Tag Archives: Hydrostor

Enbridge, Hydrogenics partner for utility-scale energy storage for renewables

UPDATE: My Clean Break column this week has some more detail.

Oil and gas pipeline giant Enbridge Inc. has invested $5 million in Mississauga, Ont.-based Hydrogenics, a leading maker of proton-exchange membrane fuel cells and electrolysis systems for producing hydrogen gas from water.

Gotta say, I wasn’t expecting this announcement. I know Enbridge has invested in fuel-cell technology before, and I know it has purchased hundreds of megawatts of solar capacity, operates wind farms and is dabbling in geopower. And yes, it has invested some money into Toronto-based Morgan Solar. What surprises me about this announcement isn’t so much the investment itself, but how Enbridge plans to strategically collaborate with Hydrogenics to bring utility-scale energy storage to renewables in Ontario. You’d think this was about using renewables to generate hydrogen during off-peak hours, storing it, and then putting it through a fuel cell to generate electricity during peak hours. And perhaps this is the longer-term vision. But the way Enbridge describes this collaboration, it has little interest in fuel cells. Instead, it wants to generate hydrogen and inject it into its natural gas pipeline assets, “proportionally increasing the renewable energy content in natural gas pipelines.” In other words — the way I read it from the press release — it wants to reduce the carbon intensity of the natural gas in its pipelines by mixing it with hydrogen. That cleaner natural gas will then be burned in natural gas-fired plants, people’s home furnaces, etc…

Perhaps I’m missing something. If there’s someone from Enbridge reading this, please correct me if I’m wrong.  (I’m right).

Here’s how the two companies describe their “Power-to-Gas” strategy in their press release:

With ‘Power-to-Gas’, the hydrogen produced during periods of excess renewable generation will be injected into the existing natural gas pipeline network, proportionally increasing the renewable energy content in natural gas pipelines for essentially the operating cost of the electrolyzer. Small quantities of hydrogen can be manageable in existing natural gas pipeline networks. With the significant scale of the natural gas pipeline network, these same quantities of hydrogen have a very meaningful impact on electricity energy storage potential.  The natural gas pipeline network represents a vast energy storage system which already exists. The utility scale energy storage leverages existing natural gas pipeline and storage assets to enable improved operability for the electrical system. Furthermore, the economics are further improved by leveraging existing gas generators to bring this renewable energy back to the electrical grid where, and when, it is needed most.

The companies said they will initially focus on Ontario. And Hydrogenics will have the opportunity to participate in up to 50 per cent ownership in a build-own-operate model for energy storage services. I have no clue how the economics will work. I mean, if the hydrogen is being blended with natural gas how can Enbridge capture that value when it sells that gas? How will this work with Ontario’s feed-in-tariff program, which doesn’t have any rules or tiered (peak, off-peak) FIT rates to encourage energy storage services? I’m very curious to learn more about this (and will over the coming days).

What’s clear is that there is momentum building for energy storage solutions in Ontario. Hydro One is testing out Temporal Power flywheels to relieve congestion on its transmission lines. Toronto Hydro is piloting bulk lithium-ion battery storage and testing underwater compressed-air storage in Lake Ontario. Annette Verschuren, former chief executive of Home Depot Canada, is heading up a new venture called NRStor that wants to bring an energy storage park to Ontario. And word has it that the Ontario Ministry of Energy — or the Ontario Power Authority — is sitting on a large draft policy paper related to energy storage that will be released later this year. Perhaps we’ll get some clarity around energy storage after all. There seems to be enough activity in the province to suggest that something is going on behind the scenes to stimulate strong interest in energy storage.

We’ll see.

NOTE: Just got my hands on a backgrounder Q&A from Hydrogenics that explains the above in more detail. A few interesting points, according to this backgrounder:

Injecting only small amounts of hydrogen into the gas grid (less than 5% by volume) offers significant potential. In large markets, like Ontario, the energy storage potential could provide power for over 160,000 homes. This is the equivalent of the new Niagara Tunnel hydro power project in Niagara Falls.


Every GJ of hydrogen produced by a Power-to-Gas application converting surplus renewable generation will displace one GJ of natural gas consumption with a commensurate reduction of 56kg of CO2 equivalent. The estimated annual GHG reduction from a 100MW Power-to-Gas project would be 25 CO2 equivalent kilotonnes.


The first stage will be to develop a 1 MW Power-to-Gas pilot project in Ontario to test the integrated system, develop gas network interconnections and work with the IESO and Canadian Gas Association to design the operating standards and market protocols to run a Power-to-Gas application. After developing commercial scale electrolyzer capability, Hydrogenics will have the opportunity to participate in up to 50% ownership in a build own operate model for energy storage projects with Enbridge.

Underwater compressed-air energy storage: Could it work?

My Clean Break column in today’s Toronto Star begins with a look at Toronto-based Hydrostor, an energy-storage startup with a unique idea. Hydrostor’s concept is simple, in many ways. It starts with big tubular balloons the size of a bus submerged 80 meters or more under water — anchored, for example, to a lake bed. On the surface a compressor system uses off-peak, low-cost electricity to pump air into the balloons at high pressure. As the balloons or bags expand the weight of the water above them compress the air. When electricity needs to be dispatched, the air is let out of the balloons and piped back to a turboexpander turbine on the surface that generates power. The company figures about 200 of these balloons, called accumulators, would create a system big enough to supply 2 megawatts for four hours. As far as cost goes, it would fall between conventional pumped storage and conventional compressed-air storage (in salt caverns), according to Hydrostor CEO Curtis VanWalleghem.

Neat idea — though obviously studies would have to be done to assess environmental impacts on the body of water. Still, the fact that 50 per cent of ther world’s population is located near bodies of water, and the fact that Hydrostor’s system uses off-the-shelf components and is highly scalable, this could be a nice niche in the emerging market for grid-scale energy storage. VanWalleghem estimates at this point that the round-trip efficiency of the system is in the ballpark of 70 per cent, which is competitive with other storage technologies, such as zinc-bromide flow battery systems offered by companies such as Premium Power.

The rest of my column urges Ontario to begin taking a more serious look at the regulatory and policy changes required to enable the integration of new technologies into the provincial grid.