June 24, 2026
When most people picture grid storage, they picture warehouses of lithium-ion battery packs. Daniel Roscoe, CEO of Roswall Development, pictures something a lot more familiar: the white cylinder in the basement.
“We have 500,000 hot water tanks in this province,” he told host Claire Quirion on Episode 75 of All Hands on Tech, “and pretty much every single one of them just turns on when you have a shower.”
That sounds mundane. The implication is not. If even a slice of those tanks could be told to heat up at noon, when there is solar on the grid, or at 2 a.m. when the wind is strong, the province gets a distributed thermal battery without anyone installing a new piece of hardware.
Roscoe has been building renewable energy projects in Nova Scotia for almost two decades. For him, this is where the next chapter of the energy transition actually happens. Not just bigger turbines. Smarter use of what is already plugged in.
The shape of the problem
Most of what Nova Scotians use energy for is heat. Heating the house, heating water, sometimes cooking. Heat is also, in Roscoe’s words, the unsexy cousin of lithium-ion in the storage conversation.
“A lot of focus on batteries and things like that for storing energy,” he said on the episode. “But most of what we use energy for in Nova Scotia is heat. Storing heat is really important, and something I want to see a whole lot more of in the future.”
The “when” is where it gets interesting. Right now, peak demand on the Nova Scotia grid lands first thing in the morning. Showers are done, hot water tanks across the province kick on at roughly the same time, and the system has to find energy to meet that spike.
“That could heat up at 12 o’clock or 3 o’clock,” Roscoe said, “once there’s a lot of solar, or if it’s windy, or at night, and give people the same quality of hot water. But if that can be more flexible, we can use that to smartly balance things like wind and sun.”
In grid-operator language, that is a demand-response asset. In household language, it is the same hot shower at 7 a.m. The tank just chose a different hour to do its heating.
Why this is suddenly possible
The piece that makes any of this work is the smart meter. Roscoe noted on the episode that every Nova Scotia electricity customer already has one unless they actively opted out. That is the infrastructure layer many places are still trying to roll out, and it is largely in place here.
The second piece is software. Roscoe pointed out that a wind turbine installed today has roughly 30 times more data points on its control system than one installed ten years ago, and that the turbines check voltage and frequency many times every second to stay in sync with the grid, which runs at 60 cycles per second. The same digital nervous system that runs a modern wind farm can, in principle, coordinate a fleet of household appliances, deciding when each one draws power so that supply and demand line up better.
That kind of orchestration is what people mean when they say “smart grid.” Roscoe’s framing makes it less abstract: it is a piece of software deciding that the most useful moment to heat a tank in Dartmouth is 2 p.m., not 7 a.m.
What this connects to
Renewall Energy, the retail company Roswall built around its renewable-to-retail licence (awarded in 2021), is the buyer for the Mersey River Wind project, a 33-turbine, 148.5-megawatt wind farm going up on former forestry land in Queens County, on Nova Scotia’s South Shore. Renewall will be the first supplier in the province to buy a wind farm’s output and sell it directly to customers rather than through Nova Scotia Power.
Halifax Regional Municipality is the anchor customer. The agreement, announced in early 2025, covers about 33,000 megawatt-hours per year, roughly 45 percent of HRM’s corporate electricity across more than 200 municipal meters, and is expected to cut HRM’s corporate emissions by about 24 percent. As of the episode, more than 30 customers had signed on, spanning municipalities, real estate, seafood, forestry, manufacturing and clean tech.
Renewall plans to provide 100 percent renewable power to the customers who sign up. That commitment is what makes flexible loads valuable. If the company has to match wind and sun output to actual customer demand, every flexible appliance, every hot water tank, every EV charger, every electric heat system, becomes a tool for hitting that match.
Roscoe sees the same logic extending outward. He noted on the episode that around 250,000 Nova Scotia homes still heat with oil, and converting those to electric heat would mean another large pool of flexible demand the grid could orchestrate. The household appliance becomes part of the system, not just a load on it.
The takeaway for tech-curious Nova Scotians
For anyone in software, data, or systems engineering, the interesting part is not the turbine. It is the layer above it, the controls and analytics that decide what happens when. Clean energy in Nova Scotia is increasingly a software field. The hardware is settled. The optimization problem is just getting started.
And the most interesting batteries in the province may already be sitting in basements.
To hear the full conversation with Daniel Roscoe, listen to Episode 75 of All Hands on Tech, available wherever you get your podcasts.