It is the objective of the project to develop a new generation of power electronics for battery based electricity storage systems and thus to extend the life-time of batteries and reduce total life cycle systems costs. The focus of the project is on modifying charge and discharge currents by suitable passive filters, power electronics and charging strategies.
An increase of life-time by a factor of two or more has been shown experimentally as a result of changes in charge and discharge conditions. The effects have been explained theoretically using battery models with solid electrodes.
Commercially available lead acid batteries will be used in this project, as they are most widely employed and as they will continue to be an important component in any electricity storage system due to their cost and dynamic behaviour.
Electricity storage systems in conjunction with sources of renewable energy have to fulfil many different requirements. Optimising charge and discharge currents is only possible if the specific requirements of an application are taken into account. The project will therefore start by defining categories of electricity storage systems with similar operating conditions concerning charging and discharging currents. Installations ranging from the North of Scotland to the Mediterranean will be included in this analysis.
Once categories of similar battery operations have been defined, the most suitable type of battery will be selected. Optimised charging and discharging conditions will be determined on the basis of existing know-how in battery technology, taking full account of the specific applications, various restrictions and acceptability to end-users.
Under laboratory conditions batteries will be tested using accelerated test procedures to measure improvements in life-time expectations and capacity. Batteries in existing installations will be subjected to well defined charge and discharge cycles to regenerate them. It is known that batteries which have suffered long misuse are damaged both irreversible and reversible. The reversible damage can be removed.
Prototypes of new power electronics will be built which will provide the battery with optimised currents during charging and discharging and effectively manage the power flow between the batteries, the power generating units and non-linear loads. Additionally an energy management system will be developed to manage the energy flow. Test installations on regenerated batteries in preselected sites representing different categories as regards electricity storage will be carried out and an analysis of the overall systems economics made. The effect of the power conditioner and energy management system on the batteries will be tested one year later.
Batteries contribute heavily to the total cost of energy systems. The increase in life-time that can be expected from experience gained in other applications, will result in a major cost reduction.
Funding SchemeCSC - Cost-sharing contracts
LE16 8DH Horninghold, Leicestershire
19009 Raphina (Pikeermi)
OX11 0QX Didcot,harwell,chilton
79110 Freiburg (In Breisgau)