What if your backpack supported a tiny, collapsable wind turbine, charging your phone while you hiked? Could mushrooms be grown and dried in the shape of houses, putting roofs over heads without felling trees? Might we extract geothermal power from pools of water at the bottom of abandoned mine shafts?
These are some of the quirky notions bouncing around the Applied Energy Research Lab of the Nova Scotia Community College (NSCC), where a team of researchers and students directs its brainpower to the climate crisis. Governments and businesses bring their ideas and money and the lab does the math, runs the experiment, or builds the prototype — in so doing, advancing technologies that cut carbon emissions in the province.
“When the push to make our electrical grid renewable started (between 2009 and 2011), it was about 80 per cent coal,” said Wayne Groszko, research scientist with the Applied Energy Research Lab. “We’re probably around 40 per cent coal today, which tells you there’s been a lot of progress. But the hardest part has yet to be done.”
The handy thing about coal is that it can be burned to produce power right when you need it. Renewables, such as wind and solar, are cheaper, cleaner and more efficient — but their output changes due to weather and time of day. Installing enough wind and solar to displace our remaining coal isn’t the problem. The problem is storing renewable power during periods of overproduction and deploying it during periods of underproduction. In Nova Scotia, said Groszko, existing wind turbines already can, at times, produce more power than the grid can use.
“It’s not that there’s a scarcity of renewable energy anymore,” said Groszko. “It’s that there’s a surplus at certain times.”
Cracking this nut — of storage and deployment — would mean getting more renewables on the grid, and several of the technologies the Applied Energy Research Lab has been toying with address exactly this issue. One of the most promising, says Groszko, might be your water heater.
If equipped with a controller, this simple household appliance could be turned on and off at the whim of Nova Scotia Power, allowing the utility to store excess renewable power as hot water precisely when that power’s being generated. Because most tanks hold 40 to 60 gallons, the customer would never notice the difference.
“One water heater is insignificant,” said Groszko, “but there are easily 160,000 in Nova Scotia.”
He envisions a program in which the provincial government pays to upgrade existing water heaters with controllers, participating customers receive a credit on their monthly electricity bill, and Nova Scotia Power gets a place to store excess power, available for deployment (showers, etc.) as needed.
This is how a “smart grid” works — and water heaters are just the start. Two companies —Neothermal Energy in Nova Scotia and Stash Energy in New Brunswick — are augmenting heat pumps with sodium acetate trihydrate, the same material used in handwarmers. It allows heat pumps to “store” hours worth of space heating, which means they, too, could become a reservoir of excess renewable power for later deployment.
Then there are EVs. Electric passenger vehicles support lithium-ion batteries of 60 to 90 kilowatt hours each, enough to power a house (with some rationing) for three days. These are tempting places to dump excess power, but the Applied Energy Research Lab has also been experimenting with “bidirectional” EV chargers. These allow power to flow both ways, such that grids can charge EVs and EVs can charge grids. This turns all EVs, whether car, truck, school bus, or lobster boat, into a province-wide renewable energy storage system.
“These technologies certainly work,” says Groszko. “And they’re practical now, at least some of them. But it’s actually really hard to beat a very old solution to this problem, and that’s pumped hydro.”
Essentially a hydroelectric dam in reverse, pumped hydro is where excess power is used to pump water from a downhill reservoir to an uphill one. When the grid needs that power back, water is sent back downhill, running a hydroelectric generator. Pumped hydro facilities can be thought of as giant batteries, with the first being built in the late 1800s, and the largest in the 1980s. They can store power at scale and last for centuries.
“A network of mid-sized pumped hydro facilities could probably meet all our storage needs in Nova Scotia,” says Groszko, who points to the Cape Breton Highlands and Cobequid Mountains as promising places to build, provided there’s a thorough regulatory framework, environmental assessment process and public “social license.”
“Wind and solar are on their way now,” he says. “The question is no longer how we’re going to affordably make enough wind and solar power. That’s happening. The question is, how are we going to use it all? I think Nova Scotia’s up for this.”
The Climate Story Network is an initiative of Climate Focus, a non-profit organization dedicated to covering stories about community-driven climate solutions.
Comments
I'm all for innovation in solution finding, but I’m equally fond of clarity and honesty in messaging; the messaging example of residential hot water tanks as an electricity storage vehicle is, frankly, silly.
It's not the case that there is a fleet of hot water tanks sitting around, filled with water at ambient temperature, waiting for that surplus power to arrive. (Sorry, honey, you'll have to shower cold today cuz, darn it, there was no surplus power overnight”). Everyone's hot water tanks will contain – who’d of thought -- hot water. I suppose the water could be overheated, even beyond boiling point if pressurized (to what purpose?). Further, once that surplus electrical energy has been converted to (now surplus?) heat, how is it proposed to convert it back to electricity?
The only seemingly plausible explanation, to my somewhat informed mind, for this HWT example is that it’s a backdoor way to get people to accept allowing power utilities to have real-time access to the on/off switches on their appliances that consume significant energy (HWT, A/C, electric baseboard heaters and furnaces, clothes dryers). The traditional framing in that case is that there is sometimes a lack of electricity and, at such times, there is a need to systemically (i.e. centrally) manage real-time demand by messaging thousands of individual homeowner appliances to shut down for a short time.
Some organizations are trying to gain that consumer acceptance by being upfront and knocking on the front door.
https://userstcp.org/the-academy/
https://www.google.com/search?q="Leonardo+energy"+electricity+demand+side+management
Pumped hydro is great but, my Spidey Sense having been triggered by HWT nonsense, its mention here makes me wonder as to the reasonable maximum amount of such storage available in Nova Scotia (dispatchable GWh) while leaving ecosystems sufficiently intact.
The further example of a surplus of electricity converted to chemical potential is also great, when on-demand heat is useful (generally in winter). I suppose one could envision such chemical energy firing the boiler of a steam turbine generator (much like concentrated solar) given sufficient quantities of the chemical and temperature differentials?
To be clear, it’s not the energy reality that is my target here, it’s the hype and horn blowing in the reportage.
Only a few degrees of extra heating in a hot water heater would be useful. It takes about 0.3 kWhs to heat 60 gallons of water one degree Celsius. Allowing for an extra 3C of heating occasionally would never be noticed by the resident but it would give the utility a place to send a kWh. Multiply that by 100,000 hot water heaters and that's 100 MWhs of storage. That's a lot! The energy doesn't get turned back into electricity. It just gets used as hot water by the resident. They use the same amount of electricity and get a discount for a allowing the utility to do it. Pretty elegant solution.
I take your point but I wouldn't call it "storage"; it's getting some marginal benefit from electricity that, if actually stored for future use as electricity, would be actually useful.
The customer wouldn't be using the same amount of electricity, they'd be using more. Which is why we are regularly told to turn down the thermostat setting on our HWTs; less cumulative energy is used when the target HW temperature setting is lower (with various, situational caveats).
Elegant this isn't. It's a marginally beneficial placeholder waiting on a better idea.
IMO.
Yes, it's storage. The hot water heater would not stay 3C warmer in my example. It would gradually reduce to its normal set temperature. The effect is to store energy as heat for a few hours. The customer uses the same amount of power because the electricity used to heat the water up a little higher reduces the amount of electricity needed later. It balances out. That's why it's called storage. Having these brief periods of extra heat is not the same as permanently setting the temperature level higher or lower.
No matter. You don't have to participate. If the power company in our province offers this service I'll be one of the first to take it both for my benefit and the community at large.
Pumped hydro is the default for anything over a few hours' storage. But, obviously, time is a factor and large-site construction takes time. He's waving away a lot of NIMBY opposition to the reservoirs up those hills. And, if he's saying PHES is hard to beat - what are his cost figures?