L16 - Grid management

Question 1

How is variations in the electricity grid measured?

Answer 1

Balanced between demand and supply

Question 2

Which are the different power system time scales?

Answer 2

.

Question 3

What needs to be considered when connecting to the grid and what can throw the grid off balance on different time scales?

Answer 3

.

Question 4

What is the difference between energy and power balance?

Answer 4

• Energy
• Long time frame, e.g. Annual (resource availability)
• Unit: Wh (kWh, … , TWh)
• Swedish electricity demand 140 TWh/year
• Power
• Instantageous power demand
• Unit: W (kW, … , GW)•Swedish peak power demand about 27 GW

Question 5

What determines the size of the baseload?

Answer 5

Find the two lowest total consumption numbers from every month. Add them together and divide by 2. This
is your approximate Base load for the months.

Question 6

Describe some ways of using electricity for transportation.

Answer 6

Electric vehicles
Electric road sysyems (ERS)
Hydrogen
Electrofuels H2 + CO2 —> e.g. methanol

Lower fossil fuel demand Increased electricity demand (and biofuels)

Question 7

How can transport vehicles contribute to grid management?

Answer 7

Vehicle-to-grid helps balance out electricity demand and avoid any unnecessary costs for building an electricity system. With V2G, the momentary electricity consumption spikes in the building can be balanced with the help of electric cars and no extra energy needs to be consumed from the grid.

Question 8

Give examples of ways to store energy.

Answer 8

Pumped hydro
Batteries
Super magnetic
High power capacitors
High power flywheel
Compressed air
Hydrogen
High energy capacitors
Long duration flywheel