If the sun isn''t shining or the wind isn''t blowing, how do we access power from renewable sources?
With the world''s renewable energy capacity reaching record levels, four storage technologies are fundamental to smoothing out peaks and dips in energy demand without resorting to fossil fuels.
Pumped hydro involves pumping water uphill at times of low energy demand. The water is stored in a reservoir and, in periods of high demand, released through turbines to create electricity.
Hydropower – including pumped storage – is expected to remain the world''s largest source of renewable electricity generation into the 2030s, according to the International Energy Agency (IEA). It uses the motion of water to generate electricity and plays a "critical" role, the IEA says, in decarbonizing the power system. It is also key to plugging gaps in energy demand.
While hydro is expected to be eventually overtaken by wind and solar, it will continue to play this important role as a dispatchable power source, the agency says.
Batteries have been around since the 1800s and convert stored chemical energy into electrical energy.
Advances in technology and falling prices mean grid-scale battery facilities that can store increasingly large amounts of energy are enjoying record growth. The world''s largest battery energy storage systems include the Moss Landing Energy Storage Facility in California, US, which currently has an energy capacity of 3,000 megawatt hours (MWh) but could eventually host 6 gigawatt hours (GWh) of battery storage.
Other countries investing in utility-scale battery energy systems include Australia, Germany, Japan, Lithuania and Chile
Thermal energy storage is used particularly in buildings and industrial processes. It involves storing excess energy – typically surplus energy from renewable sources or waste heat – to be used later for heating, cooling or power generation.
Liquids such as water, or solid materials such as sand or rocks, can store thermal energy. Chemical reactions or changes in materials can also be used to store and release thermal energy.
Water tanks in buildings are simple examples of thermal energy storage systems. On a much grander scale, Finnish energy company Vantaa is building what it says will be the world's largest thermal energy storage facility. This involves digging three caverns – collectively about the size of 440 Olympic swimming pools – 100 metres underground that will store heat and supply a district heating network whenever needed. Vantaa says the site could heat a medium-sized city for a year.
Underground thermal energy storage projects such as this create the possibility of storing waste heat from data centres, cooling processes and waste-to-energy sites below ground – and could have a big impact as the energy transition advances.
The global market for thermal energy storage could triple in size by 2030, according to the International Renewable Energy Agency – from 234GWh of installed capacity in 2019 to more than 800GWh.
Mechanical energy storage harnesses motion or gravity to store electricity.
For example, a flywheel is a rotating mechanical device used to store rotational energy that can be called up instantaneously.
"Flywheel technology has many beneficial properties that enable us to improve our current electric grid," says the Energy Storage Association, the US national trade association for energy storage.
Other mechanical systems include compressed air energy storage, which has been used since the 1870s to deliver on-demand energy for cities and industries. The process involves storing pressurized air or gas and then heating and expanding it in a turbine to generate power when needed.
Energy consumption and production contribute to two-thirds of global emissions, and 81% of the global energy system is still based on fossil fuels, the same percentage as 30 years ago. Plus, improvements in the energy intensity of the global economy (the amount of energy used per unit of economic activity) are slowing. In 2018 energy intensity improved by 1.2%, the slowest rate since 2010.
Effective policies, private-sector action and public-private cooperation are needed to create a more inclusive, sustainable, affordable and secure global energy system.
Benchmarking progress is essential to a successful transition. The World Economic Forum''s Energy Transition Index, which ranks 115 economies on how well they balance energy security and access with environmental sustainability and affordability, shows that the biggest challenge facing energy transition is the lack of readiness among the world''s largest emitters, including US, China, India and Russia. The 10 countries that score the highest in terms of readiness account for only 2.6% of global annual emissions.
To future-proof the global energy system, the Forum''s Centre for Energy & Materials is working on initiatives including Clean Power and Electrification, Energy and Industry Transition Intelligence, Industrial Ecosystems Transformation, and Transition Enablers to encourage and enable innovative energy investments, technologies and solutions.
Additionally, the Mission Possible Partnership (MPP) is working to assemble public and private partners to further the industry transition to set heavy industry and mobility sectors on the pathway towards net-zero emissions. MPP is an initiative created by the World Economic Forum and the Energy Transitions Commission.
Is your organisation interested in working with the World Economic Forum? Find out more here.
Energy storage was a focus at this year's UN Climate Change Conference, COP29, as delegates looked to agree on ways to support the previous COP's target of tripling renewables by 2030.
The COP29 'grids and storage' pledge includes a commitment to support the transition by increasing power system storage capacity six-fold by 2030.
Giant bricks are not what most people think of when they hear the words "energy storage", but they are a key element of a gravity-based system that could help the world manage an increasing dependence on renewable electricity generation.
Global renewable capacity could rise as much in 2022-2027 as it did in the previous 20 years, according to the International Energy Agency. This makes energy storage increasingly important, as renewable energy cannot provide steady and interrupted flows of electricity – the sun does not always shine, and the wind does not always blow. As a result, we need to find ways of storing excess power when wind turbines are spinning fast, and solar panels are getting plenty of rays.
Batteries would seem to be the obvious solution, but there are several obstacles to be overcome first, including high prices and a lack of standardization around technical requirements, as Deloitte points out.
Here are four innovative ways we can store renewable energy without batteries.
The gravity-based system mentioned above has been devised by a company called Energy Vault. It uses the energy produced when renewable generation is high to raise 30-tonne bricks into the air inside a special building.
The blocks are all stored within modular buildings that can be built up in units of 10 megawatt-hour to whatever size is required.
Hydropower is by far the world''s biggest source of renewable electricity generation.
Pumped hydroelectric storage operates according to similar principles to gravity-based energy storage. It pumps water from a lower reservoir into a higher reservoir, and can then release this water and pass it downwards through turbines to generate power as and when required.
Water is pumped to the higher reservoir at times when electricity demand and prices are low. It is released when electricity demand rises.
Pumped storage hydropower makes up 94% of the world''s energy storage, the International Hydropower Association says, adding that studies suggest a significant potential to scale this up even further.
While pumped hydro moves water upwards, compressed air energy storage (CAES) involves moving energy underground.
It works by using surplus power to run a rotary compressor that condenses air. This highly pressurized air is then packed into an underground cavern or container and can later be released, heated and expanded in a turbine to generate power.
About Energy storage devices
As the photovoltaic (PV) industry continues to evolve, advancements in Energy storage devices have become critical to optimizing the utilization of renewable energy sources. From innovative battery technologies to intelligent energy management systems, these solutions are transforming the way we store and distribute solar-generated electricity.
When you're looking for the latest and most efficient Energy storage devices for your PV project, our website offers a comprehensive selection of cutting-edge products designed to meet your specific requirements. Whether you're a renewable energy developer, utility company, or commercial enterprise looking to reduce your carbon footprint, we have the solutions to help you harness the full potential of solar energy.
By interacting with our online customer service, you'll gain a deep understanding of the various Energy storage devices featured in our extensive catalog, such as high-efficiency storage batteries and intelligent energy management systems, and how they work together to provide a stable and reliable power supply for your PV projects.
