VL zu Energy Flashcards
Efficiency (Formel)
useful energy / supplied energy
Meaning of installed power
= how much power (energy/second) a product/power plant can produce even when in full operation
Meaning of capacity factor
= shows how much energy a power plant delivers, not how much it can deliver
capacity factor %
delivered energy (Wh)/ installed power (W) * days * hours (h)
= result *100
levelized cost of energy (LCOE)
costs over lifetime / electric energy delivered over lifetime
Meaning of efficiency
= How much of the supply energy is converted to the useful energy, e.g. electricity
Analogy for energy
How much water is in a bowl
Analogy for power
How fast is the water flowing out of the bowl
Fossil fuel: efficiency + normal installed power
efficiency 33%
normal installed power 2000 MW
Solar: efficiency + normal installed power
efficiency 15%
normal installed power 10kW - 2000MW
Nuclear: efficiency + normal installed power
efficiency 33%
normal installed power 4000MW
Hydro: efficiency + normal installed power
efficiency 95%
normal installed power 4000MW
Wind: efficiency + normal installed power + delivered energy
efficiency 40%
normal installed power 2MW
delivered energy 6000MWh a year
Smart grid functions
- Many small power producers. Mainly wind and solar power
- more advanced measurement and control system and a built in energy storage
- Storage – pumped hydro, batteries, hydrogen(gas), flywheel
- fleet of electric cars are part of the grid
- A flexible grid: two ways power flow where consumer is also producer (“prosumer”)
- Continuous communication between consumer and producer
- Weather prediction
Smart grid goal
A higher amount of variable renewable power production
smart grid examples
- Your dishwasher starts when the electricity price is low (due to low energy usage or high energy availability)
- A factory shuts down low-priority activity when there is no wind
- Vehicle to grid V2G: your electric car communicates with the grid and charges when there is wind and sell electricity when there is no wind
Energy solutions for the future
- Geographical distribution of the power plants
- Mix of variable sources with different characteristics
- Higher amount of renewable controllable sources (bioenergy)
- Smart grids that match production with consumption
- Increased storage of electricity (batteries, hydrogen,…) during over production
- Use the excess energy to produce district heating, hydrogen
- Better weather forecasts
- Energy efficiency
- Change our energy use. When we use and how much
- Periodically higher electricity prize
Fossil fuels +/-
Positive Effects
+controllable
+scalable to any rate (fuel)
+placed anywhere
+simple
Negative effects
-emissions
-fuel costs
-mining
-Excess heat (unless it’s used)
Bioenergy +/-
Positive Effects
+ Can be Co2 neutral, Co2 are released in combustion are stored by plants
+ Often rest products, waste from food, agriculture and forestry
+ Can have high efficiency. Combined heat and power <100% efficiency
Negative effects
- Intensive forestry gives monoculture, decreased biodiversity,
- Acidification of the forest
- impoverish the soil, lead to eutrophication and decrease biodiversity
- can increase food prizes
- Competition of bioenergy can give air pollution. Especially from small scale firewood
- Renewable, but limited. It takes some time to grow
Solar +/-
Positive Facts
+ Renewable
+ No Co2
+ No fuel costs
+ Simple, no moving parts (long life time)
+ Only choice sometimes
+ Scalable
Negative effects
- Variable source (day/night, seasons)
- Need critical materials, i.e. mining (environmental problems, geopolitically sensitive, bad working conditions)
- Need to cover large area
- Need supporting system (batteries, hydrogen, more complex electric grid)
Nuclear +/-
Positive effects:
+ Controllable (slowly)
+ High power and energy density
+ No Co2
+ Reliable and long life time (60-80 years)
+ Low area and material demand (lowest of all technologies)
Negative effects:
- Potentially dangerous
- Waste
- Excess heat
Hydro +/-
Positive effects:
+ Renewable
+ Controllable
+ Can act as energy storage
+ No fuel costs
+ Simple
Negative effects:
- One of the largest impacts humans make on the planet
- Dams hinders fish migration
- Flooded area have higher Co2, due to increased decay and fewer Co2 consuming plants
- destroys/changes the ecosystem
Wind +/-
Positive effects
+ No CO2
+ No fuel costs
+ Renewable
Negative effects
- Variable source
- Need critical materials, i.e. mining (environmental problems, geopolitically sensitive, bad working conditions)
- Need to cover large area (even more then PV)
- Need supporting system (batteries, hydrogen, more complex electric grid)
- Effect the local ecosystem in many ways and many animals avoid wind power parks
- Ugly, noisy
Seasonal variations of energy plants
- Nuclear power: decrease when refueling
- Geothermal: Constant production
- Hydropower: follows precipitation and spring flood
- Natural gas: peaks in the summer to meet the need for air conditioning
- Wind: lowest in late summer
- Sun (PV): Very low during the winter
