A recent report by the National Renewable Energy Laboratory (NREL) has outlined 3 emerging technologies that could boost the US’ renewable energy storage capacity up to 3,000% by 2050. High-capacity batteries with long discharge times (up to 10 hours) could be valuable for storing solar power at night or increasing the range of electric vehicles. According to recent projections, more than 100 gigawatts’ worth of these batteries will likely be installed by 2050. This could have a significant impact on the viability of renewable energy.
One of the biggest obstacles is limited supplies of lithium and cobalt, which currently are essential for making lightweight, powerful batteries. According to the World Economic Forum, around 10% of the world’s lithium and nearly all of the world’s cobalt reserves will be depleted by 2050. Nearly 70% of the world’s cobalt is mined in the Congo, where working conditions are not ideal.
1. New batteries
Scientists are trying to find ways to recycle lithium and cobalt batteries, and to design batteries based on other materials. Tesla plans to produce cobalt-free batteries within the next few years. Others aim to replace lithium with sodium, which has properties very similar to lithium’s but is much more abundant.
2. Safer batteries
One important area that is being looked into is safety. Scientists are developing solid electrolytes, which would make batteries safer. It is much harder for particles to move around through solids than through liquids but according to the World Economic Forum, encouraging lab-scale results suggest that these batteries could be ready for use in electric vehicles in the coming years, with target dates for commercialization as early as 2026.
While solid-state batteries would be well suited for consumer electronics and electric vehicles, for large-scale energy storage, scientists are pursuing all-liquid designs called flow batteries. In these devices both the electrolyte and the electrodes are liquids, which allows for fast charging. These systems are currently very expensive, however, but work is being done to try to reduce the production costs.
3. Battery alternatives for renewable energy storage
Concentrated solar power plants use mirrors to concentrate sunlight, which heats up hundreds or thousands of tons of salt until it melts. This molten salt then is used to drive an electric generator, much as coal or nuclear power is used to heat steam and drive a generator in traditional plants. These heated materials can also be stored to produce electricity when it is cloudy, or even at night. This approach allows concentrated solar power to work around the clock.
Utilities need to store a lot of energy for indefinite amounts of time. According to the World Economic Forum, this is an area where renewable fuels like hydrogen and ammonia could play an important role. Utilities would store energy in these fuels by producing them with surplus power, when wind turbines and solar panels are generating more electricity than the utilities’ customers need.
Hydrogen and ammonia contain more energy per pound than batteries, so they work where batteries don’t. They could be used for rocket fuel, as well as for shipping heavy loads and running heavy equipment. Today these fuels are mostly made from natural gas or other nonrenewable fossil fuels via very inefficient reactions.
It is now possible to make hydrogen fuel by splitting water molecules using electricity. The key challenge is optimizing the process to make it efficient and economical.
