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Solar Battery Storage for Your Home

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    In the growing list of renewable energy sources for residential use, solar energy bags the top spot. A research done by the Solar Energy Industries Association in 2018 found a healthy increase of homeowners in the United States opting to install home solar systems. As a result, the residential solar sector is projected to grow into a $4.5 billion market by 2023.

    Along with giving you clean and green energy, another alluring benefit of a solar home system is the long-term cost-benefit. As a homeowner, you rely on your energy generating system instead of buying electricity from the utility grid. That’s money put back into your pocket every month.

    To make home solar systems as self-sufficient as possible, domestic and international competitors have mined into a new vein of solar power equipment besides solar panels – solar batteries. Whereas solar panels generate electricity, solar energy storage batteries have been perfected and diversified to store the surplus electricity generated. 

    Therefore, you stand to gain by installing a solar power system in your home. However, the transition to solar can be a daunting task for the typical homeowner. So, here is vital information you need to know about solar energy and storage batteries to help you switch to solar power.

    Solar Energy – The Answer to Your Consumption Needs

    The sun gives more than just warmth, light, and a good tan. In this century, we have finally begun to appreciate the sun for what it truly is – a renewable source of energy. Through the smart invention of the photovoltaic cell, we have found a way to trap the raw power that sunrays possess and convert it to electricity. Once passed through an inverter, this energy can safely power your TV, dishwasher, water heater, etc.

    Solar power is not only clean but also free, and this has rung the dinner bell for companies to invest in home solar energy systems that you can rely on for your electricity consumption needs.

    Solar batteries cannot function without solar panels. Thus, let’s first have a look at solar panels to understand their importance in residential solar systems.

    Solar Panels

    Solar panels are the glass-like slabs that people have been installing on their roofs and in their yards. They are one of the most important inventions of modern times since they are the primary component in any home solar system. A typical solar panel is a collection of small 6″x 6″ cakes made of silicon, a naturally conductive material.

    When sunlight hits a silicon cell, it reacts to the electrical and conductive chemistry, generating a small electrical charge. When a number of these cells are connected in series, they form a functioning solar panel.

    Multiple solar panels used together will not only generate enough energy to meet the needs of a modern home but also a surplus to be diverted to charging solar batteries. 

    The power generated by solar panels is measured in kilowatts (kW) and energy consumed by a home or an appliance is measured in kilowatt-hour (kWh). 

    Solar panel

    An average home uses between 25 kWh to 30 kWh per day. The consumption rate depends on whether there are high power consuming appliances in the house like air conditioners or pool heaters.

    Solar Energy Storage Batteries

    The evolution of solar-plus-storage, which is when solar panels are connected to solar batteries for storage of surplus electricity, has revolutionized home solar systems. Today, installing solar modules will give you the advantage of storing the extra energy produced by the system in a solar battery bank. This adds to the effectiveness of your power generating system.

    Most home solar systems are those installed by consumers who are already a part of an existing energy utility grid. These systems are called grid-tied home solar systems.

    When possible, installing a grid-tied solar system is advisable because of the energy security and cost benefits to you, the end-user. In doing so, you ensure that in times of power outages or bad weather, your home draws the much-needed energy from the storage batteries.

    There are also financial benefits of installing a home system with a solar battery bank. On sunny days, the system produces excess electricity that you can send to the conventional utility grid for credits. So, later when you must draw from the network, you can redeem the credits accumulated through your previously tucked away excess solar power.

    Together, the expense sheet of a homeowner on a solar system backed with solar batteries on a grid-tied system is balanced more neatly than those solely buying from the utility grid.

    Depth of Discharge (DoD)

    Solar batteries are like reservoirs that you can dip into when needed. Just like how a bone-dry repository has difficulty in absorbing water in the future, solar battery should not be used until the charge in them is completely depleted. Doing this saps the life out of the battery. It then starts storing power to a lesser capacity than the one stated on the box. 

    If this total depletion continues, the life cycle of the battery is harmed even more. In the end, you will be forced to replace it well before the prescribed date of renewal.

    Depth of Discharge (DoD) is an indicator of exactly how low you can run a battery’s charge. It is an exact percentage of the battery’s power that every manufacturer provides the customers. 

    Going over the limit will adversely impact the future performance of the energy storage unit. 

    To simplify, consider the DoD of your solar battery is 70%, and your battery capacity is 10 kWh. The figures indicate that the battery should not be drained by more than 7 kWh. Instead, it must first be recharged to full capacity.

    An illustration of depth of discharge for solar energy storage batteries

    A lower DoD essentially means that you will have to recharge the battery more often. Such types of solar cells are generally cheaper. A solar cell that allows for 90% DoD will be more expensive but require fewer charge cycles.

    What are Solar Energy Storage Batteries Made of?

    Lithium-Ion

    A time-tested gold standard material used to make solar batteries is lithium-ion. Batteries having a lithium-ion chemical composition have been in use for decades in car batteries to the small cell keeping your wristwatch ticking.

    The lithium-ion industry has matured to perfection over the years. This is evident through the improved life span of the batteries and their portability, which is made possible by the small size and lightweight. But the benefits don’t come cheap since lithium solar batteries are usually on the higher end of the cost scale.

    All reliable producers of home solar systems have a lithium-ion solar battery stocked in their shelf, from market leaders like Tesla and LG to smart start-ups.

    Lead Acid

    Another well-tested battery composition is lead-acid. Unlike other batteries, lead-acid type are the cheapest solution to your energy storage needs. Lead-acid solar batteries are a favorite of customers who wish to live entirely off the grid. Their relatively inexpensive cost allows for considerable stacking opportunities when an array of these batteries is used to store a potentially massive amount of electricity for later use.

    Unfortunately, the cheap cost gets offset by the fact that these batteries also suffer from having the shortest lifespan in the solar battery market. Therefore, you might end up using and disposing of a lot of lead-acid batteries in a span of a few years.

    Saltwater

    Saltwater batteries are the only solar battery on the market that are environmentally friendly. They are the latest in a wave of technological innovation affecting the residential solar market.

    The batteries use a saltwater electrolyte solution to store electricity that can later be discharged for usage. Since they don’t use any heavy metals in their composition, these batteries are a recycler’s dream.

    The only downside to this technology is that it is still new, placing it in the mid-range of cost. In addition, the last company, Aquion, to invest in saltwater solar batteries filed for bankruptcy in 2017, something that has garnered this battery model bad press. 

    However, the future seems open to possibilities as the company also managed to climb out of bankruptcy in the same year successfully. It has since initiated phase 2 in its research and development.

    Leading Solar Energy Storage Batteries Providers and Price Ranges

    Tesla

    Since 2015, Tesla has been at the front of the pack in the production of dependable solar batteries. Their flagship model, the Tesla Powerwall, is pegged by critics to be the best in the range.

    The Powerwall is a stackable solar battery that has a capacity of 13.5 kWh and is enough for the average home’s energy needs. Tesla has developed its lithium-ion battery in partnership with Panasonic, and the resulting product is believed to be of very high quality. The cost of one battery unit is pegged at $10,100.

    An intelligent cooling software in the battery that helps reduce the chances of breakdown and maintenance makes up for the price. 

    Another essential add-on included in the market price of the Tesla solar battery is a built-in inverter. It is a necessary and costly component that is missing in solar batteries sold by other companies.

    LG

    LG is one of the main rivals of Tesla in the solar battery market. It has a battery model called the LG Chem solar battery system.

    At 9.3 kWh, the LG Chem is a decent solar battery that should be able to power a home that does not have massive power-consuming machines. It is best suited for homes that are connected to a power utility grid.

    Including installation charges, the LG solar battery can cost between $11,000 and $13,000.

    Sonnen

    Sonnen is a fast-growing German company founded in 2010. It has a share in the European market and the United States through a network of agents and installers.

    Sonnen’s Eco battery core unit has a small capacity of 4 kWh but can be stacked to 16 kWh. Smart software within the battery system stores data relating to your home’s energy needs. It then uses the information to provide you with a genuinely futuristic solar experience.

    With pre-installation costs of $9000, the Sonnen Eco is an expensive solar battery. But, it comes with a warranty of functioning at 70% of optimum levels for ten years, which is higher than that of competitors. 

    Immediate Federal Incentives and Long-Term Saving on Solar Battery Costs

    As per Federal incentive programs aimed at renewable power systems in 2020, if you install any solar battery on your residential property, you can expect to receive a 26% federal tax credit on the market price of the component. However, there is a catch. The batteries must be charged only by solar panels since they are a storage unit and not renewable energy sources on their own.

    Provided you stick to that rule, you are assured a couple of thousand dollars off your solar battery, adding to its attractiveness to buyers.

    Solar batteries mostly come with a 10-year warranty. However, in most cases, the technology behind solar cells is powerful enough. This allows you to use the working albeit less effective battery even after the lapse of the warranty period. Considering that this means you could end up using a battery up to double the warranty years, they more than pay for themselves in the long-term.

    Assuming nothing breaks and maintenance of components is done when required, solar batteries have the potential to pay for themselves twice over, until a replacement is needed.

    The Takeaway

    Solar batteries, when connected to a home solar system, will make you pay less, if anything, for power. They provide an attractive return on investment, increase the value of your property, and help the country take steps towards energy independence. All this is achieved while protecting the environment, making it a win across the board.

    Stephanie Colaco
    Stephanie Colaco

    Stephanie is a writer and editor, with a love for gadgets and all things solar. In her spare time, she enjoys reading and chasing unicorns with her 9-year-old.