Enabling Renewables to Power Grids

Technology enabling renewables to power grids is necessary to facilitate the green energy transition. Storelectric offers safe, clean and cost-effective energy storage at truly grid scale (Gigawatts and Gigawatt-hours).

Why is Energy Storage Needed?

Natural resources such as wind and solar are unpredictable, only generating electricity when nature’s conditions allow. This makes them unreliable and unsuitable for satisfying either baseload or variable demand, requiring costly back-up generation for when it is not available. They also have no natural inertia, so offer little grid stability.

  • Storing renewable energy for use when needed improves their un-subsidised cost effectiveness and viability.
  • Doing so with inertial systems provides cheaper and more efficient grid stability.
  • Together with renewables, such storage greatly increases the profitability of both & reduces grid reinforcement.

Batteries cannot do this: their short plant life, too-low lifetime-average grid-to-grid efficiency, lack of inertia, resource scarcity for manufacture, small size and limited capacity make them suitable for only smaller-scale work. Only by enabling renewables with effective energy storage can we achieve reliable grid stability.

Compressed Air Energy Storage (CAES)

CAES technology uses surplus low-price electricity to pressurise air, which is stored underground in very high capacity salt caverns, just as much natural gas is currently stored world-wide. When needed, this air is released to regenerate electricity. It supports all generation technologies.

Built in conjunction with renewables, CAES greatly reduces grid connection and reinforcement, and improves the profitability of both storage & generation. It is safe, far underground, and salt caverns are naturally hermetic and self-sealing.

The application has been proven in Huntorf in Germany (from 1978) and in McIntosh, Alabama, USA (1991), which are both successful and safe, but only 42-54% efficient. Storelectric’s plants will achieve close to 70% efficiency and up to 100% renewable, & provide grid stability 24/7. They can satisfy global energy storage needs: there are suitable geologies world-wide.

Graphic demonstrating how CAES technology works

Why is Storelectric Different?

Storelectric’s CAES can uniquely make both existing and renewable generation more profitable, dramatically cut emissions and provide complete and affordable energy security to countries and regions. The company is developing two CAES technologies: Green CAES based on Thermal Energy Storage (TES) and dual-fuel Hydrogen CAES. A CCGT Hybrid version is more efficient, lower emissions and more powerful than Hydrogen CAES. All can deliver real inertia, reactive power/load, voltage/frequency control – all 24/7 – and Black Start. This makes a reliable and resilient energy transition and Net Zero grid much more affordable and less disruptive.

All plants are low-risk simplifications of existing plants that have run for decades, using off-the-shelf equipment well proven in power generation & other industries. Green CAES has been validated by Costain, Arup, Mott MacDonald, Fortum, Mitsubishi Power (MP), Siemens and others; a 40MW first-off commercial plant is planned. H2 CAES is like a CCGT, so a small plant is not needed; also validated by MP. There is no technical reason not to build a first plant each at large scale (100s MW or more).

Storelectric has a developing consortium of blue-chip multinational partners, with land and salt caverns ready to go, and supportive planning authorities. There is great interest in financing follow-on plants world-wide. Global market potential for peak smoothing alone is 1,750GW (>$1trn capex, $10trn p.a. opex), with first-mover and technology advantages. Siemens and MP say that they can build them with their current range (others can too); MP will consider offering EPC performance guarantees on the first.

Projects using any of our technologies are eligible for approval as Projects of Common Interest in the 35 European countries of ENTSO-E, giving access to the multi-€bn Connecting Europe Facility and ECB funding for energy, and assistance with permits: one has already been approved. This shows that it is important infrastructure at a continental scale.

The European Opportunity

Most European countries are decarbonising fast. To power grids mainly by wind and solar would require tripling or more the grid’s size to take the intermittency of renewable generation, as well as procuring the balancing and ancillary services. If the renewables are connected through our storage, most of this would not be required.

Any project that is still in the study or prestudy phase and is on the salt basin (see map) will be of interest: project lead times are 3-7 years (mainly due to the time to make the caverns), therefore take longer than the wind and/or solar farms. Storelectric’s technology is much less affected (e.g. efficiency, cooling) by heat than are batteries, and deliver (concurrently with balancing and ancillary services) all the stability services that the grid will start to need when renewable supply exceeds ~25% of grid demand.

Potential Locations

Initial locations will use salt caverns for their air storage: these are man-made cavities within the salt basin. The general areas of salt basin are in this map; specific locations need to be validated geotechnically. Salt basins and other hard rock geologies (mines etc.) are suitable for 4-12 hour storage durations. Longer storage durations will be provided by storing the air in porous rocks, e.g. saline aquifers, depleted hydrocarbon wells; they need to be developed, whereas salt caverns are well known as ~⅓ of Europe’s natural gas stocks are held in very similar caverns, and they are widely used in the petrochemicals and other chemicals industries.

The Opportunity

Enabling renewables through Storelectric’s CAES technology offers all European countries the opportunity not only to decarbonise affordably, reliably and resiliently, but also to lead the world in the energy transition.

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