Map of energy storage technologies
Renewable energy’s share of British electricity generation from wind and solar technologies reached record levels of 26% in the past year. This is excellent news for our national carbon emissions, but the grid is under increasing pressure to manage this intermittent power supply.
The on-and-off nature of renewable energy means that to avoid unexpected blackouts and surges it must be integrated into the national electricity grid alongside energy storage. That is the challenge that lies in the background as the UK government announced it will invest £246m in research funding on a four-year energy storage strategy focusing on battery innovation.
It is hoped that the “Faraday Challenge” will break down barriers to new battery technologies and introduce new business models. The plan is to establish a Battery Research Institute and drive innovation, particularly for the electric vehicle industry. However, the plan’s size and scope sends mixed signals to the energy storage sector and brings confusion on the longer-term direction.
The Faraday Challenge is focusing on known technology, looking for innovation in established and publicly recognised lithium-ion batteries. But on top of the well-known lead-acid (car) and lithium-ion (electronics) batteries, there are many alternative technologies for energy storage.
These include a range of other electrochemical storage devices, such as sodium-sulfur, metal-air, sodium-ion, flow batteries, and supercapacitors, as well as other energy storage devices such as pumped-hydro, flywheels, compressed-air (CAES), and superconducting magnets (SMES).
As shown in the graphic below, these technologies can be assessed by their power output and by the duration for which they can deliver this power (energy stored).
The US, Germany, Australia, South Africa, Korea and China are all ahead of the UK in lithium-ion technology. The government’s intervention is dwarfed by Tesla’s Gigafactory, built for US$5 billion (£3.8 billion) to produce half a million car batteries a year when in full production – and by the recent announcement about the world’s largest lithium-ion battery in Australia. China produces 55% of all lithium-ion batteries globally. These are daunting glimpses of the scale at which competing nations are tackling battery storage technology.
In truth though, it is not investment in more lithium-ion research that would give Britain a foothold. It should be genuinely original and fundamental research into new, breakthrough technologies, perhaps with a focus on sustainable and low-cost materials. The Faraday Challenge fund, so far, does not seem to consider real innovation, but is looking for ready-to-roll technology – it is more like a grid subsidy, cloaked as a research fund.
No surprise then, that within a day of the Faraday Challenge launch, the government announced a ban on new diesel and petrol cars from 2040, coupled with a £255m fund for councils to tackle emissions. With such a deadline – and rising demand for electric vehicles globally – is the government forcing the hand of energy storage researchers to focus solely on
lithium-ion innovation? Furthermore, the National Grid committed more than £66m to deploying medium-scale frequency response energy storage projects last year, all based on lithium-ion technology.
The Faraday Challenge fund is tentatively aimed at two niches for the UK market, automotive batteries and domestic storage. These are both sectors where lithium-ion batteries have proven to be good, albeit expensive, options when there are potentially better and cheaper candidates for stationary storage such as flow batteries or compressed air storage.
We believe that a breakthrough to new markets in energy storage will be a move away from lithium-ion – a manufacturing market in which the UK simply cannot compete globally. And if it did want to take on the well-established Asian nations, then it would need a lot more than £246m.
So which innovative fields offer a chance for leadership? Well, redox flow batteries are not included in the fund description, despite having been a leading technology for decades – and one which specifically targets the sweet spot in energy storage from very small communities to city grid scale. It was also a leading technology for energy storage more than 13 years ago.
Flow batteries work entirely in the liquid phase, with the soluble charged materials staying in solution. Unlike conventional batteries, the electrodes do not contain the active materials – and energy storage can be separated from power generation in the battery. It is much like heating water over a heating element and storing the hot water in a separate tank until it is needed.
This is a key advantage of a flow battery as it allows flexible systems to be manufactured to suit a wide variety of energy needs, from 5 kWh systems that would serve a few average homes, to 10s of MWh systems suitable for grid storage, their storage capacity being dictated by the size of the storage tank, not the electrodes.
The wealth of alternative chemistry that may be used in a flow battery is also a major selling point. The possibility of using abundant, low cost, organic materials to power the batteries is increasingly clear. But flow batteries, along with many other electrochemical storage technologies, only work as stationary storage. It seems the government’s prime concern is with the automotive industry, where lithium-ion has the edge. Long-term stationary storage is still not truly being considered.
Frankly, the UK’s investment is not enough to make a step-change in the energy storage industry. That is especially true if the genuine intention is to set up manufacturing streams, establish an institute to facilitate innovative battery research and to explore fundamental science. The government’s intentions are not clear. Are they looking to kickstart venture capital to subsidise the industry? In the first half of 2017, more than US$1 billion (£760m) was raised this way for battery, smart grid and energy-efficiency technologies in the US.
Is this a first phase of investment? How will the technology be retained in the UK once innovations are made? Does the government want frontier research and new market breakthroughs, or something quick? Those are almost always mutually exclusive. In order to establish and grow companies that will create or dominate new markets, we need long-term investment into frontier research, not a four-year business plan for tech in which plenty of other countries have already built up a commanding lead.