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Evaluating the Impact of Altered Electricity Systems

Bangay, Carolin LU (2019) FMIM01 20191
Environmental and Energy Systems Studies
Abstract
In the light of the importance of climate change and the emissions that have induced it, the ability to calculate the effect on emissions by changing transmission capacity is vital. A model to perform such indicative calculations is developed in this thesis. After researching how the current electricity system is organised, the effects on GHG emissions that are expected from increased renewable electricity production and increased transmission are considered. For the model, wind and demand data was processed to form a model of linear dependence between areas. Nuclear and solar power production were assumed to maintain a constant level of generation, whilst bio- and hydro power generation were assumed to be proportional to demand. Carbon... (More)
In the light of the importance of climate change and the emissions that have induced it, the ability to calculate the effect on emissions by changing transmission capacity is vital. A model to perform such indicative calculations is developed in this thesis. After researching how the current electricity system is organised, the effects on GHG emissions that are expected from increased renewable electricity production and increased transmission are considered. For the model, wind and demand data was processed to form a model of linear dependence between areas. Nuclear and solar power production were assumed to maintain a constant level of generation, whilst bio- and hydro power generation were assumed to be proportional to demand. Carbon data was found by means of a literature search. The algorithm began with a linear optimisation segment, dispatching the cheapest power available. This was followed by a step-wise examination whether transmission capacities could balance out the production over the areas. If deficits remained, a second economic dispatch commenced locally. The results came reasonably close to the expected values in a base case, however a malfunction regarding exchange balances was discovered. A scenario considering the nuclear trends of Sweden, Finland, Germany and the UK gave that the shutdown of nuclear will lead to an increased amount of GHG emissions if all other generation capacities remain. This is likely a trustworthy result as it is mostly determined by the initial dispatch, before exchange balancing displays major faults. A scenario, where all the relevant interconnectors in the ENTSO_E’s 2018 TYNDP were realised, did not however yield carbon savings if the parameters defining the 2018 base case remained. This result may be explained by the additional transmission capacity not being used for additional renewables, rather that cheaper fossil power could travel further. However due to the exchange imbalance this scenario may not be viable at all, as it is more dependent on the parts of the model handling transmission. There are many ways of improving the model, highlights being resolving the exchange imbalance bug, and building better models for demand, wind and hydro power production. After the improvements are made, the model may be capable of the tasks it was designed for. (Less)
Abstract (Swedish)
Detta examensarbete ämnar att undersöka om och hur man skulle bygga en modell för att kunna beräkna utsläppen av växthusgaser vid förändringar av transmissionskapacitet. Arbetet avhandlar hur det nuvarande elsystemet är uppbyggt och påverkan på utsläppen av växthusgaser ifrån ökad produktion av förnyelsebar elproduktion och ökad transmission av elektricitet.

Utifrån att studera vind- och lastdata kunde en modell av linjärt beroende mellan olika områden upprättas. Kärnkraft och solkraft modellerades till att producera el på en konstant effekt, medan biokraft och vattenkraft antogs följa lasten proportionellt. Data för koldioxidutsläpp ifrån olika kraftslag erhölls ifrån en litteraturstudie.

Modellens algoritm påbörjas med en global... (More)
Detta examensarbete ämnar att undersöka om och hur man skulle bygga en modell för att kunna beräkna utsläppen av växthusgaser vid förändringar av transmissionskapacitet. Arbetet avhandlar hur det nuvarande elsystemet är uppbyggt och påverkan på utsläppen av växthusgaser ifrån ökad produktion av förnyelsebar elproduktion och ökad transmission av elektricitet.

Utifrån att studera vind- och lastdata kunde en modell av linjärt beroende mellan olika områden upprättas. Kärnkraft och solkraft modellerades till att producera el på en konstant effekt, medan biokraft och vattenkraft antogs följa lasten proportionellt. Data för koldioxidutsläpp ifrån olika kraftslag erhölls ifrån en litteraturstudie.

Modellens algoritm påbörjas med en global optimering där de kraftverk med billigast marginalkostnad sätts igång för att mätta lasten av samtliga områden. Detta följs av en stegvis undersökning huruvida transmissionsledningarna mellan områden kunde balansera ut områden av (netto) över- och underproduktion. Ifall områden med underskott inte fullkomligt balanserats av importer initieras en lokal optimering, där den billigaste kraften produceras lokalt. Resultaten av att använda indata motsvarande 2018 kom relativt nära de verkliga siffrorna, men ett fel uppdagades, gällande att balanser beräknade ifrån modellerad transmission inte stämmer. Ett scenario gällande de planerade förändringarna i kärnkrafts- och transmissionskapacitet upp till år 2024 gav att växthusgasutsläppen ökar ifall alla andra parametrar ifrån 2018 hålls konstanta. Detta resultat är nog pålitligt, eftersom de mest avgörande beräkningarna avgörs innan balanserna i transmissionen har haft påverkan. Ett andra scenario, där alla relevanta ledningar i ENTSO_E:s tioårsplan (TYNDP 2018) förverkligades, gav dock inte några koldioxidbesparingar ifall alla produktionskapaciteter hölls konstanta. Resultatet kan förklaras med att den ökade transmissionskapaciteten inte användes för förnyelsebara tillskott, snarare att billig fossil kraft kunde färdas längre. Dock på grund av obalansen i transmissionen är kanske inte detta scenario pålitligt alls, då resultaten beror mer av effekterna av transmission även i modellen.

Det finns många sätt att förbättra modellen, bland de viktigaste ingår att lösa problemen kring obalanser, samt att modellera last, vind- och vattenkraft bättre. Efter att dessa förbättringar är gjorda är det möjligt att modellen tjänar sitt syfte. (Less)
Popular Abstract
In line with their climate goals, the EU is headed towards large-scale power grid expansions. The amount of green-house gas (GHG) emissions that could potentially be saved may be calculated by means of modelling.
It is now commonly accepted that emissions of GHGs have a harmful impact on the Earth’s climate. The European Commission acknowledge that 75 % of EU emissions arise from the energy sector*, prompting reductive measures such as increasing renewables and energy efficiency.

HOW GRID EXPANSION CAN HELP
In the Nordic countries, hydro and nuclear power, which emit rather little GHGs, are utilised to a great extent as base power. Other countries, such as Germany and Poland produce power with a larger share of fossil fuels, which... (More)
In line with their climate goals, the EU is headed towards large-scale power grid expansions. The amount of green-house gas (GHG) emissions that could potentially be saved may be calculated by means of modelling.
It is now commonly accepted that emissions of GHGs have a harmful impact on the Earth’s climate. The European Commission acknowledge that 75 % of EU emissions arise from the energy sector*, prompting reductive measures such as increasing renewables and energy efficiency.

HOW GRID EXPANSION CAN HELP
In the Nordic countries, hydro and nuclear power, which emit rather little GHGs, are utilised to a great extent as base power. Other countries, such as Germany and Poland produce power with a larger share of fossil fuels, which emit more GHGs. By connecting countries with more fossil production with the Nordics, power that otherwise would have been produced locally by fossil fuels can be displaced by power which causes less emissions. The increased connection also gives more possibilities to increase the amount of deployed intermittent renewables: high voltage lines can export power from an area with excess, so the power is not wasted. However, if for instance the wind does not blow in a local wind park, power from windier areas can be imported.

HOW TO CALCULATE GHG EMISSIONS
To calculate the GHG emissions that potentially can be saved by increasing interconnections between areas, modelling could be employed. Such a model of the Northern European electricity system was built to consider the variability of demand and wind power production, the power production capacities in each country and the transmission lines in between. The model emulates reality by first determining the power types that would be activated (and their locations) in a market setting without interconnection constraints – that is, total load is met at the lowest cost of power. Next, as the cheapest power production and demand may be located in different areas geographically, the model attempts to transfer the excess production from some areas to areas with deficits. If imbalances still exist a second market process is initiated locally.

OUTCOME OF AN EMISSIONS MODEL
The model discussed here was found to produce values relatively close to actual recorded values for 2018 if input for the same year was provided. By adjusting parameters in the model, different scenarios can be tested. One such scenario included adjusting all nuclear and transmission capacities to what they are expected to be in 2024. Keeping all other input the same as the 2018 base case, the results showed that the carbon emissions would increase by around 25 %. This is likely to be a trustworthy indication as there were few flaws associated with the most vital parts of the algorithm and as much of the input data is not expected to change radically between 2018 and 2024. Another investigated scenario was the realisation of expected network developments up until 2035 materialise, all other input remaining the same. The model output gives a 2 % increase in emissions from the 2018 base case, on the contrary to expectations. This could be explained by discovered faults in the model, yet also that the (intermittent) renewable production was not modelled to increase, as it should in reality.

USE OF THE MODEL
The purpose of the built model was to indicate what impacts that different configurations of the electricity system may have on the emissions from the power sector. The built model may have produced some interesting results, however many improvements should be made – most importantly with respect to resolving faults, including growth of renewable energy in future scenarios and improving hydro power modelling. The current model is a promising basis for further development – if the improvements are made and the models function validated, it may become a helpful tool for calculating emissions.

* European Commission, “COMMUNICATION FROM THE COMMISSION - A Clean Planet for all,” European Commission, Brussels, 2018 (Less)
Please use this url to cite or link to this publication:
author
Bangay, Carolin LU
supervisor
organization
course
FMIM01 20191
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Linear Programming, Transmission, Energy Systems, Green House Gas, Emissions, Electricity Systems, Modelling.
report number
ISRN LUTFD2/TFEM—19/5147--SE + (1-92)
ISSN
1102-3651
language
English
id
8983849
date added to LUP
2019-06-14 15:06:47
date last changed
2019-06-14 15:06:47
@misc{8983849,
  abstract     = {In the light of the importance of climate change and the emissions that have induced it, the ability to calculate the effect on emissions by changing transmission capacity is vital. A model to perform such indicative calculations is developed in this thesis. After researching how the current electricity system is organised, the effects on GHG emissions that are expected from increased renewable electricity production and increased transmission are considered. For the model, wind and demand data was processed to form a model of linear dependence between areas. Nuclear and solar power production were assumed to maintain a constant level of generation, whilst bio- and hydro power generation were assumed to be proportional to demand. Carbon data was found by means of a literature search. The algorithm began with a linear optimisation segment, dispatching the cheapest power available. This was followed by a step-wise examination whether transmission capacities could balance out the production over the areas. If deficits remained, a second economic dispatch commenced locally. The results came reasonably close to the expected values in a base case, however a malfunction regarding exchange balances was discovered. A scenario considering the nuclear trends of Sweden, Finland, Germany and the UK gave that the shutdown of nuclear will lead to an increased amount of GHG emissions if all other generation capacities remain. This is likely a trustworthy result as it is mostly determined by the initial dispatch, before exchange balancing displays major faults. A scenario, where all the relevant interconnectors in the ENTSO_E’s 2018 TYNDP were realised, did not however yield carbon savings if the parameters defining the 2018 base case remained. This result may be explained by the additional transmission capacity not being used for additional renewables, rather that cheaper fossil power could travel further. However due to the exchange imbalance this scenario may not be viable at all, as it is more dependent on the parts of the model handling transmission. There are many ways of improving the model, highlights being resolving the exchange imbalance bug, and building better models for demand, wind and hydro power production. After the improvements are made, the model may be capable of the tasks it was designed for.},
  author       = {Bangay, Carolin},
  issn         = {1102-3651},
  keyword      = {Linear Programming,Transmission,Energy Systems,Green House Gas,Emissions,Electricity Systems,Modelling.},
  language     = {eng},
  note         = {Student Paper},
  title        = {Evaluating the Impact of Altered Electricity Systems},
  year         = {2019},
}