One of the biggest challenges facing the renewable energy movement comes in the form of storage. It seems like everyday scientists are developing more efficient ways of harnessing the power provided by natural elements, but there still remains one elusive problem. At the moment renewable energy can only be stored on a short-term basis, and while lithium-ion batteries are rapidly gaining ground, it will take more to get renewable energy storage to the next level.
This problem is being addressed through several different projects, although it's mainly focused on a massive scale. Even though you won't be seeing any of the following systems in your home any time soon, it's good to know things are moving forward.
Storage in Hyrdostation Form
Storing energy through means of hydro tanks have been around for some time. In fact, it's probably one of the oldest methods of storing energy. The concept behind it is pretty simple, which involves pumping water into a uphill backup reservoir. When electricity is needed the water is released through a turbine. There is company in the UK called Tidal Lagoon Power that wants to build lagoons around the UK coast and hopefully create some modern hydro storage systems.
Storage in Gas Form
Several companies have invested in research related to storing excess energy in gas forum. These include the big car company Audi and Siemens, the world leader in power tools production. The aim is to substitute natural gas through electrolysis, turning the excess energy into hydrogen. The hydrogen, or rather methane, can be stored indefinitely and used on demand. Siemens is taking a slightly different route by turning the hydrogen into a clean form of ammonia, hoping to produce emissions-free fertilizer for farmers.
Storage in Air Compressed Form
This is definitely one of the more interesting ways energy can be stored indirectly. Currently there are a small number of projects that store compressed air underneath water in balloons, such as the one in Toronto Canada. Whenever the need for extra energy is needed the air is released through pipes and flows towards a turbine, which generates electricity. Unfortunately this method requires a specific rock formation, so whether it will be successful on a large scale remains to be seen. At the moment there are several big projects pending from countries like Germany and America.
Storage in Train Form
Apparently trains can also be used for energy storage and they work in a very similar way to hydro electricity. A company in Nevada (Advanced Rail Energy Storage) is currently busy constructing an uphill railroad. Heavy loaded trains will then be pushed to the top of the hill while connected to an overhead wire. When electricity is needed the trains are released down the hill and boom, energy is generated.
It's unfortunate that South African home owners won't be taking advantage of any of the above mentioned systems, but it's the mentality of these projects that really matter. Storing energy during the summer in order to use it for the winter has become a big focus point, even for guys like Musk. Won't it be nice to get solar batteries that store energy for more than just a few days? This is something that can actually happen given enough time and research.