More on solar and wind batteries

Wind and solar batteries in a renewable energy installation store excess electricity for later use when the solar modules or solar panels or wind turbines produce energy surplus. In conjunction with a photovoltaic system, solar power can also be used when there is no sunshine, i.e. when the solar modules are not currently generating electricity but it was generated previously. It stores surplus energy to use at another time of the day or when there is no production.

Photovoltaic systems without batteries produce solar power that must be used instantly. This could be not the best option for some consumers, as electricity is mainly generated during the day. During this time, however, the electricity demand could be low. As a rule, the demand increases significantly in the evening hours. With a battery, you can use solar power not needed during the day when you really need it.

Without having to change your habits, you can achieve

• the sustainable reduction of your electricity bill,
• your personal contribution to the energy turnaround and the optimization of your own consumption, and
• increasing independence from the energy supplier.

For operators of private photovoltaic systems, it is now cheaper to consume the solar power themselves than to feed it into the public grid and receive the feed-in tariff for it. As a result, the demand for storage facilities has increased significantly and due to the increased own consumption, the electricity costs decrease significantly.

With access to a wide range of products from various manufacturers, we can help you find the right battery for your wind turbine or solar power systems, so it can store electrical energy to use when the solar modules or solar panels or wind turbines do not produce enough.

How much storage capacity do I need in my batteries?

The amount of capacity you need for your batteries will depend on several factors and the specific use you will make of the batteries. Here are some steps that can help you determine the right capacity:

• - Determine the purpose: What are you going to power with the batteries? It could be a house, a facility, a vehicle, electronic equipment, etc.
• - Calculate the energy demand: Analyse how much energy will be consumed by the devices or facility you plan to power with the batteries. This is measured in watts (W) or kilowatts (kW). You can consult device specifications or use energy meters to obtain this information.
• - Estimate the backup time required: Decide how long you want the batteries to provide backup power. This may vary depending on your needs and the availability of other power sources.
• - Calculate the storage capacity: Multiply the power demand in kilowatts (kW) by the required backup time in hours (h). This will give you the total capacity needed in kilowatt-hours (kWh).
• - Consider additional factors: In addition to the power demand, you should consider other factors such as the efficiency of the battery system, the depth of discharge (DOD), the ambient temperature and the expected lifetime of the batteries.

It is important to mention that, in some cases, it may also be useful to consider the charge and discharge rate batteries can handle, especially if you plan to use renewable energy to recharge them.

If you need considerable storage capacity or have specific requirements, it is advisable to consult a professional or a company specialising in energy storage systems to get an accurate assessment and a solution tailored to your needs.

What types of batteries are there and what are the differences?

There are several types of solar batteries available on the market, and each has its own characteristics and differences. Below is an overview of the most common types of solar batteries and their differences:

Lead-acid batteries:

Liquid electrolyte lead-acid batteries: These are the oldest and most common in solar applications. They have proven technology and are affordable, but are heavy and need regular maintenance, such as replenishing with distilled water.

Lead-acid gel batteries: Use a gel electrolyte instead of liquid, which makes them less prone to spills and leaks. They are more expensive than liquid electrolyte batteries, but require less maintenance.

Lithium-ion batteries:

Lithium-ion iron phosphate (LiFePO4) lithium-ion batteries: These are known for their durability, high efficiency and long life. They are maintenance-free, lighter and more compact than lead-acid batteries, and can be discharged more deeply without damage. However, they tend to be more expensive than lead-acid batteries.

Lithium-nickel-nickel-cobalt-manganese (Li-NiCoMn) lithium-ion batteries: These are a cheaper but less durable option than LiFePO4. They have a good energy density and are lightweight.

Monoblock batteries:

Monoblock batteries are generally compact units that contain multiple cells and components in a single block. They are available in various capacities and sizes, but are usually smaller and more portable compared to stationary batteries. Some monoblock batteries, especially lead-acid batteries, may require periodic maintenance, such as checking and replenishing the level of distilled water in the cells. These batteries are used in smaller, more mobile applications, such as solar power systems for caravans or boats, recreational vehicles, and residential backup power systems. They have a moderate service life and are suitable for lighter, occasional applications.

Sealed Maintenance-Free Batteries:

Sealed maintenance-free batteries, such as AGM (Absorbent Glass Mat) and VRLA (Valve-Regulated Lead-Acid) batteries, have a sealed design that prevents electrolyte leakage and do not require regular maintenance. They come in a variety of sizes and are suitable for applications where access is limited. As the name suggests, these batteries are designed to require no regular maintenance. There is no need to check or top up the water level, which makes them more convenient in many applications.  These batteries are suitable for a wide range of applications, including power backup systems, security systems, emergency lighting systems, telecommunications systems and more, where a reliable power source is needed without constant maintenance. They have a moderate to long service life, depending on the type and conditions of use.

Stationary Batteries: 

Stationary batteries are designed for stationary or fixed applications and are generally larger and heavier than monoblock batteries. They may have a sealed or unsealed construction, depending on the type, but are often used in applications where high energy storage capacity is required. Stationary batteries can be either maintenance or maintenance-free, depending on the specific type. VRLA and AGM batteries are examples of maintenance-free stationary batteries. They are used in applications where larger energy storage capacity is required and where ease of maintenance is a secondary concern. This includes critical backup systems, large-scale renewable energy systems and industrial applications. They tend to have a longer service life and are suitable for applications requiring long-term durability.

Flow batteries:

Vanadium flow batteries: Use vanadium solutions instead of solid or liquid electrolytes. They are known for their long life, flexible charge and discharge capability, and are suitable for large-scale energy storage applications, but tend to be expensive.

Solid-state batteries:

Solid-state batteries: These are under development and use solid electrolyte technology instead of liquid or gel. They promise higher efficiency, safety and longer life, but are still in the process of commercialisation and can be expensive.

The main differences between these solar batteries include lifetime, cost, energy density, efficiency, maintenance, and charge/discharge capability. The choice of solar battery will depend on your specific needs, budget and the conditions of your solar installation. It is important to consult with a solar professional to determine the best option for your project.

If you have any additional question regarding what batteries to use please contact us at info@tienda-solar.es