This article was previously published in Marine Renewable Energy.
From Norwegian lakes to artificial islands or the distributed potential of electric vehicle fuel cells, it seems no notion is too far-fetched to escape the attention of power producers and grid operators seeking a means of energy storage. Naturally, however, one has to assume most of these grand ideas will ultimately never make it off the drawing board. The need for energy storage will not go away, though.
If anything, it can only grow as renewable energy production from intermittent power sources expands worldwide. So what storage concepts, realistically, will be used? Pumped hydro obviously has to be a front-runner. Already established in countries such as Norway and Spain, this is a simple, tried-and-tested approach to storing energy on a scale that is ideal for national or pan-regional grids.
But pumped hydro cannot work everywhere. In some places the orography might not be right, or water may be scarce. Sure, pumped hydro power can be imported from elsewhere, but there are limits to how far you can transport the energy before it becomes uneconomical.
So for communities that cannot develop pumped hydro power, or cannot afford the interconnectors needed to get it from abroad, or simply want a more distributed or modular form of energy storage, there must be another way. Thankfully there is: good old battery power.
The technology has tended to get bad press in the past, being knocked over issues ranging from performance (in the case of range anxiety with electric vehicles) to safety (in the case of aircraft fires caused by lithium-ion cells). But there are also a lot of positives that do not get talked about.
Grid-integrated battery arrays are already being deployed in increasing numbers not just in obvious locations such as island communities but also as part of mainstream grid infrastructure in countries such as China. There they help utilities cope with daytime shifts in energy use, deal with peak loads (thus avoiding demand response charges or substation upgrades) and help with frequency and voltage support.
And, naturally, batteries are intimately associated with renewable energy. The most obvious application is at the end-user level. Germany, for example, is experiencing a boom in battery sales linked to residential and commercial solar panel deployment, where end users are keen to increase self-consumption and minimise utility payments.
However, grid operators and renewable power producers can (and do) use battery storage to save power that would otherwise be lost during curtailment periods, as well as helping control ramp rates and fluctuations in solar or wind output.
Renewable power developers and grid operators looking for battery-based storage can now choose from a range of reliable technologies and vendors. Some of these, such as BYD of China, have an extensive pedigree in battery technology. Meanwhile others, such as ABB, may be already familiar from a grid equipment setting.
GE, to take one example, has not only consolidated its position as the world’s number one wind turbine vendor, according the 2012 figures from the analyst firm BTM Consult, but is also a significant player in energy storage.
Its Durathon battery system is the result of a USD$250 million, five-year research effort and is based on sodium-nickel chemistry, which the company says “delivers enhanced safety, performance and, with its long cycle life, value.”
For renewable energy developers, working with a company such as GE has the advantage that it is a known vendor already likely to be present elsewhere in the supply chain. In addition, these companies fully understand the needs of the energy industry. Durathon, for instance, is not just a battery but a complete offering that comes with control applications, system integration, optimisation and service schedules.
Deploying battery storage is likely to be much quicker and easier than building new pumped hydro installations. And the modular nature of battery units means the capital and running costs of an installation can be increased in line with renewable power plant build outs.
True, such installations may not have quite the grandeur of an artificial island or a pumped hydro plant concept like Gorona del Viento, which will power the entire community of El Hierro in the Canary Islands. But for easy, simple and flexible energy storage, for the time being the humble battery takes a lot of beating.