The Future of Batteries: a Distributed Approach to Energy Storage
Written By: Edward Colby
The energy generation landscape is changing rapidly. On the one hand, demand is growing as population increases and more nations industrialise. On the other, the supply side is making use of more forms of renewable and intermittent energy sources, such as wind and solar. While electricity storage has long been regarded as an important, albeit expensive and difficult solution to grid balancing, this dual challenge means that we now require more efficient methods of energy storage than ever before, especially at times of peak demand. Fortunately, technology advancements have brought more cost-effective options, particularly in the field of batteries, to the fore.
Energy storage units are already in use to contend with intermittent supply, with large-scale batteries being employed to stabilise intermittent power generated via wind farms. These energy storage units can also be employed to back up a grid shortfall and cover for downtime, and are typically formed of either banks of lead acid batteries (~1MW), NaS (~10s of MW), or lithium ion batteries (~10s MW). These back-up batteries can be made portable, and transported (often by lorry) to areas as required for use by electricity aggregators needing to provide extra power in times of shortfall.
A further method being considered for the future is that of distributed storage, under which much smaller battery units are used by individual households and, when interfaced with other similar deployments situated nearby, can offer a capacity that would be both flexible and large enough to cover peak demand within a locale. The battery units would be lithium-based technology, but in much smaller quantities that do not require the specialist delivery and installation of large-scale options. These units are designed to provide the highest power densities available of current technologies, but would be small enough to store in areas such as a garage.
Battery technology is available to provide this type of distributed storage function, however, what is needed for widespread adoption is for specialists to develop technology that provides improved cost per cycle, which battery manufacturers are pushing to achieve. In addition it requires specialist development of low cost, efficient power electronics.
SEE OTHER TOP STORIES IN THE WDM CONTENT NETWORK
To implement an efficient distributed storage network, we need to be able to exchange energy between the generating source, grid and storage units with minimal losses, and a round trip efficiency of 90 per cent is a realistic but challenging target. This would allow users the flexibility to power items such as an electric vehicle, or enable the grid to draw on the distributed storage in times of peak demand or power losses and ensure we keep the lights on.
These energy storage units can be configured so that users can make choices about how they use their generated and stored energy, for example, allowing it to be returned to the grid in times of over supply – perhaps for a profit – or using it themselves. Certainly, it is possible that local areas could become energy self sufficient by employing a high concentration of energy storage units in combination with generators using renewable power sources such as wind and solar. If enough of them were in play, multiple small storage battery units could provide a backup to the national grid at times of peak demand. They could also form part of a ‘smart home’ architecture, whereby the energy storage interface can ‘learn’ to automate the best energy storage and usage patterns for the individual’s circumstances. This home hub could, for example, ensure that the user benefits from the best tariffs in return for feeding energy back in to the grid, or enable charging of their electric vehicle at the most economically attractive time.
We are reaching a point where the technology is affordable, and the lifecycle sufficient. Transmitting power from the grid with a low cost, reliable power converter to a battery storage unit and vice versa, on demand and efficiently, is the next battery challenge. With a smart approach, and the application of sophisticated power electronics technology to achieve it, distributed energy storage could be a reality very soon.
Major move forward for UK’s nascent marine energy sector
Although the industry is small and the technologies are limited, marine-based energy systems look to be taking off as “the world’s most powerful tidal turbine” begins grid-connected power generation at the European Marine Energy Centre.
At around 74 metres long, the turbine single-handedly holds the potential to supply the annual electricity demand to approximately 2,000 homes within the UK and offset 2,200 tonnes of CO2 per year.
Orbital Marine Power, a privately held Scottish-based company, announced the turbine is set to operate for around 15 years in the waters surrounding Orkney, Scotland, where the 2-megawatt O2 turbine weighing around 680 metric tons will be linked to a local on-land electricity network via a subsea cable.
How optimistic is the outlook for the UK’s turbine bid?
Described as a “major milestone for O2” by CEO of Orbital Marine Power Andrew Scott, the turbine will also supply additional power to generate ‘green hydrogen’ through the use of a land-based electrolyser in the hopes it will demonstrate the “decarbonisation of wider energy requirements.”
“Our vision is that this project is the trigger to the harnessing of tidal stream resources around the world to play a role in tackling climate change whilst creating a new, low-carbon industrial sector,” says Scott in a statement.
The Scottish Government has awarded £3.4 million through the Saltire Tidal Energy Challenge Fund to support the project’s construction, while public lenders also contributed to the financial requirements of the tidal turbine through the ethical investment platform Abundance Investment.
“The deployment of Orbital Marine Power’s O2, the world’s most powerful tidal turbine, is a proud moment for Scotland and a significant milestone in our journey to net zero,” says Michael Matheson, the Cabinet Secretary for Net-Zero, Energy and Transport for the Scottish Government.
“With our abundant natural resources, expertise and ambition, Scotland is ideally placed to harness the enormous global market for marine energy whilst helping deliver a net-zero economy.
“That’s why the Scottish Government has consistently supported the marine energy sector for over 10 years.”
However, Orbital Marine CEO Scott believes there’s potential to commercialise the technology being used in the project with the prospect of working towards more efficient and advanced marine energy projects in the future.
“We believe pioneering our vision in the UK can deliver on a broad spectrum of political initiatives across net-zero, levelling up and building back better at the same time as demonstrating global leadership in the area of low carbon innovation that is essential to creating a more sustainable future for the generations to come.”
The UK’s growing marine energy endeavours
This latest tidal turbine project isn’t a first for marine energy in the UK. The Port of London Authority permitted the River Thames to become a temporary home for trials into tidal energy technology and, more recently, a research project spanning the course of a year is set to focus on the potential tidal, wave, and floating wind technology holds for the future efficiency of renewable energy. The research is due to take place off of the Southwest coast of England on the Isles of Scilly