Or, at least, stuff I didn’t know anything about and the geek in me geeked out over.
We hear lots of talk these day about energy. More specifically, clean energy. We hear a lot about it, but is anyone doing anything about it? Turns out, people are doing something about it. Thanks to the Canada West Foundation for some of the following highlights:
I did hear a little bit last week about reclaiming unused oil wells to store stuff. It’s actually more than that, and it’s very interesting.
Renewell Energy, a U.S. energy storage start-up, has developed what it calls “gravity well” technology to convert abandoned oil and gas wells into low-cost energy storage opportunities. In essence, by raising an object from a lower elevation to a higher one, energy can be stored as gravitational potential. When the object is released, its downward return can be used to turn a turbine to generate electricity.
The gravity well uses a high-efficiency electric motor to raise and lower a large cylindrical weight, consisting of used oilfield tubing and high-density filling, within the borehole. It’s a smart use of abandoned oil wells and results in minimal environmental impacts. And because the average well is nearly two kilometres deep, the system can store a great deal of energy for every kilogram of cylinder weight.
Researchers in Finland have developed the world’s first working sand battery. The battery stores thermal energy by using cheap wind and solar electricity to heat 100 tonnes of sand to around 500°C. Due to sand’s low heat-transfer coefficient, researchers believe the battery could maintain these temperatures for several months, enabling it to provide heat for homes and offices throughout the winter when electricity is more expensive.
Thanks to solar water heaters and underground thermal storage, the Drake Landing Solar Community in Okotoks, Alberta can supply 90 per cent of space heating and 60 per cent of hot water needs year-round using solar energy alone. The community’s Borehole Thermal Energy Storage (BTES) system consists of an array of 144 boreholes drilled to 35 meters deep and filled with a high thermal conductivity grouting mixture. When excess hot water is produced by each home’s solar collectors, it is used to charge the BTES by pumping it underground to store the thermal energy. Then, when space heating is needed, cooler water can be pumped through the system to pick up the residual heat and transfer it back to the homes. After three years of charging, the BTES can maintain temperatures of 80°C for nearly the entire heating season.
Two proposed pumped-hydro projects—TC Energy’s Canyon Creek Pumped Storage project and Montem Resources’ Tent Mountain Pumped Hydro Energy Storage project—will bring nearly 7,600 MWh of energy storage to Alberta in the next five years. The Canyon Creek project consists of two man-made reservoirs separated by 500 m in elevation and connected by seven kilometres of pipe. Tent Mountain will use two existing reservoirs left over from coal mining operations in the area and is part of a larger project by Montem that will include a 100 MW Offsite Green Hydrogen Electrolyser and 100 MW Wind Farm.
And, of course, we’ve all heard about how rare and expensive lithium is as we use it to power batteries for electric vehicles. There may be some alternatives soon.
- Iron air – non-toxic and uses some of the most widely available materials on earth—iron, water and oxygen. Set to be deployed at two U.S. coal power plants due for retirement.
- Aluminum sulphur – uses aluminum, the world’s second most abundant metal, and sulfur, which is often a waste product from industrial processes.
- Sodium sulphur – a type of molten salt that can be processed from sea water.
- Sodium ion – as noted above, sodium is abundant and a fraction of the cost of lithium.
- Fluoride-ion – may be up to ten times more energy dense than lithium ion batteries.
It’s certainly encouraging to see that not only are there alternatives to fossil fuels, we’re working on developing them.