Energy Flashcards
What is energy and why is it different from power?
- Energy is the capacity to do work. joule (J)
- Power is the rate at which energy is transferred or converted. It measures how quickly work is done or how quickly energy is consumed. watt (W)
Explain the term TPES (Total Primary Energy Supply)?
- Amount of “raw” energy required before any conversion or transformation. Includes all energy sources, such as fossil fuels, renewables, and nuclear energy.
Explain the term TFED (Total Final Energy Demand)?
- TFED is the sum energy consumption at the end-use level, from sectors such as residential, commercial, industrial, and transportation.
In 2019, approximately what was the global TPES (remember to state units)?
Approximately 606EJ
In 2019, approximately what proportion of the global TPES was derived from fossil fuels?
- Approximately 84% of global primary energy came from coal, oil and gas in 2019.
In 2019, approximately what proportion of global TPES was derived from renewables (including hydro)?
- Approximately 27%.
In 2019, approximately what was the proportion of TPES in Ireland from fossil fuels?
- Approximately 87%.
In 2019, approximately what was the proportion of TPES in Ireland from renewables (including hydro)?
- Approximately 4.3%. Total of 1,461 kto2 in 2019.
Briefly state what is meant by the “energy trilemma”?
Its 3 interconnected challenges for energy systems:
Security: Reliable and stable energy supply.
Sustainability: Environmentally responsible practices.
Equity: Accessible and affordable energy for all.
Challenge: Balancing these goals is tricky because improving one may affect the others.
Importance: Finding a balance is key for sustainable and resilient energy systems.
Explain the term LCOE (Levelized Cost Of Electricity)?
The avg per-unit cost of generating electricity over the lifetime of a generation technology.
Life-cycle cost of delivering one kWh of electricity
LCOE=(Present Value of Lifetime CAPEX and OPEX (€))/(Lifetime Generation (kWh) )
CAPEX=capital expenditure
OPEX=operating expenditure
It considers all costs (initial, operating, maintenance, fuel, and financing) and divides by the total electricity produced.
Used to compare the cost of electricity generation across different technologies and evaluate the economic viability of a power project.
Lower LCOE indicates a more cost-effective and competitive electricity generation source.
What are the problems with LCOE?
- LCOE assumes that every kWh of electricity is equally valuable, regardless of instantaneous demand (i.e. market value).
- Tends to undervalue dispatchable plant.
- Tends to overvalue wind (typically high at night)
- Increased renewables (RES) tend to increase LCOE of FF generation
- OPEX includes fuel costs now and in the future and so has large uncertainties
- OPEX estimate can include indirect subsidies e.g. government insurance
- Net present value embeds a discount rate, an assumption on mode and cost of financing.
Besides the wholesale price of electricity (i.e. the LCOE), what other factors contribute to the price paid by consumers?
Transmission and Distribution Costs
Grid Operation and Maintenance Costs
Regulatory Costs
Taxes and Levies
Retail Margin
Energy Efficiency Programs
Renewable Energy Credits (RECs) and Subsidies
Demand-Side Management Programs
Weather and Market Conditions
Capacity Payments
Infrastructure Investments
What types of direct subsidies can be offered to electricity generators?
Payment from government to producers or consumers
Tax expenditures:
– Tax credits
– Measures that reduce taxable income
– Preferential tax rates
– Tax deferrals
Excise taxes or Tariffs
What type of indirect subsidies can be offered to electricity generators?
Insurance
Loans or loan guarantees
Provision of services:
– Environmental and health/safety
– Regulatory framework
– Infrastructure services below market price (e.g. grid, BoS)
– Defence/security
Research and development:
– Basic research
– Applied research
—Existing technologies
What is meant by “Energy Return on Energy Invested (EROEI or EROI)”?
Measures how much useful energy you get compared to what you put in.
Used to assess whether a source of energy is a net contribution to supply.
It is effectively an Net Energy Return
EROEI=(Energy delivered to final consumer)/(All energy input required to deliver that energy)
Ratio of usable energy gained to energy invested
Shows how efficient and sustainable an energy source is.
Higher ratio is better—more energy out for every unit in.
