Firming Renewables
Key requirements that impact hydrogen storage for renewable firming
Safety is important because in new grid architectures, storage will often be close to people and infrastructure.
Tolerance for variable hydrogen feed rates is important because the electrolyzers, which produce the hydrogen, are powered by constantly varying renewable generation. Systems which can’t tolerate variable hydrogen feed rates, like ammonia synthesis or systems like some LOHCs, that use catalysts (which degrade rapidly under heat cycling), will perform well below optimum capacity and require more frequent maintenance.
Scalability is important because electricity systems can scale from tiny mini-grids with a load of a few 10’s of kilowatts (kW) to major hubs requiring 100’s of megawatts (MW); and storage needs that scale from megawatt hours (MWh) to terawatt hours (TWh).
Ease of Transport is important because the ability to transport energy from one location to another, without requiring poles and wires substantially improves the economics of renewable generation.
Microgrids
Within the Renewable Firming market Carbon280 are focusing on the needs of Microgrids. This is for three reasons:
Microgrids are the future of all electricity networks. See “What’s the big deal about Microgrids”.
The Microgrid market is at $28.6B market (2020) with a compound annual growth rate of 10%. Although Global Market Insights have put the CAGR at 24%. The microgrid market is leading the transition away from fossil fuels.
The Microgrid market is an ideal “beachhead” market, where we can trial the technology on small scale isolated grids and then progress to larger integrated grids on the back of those successful trials.
What’s the big deal about Microgrids?
In their submission to Western Australia’s Economics and Industry Standing committee Horizon Power say:
“Australia’s electricity systems, however, are now confronting the most transformational period of change since Edison and Tesla kick started the industry in the late 1800’s… [and] these changes, also being experienced around much of the world, are driving the need for entirely new system architectures designed to harness the full potential of a high-DER [Distributed Energy Resource] future.
In this context, Horizon Power is leading the development of ‘advanced’, microgrids as a fundamental building block of low-cost, high-DER electricity systems.”
What is a microgrid?
A microgrid is a small electricity grid that may or may not be connected to a separate network. Isolated microgrids may service a remote mainland community, an Island like Australia’s Lord Howe or a mine. Connected Microgrids are integrated into the larger grid, but can function independently of the main grid and are more resilient to extreme events like bushfires. As a consequence companies like Google, Facebook and Microsoft are moving their Californian data centres to microgrids. In December 2020 the US administration increased funding for microgrids.
In Australia, Western Australian utility Synergy says “microgrids could be the next big thing” because they provide resilience and make it easier to manage distributed energy generation and distributed storage and will drive down costs.
Globally, microgrids are the future of major grids because they offer improved resilience and make it easier to integrate renewable generation.
Traditionally microgrids are powered by fossil fuels such as diesel or gas. However, increasingly microgrid developers are looking towards renewables.
Eliminating fossil fuels from electricity generation
The combination of renewable generation with lithium batteries has got us tantalizingly close to zero carbon, 100% renewable electricity grids. But completely getting rid of our dependence on fossil fuels for electricity generation, is surprisingly hard.
While wind and solar can generate very cheap carbon-free electricity, they can only do so while the sun is shining or the wind is blowing. Fortunately, lithium batteries can be charged with surplus electricity also known as “spilled energy”, which is the electricity being generated by the renewables that exceeds the demand of the microgrid and which is otherwise wasted.
However, the energy that batteries can store is limited to around 4 hours at full power and for a typical microgrid in Australia there are usually a few periods during the year where there is insufficient sun or wind to meet the grid load. Carbon280 modeling shows that energy debt can accumulate to over 120 hours for solar only grids. Adding additional batteries can be enough to last the night, but buying enough batteries to last 120 hours is completely uneconomic. And it is because of this, that even modern micro-grids like Google’s or that on Lord Howe Island still rely on diesel fuel for backup.
Hydrogen is the answer for longer duration backup
According to a 2015 study by Oliver Schmidt from Imperial College London, “excluding pumped hydro and compressed air energy storage, which have limited geographic suitability [and are not scalable for microgrids], hydrogen storage is already most cost efficient in 2015 for discharge durations beyond 1 day.”
Green hydrogen is produced by using electrolysers that split water – H2O - into hydrogen and oxygen and is powered by surplus electricity from renewable generation. At a later stage the hydrogen and oxygen can be used in fuel cells, engines and turbines, to make electricity. But while electrolysers, and fuel cells are commercially available, the missing technology piece in the hydrogen supply chain is hydrogen storage. And this is all to do with the special nature of hydrogen.
As the graph on the left shows, while hydrogen is the most energy dense fuel available – 1kg of hydrogen contains nearly 3 times the energy of 1kg of diesel. On a volume basis, the situation is reversed; liquid hydrogen has a density of 8 MJ/L whereas gasoline has a density of 32 MJ/L, and it takes an enormous amount of energy to liquefy hydrogen because it is such a light gas. We need a way to compress hydrogen into a smaller space economically.
This is the problem that Carbon280's HydrilyteTM hydrogen storage system solves.
Hydrilyte™ Hydrogen Storage System
Hydrilyte™ enables Zero Carbon electricity
Renewable firming products
Hydrilyte™ Storage Systems for Microgrids
Our HydrilyteTM Storage Systems will be fully containerised so that they can be delivered to site and quickly installed. The HydrilyteTM Microgrid Storage Systems will remotely monitored and alarmed. They are being designed to be maintained by an up-skilled diesel mechanic to facilitate the transition of maintenance to the Utility responsible for the microgrid.
Hydrilyte™ Storage Systems for Major grids
Our Major Grid product line will be modularised to facilitate transport to site and efficient assembly. The Major Grid product line will be available as a multi-train batch system or multi-train continuous system.