Technology

I googled Pyhäsalmi Mine gravitricity "2 MW" and EVERY article covering this has also cited 2 MW.

Now, under Occam's Razor, what's more likely:

1. Absolutely none of the article writers have any clue what the difference between a MW and a MWh is because none of them remember any physics
2. Some of them could suspect that it's wrong, but an authoritative source of the claim wrote/said 2 MW capacity when they meant "2 MW peak generation" or "2 MWh storage" (I'd presume Gravitricity, but I'm struggling to find such a source, myself)
3. One writer miswrote/misquoted as per 2, and everyone is mindlessly recycling that original article's contents with no attribution or care.

I don't know which one it is. But I'd generally lean against 1.

How many horsepower is your car's gas tank?

Mistakes like this could be avoided if we just used joules for energy and watts for power.

It's the independent 🤷‍♂️

That's a miniscule amount compared to PSH facilities, whether it's 2 MW capacity or 2 MWh storage.

It's a cool concept but practically seems limited to niche applications due to the small capacity. Granted it is a prototype, but it also seems intuitive that pumping large amounts of water would be more efficient than moving solid blocks of heavy material for a gravity battery design.

Jiggawatts

Just walked the distance of 1.8 km/h.

This is one of those ideas that in hindsight seem so simple and obvious that it makes one wonder how nobody thought of it prior. Absolutely brilliant.

The weight doesn't have to "free fall" for this to work. It could be a huge boulder that's lifted a few centimeters per hour. And then it can be dropped a few centimeters per hour when needed.

It will be similar to a big pulley.

The weight will pull the turbine, the turbine will require a torque to generate current. This torque will act as an upwards force against gravity. This force will slow the fall of the weight significantly. The turbine 'consuming' the torque allows the weight to fall.

The higher the power output the faster it will fall. This will be adjustable. No power out = stationery. A small amount of power out, the descent speed will be tiny. A faster fall a higher power output.

This won't be designed to fall at full speed. It'll be designed for a long slow descent. The theoretical power will likely be much higher. It will be limited by the turbine and wiring capacity that's rated at 2MW.

If your calculations are correct it will be able to generate $1.50 a second. It will also consume power that is below market price/free/paid to consume when it 'charges'. It also provides the utility of stabilising the electrical grid against renewables. Increasing the capability of the grid to support more cheap renewable energy, without the lead time of nuclear or the pollution of biofuel.

How something be turning a huge ass generator (most likely) AND be in free fall...

Just guessing here but I think they are playing with gear ratios. A large turbine with high resistance being slowly turned by a heavy weight could generate power for an extended period of time.

EDIT: Maybe the shaft is the turbine. Like a big rotating corkscrew.

The turbine is the part that turns potential energy into rotational energy. The generator turns that rotation into electricity.