Renewable energy, by nature, is unreliable.
Solar panels require sunlight, wind turbines require wind, hydroelectric requires flowing water and so on. Unfortunately, not all of these are always readily available. In somewhere like Scotland, which is a generally cloudy country, solar power isn’t a preferable choice of renewable energy. California’s drought is wreaking havoc on the hydroelectric industry.
On the other hand, sometimes there can be abundance of sunlight or wind, which results in the production of more energy than needed. Currently, this excess energy is often times not being used and is essentially wasted. This is often a major criticism of renewable energy and one the industry has been working to address for some time.
As it turns out, the solution is a concept we’re all familiar with: storage.
Saving it for Later
While the science and engineering behind energy storage is quite complex, the idea is simple. For example, a solar farm with a storage system–say, a large battery–can save up that extra energy generated during sunnier days and use it on the days on which less energy is generated. This solves much of the problem with the intermittency of renewable energy.
The applications are also extremely broad, with storage serving a purpose in both the commercial and residential sectors. In the residential solar sector, storage is expected to see a tenfold growth by 2018. In part, this is because the incentives to have a home solar storage system are so great. Not only does it allow for energy independence during times of crisis, but even using stored energy daily rather than buying energy from the grid can lead to major cost savings.
Read more here: http://www.energydigital.com/renewables/3746/Why-Storage-Matters