5 Weird Ways to Store Energy

https://www.youtube.com/watch?v=yhC9ppP-cHk&t=617s

What is pumped-storage hydropower also called?

Water batteries

In pumped-storage hydropower, what do the two reservoirs at different heights store energy as?

Gravitational potential energy

In pumped-storage hydropower, what pumps water uphill?

Excess electricity

In pumped-storage hydropower, what happens to the water that is pumped uphill?

Flows back down through turbines

In pumped-storage hydropower, what generates power?

Water that flows down through turbines

Are pumped-storage hydropower small or big?

Big

Can pumped-storage hydropower store energy for short or long periods?

Long

What are pumped-storage hydropower widely used for?

Grid backup

What are pumped-storage hydropower widely used to do?

Smooth out variable sources

Examples of variable sources:

Solar and wind

How much energy does the Fengning plant in China store?

40 GWh

The energy that Fengning plant in China stores is enough for how many people for a week?

340000

How efficient is the Fengning plant in China?

76%

How much energy is the upcoming Snowy 2.0 project in Australia designed to store?

350 GWh

How many people for a week can the Snowy 2.0 project in Australia supply to?

3 million

What does geomechanical storage use?

Pressurized rock

What happens to water for geomechanical storage?

Pumped 300-500 meters underground into rock formations

During geomechanical storage, what happens to rock formations after water is pumped into them?

Slightly deformed

What stores energy in geomechanical storage?

Deformation of rock formations

How does geomechanical storage get power?

By releasing pressurized water up to drive turbine

How much power has Quidnet demonstrated that geomechanical storage stores?

35 MWh

How long has Quidnet demonstrated that geomechanical storage stores power for?

6 months

How efficient is the geomechanical storage for Quidnet?

50%

Advantages of geomechanical storage compared to massive surface reservoirs:

Easier, cheaper deployment

What do thermal batteries store?

Heat

What does electricity do for thermal batteries?

Heats resistive material to high temperature

Examples of resistive materials that electricity heats for thermal batteries:

Bricks, rocks, sand, molten salts

How hot are resistive materials heated to for thermal batteries?

500-1700 degrees celsius

What keeps the heat in for thermal batteries?

Heavy insulation

What can the stored heat in thermal batteries be used for?

Industrial processes

Examples of industrial processes that the stored heat in thermal batteries can be used for?

Furnaces and kilns

How efficient can the stored heat in thermal batteries reach when used for industrial processes?

95%

Is it easy to convert the stored heat in thermal batteries back to electricity?

No

At what temperatures do steam turbines work at?

Low temperatures

Examples of high-temperature concepts for thermal batteries:

Thermophotovoltaics

What does TPVs stand for?

Thermophotovoltaics

What do TPVs turn infrared radiation into?

Electricity

Efficiency of TPVs:

44%

Example of thermal batteries:

Molten-salt thermal battery at Ouarzazate Solar Power Station in Morocco

How much power does the Ouarzazate Solar Power Station store?

2800 MWh

What do ice batteries store energy as?

Cooling capacity

What is electricity used to do at off-peak times for ice batteries?

Freeze water or other materials

What does the ice in ice batteries do?

Cool buildings or coolant loops

What is the purpose of ice in ice batteries cooling buildings or coolant loops?

So air conditioners draw less power during peak hours

What type of materials are used for ice batteries?

Materials with high latent heat of fusion

Examples of materials with high latent heat of fusion:

Water, paraffin wax, salt hydrates

Why are materials with high latent heat of fusion used for ice batteries?

So lots of cooling can be stored in small volume

Disadvantage of using salt hydrates for ice batteries:

Freezes unevenly and corrodes equipment

Example of ice battery:

11 Madison Avenue in New York City

How much ice is produced each night in 11 Madison Avenue in New York City?

227000 kg

What is the ice produced by 11 Madison Avenue in New York City equivalent to in terms of power?

22.5 MWh

What do ice batteries help to do?

Lower cost and ease stress on grid

Examples of microorganisms used in microbial fuel cells:

Bacteria, algae, fungi

What do microorganisms in microbial fuel cells do?

Metabolize biomass

Examples of biomass that microorganisms metabolize in microbial fuel cells:

Soil and wastewater

What is the result of microorganisms metabolizing biomass in microbial fuel cells?

Electrons stripped from molecules

What happens to electrons in microbial fuel cells?

Sent through circuit

What does the electrons in the circuit in microbial fuel cells generate?

Electricity

Do microbial fuel cells produce high or low power?

Low

What are microbial fuel cells suited to?

Small loads

Examples of small loads that microbial fuel cells are suited to?

Remote irrigation controllers or pollution sensors

Are microbial fuel cells suited for city-scale storage?

No

What can microbial fuel cells help treat?

Wastewater

What is research on microbial fuel cells ongoing to improve?

Architectures and materials

How much power did a 2024 design of microbial fuel cells reach?

10 milliwatts per square cm

Trade-offs of unique ways to store energy:

Efficiency, scale, cost

What are the unique ways to store energy being used to complement?

Renewables

What are the unique ways to store energy being used to stabilize?

Power grids