Lithium vs.


Grid-tie solar systems do not use batteries but if you want to take control of your own power generation and reduce your dependency on grid energy then you will need a battery based Hybrid or Off-Grid solar system.

Choosing the right battery chemistry is imperative

Reliable, cost effective, scalable, long life, maintenance free energy storage is the "Holy Grail" for renewable energy. A great deal of research and development in battery chemistry and technology has taken place over the last decade. Lithium-Ion batteries have emerged technically superior and are now ubiquitous in our gadgets, computers, electric cars, industrial and utility grade storage, etc. The mass production of lithium batteries in recent years has driven the price down dramatically to the point where it has become the most cost-effective, commercially available energy storage technology. The demand for these new batteries is insatiable as Electric Vehicles (EVs) and hybrid solar systems become ever more popular.

Until very recently Lead-Acid has been the de facto standard battery chemistry. It is however very old and now obsolete energy storage technology which is fundamentally ill suited to modern day hybrid and off-grid solar applications. Lead-Acid batteries come in several forms including Valve Regulated Lead Acid (VRLA), Anodised Glass Matt (AGM), gel, flooded, lead carbon, etc. Make no mistake though, they all fall under the Lead-Acid chemistry family and are plagued by the same problems. Lead-Acid's limitations include low cycle counts, low energy density, explosive gas emissions, frequent replacement costs, low depth-of-discharge (DOD) capability. Lithium-Ion batteries solve all of these problems as shown in the comparison table below:

From a financial point of view Lithium batteries are still more expensive upfront compared to lead-acid but they have a much lower Total Cost of Ownership (TCO) over the 25 year lifespan of the solar system due to their high cycle count ratings and long service life. The table below compares the financial characteristics of the Lithium-Iron Phosphate batteries versus AGM and Motolite batteries for 10kWh of storage capacity:

It is for the aforementioned reasons that Solarius does not offer lead-acid batteries; they are a waste of money and incompatible with our pledge to offer only the best technology for reliable solar systems that last for at least 25 years. We are proud to be the largest installer of Alpha-ESS Lithium-Iron (LiFePO4) batteries in the Philippines. The chemistry of these batteries is slightly different from those found in your mobile phone but part of the Lithium-Ion family and specially designed for solar applications. Unlike the mobile phone variants, they do not use precious metals such as Cobalt which lowers the cost per kWh while delivering much higher cycle count ratings albeit with slightly lower energy density.

It is imperative that you do not fall victim to local installer's tactics of luring you in with the low upfront cost of a lead-acid based solar system; it won't last and will cost a fortune in replacement costs. We can fit lithium batteries to some of the better ordinary hybrid and off-grid inverters as long as the battery voltage parameters can be manually programmed within the specified range. The Alpha-ESS inverters have built-in BMS and integrate seamlessly with the batteries with full online monitoring capabilities.

We offer 3kWh, 5.7kWh, and 10.3kWh residential modules that can be paralleled for a maximum capacity of 62kWh. We also offer high-voltage battery modules for commercial, industrial, and micro-grid applications scalable from 51kWh to 1MWh.

Please contact us for more advice and a quote for your energy storage needs.