L3 Flashcards
What are the key strategies for transformation in the energy sector consistent with Paris?
- Improve energy efficiency
- final energy demand in 2050, +20 to -10% relative to 2010 levels
- not switching fuel but improving tech fro the same output with less energy - Electrify energy end us
- mobility, buildings and industry
would need to consider where the energy is being sourced - Decarbonise the power sector
- carbon intensity fo electricity about 0 or negative in 2050 - Subst. residual ff with low-carbon options
- eg. sustainable bio-based fuels or green hydrogen for transport
Can you speak to the predications in the energy sector from 2030 to 2100?
FF show a clear decline but with variations until the mid-centry
coal has a strong decline, oil declines to a lesser degree, gas decline depends on assumption about capture technology
Renewables are called up robustly
15% of primary energy in 2020 to 50-65% of primary energy by 2050
What is the role of the electricity sector in decarbonisation?
- essential for daily life and clean energy provision
- demand has grown steadily ~3.4%/yr over the last 40 years
- electricity currently the largest source of emissions in the global energy sector?
- electrification of demand sectors is a key mitigation lever
- emissions cuts from electricity production are central to achieving net zero
- there is a potential for net negative emissions if offset residual emissions in other sectors
What are potential mitigation apporaches in the electricity sector?
Approaches with varying effectivness to achieve net zero Co2 emissions = not all mitigation measures are equally effective or desirable
- renewables - wind,s solar etc.
- more efficient coal-fired power generation - supercritical and ultra-supercritical
- switching from coal to natural gas
- phasing out unabated ff entirely
- switching to or co-firing with biomass
- nuclear
- green hydrogen
- carbon capture and storage
Are we on track to achieve this transformation - ff perspective?
- Primary mix of electricity is still made up of a v high share of ff
South Africa per capita electricity from ff is 97% compared with 45% in the UK
Sweden has a v low ff per capita electricity relying mainly on 67% renewables due to a lot of hydro energy
Brazil has 77% renewable - mainly biomass due to abundant forest
- coal still dominates 40% of global power production
we are still building new coal plants and ~10% of them are the least efficient = subcritical plants
coal fired retirement is increasing but not fast enough - prevent more coal power plants without ccs - committed emissions are problematic and there is a need for early retirement of polluting infrastructure
Co2 emissions from coal have plateaued and may have peaked but decline is not fast enough to be in line with the pairs benchmark
Are we on track for this transformation - renewables perspective?
- Renewable energy now makes up 26% of electricity generation - majority hydro (16%)
- solar PV and onshore wind reaching cost parity with conventional power
other technologies are not on track and need more investment to reduce costs eg. bioenergy, hydro and geothermal - there have been government commitments and subsidies from Indian and Chinese government resulting in a high deployment of this tech
- CCS plants remain v expensive but developing countries can take advantage of this technology
Where are we now with CCS and where do we need to be to meet the pairs agreement?
Currently:
30 large scale CCS plants in opp
11 under construction
153 in development
capacity together would be 244 MtCo2/yr capture capacity
Paris Agree:
1000s CCS facilities
Several GtCo2.yr of CCS by 2050
How does electrification of other sectors play a role?
Most 1.5o scenarios include the electrification of ff depdent sectors like transport, heating and industry
renewables will be key in the future energy systems
Speak to supply and demand of renewables
Time of peak supply do not match to time of peak demand
- industry and commercial sector during the day demand is high
supply is variable - seasonal and within a day
supply is intermittent over a range of timeselves - significant variation from average in each trace
this presents a challenge to ensuring consistent electricity supply.
there is a mismatch and requires a flexibility in the system to ensure a constant supply in electricity
Can you give examples of things that are predictable, relatively predictable and hard to predict
Seasonal and daily cycles - predictable
weather patterns - relatively predictable –> have got more predictable over time
brief interruptions - hard to predict thus have to have flexibility in the system to deal with these kind of shocks
What is a capacity factor?
a metric quantifying the typical output of a generating source over a given time period
the ratio of actual electrical energy output over a given period of time to the max possible electrical energy output over the same period
Capacity factor = actual energy produced/ energy produced if system running 100% of the time
Why does electricity sources not generate at full capacity all of the time?
- planned or unplanned maintenance
- intentional ramping up and down of supply to meet demand/response to the economics of generating at the current electricity price
- unavailability of fuel - including wind, sunlight, and water for renewables
- other environmental factors
capacity factors may vary by geographical location and time of year
What is capacity credit?
The conventional thermal capacity that an intermittent generator can replace while still delivering the same reliability of supply to energy users
typically a percentage - capacity credit is the % of the sources rated capacity which it may be statistically relied upon to provide at times of peak demand
What happens to capacity credit when deployment of an intermittent generation source increases?
capacity will tend to decrease
What is another word for capacity credit?
de-rating factor
