Energy storage using batteries is accepted as one of the most important and efficient ways of stabilising electricity networks and there are a variety of different battery chemistries that may be used. Lead batteries are very well established both for automotive and industrial applications and have been successfully applied for utility energy storage but there are a range of competing technologies including Li-ion, sodium-sulfur and flow batteries that ar. Energy storage using batteries is accepted as one of the most important and efficient ways of stabilising electricity networks and there are a variety of different battery chemistries that may be used. Lead batteries are very well established both for automotive and industrial applications and have been successfully applied for utility energy storage but there are a range of competing technologies including Li-ion, sodium-sulfur and flow batteries that are used for energy storage. The technology for lead batteries and how they can be better adapted for energy storage applications is described. Lead batteries are capable of long cycle and calendar lives and have been developed in recent years to have much longer cycle lives compared to 20 years ago in conditions where the battery is not routinely returned to a fully charged condition. Li-ion batteries have advantages in terms of energy density and specific energy but this is less important for static installations. The other technical features of Li-ion and other types of battery are discussed in relation to lead batteries. A selection of larger lead battery energy storage installations are analysed and lessons learned identified. Lead is the most efficiently recycled commodity metal and lead batteries are the only battery energy storage system that is almost completely recycled, with over 99% of lead batteries being collected and recycled in Europe and USA. The sustainability of lead batteries is compared with other chemistries.••Electrical energy storage with lead batteries is well established and is being successfully applied to utility energy storage.••Improvements to lead battery technology have increased cycle life both in deep and shallow cycle applications.••Li-ion and other battery types used for energy storage will be discussed to show that lead batteries are technically and economically effective.••The sustainability of lead batteries is superior to other battery types.Energy storage systemLead–acid batteriesRenewable energy storageUtility storage systemsThe need for energy storage in electricity networks is becoming increasingly important as more generating capacity uses renewable energy sources which are intrinsically intermittent. The spinning reserve of large networks is becoming less able to maintain power quality with increased renewable inputs and the strategies needed to optimise renewable input without curtailment or other measures are driving a move to energy storage. Electrochemical energy storage in batteries is attractive because it is compact, easy to deploy, economical and provides virtually instant response both to input from the battery and output from the network to the battery. There are a range of battery chemistries that can be used and lead batteries offer a reliable, cost-effective solution which can be adapted for different types of energy storage applications,,,,,.Lead–acid batteries are supplied by a large, well-established, worldwide supplier base and have the largest market share for rechargeable batteries both in terms of sales value and MWh of production. The largest market is for automotive batteries with a turnover of ∼$25BN and the second market is for industrial batteries for standby and motive power with a turnover in 2015 of ∼$10BN. The majority of industrial batteries are used for standby applications to provide secure power for telecommunications, data networks, national securit. 2.1. Lead–acid battery principlesThe overall discharge reaction in a lead–acid battery is:(1)PbO2 + Pb + 2H2SO4 → 2PbSO4 + 2H2OThe nominal cell voltage is relatively high at 2.05 V. The positive active material is highly porous lead dioxide and the negative active material is finely divided lead. The electrolyte is dilute aqueous sulphuric acid which takes part in the discharge process. On discharge HSO4− ions migrate to the negative electrode and produce H+ ions and lead sulfate. At the positive electrode lead dioxide reacts with the electrolyte to form lead sulfate crystals and water. Both electrodes are discharged to lead sulfate which is a poor conductor and the electrolyte is progressively diluted as the discharge proceeds (Fig. 1). On charge the reverse reactions take place. As cells approach top-of-charge and the electrodes have been progressively converted back to lead dioxide and lead, the specific gravity of the electrolyte rises as the sulfate concentration is increased. Further charging will result in water loss as it is electrolysed to hydrogen and oxygen but the over-potential at which this occurs is sufficiently high for water loss to be manageable by controlling the charging voltage. For flooded batteries, correct selection of the grid alloys and charging parameters reduce water loss to very low levels so that adding water for battery maintenance only needs to be carried out occasionally. If, however.
