In Greek mythology, the story of Sisyphus is one of pointless labor. Sisyphus — so the story goes — was a self-aggrandizing king whom the Gods punished by forcing to roll an immense boulder up a hill, only to have it repeatedly roll back down. He repeats this pointless labor for all eternity.
But what if the labor wasn’t pointless? The term “Sisyphean” conveys the idea of work considered both laborious and futile. But what if you could turn that idea on its head?
That’s what several technology companies now propose with regard to utility-scale energy storage: using the idea behind the Sisyphus myth to create something useful.
Check out the video embedded above. It illustrates one such proposal. What you will see is a machine, building something — but what? The answer is: nothing. Like Sisyphus, the machine simply lifts heavy blocks and then releases them. The idea here is that when the nearby windmills generate excess power, then instead of selling that power into the market, it’s used to lift the blocks. Then, when electricity prices rise and the wind stops blowing, the machine drops the blocks and — using gravity and presumably flywheels — generates power.
A Swiss company called “Energy Vault” is developing this technology using a $100 million investment from the Japan-based SoftBank. You can read more about it here.
We have read about a similar idea described as “mountain storage” — the idea wherein a machine uses cheap wind, solar or hydro power to drag train-car sized loads of sand up mountainsides and then releases the sand downhill to generate electricity when the price is right. Potentially, such technology could compete with lithium-ion battery storage systems. A recent study by the International Institute for Applied Systems Analysis, for example, has found that combining hydro-power with mountain storage could represent a realistic option for micro-grids, remote islands and areas with high electricity costs.
Currently, lithium-ion battery storage remains the fastest-growing storage type in the United States. However, the relatively short bursts in which the lithium-ion systems deploy power may become increasingly problematic as more solar and wind resources come online. Such systems also raise their own environmental concerns regarding the disposal of spent batteries.
You can read more about these issues and gravity-power storage options at articles here and here.
Is a policy analyst consultant for TCAP, a coalition of political subdivisions in Texas that purchase electricity in the deregulated market for their own governmental use. Because energy costs are typically a significant budget item to our members, TCAP is consistently looking for ways to save our members money, through cost-saving contracts, energy efficiency or demand response programs.
Suggestion, variable ballast. Cuckoo clock has weights on chain. Unbalanced weight equals one weight going up, the heavier one going down. Now think of gym equipment with many weight plates, joined by a cotter pin. Two stacks of 1000 pound plates joined by a pulley or even refillable sandbags. Note you can move the pulley wheels or change pulley gearing to enhance the unbalance factor as well add clockwork rachets to alter the outputs and slow the drop. You can also use elevator counterweights and alter box contents. Two elevator cars (one at bottom holding 1000 pounds, one empty at top), if you add 1000 pounds to empty elevator, both will balance at 50% height. But if you make the bottom one 800 pounds and the top 1000 pounds, the heavier one will meet at bottom. Easier engineering would be a marble wheel like a water wheel. So long as one marble cup is heavier than the others, the wheel rotates to lower weights.