Renewable sources are developing fast and are coming online quickly. This is especially true for solar panels which have come down in price considerably due to overproduction. The price of installation has also dropped, making this a very attractive clean energy option. [Engerati-Cheaper Solar Installations-Watershed Moment for Distributed Generation and Renewables].
However, clean energy sources such as solar and wind are not always generating power when we need them to. It is therefore critical that the excess power generated during sunny and windy spells is saved for when it is required.
According to the European Wind Energy Association, at the end of 2013, the UK had 10.5GW of wind turbine capacity installed, with more projects in the pipeline. As the percentage of energy generated from renewables escalates, the intermittency issue grows in urgency. Countries like Germany and Ireland find themselves in a predicament as they work towards highly ambitious renewable goals. For this reason, energy storage research and development has become central to their clean energy goals.
Germany, with the highest renewable capacity in Europe, is now experiencing technical problems as a result of its intermittent supplies from renewables. The biggest problem is maintaining a sufficient and reliable supply of power to consumers in the face of fluctuating levels of wind and solar power.
Conventional power plants do offer back-up supply in order to meet demand but because different plants take varying times to come online (48 hours for nuclear, 12 hours for coal-fired, a few hours for modern gas power plants, and 10 seconds for dam water to be released for hydropower), having a back-up constantly available means that these power plants will need to run most of the time. This can prove to be highly inefficient and costly.
The integration of renewable energy supplies into the high voltage electricity grid is another major issue. For instance, Ireland’s wind power generation is highest at night when business consumption is low. As a result, a large portion of wind energy is lost as it cannot be easily transmitted across the grid.
Energy storage is therefore vital to any future energy system that receives large quantities of variable and uncontrollable renewable energy. Energy storage will provide flexibility and will reduce the need to rely on fossil fuel back-up power.
Lots of storage variety
Today, there are a number of energy storage technologies which include direct electrical storage in batteries, thermal storage as hot water or in the fabric of buildings, using compressed air energy storage, or chemical storage (hydrogen). But, finding the most effective and reasonably-priced approach is proving to be tricky.
The right storage mix has to match the nature of the renewable energy source, the demands of the power grid, and the physical nature of the landscape and geology. Political and public opinion also comes into play. Energy storage development calls for participation from private investors, the government and the utilities. Without a clear vision from all parties, energy storage development will stall. Collaboration between all parties is key.
Another problem with energy storage is that it tends to be quite costly. But, with Tesla’s gigafactory, we may see battery prices come down significantly. Hopefully large developments like this will bring a competitive edge to the market. [Engerati-Will Tesla’s “Gigafactory” Crack the Energy Storage Market?]
Energy storage-the missing piece
So while renewables development is increasing, many governments are missing a critical piece to the clean energy puzzle-energy storage.
In Japan, 15% of supplied electricity has been cycled through a storage facility. In Europe, the figure is closer to 10%, with Germany being the leading nation.
In Germany, authorities have chosen pumped hydro storage as an energy storage solution and a regulatory framework has been developed around it.
Current UK energy storage deployment consists of pumped hydro (3,000MW), batteries (10MW) and liquid air (0.3MW). The UK’s geography restricts the possibility for pumped hydro and compressed air storage. But it’s not just the geography that is limiting options. The UK government’s current “technology-neutral” view may run the risk that some of the alternative technologies, not yet ready for deployment, will not have the support they need to develop in time to address the challenge they are required to meet.
Japan’s focus on energy storage
An analysis in 2012 indicated storage would have the greatest effect when deployed closest to demand. There may be a case for installing energy storage at the building level, in blocks of flats or residential areas, industrial estates or commercial districts – far more widely than at it is at present.
In Japan, sodium-sulfur batteries have been installed widely and successfully at the electricity distribution level. This could be an option for the UK.
The Japanese government is also supporting the installation of residential fuel cells in order to drive down prices [Engerati-Fuel Cells To Power Japan]. Between 2004 and 2008 prices dropped by 73%, and the installed base is increasing each year. This is Japanese investment that the UK (and other countries) could capitalize on. More international collaboration will be required.
The full benefit of renewable energy will not be harnessed effectively if appropriate energy storage solutions are not developed. In addition, we will never be able to reduce our dependence on fossil fuels, only accelerating climate change further.