Until people start really looking into solar panels, it was unclear that energy storage needed to be put in place in order to be mostly self-reliant for electricity purposes. To be clear for anyone who doesn’t know, solar panels without energy storage makes use of the electricity generated through the day and then the excess energy is sold to the nearest supplier. As payment, the local electricity company credits the seller who typically cashes them in for the supply of electricity from them at night or during winter months. To skip that process and use electricity generated by your solar panels at night, energy storage devices are needed.

What to Know about Energy Storage Batteries

Like every competitive market, solar energy storage batteries are available with all types of specifications. This makes it harder to decide which one is best for your solar charger setup but it also gives you plenty of options to choose from to store your charge. Energy storage batteries do not last anywhere near as long as solar panels do so this is one aspect that needs to be considered before purchasing it. Other things to think about are the round-trip efficiency, the capacity and power ratings, depth of discharge, and the warranty.

Lead, Lithium, or Saltwater?

Deep-cycle batteries for off-grid systems are separated into three categories determined by their chemical composition, which is lead-acid, lithium-ion, and saltwater for charging. Lead acid battery types are perhaps the longest running energy storage battery out of the three. It has been in use for years but has a somewhat limited lifespan. They are, however, the cheapest batteries on the market and are particularly favored with people who wish to store a lot of energy. Saltwater batteries are a more recent addition to the energy storage sector and have eliminated the use of heavy metals and instead uses saltwater electrolytes for solar charging. Unlike the lithium and lead batteries, saltwater batteries are recyclable due to the absence of metals. The problem with saltwater solar batteries as a solar charger is that they are so new that they are pretty untested which is an issue for some people. Lithium-ion energy batteries are the notable favorites when it comes to energy storage. However, they are the more expensive option suggesting that people prefer quality over affordability. Compared to the other types of energy storage batteries, lithium-ion batteries have a much longer lifespan than those of the saltwater or lead acid. The depth of discharge of a lithium-ion battery is higher than the lead-acid ones but slightly lower than the saltwater ones. Overall, lithium batteries are much lighter than the alternatives and can be more compact. 

The Tesla Power wall 

The Tesla Power wall

An absolute winner among the energy storage batteries is the Tesla Power wall. Most energy storage batteries are chunky and take up a lot of space, but very few with the Power wall included are small-scale. Probably due to the soaring popularity of this model the Power wall battery has actually increased in price from $5,500 to $6,700 as of April 2018. The Tesla Power wall is described as a “rechargeable lithium-ion battery with liquid thermal control.” These batteries are great for working with solar panel setups and help people to become completely electricity independent. The Power wall stores energy generated throughout the day for use during the night and for overcast or rainy days when limited amounts of energy is created.

Power wall Costs

As mentioned above, the Power wall price has increased over the years but so has the model. The Power wall 2.0 battery is now available and it can store double the energy of the original Power wall battery. As the saying goes, you pay for what you get—and that is definitely true in this case. The 2.0 version of the Power wall costs $6,700 with supporting features costing an additional $1,100 which brings the price to $7,800. Unfortunately, the amount doesn’t stop there, the installation fees can add a further $2,000 to $8,000 onto the price so again you are looking at a hefty sum of money for this battery. Contemplating buying this particular model will ultimately depend on your reason for wanting an energy storage battery as well as the rates of the electric supplier.

How Does the Power wall Work?

Like most energy storage batteries, the Power wall caters for daily electricity use and is paired with a solar panel system. When the sun is in the sky electricity is generated and used within the home. Any additional electricity created gets sent to the Tesla Power wall for storage. If you don’t have an energy storage battery, the excess electricity would be sent to the electric grid. When the sun sets and the solar panels are no longer generating electricity, the Power wall kicks into action and starts supplying the home with the additional energy that it has stored. For those without storage batteries, this is the point when you would start using your credits from selling the extra electricity for a supply. Basically, a storage battery enables you to use all of the electricity that is generated by the solar panels during times that is convenient for you. This setup typically works over the course of a day so it probably won’t be beneficial for everyone considering the climate differs from place to place. Those looking to store large amounts of energy may need to invest in more than one energy storage battery. Although you are more electricity independent with a Tesla Power wall battery, you are still not completely disconnected from the electrical grid. For a few days or weeks of bad weather and intermittent cloud, you will still need to harness electricity from the grid.

As far as energy storage batteries go, the Tesla Power wall is brilliant. It comes with an unlimited 10-year warranty and, although expensive, it is highly regarded in the solar battery world. Like all batteries, the Power wall’s battery life will start to deteriorate over time, but this is a common issue with all batteries. The energy storage batteries are still a relatively new addition to the solar industry which means that knowledge and developments are still underway. Over time, we expect to see much more efficient, stronger, and affordable options for energy storage but for now, the Tesla Power wall shines brightly.