Energy storage technology is the key to unlocking the potential of clean and renewable energy. This is because the most promising energy production sources, solar and wind, have varying energy outputs. Breakthroughs in energy storage technology will make electricity more available, reduce energy costs, and help more homes access electricity.
Why Are Energy Storage Solutions Important for Clean Energy?
Solar and wind energy are the most prevalent and promising clean energy sources today. However, these two energy production methods suffer from inconsistency in energy output. Solar energy systems are at their optimal output when there is bright sunshine. Power production goes down when there is cloud cover and at night.
Energy storage solutions enable storing energy to be drawn when the energy system is not producing optimally. This gives the solar energy system continuity and stability. Off-grid solar energy systems are very reliable when battery backup is installed.
What Are the Energy Storage Systems Available Today?
Hydroelectric energy systems are the biggest producers of energy around the world. Water is stored in reservoirs and released through turbines to produce power. Hydroelectric power stations are expensive to put up and require grid development to transfer power to where it is needed.
Thermal energy production works by storing heat in water, molten salts, or other liquid electrolyte solutions. Chemical changes in the electrolyte release heat, which then generates steam to run electric steam turbines.
Geothermal energy systems
Geothermal systems tap superheated water deep underground to run steam turbines.
Hydrogen is a combustible and light gas that makes it ideal for vehicle engines, fuel cells, and gas turbines. Hydrogen is considered clean energy because it produces water when combusted.
This is a kinetic energy storage system that produces energy by spinning a rotor in a frictionless enclosure.
Solar Energy Systems
Solar energy systems convert sunlight into electricity using photovoltaic cells. Solar systems take the biggest share of off-grid power production. Solar energy systems can be installed anywhere for different types of residential and commercial uses.
Battery Storage Technology
Batteries are electromechanical energy storage systems. Lead-acid batteries are the most common, but they face stiff competition from lighter and higher energy-dense lithium-ion and lithium-sulfur batteries.
Batteries are portable and come with lifetime charging capabilities. But they differ in energy density and cost. Batteries have become popular for energy storage because they come in different sizes, making them suitable for a wide range of applications.
Batteries can act as secondary energy storage when coupled with any of the other energy storage systems above. They are easy to install because they are plug and play. Battery storage capacity is estimated to be doubling every ten years, which has led to the cheaper, lighter, long-lasting batteries of today.
Challenges of Energy Storage Systems
Energy storage technology will be crucial in developing a renewable energy grid. In cases where grid development is too expensive, energy storage technology plays an important role in making off-grid power availability continuous. Better energy storage technology will play a crucial role in making power available in more homes. But several challenges stand in the way of energy storage technology progress.
Batteries still overwhelmingly use lithium and cobalt. These are rare and expensive materials. in the push for mass adoption of clean energy, it is doubtful that these materials would be available or last long. Batteries would also become more expensive with time as these materials become scarce.
Energy scientists are working on making batteries from cheaper materials like graphite and sodium. Sodium-ion batteries would be the ideal replacement for lithium-ion batteries because sodium is widely available for mass production at low costs.
Solar panel developers are also struggling to raise the efficiency of photovoltaic cells above the theoretical 30%. This means the current PV panels in the market are only converting 30% of sunlight into energy.
Scalability and Safety Issues
The existing energy storage technologies are relatively inflexible when it comes to scaling up and down. Batteries can deliver power up to the maximum rated output. To draw more power, you need to add more batteries or replace the battery with a higher capacity battery.
Different storage technologies face different safety concerns. Lead-acid batteries worried environmentalists because of lead toxicity when these batteries were discarded. Lithium-ion batteries are unstable in hot temperatures and can explode.
Batteries take 30-40% of total costs for energy storage systems. In 2019 Lithium-ion battery cost was $156/kWh. Energy experts opine that battery costs need to go below $125/kWh to enable accelerated energy storage system adoption using batteries for backup. Battery costs are not falling as fast as needed, and there is worry over the availability of the materials needed to manufacture these batteries.
What Are the Promising Technologies in Battery Development?
1. High Energy and Voltage Li-Ion Batteries
Research in raising the performance of Li-ion batteries is looking into how to increase cathode voltage while keeping capacity losses as low as possible. Cathodes in today’s Li-ion batteries perform in the range of 150–180 mAh/g at 3.5–3.8 V (Li), with an output lower than 700 Wh/kg oxide energy. Research goals are aiming at combining lithium and new materials that will make high voltage and energy batteries.
2. Lithium-Sulfur Batteries
The lithium-sulfur battery holds much promise because it has a higher energy density compared to other lithium combinations. But it faces performance challenges from the Li-polysulfide formation when sulfur dissolves in the electrolyte. The lithium metal anode is also prone to dendrite formation, which lowers battery conductivity. Much research is going into ways to overcome these challenges because the Li-S battery could bring down battery costs drastically.
3. Solid-State Li-Ion Batteries
Today’s Li-ion batteries use a liquid electrolyte, which is the primary cause for worry about safety. Developing solid-state electrolytes will make Li-ion batteries with increased power and energy density. These batteries will also have a longer lifetime. The research is looking into using block copolymer cathodes.
What is the Impact of Better Energy Storage Technology?
Better energy storage will change the world in a big way. It translates into better access to power for many unconnected homes and villages. With electric power come plenty of opportunities in manufacturing, entertainment, and access to education resources. For example, transport will change in a big way when planes and cars can safely use clean and renewable energy.
Here in South East Asia, power availability will come with more comfort at home with solar air conditioners. Residential power availability has a big change in health and nutrition. Families can preserve their food and medicine for longer, cutting down on wastage.
At a larger community level, reliable energy storage holds the promise of more reliable and cost-efficient microgrids. These grids serve less than 100 homes. They are easier to maintain and less prone to blackouts. They are less exposed to threats that face centralized grids, for example, terrorist threats and extreme weather events.
Energy storage technology is evolving rapidly with a higher capacity for holding energy. Cheaper costs will encourage more residential and commercial applications, changing the world in drastic ways.