The greatest challenge that solar power faces is energy storage. Solar arrays can only generate power while the sun is out, so they can only be used as a sole source of electricity if they can produce and store enough excess power to cover the times when the sun is hidden.
Traditional batteries have not been up to the task, but recent innovations in energy storage are rapidly resolving the issue. Research is still ongoing, but many of the newest developments have the potential to turn solar power into the dominant source of energy. You think it’s impossible? The IRENA already confirmed in their 2014 report that it is equally, or in many cases, more cost-effective to use alternative energy for power production rather than fossil fuels.
Nature itself has provided the inspiration for one of the most promising ways to store energy. A team at RMIT University has come up with a new storage method that manages to be about 3000 percent more efficient than traditional batteries. It also has the potential to help with energy capture and storage in a variety of smaller contexts, such as cell phones, watches, and even electric cars. That widespread potential will most likely be enough to ensure that this technology gets all of the support that it needs to mature into a powerful tool.
The new method relies on the combination of a supercapacitor and a powerful new electrode. The supercapacitor works as the gateway to the new system. It can absorb and discharge energy very quickly, but it can’t store very much energy at once. Previously, that meant that they were almost useless for storing solar power. The new electrode fixes that problem. It uses a large set of repeating circuits to hold energy and carry it through the system. The new electrode is a much more efficient form way to store energy than traditional batters, both in terms of cost and space. Combining the two systems creates a system that can hold a huge amount of energy and transmit that energy with high speed and efficiency.
While most research into storing solar power focuses on finding alternatives to batteries, there are some contexts where they remain useful. Most power plants are reluctant to use batteries because they are relatively expensive and take up a lot of space compared to the amount of energy that they store. That prevents them from being viable for large facilities in most cases. On the other hand, those problems aren’t important for private homes. They don’t need to store a huge amount of energy at once, and batteries that are big enough to meet their needs are reasonably affordable. In many cases, the simplicity of using an array of batteries is more valuable than the increased efficiency of other methods.
The new Tesla Powerwall 2 is proof that batteries are strong option for storing domestic solar power. It can store more energy in less space than previous models, so it’s fairly easy to fit it into an existing home. It also includes an inverter, which is necessary to run most appliances on solar power. It doesn’t have quite as much power as most of the alternatives, but it’s more convenient than they are, which encourages adoption on a small scale.
The easiest way to store solar power is to keep it in a form other than electricity. That’s almost impossible for the average homeowner, but large power plants have been using the method for years.
Pumped storage is the oldest and most popular method. Solar energy is collected and sent out to homes as normal, but the excess is used to pump water up a tower into a storage reservoir. When the plant needs to release more energy, some of the water is allowed to flow down again to spin a turbine. This creates a temporary hydroelectric plant. A similar method uses the excess energy to heat salt, which can be used to create steam to spin the turbine.
These methods are already reliable and reasonably efficient, but they also take expensive infrastructure. That rules them out for most homes, and even for many local governments, but large organizations can build them now to meet the power needs for entire regions.
Solving the Storage Problem
All of these methods can help to make green energy available to more people, but none of them are going to be a solution on their own. They all work best in different situations, and engineers can usually get the best results by matching the storage method to the situation. The best hope for green energy is to use a mixture of these techniques and many others to maximize their efficiency.