CONCLUSION
In order to conclude our project, we have raised a series of questions that will make us aware of the situation in Scotland in the future. These questions are as follows:
ANALYSIS
1. Can Scotland be 100% renewable for electricity in 2032?
In this case we have used high demand and only a renewable supply, run through EnergyPlan.
As a result, the amount of export is higher than the import. Thus, it can claim that Scotland can be a 100 % renewable country by under these conditions, nevertheless, the grid instability would be enormous.
Compared to the import and export Scottish profile from 2016, it was around 300 and 12000 GWh respectively. When compared to this scenario, the amount of import is 40 times different. We won’t have enough export and import capacity and we cannot rely on the UK imports. It is possible to be 100% renewable but the instability is huge.
2. Can storage be used to eliminate the need for import?
In this case we have used high demand and only a renewable supply, run through EnergyPlan.
The maximum need of storage is the lowest point of the graph at 1221 hours from the beginning which is around 950 GWh.
When compare to one of the largest hydro storage of Scotland, Cruchan hydro scheme, the needed capacity is around 100 times.
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In conclusion, it not possible with the existing technology (pumped hydro) to store those large amounts of energy in order to avoid imports.
3. What base load capacity would be required in Scotland to keep the same amount of 2016 imports?
In this case, we use as well the high demand scenario condition but the supply is based on 20GW of RES and the existing gas power plants.
The result showed in the blue is the total amount of import, 6737 GWh. In order to reduce this number to the same amount as 2016 import (a stable flow), we need to add 2.6 GW of gas (having an overall capacity of 4.3 GW gas).
The new result showed in red is the total amount of 343 GWh which is similar to 2016 import as shown in the black bar.
In short, with a future renewable supply of 20GW by 2032, the amount of gas needed in order to have a reliable system is 4.3 GW of gas. This means that we need 2.6 GW of extra gas capacity by 2032.
3.1 If gas, how much CO2 would be emitted during a typical year? (High demand scenario)
By analysing data from energy plan renewables cannot run on it’s on, therefore base load is required to run the systems to start off. If gas is used as a base load to run the renewable systems it is important to determine how much gas is potentially required and will be dispatchable or non-dispatch able to run.
As seen above, currently we are emitting nearly 5.9 megatons of carbon dioxide emission. This data is analysed to compare if 100% renewables are used or if the gas capacity of 4 Gigawatt (GW) is added. The first orange bar chart indicated when running 100% renewables a small amount of carbon dioxide is emitted. This is due to biomass. Biomass is a renewable energy source which provides electricity when burning the feedstock, mainly wood. When comparing this to the 2016 emission data result, nearly 92% carbon emission will be reduced which would be an ideal case. As renewables cannot operate on it in other scenarios was taken when the gas capacity of 4GW is added for a stable electricity generation to the grid. The total renewable energy gas capacity of 20 GW plus gas capacity produce 4.72 Mega ton of carbon dioxide emission. This reduces current carbon emission by 20%.
CONCULSION
Based on these conclusions negative carbon emissions will not occur for 2032 or beyond. However, we can state we will have a reduced carbon emission from 2016 to 2032 by 20%. The graph below indicates a reduction of 66% from the baseline year 1995 which was determined by the Kyoto protocol and Paris report. This drastic change in carbon emission reduction indicates, we are leading to reduce carbon emission and can tackle global warming.Based on results from EnergyPlan and the analysis for each case it can be concluded that Scotland can be 100% renewable as the export capacity of 20.58 TWh is greater than the import which is 12.36TWh by 60%.
As the base load is required and environmental impact is a major focus, Scottish Government is predicting the carbon emission will be negative in the future. This is due to the use of carbon capture storage. In 2011 Scottish Power proposed to convert Longannet power plant in Fife to a large-scale carbon capture and storage plant. As this proposal was scrapped due to not enough funding for the development.
Carbon capture storage is a complex system and at the moment the storage system will not happen very soon. It is important to have an appropriate location for the storage site for compressing the carbon dioxide gas. Further research, development, planning and funding is required.
Based on this conclusion negative carbon emissions will not occur for 2032 or beyond. However, we can state we will have a reduced carbon emission from 2016 to 2032 by 20%. The graph below indicates a reduction of 66% from the base line year 1995 which was determined by the Kyoto protocol and Paris report. This drastic change in carbon emission reduction indicates, we are leading to reduce carbon emission and can tackle global warming.
To run the renewable energy system a base load is necessary to run a stable electricity production. The base load we can use to start the operation of the system are nuclear and gas PowerStation. It is predicted and still discussed, that the nuclear power station will be closed by 2032 or the following years. Therefore it is important we analyse if nuclear power station life can be extended. To operate renewables a suitable based load is needed that is dispatchable as it will only be used to operate when demand is increasing and the wind is not available. Based on this nuclear will not be a suitable option as it needs to run on the constant operation and cannot operate in a flexible mode. This concludes that we can run electricity generation with nuclear.
Based on these conclusions we can create a path to become more sustainable and create a suitable model to generate electricity in Scotland based on high renewable resource.
RECOMMENDATION
Final recommendations for future planning of electricity supply in Scotland
Transmission grid
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What is the recommendation to become 100% renewables?
To be 100% renewables it is important to have a significant strong interconnection, this is due to our results based on the graph that can be seen below. If we use the renewable resource to reduce electricity price and meet demand we have analysed our results that were determined by our data in Energy plan. It is predicated by 2032 we can have approximately 14 GW of export. As the interconnections are not strong we will lose 8 GW of energy due to export limitation. This is a lot of energy which will be wasted and therefore the first step is to develop and improve a stable and strong interconnection between UK and Europe to avoid loss of energy as it will have impacts on demand and economic. It is also important to accommodate wind energy when it’s not available as we cannot reply on export only, therefore, import is equally important to meet Scotland’s electricity demand.
Gas capacity
As analysed before base load is required and the suitable one is gas power. To operate the renewables we need the additional increment of gas capacity by 2.3 GW to have a total capacity of 4GW with current capacity.
The life of existing nuclear power stations
And we can also conclude, nuclear is not a suitable option as a standby for renewable energy, especially wind energy is required, therefore we do not recommend to extend the life of the 2 nuclear power station in Scotland. Instead we can replace them with 2 new gas power stations on the sites at Hunterston and Tonrness and use the existing electrical connections to the network. The current combined cycle gas turbine (CCGT) station at Peterhead needs to be maintained and replaced in the upcoming years to run smoothly with the combination of renewable systems
