By Dr Geoffrey May, Battery Science Consultant for the Consortium for Battery Innovation
While there are various options for battery energy storage, lead batteries arguably provide by far the most cost-effective and sustainable solution. Add these batteries to microgrid systems and this combination opens a world of opportunities for remote communities.
For Africans living without access to reliable electricity and communities seeking electric power microgrids, using solar photovoltaic (PV) and wind generation with battery energy storage offers a lifeline. It guarantees better healthcare, access to education, and many other life-changing opportunities. Microgrids are usually wholly disconnected from public electricity supply networks, and the alternative to solar PV or other renewable energy sources is diesel generation. This alternative is expensive and needs regular deliveries of fuel whereas a solar PV or wind installation with energy storage has minimal operating costs once implemented.
Since lead batteries are available in a variety of types and capacities, this makes them easily adaptable to the often unique requirements of a microgrid project. The majority of operators select valve-regulated technology, either with absorptive glass mat (AGM) or gelled electrolyte. These require no routine maintenance in terms of water addition in service and will provide a long life output in many environments.
As many countries manufacture lead batteries, there are strong networks of distributors and installers across the world. The batteries are intrinsically safe and, importantly, can be fully recycled at end-of-life with a value that makes their return for recycling economically advantageous for the user. Of course, there are alternatives, such as lithium-ion. Moreover, there are pros and cons in all battery applications which need to be considered by the user. For microgrids, the reliability, safety and hardiness of lead batteries make them an ideal option. Another critical factor, as ever, is cost. Lead batteries are typically $150-200/kWh, which is significantly below the cost of some other technologies. Safety is also key. Lead batteries use aqueous electrolytes and in the event of an accident or fire pose a low risk.
The Consortium for Battery Innovation (CBI) has played an essential role in the development of advanced batteries for energy storage. Battery life is a crucial factor in the economics of installations, and for this type of application, batteries may be subject to shallow cycling without always being returned to a full state-of-charge. This weakness can result in reductions in battery life and performance. However, the Consortium has invested in developments that have made significant improvements to shallow cycling behaviour. The use of special carbon additives to the negative plates reduces sulfation, and these innovations have been widely adopted across the industry.
Proof that battery storage changes lives
There are many excellent examples of microgrids already successfully operating across Africa. For instance, in Satrokola, Madagascar the Italian company Tozzi Green has installed two microgrids. The first installation was rated at 15kW/58kWh and used a 10kW wind turbine and a 1.5kW solar PV plant to provide power. Energy is stored in large 1200Ah tubular gel advanced lead batteries, which can store 115kWh. The energy demand has continued to increase, and more recently a new 60kW wind turbine has been installed with a much larger battery installation capable of storing 600kWh using pasted plate gel monoblocs.
The California-based battery company, Trojan Batteries, has worked extensively in Africa to install microgrids in various countries. Trojan partnered with Green Village Electricity Projects, a solar PV developer in West Africa, to provide electricity to the village of Bisanti in Nigeria. This village is a community of 260 households, and 60 businesses and power is provided for street lighting, business premises and homes. The project has resulted in a 50% reduction in energy-related expenditure and an 8% reduction in the incidence of malaria.
Technically it has a 24kW solar PV array and uses large flooded industrial lead batteries to store energy. Schneider Electric provided the inverter and charger. Trojan has also worked with E.On Offgrid Solutions (Rafiki Power) in Tanzania to install a microgrid at Ololosokwan for the local community and in other locations. This project comprises a 6kW solar PV panel and a Victron charger and inverter with 18kWh of energy storage using deep cycle AGM lead batteries. The installation has an advanced monitoring and management system providing for open and secure end-to-end asset connectivity, data management and advanced analytics, which has significantly reduced operational and maintenance costs for the project.
Lead batteries are an essential part of successful renewable energy installations for remote communities, which are necessary for sustainable development and many companies are active in this area. More localities can exploit the benefits of reliable, low-cost electricity supplies thus assuring future growth. Also, the technology is improving all the time. Members of the Consortium for Battery Innovation, which includes battery companies from around the globe, are supporting significant new research plans, resulting in a significant leap in performance.
For microgrids, the next generation of lead batteries supported through research by the Consortium will improve cycle life by up to five times. This technical development means longerlasting batteries with higher reliability. For people and communities across Africa, this technology offers a transformative opportunity to improve their lives and wellbeing. ESI
About the author
Dr Geoffrey May is the Battery Science Consultant for the Consortium for Battery Innovation. Formerly, he was CTO of Hawker Batteries (now EnerSys) for many years and then had the same position with FIAMM before setting up his own consulting business, Focus Consulting. He has an MA and a PhD from the University of Cambridge and is a Fellow of the Institute of Materials and a Chartered Engineer.
www.batteryinnovation.org | Twitter: @CBIbatteries LinkedIn: Consortium for Battery Innovation