Battery technology has come leaps and bounds in the last 10 years and will continue to evolve and develop further.
Each technology has its own merits and there is always a trade-off between technology, performance cost and recycling potential.
Solar installations have been using a mix of two primary technologies for the past five years: lead-acid and lithium-ion. As technology changes are advancing rapidly in both energy conversion and energy storage, it is crucial to understand how to maximise on the potential of solar energy for the future of the built environment.
Types of battery technology...
The predominant lead acid type (PbA) has been a sealed gel mat configuration, which is maintenance-free and has a life expectancy average of around five years for a street lighting application.
A recent adaptation of PbA technology is lead crystal, which uses an electrolyte that crystalises when charged or discharged. This new type of technology, combined with the use of high-quality plates, considerably improves battery performance. With only slightly higher-energy density than Pb gel mat and at a similar weight, these new batteries are still a very cost-effective solution for street lighting applications, granting an expected life of between seven to 10 years.
Lithium-ion, on the other hand, has much higher energy density and lower weight, with a life expectancy of now 10+ years. However, it has a well-documented downside for long-term application in cold conditions.
Below 0°C, a phenomenon known as ‘lithium plating’ occurs, which is the formation of metallic lithium around the anode during charging. It is, therefore necessary to carefully control the charge rates of lithium cells at temperatures ranging between 10°C to 0°C and to stop charging when the battery temperature reaches a point of 0°C or lower.
The future of battery technology...
There are a variety of other battery technologies that are currently in the prototype phase or early stages of adoption.
• Sodium ion – sodium is an abundant material, and with rapidly improving energy densities aiming at the lithium-ion specification, this has great potential for a low-cost, long-life battery solution.
• Cobalt-free lithium-ion - this technology has a similar specification to existing lithium-ion but with much lower manufacturing costs and a slightly shorter life.
• Silicon anode lithium-ion – this technology has a longer life with less environmental impact.
The sustainability of battery technologies...
A consideration with all battery technologies is the question of how to deal with them in their end-of-life stage.
By factoring this into the materials used, the industry can push forwards to find sustainable and recyclable solutions.
• 74% of the lead that is used to manufacture batteries in Europe comes from recycled stock.
• 5% of lithium-ion batteries in Europe are currently recycled.
If this is considered an essential part of a specification from day one, this is a step in the right direction towards implementing technology for a sustainable future.
OG2 Lighting is a designer, manufacturer and installer of solar solutions.
OG2 have developed a product range that will change the direction of residential, amenity and street lighting for a wide range of applications.
Discover more about OG2’s solar solutions here > https://www.ogtwo.com