In the electricity grid, the power supply must match the demand at any given moment, requiring constant adjustments to the supply to match the demand. Typically, most electricity grids operators did not store energy because of the high expenses involved and instead relied on dispatchable, non-renewable fossil fuel power to match the demand. The advantage of fossil-fuel-powered energy is it can be turned on and off according to the demand in the grid. However, fossil-fuel-powered plants operate with maximum efficiency at full-output and maintaining the power generation facilities (peaking power plants) for generation only during peak-demand times will still add to the cost of energy; not to mention the carbon footprint from the power generation. The increased regulatory push for renewable energy as well as a rise in demand for clean energy from corporate and individual consumers have now brought renewed interest in large scale storage of energy.
The most popular sources of renewable energy; wind and solar are variable or intermittent sources of energy, dependent on weather conditions and the time of the day. Electricity generation from solar and wind sources are lowest when it is cold, dark and with low wind speeds. Also, it is during these periods that are cold, dark or without wind that the electricity needs are also the highest. Power generation from wind or solar cannot be adjusted according to the demand in the grid; meaning that a grid with a higher percentage of energy from wind or solar would require mechanisms to smoothen out the variable output. One of the solutions for this problem is the storage of the energy during peak-generation, low-demand times to be discharged during high-demand, low-generation time. The advantage of energy storage is that it can smooth out the irregular supply of energy from renewable sources and that they can discharge power to the grid much faster compared to the time it takes for fossil fuel sources to ramp up. In the modern electricity grid that aims to be fully renewable, energy storage will be the most vital cog in this balancing act to create a more flexible and reliable grid system.
As more and more nations are targeting a higher percentage of renewable or clean energy in the next decade, how far these targets would be met would depend to a large extent on the development of cheap means of large-scale energy storage. Policy-wise, Europe is getting ready for a revolution in energy storage. The European Union’s Clean Energy Package (CEP) sets an ambitious target of 32% renewables by 2030. Add to that the directives on energy efficiency, better consumer rights and creating a smarter electricity grid and market; Europe is undoubtedly positive for research and developments in energy storage.
Globally, the most used grid energy storage is pumped hydro. Compressed Air Energy Storage (CAES), flywheel storage, Hyrdogen storage, Thermal Energy Storage and a variety of battery technologies are being used with varying success in the world. Except for pumped hydro and to an extent battery storage, most other energy storage technologies are in their nascent stages and account for a minute percentage of the storage capacity. The renewed interest and investments in energy storage will spur research and development in energy storage technologies and bring the costs down. R&D in battery technologies is at an all-time high due to their applications in grid storage, electric vehicles as well as residential energy storage systems. The price of Lithium-ion batteries is now less than one-tenth of what it was a decade ago. Bloomberg projects battery storage costs to drop below $50 per kilowatt-hour by 2030. According to research from MIT lab conducted across four locations in the US, the cost of energy storage should be as low as $20 per kilowatt-hour to get to a 100 percent renewable grid.
Cheap residential energy storage and smart systems have the potential to change the energy consumption habits of customers and save us millions of euros in energy costs. Peak demands windows are brief periods of high energy consumption; typically, evenings and mornings during winter months in Europe. Residential energy storage when working together with a smart home system can change these consumption habits to save energy for the customer. Water retains heat well, which means that water heaters if turned on when electricity is cheaper, can heat and store the hot water to be used throughout the day. A residential energy storage system can charge itself when electricity is cheap and disconnect the home from the grid and use the stored power during peak-demand hours. Such systems also open the possibility for customers to become prosumers who can sell their stored power back to the grid. In the next two decades, when electric vehicles phase out internal combustion engine cars, the load from charging a large number of vehicles would fall on the electricity grid. However, the good news is that electric vehicles remain parked during most of the day and night and can be charged during the hours when electricity is cheaper.
With the rising demand for renewable energy and global sales in electric vehicles projected to keep going up, it definitely is exciting times ahead for energy storage technologies. The virtual conference, Energy Storage and Battery Solutions during the 2020 crisis bring together experts and decision-makers from leading energy and technology companies in Europe to discuss the latest technologies and explore opportunities and developments in energy storage. Connect with us to join the discussion.