Solar power for the home has been around in one form or another for decades. Many early systems were relatively small and only powered the hot water system or pool heater. These didn’t require battery storage because the power was only used when the Sun was shining. More modern Solar power systems are different. They are larger, powering the whole household, and they are used at night after the Sun has set. So a Battery storage system for the energy is essential.
An alternative to solar battery systems is to use power from the main electrical grid at night. This technique had some users, but it never really made full use of the potential for Solar Power. Most of the potential energy during the day was never used, because people were not at home during the middle of the day. So the Solar energy was not there when it was most needed.
An examination of energy consumption in most homes during the day shows that most electrical power is needed during the early morning and mid-evening, around 8 am and 8 pm. By contrast, most solar energy is produced between 9 am and 3 pm. These hours of energy production and hours of energy need do not overlap. If we want to make use of the solar energy produced during the day we need to store it during the day for use later on.
Some solar energy produced during the day was used later on. For example, hot water was heated during the day and mostly used at night. And pool heating or cleaning was done during the day so the pool was ready at night. This was the principle of the older solar systems. But if we want to use power at night we need to use a large battery system for solar electricity storage.
There are four common types of Solar Batteries:
Lead Acid – These are the type of battery found in most cars. They are old technology, and bulky, but they are considered reliable.
Lithium-Ion – These are a more recent technology, and rapidly improving, largely due to their use in everything from mobile phones to electric cars. Most Solar home systems use Lithium-ion. But they are a little prone to damage unless the system is designed to charge and discharge them safely and keep them temperature stable.
Flow – These have recently started to become popular, and are based on zinc-bromide liquid. They seem better for large power requirements, and should last for about 30 years. They appear to be a safe and reliable option, though they are still in the early days.
Sodium Nickle Chloride – Another recent technology that is becoming popular, this is considered more environmentally friendly than other battery options. They look to be safe for high power situation, but they are expensive and the long term life span is uncertain.