L10 - Renewables 1: Solar energy and intermittency Flashcards
What is intermittency?
That renewable energy cannot always consistently produce energy at all hours of the day
What is net load and what is its properties compared to load?
Net load—the total electric demand in the system
Net load has:(compared to load)
- more variability
- steeper ramps
- less (or no) room for baseload
What are some options to prevent intermittency?
- Spread out sources over large region
- Use different intermittent sources
- Storage
- Demand side management
- Smart grids
- Curtailment in extreme situations
What is solar luminosity?
Output power of the sun: Stefan-Boltzmann law
P = AεσT^4= (4πr^2)εσT^4
Describe the unusual characteristics of solar power.
- very large resource base
- large area requirements (compared to fossil & nuclear)
- distributed & modular (can be close to consumer, efficient at small scale, not a lot of scale advantages from larger plants)
- high investment costs but zero fuel costs
- but intermittent –variable output at daytime (time of day, clouds), and no output at night
- reliable 24 h cycle fits well with short term timescales of storage (batteries or pumped hydro), so storing solar energy is often profitable.̶Contrast with wind (variations typically last 1-3 weeks).
- seasonal variations
What is solar PV?
Solar photovoltaic power (solar cells)
What is the main issue with solar PV?
Cost
Which countries dominate solar PV?
USD 50 Billion
China is the dominant player; about 80% of the world’s solar manufacturing supply chain runs through China
What is the payback times for PV systems and wind turbines compared to their lifetimes?
- crystalline PV system:1 -2 years
- thin-film PV system:8 -16 months
- wind turbine:3 months
•compare with lifetime: 25 years or more
What is CSP?
Concentrated solar power
Concentrating solar power (CSP) plants use mirrors to concentrate the sun’s energy to drive traditional steam turbines or engines that create electricity.
How big is the worldwide capacity of CSP?
Currently, there is over 25 GW of installed CSP capacity worldwide and more than 2000 MW under development
Which are the four main types of CSP? Properties of them?
- Linear Fresnel Reflectors
- Towers (CRS)
- Parabolic Troughs
- Parabolic dishes
Give examples of other solar technologies.
Solar chimney
Solar heating
Tube collectors
What is the future of solar energy?
In the coming years, technology improvements will ensure that solar becomes even cheaper. It could well be that by 2030, solar will have become the most important source of energy for electricity production in a large part of the world. This will also have a positive impact on the environment and climate change.
