The term “energy storage” is one that we are going to become accustomed to in the coming decade, as the payoffs around renewable energy start to bear fruit.
Simply put, energy storage is exactly what it sounds like — capturing energy like electricity in order for it to be used later. That means if there is an excess of energy being produced through the likes of wind, then the excess can be captured in order to be used down the line or on other things that need energy.
To industry people, it seems like the advantages are self-explanatory, more bang for your energy buck and saving of costs and more. But for a consumer, is it something of which they should be aware?
If a report unveiled around Energy Storage Ireland’s annual conference last month is anything to go by, then consumers will also be winners as the burgeoning industry gets stronger.
It will also play a part in the climate crisis by reducing carbon, Energy Storage Ireland said.
The report found that energy storage could cut Ireland’s annual carbon emissions by more than 1 million tonnes and reduce annual electricity bills by more than €85m.
Head of Energy Storage Ireland, Bobby Smith, said: “Energy storage helps ensure a safe, secure, supply of electricity for homes, businesses and farms across Ireland and Northern Ireland.
“No electricity system can operate without a back-up and in Ireland this has traditionally been provided by fossil fuel generation.
“This new report from Baringa shows that over the next 10 years, we can store increasing amounts of wind and solar power in energy storage projects and use it to support the system instead of relying on coal or gas.”
In Ireland’s case, energy storage is primarily focused on electricity and ensure a secure supply. If a fossil fuel generator should suddenly stop providing electricity, there is an immediate risk to the system when replacement power must be found immediately to meet electricity demand, Energy Storage Ireland said.
That means if there is an emergency situation, energy storage projects in Ireland respond in milliseconds to ensure the lights stay on, the body said.
The most common form of energy storage in Ireland is battery storage. A battery storage project uses lithium-ion batteries, the same basic technology as is used in smartphones or in laptops, to store electricity.
When there are large volumes of wind energy on the system a battery storage project stores this power and keeps it ready for when it might be needed to keep the electricity grid secure or to respond to sudden spikes in demand.
The more energy storage we have on the system, storing electricity generated by wind or solar, the less we need to rely on fossil fuels, Energy Storage Ireland said.
Mr Smith said the crisis in Ukraine due to the Russian invasion has brought it home starkly about energy as a precious commodity, as well as the climate crisis challenge.
“The need to decarbonise our energy supply is the greatest challenge humanity faces but since the start of this year we have faced a new, different, and growing, energy crisis.
“The invasion of Ukraine and our dependency on imported fossil fuels means Irish electricity consumers have seen dizzying increases in their bills and the worst may yet be to come.
“Energy storage is an essential part of decarbonising our electricity system. It allows us to fully harness our renewable energy resources and replace expensive, polluting, fossil fuels.
“To accelerate the delivery of energy storage, we need a coordinated strategy from policymakers in Ireland and Northern Ireland to redesign the electricity market to replace our fossil fuel back-up with a cleaner, cheaper, alternative.”
In the Energy Storage Ireland report, carried out by consultancy firm Baringa, it found that: By participating in the Irish day-ahead energy market, energy storage can reduce day ahead carbon emissions by 50% by using long-duration storage technologies. This makes a material contribution to meeting ambitious 2030 power sector decarbonisation goals.
Strategic deployment of energy storage in transmission-constrained regions of the network reduces the dispatch-down of renewable generation from constraints without the need for network reinforcement, unlocking additional carbon savings.
By contributing to security of supply, helping to support renewable capacity, and displacing fossil fuels in the balancing market, energy storage can deliver a net saving to end consumers in Ireland of up to €85m per year.
These benefits are additional to the carbon, renewable curtailment, and end consumer savings offered by energy storage through the provision of zero-carbon system services.
Energy storage helps the integration of renewables at all stages by ensuring that generation is not wasted; reducing oversupply by up to 60%, constraint volumes by up to 90%, and curtailment by 100%.
The report said: “Energy storage encompasses a broad range of technologies including chemical, electrical, thermal, electrochemical, and mechanical storage.
“Each of these technologies has distinct characteristics and capabilities, such as speed of response, efficiency, and storage capacity, which means that they can provide a variety of valuable services to the Irish all-island power system.
“We have used our in-house power market modelling capability to analyse a series of portfolios of energy storage capacities and durations, though we have remained technology-agnostic across our two phases of study: We first considered the system-level benefits unlocked by the deployment of energy storage from participation in the day-ahead power market in terms of lower CO2 emissions, security of supply, and end consumer savings in 2030.
“We then analysed the strategic deployment of energy storage capacity in regions of the network with transmission constraints, using County Donegal as a case study, to determine the further carbon reductions and end consumer savings offered by maximising renewable generation in these areas.” That is where the savings to both industry and consumers came in. However, neither government in the Republic or the North have long-term capacity targets for energy storage, the report warned.
Some politicians have been listening.
In the Dáil this month, Sinn Féin TD Darren O’Rourke asked Environment Minister Eamon Ryan “the way in which he intends to build the State’s energy storage capacity which has the potential to cut annual carbon emissions by more than one million tonnes” and “if he will prepare and publish an energy storage strategy”.
Mr Ryan said energy storage encompasses a broad range of technologies that “provide a variety of critical services” to the all-island power system.
“Maintaining security of supply while integrating greater levels of renewable generation will require a very high penetration of variable electricity on the Irish grid, with increased storage capacity providing a low-carbon substitute for high greenhouse gas emitting power generation fuels, such as peat and coal.
“EirGrid has reported that a number of battery projects have been contracted via two mechanisms: SEM Capacity Auctions and DS3 Systems Services. There is currently approximately 500MW of short duration batteries on the all-island system providing system services, as well as 292MW of pumped hydro storage.
“There are also approximately 500MW of batteries either connected, or contracted to connect to the system over the next four years, to provide capacity to the all island power system. In addition, EirGrid will soon publish the final results of the second Renewable Electricity Support Scheme which makes provision to couple renewable generation with storage capability at project sites. This will help to broaden the energy mix and support security of supply.”
The Climate Action Plan (CAP) 2021 acknowledges the critical role of energy storage in supporting a power system comprised of up to 80% renewables and the need to develop storage capacity, he added.
“My Department has committed to developing an electricity storage policy framework that supports the 2030 CAP targets and supports increased storage capacity. The framework is due to be published early next year. In combination, the Commission for Regulation of Utilities will be reviewing the regulatory treatment of storage, including licensing, charging and market incentives, which is to be completed by the end of 2023.”
The Dáil exchanges follow expertise from industry leaders in Oireachtas Committees earlier this year.
President of the Irish Energy Storage Association, Paddy Phelan, laid out the picture well.
“Decarbonising electricity requires significant additional wind and solar generation and the phasing out of fossil fuel generation, with natural gas used largely as a transitional fuel until decarbonised biogas, green hydrogen or other measures come on stream.
“There are two main challenges to operating the grid primarily on wind and solar power. The first relates to grid stability. Up to now, big heavy fossil fuel-driven turbines and generators have had enough momentum to ride through the bumps.
“We now need to replace these with plants that can respond very quickly, going from zero to full output in a fraction of a second. The second challenge relates to the variable output from wind and solar generation. This variability creates the need for plants which can absorb energy when there is too much wind or solar generation to make up the deficit when there is insufficient wind and solar power to meet the demand.
“On the role of energy storage, batteries with, for example, half an hour's worth of storage can provide a very fast response to provide grid stability. Plant capable of storing 350 MW is currently in operation and this capacity is expected to rise to 600 MW by 2023, which shows that the energy storage industry can deliver and is delivering.
“The variability in output from wind and solar generation can be managed by using different technologies offering different durations of storage. These include different types of batteries, pumped hydro storage like that used at Turlough Hill and compressed air or liquid air energy storage. These can provide output for up to 12 hours, which would cover most variations in wind and solar output.”