SOLAR POWER STORAGE BASED ON LEAD-ACID AND GEL-LEAD TECHNOLOGIES
LEAD-BASED BATTERIES HAVE BEEN DEPLOYED FOR MANY YEARS IN INDUSTRY, AND THE AUTOMOTIVE INDUSTRY IN PARTICULAR (CAR BATTERY). THE TECHNOLOGY IS THEREFORE APPROPRIATELY TESTED AND LONG-TERM EMPIRICAL DATA IS AVAILABLE FOR LEAD-BASED BATTERIES. LEAD-ACID BATTERIES ARE STANDARD. RECENTLY, GEL-LEAD BATTERIES HAVE ENTERED THE MARKET, WHICH ARE MORE EXPENSIVE THAN LEAD ACID BATTERIES, BUT ARE MORE SERVICING FRIENDLY.
Lead-based batteries cannot be charged/discharged as often as photovoltaic storage units using lithium ion batteries (number of cycles). More than 3,000 cycles are not (yet) possible with today's lead-based batteries for photovoltaic systems. Nor can lead-based batteries be as exhaustively discharged (limit at 80% max.) as lithium ion batteries. For the same storage capacity there is less effective storage capacity available compared to lithium ion batteries. The efficiency of a solar power storage system is also lower using a lead technology system (up to 86%). However, solar power storage systems based on lead are considerably cheaper to date than lithium ion based solar power storage systems.
LITHIUM ION TECHNOLOGY SOLAR POWER STORAGE SYSTEMS
LITHIUM ION BATTERIES HAVE NOT BEEN DEPLOYED IN INDUSTRY AS LONG AS LEAD BASED BATTERIES. THERE ARE THEREFORE FEWER EMPIRICAL DATA AVAILABLE WITH REGARD TO THE LONG TERM DURABILITY OF LITHIUM ION BATTERIES. THEY ARE CURRENTLY SIMULATED IN ACCELERATED AGEING TESTS.
To date, photovoltaic storage systems using lithium ion technology are considerably more expensive than lead-based batteries. On the other hand, in comparison, lithium ion batteries can be charged/discharged considerably more often (up to 7,000 times for lithium titanate batteries), more exhaustively discharged (up to almost 100%) and achieve efficiencies up to 95%.