Renewable Energy Solutions 1 Flashcards
What are some key assumptions we will use surrounding populations and energy use?
- Populations will always have a demonstrable need for input - resources, feedstock, food, materials
- Populations levels continue to grow
Activity will have multiple impacts - systems thinking?
What are some known observations around populations and energy consumption?
- Populations tend to be possessive - resource, wealth, growth
- Environments tends to be the “ballast” that picks up the unintended “cost”
- Impacts tend to come as either direct or indirect (implied)
- Impacts can be characterised as materials or energy
What are the hockey stick curves
- Refer to a pattern of data that shows a long period of relatively little or no change, followed by a sharp sudden increase
- Climate change: shows relatively stable global temperature for around 1,000yrs, followed by a steep rise starting in the late 19th and 20th centuries due to human-caused GHG emissions
- Also related to economic growth, FDI, urban population, energy use etc (al very much linked)
What are the measurable affects on the environment of the impacts of the hockey stick curves
- CO₂, NO, CH₄, O₃, surface temp, ocean acidification, marine fish capture etc
- All showing similar hockey curves - affect all future generations
What does this image very basically show?
Seen as a surrogate for energy consumption/energy use
How much CO₂ was produced when Radcliffe coal power station was still operating?
For every minute the pace was operating, the mass of 3 elephants in CO₂ was produced
What is the current materials used in solar pannels and their associated issues?
- Silicon (95% market) - single crystaline silicon (high energy + water intensive to obtain) - currently cheaper as used from a second life in semiconductors
- Cadmium Telluride (CdTe) (4% market) - scare elements
- Copper indium gallium selende (CIGS) (1% market) - scare elements
What is concentrated solar thermal?
- Refers to a technology that uses mirrors or lenses to focus sunlight onto small areas, generating heat that can be used to produce electricity
- CST systems are designed to harness the sun’s energy more efficiently than traditional solar panels by concentrating sunlight to create high temperatures
How does concentrated solar thermal work?
- Concentration of sunlight: array of mirros (heliostats) are used to track the sun and reflect + focus the sunlight onto a central receiver
- Heat generation: The concentrated sunlight heats a working fluid to high temperatures
- Power generation: the heated fluid produces steam, which drives a turbine connected to a generator to produce electricity
- Some CST systems use molten salt (heat retaining materials) to store heat for hrs/days - allowing power generation when sun isnt shining
What are two important features of heat transfer fluids?
- Have the ability to move them through pumping
- Must have a high heat capcity
- Must be chemically intert to pump/pipes that your moving it in
What is electricity and why can we not generate it?
- Electricity is energy transported by the motion of electrons
- We do not make electricity, we CONVERT other energy sources into electrical energy
Why does offshore wind increase the demand for finite resources
- Because instead of having one large motor used in a power station, we have lots of little motors in each turbine
What are some key challenges for offshore wind farms?
- Hurricane Exposure, Waves, Sea Bed Stability
- Deep water foundations > 40m can open vast resource
- Tough Service Environment, Need Autonomous Operation
- The blades cannot be easily recycled and generate a huge amount of landfill material
- Materials which they are made from (polymers) come from non-renewable
- Use generators requiring copper+magnets
There is likely growth in Offshore Growth Potential
What are the drivers?
- Renewable Obligations (UK, US)
- Kyoto compliance (Germany, Ireland)
(over 30GW of specific sies in various stages have been announced)
How much copper is in a wind turbine?
5.3 tonnes/MW generated (on land);
15.3 tonnes/MW (offshore) - more for offshore as we must transport that energy back to on-land
What are the 3 things rare earth elements is predominatly used for?
- Electrical and electronic devices (58%)
- Electric vehicles (19%)
- Wind Turbines (4%) - keep in mind old figures
What is expected to happen to the demand of Neodymium in the next 100yrs (rare earth element)
Vastly increase
(sourced mainly in Mongolia & China - know damage on the environment similar to cobalt - DRC)
Dams are another ‘clean’ way to generate energy e.g. Grand Ethiopain Dam - Africas largest hydro-power venture
Breifly mention some benefits and drawbacks?
- Power generation to lift people out of poverty (6.5 GW Hydro)
- BUT restricted Nile flow in Sudan+Egypt and impact aqua and agriculutre downstream = internation tensions
- displacement of people + biodiversity
