by the system but is throttled or limited because it cannot be consumed by the business and is not allowed to be fed back into the utility grid. A BESS means that this excess energy can be stored and used when needed e.g. at night.