18 May 2022

Solar farms have the potential to help you achieve net zero by 2050. However, they can’t do it alone. The issue with solar energy – similarly to wind energy – is that it’s not always consistent and doesn't always produce enough energy when demand is at its height. As solar energy starts to fall in the evening, energy usage starts to mount as consumers come home from work and go about their evening routines.

That’s where battery storage facilities come in. For a solar farm to be able to achieve optimum results, it needs to have a battery energy storage system to support it. Photovoltaic panels used in solar farms will generate different variants of energy throughout the day. Different factors will determine energy production – from the time of day to the season and whether there are any obstructions.

When installing infrastructure for solar farms, we recommend locating a battery storage facility nearby to allow a seamless transition. We’re exploring the integration of solar farms with battery storage facilities and how they can be the answer to our renewable energy needs.

What is a Battery Energy Storage System?

A battery energy storage system exists to store electricity in another energy form until it is needed, at which time it is released back into energy. The most popular choice for an energy storage system is lithium-ion batteries. It’s important to remember that no battery storage system is 100% efficient but it can make up for the drop in energy production that typically occurs at peak times.

Investing in a battery storage system allows you to increase the resilience and efficiency of the solar farm to meet the electricity demand. Every battery storage facility has a different energy and power capacity. Your developer will be able to advise you on which one is best for your specific solar farm.

There are different types of battery storage systems that are used for different purposes. In some scenarios, short-term storage is used to mitigate against any output fluctuations that may occur from passing interference, such as clouds. The most commonly used battery energy storage systems serve as long-term storage to provide electricity when there is not enough solar energy being gathered.

Why You Should Integrate Solar Power and Battery Storage

While you can develop your solar farm without a battery storage facility, you’ll be limiting the potential of your renewable energy.

Investing in the integration of solar power with a battery storage system will help to balance your electricity. Without a storage system, your electricity has to be generated and consumed concurrently, meaning that your energy potential is often curtailed to prevent it from becoming over generated and causing reliability issues. While this might sound like an ideal situation, you’ll find yourself without any energy when there is no solar power to utilise.

That’s where your battery storage system kicks in. The battery system will be charged at times when your solar panels are generating more energy than is required, allowing it to be dispensed into the battery as another form of energy. You can think of your battery energy storage facility as an insurance plan for times of peak usage.

Using battery storage systems can also help build the resilience of your solar farm to act as backup power during times of electricity outage. These systems can prove vital for essential services, such as medical facilities and communications. Storage systems can be used to scale portable power units.

Types of Energy Storage for Solar Power

For a solar farm to be successful, it needs to be paired with an energy storage system. Solar panels are typically coupled with batteries as electrochemical storage. The popularity of solar farms means that other energy storage systems are being utilised to create a fully ‘clean energy’ system.

1. Electrochemical storage

Electrochemical storage uses batteries, similar to what you’ll find in your home electronic devices and smartphones. The electricity goes into the battery, creating a chemical reaction to store the energy. When the battery is no longer being charged, this chemical reaction happens in reverse and causes the energy to come from the battery. Lithium-ion battery cells are the most popular but alternatives include sodium, nickel, and lead batteries.

2. Hydropower pumped storage

Hydropower pumped storage is a technology that utilises water. The electrical energy works to pump water into a reservoir at times when energy demand is less than the energy being generated. When the demand increases, the water flows downhill and turns a turbine, transferring the energy into electricity. This pumped storage system has been utilised for almost a century but requires significant space and natural reservoirs, either man-made or natural.

The process of establishing a pumped hydro storage system can be timely and costly. As there are more efficient alternatives available, most solar farms overlook the option of pumped hydro storage – although they could pose as a potential option for large agriculture properties.

3. Thermal energy storage

A thermal storage system utilises a fluid to store heat. Molten salt and water are popular choices for this liquid, with the thermal material typically stored in an insulated tank until demand for solar power outstretches supply. While the energy can be used to heat or cool a system, it can also be utilised to produce electricity.

When electricity is required, the heat is utilised to boil water and drive a turbine to provide electrical power. These thermal energy storage systems require a large space to be developed and aren’t a practical option for smaller solar farms.

4. Flywheel storage

Flywheel storage is a system that utilises a heavy wheel that sits on a rotating shaft. The wheel turns faster as energy is used before it is attracted into an electric generator. This generator utilises electromagnetism to control the speed of the wheel. A flywheel is ideal for short-term storage but is extremely limited in its capacity.

While these energy storage systems present an alternative, we recommend pairing your solar farm with a battery energy storage system to have uninterrupted renewable energy.