Amendments to the Renewables Obligation (Scotland) - Technical Note
This note summarises the potential impacts of increased hydro electricity generation capacity in Scotland, occurring as a result of the amendments proposed by this consultation.
The system-wide impacts of this legislative change have been assessed in terms of:
1. Electricity generation from renewable sources
2. Greenhouse gas emissions
The Scottish Electricity Dispatch Model ( SEDM) was used to model three scenarios, outlined below. These scenarios cover a range of estimates concerning how much additional hydro DNC would be added to the system, from 2019 onwards, and are based on the latest intelligence from the key operators in this sector:
i. Low – zero additional hydro capacity (counterfactual)
ii. Central – 10 MW additional hydro capacity
iii. High – 50 MW additional hydro capacity
High and low impact estimates have been modelled for each of the scenarios above, reflecting the range of actual observed load factors in Scottish hydro stations in recent years.
Electricity Generation from Renewable Sources
The introduction of additional hydro generation capacity could result in an increase in electricity generated from renewable sources in Scotland. Table 1 outlines the potential ( GWh) impacts on renewable electricity generation in Scotland of each of the three scenarios outlined above.
Table 1: GWh Renewable Electricity Generation
|Scenario||Additional Hydro Capacity ( MW)||Additional Renewable Generation (Annual, GWh)||Additional Renewable Generation (Annual, GWh)|
The central and high scenarios represent between 0.6-3.0% of Scotland's existing hydro generation capacity, and would contribute towards Scotland's renewable electricity target.
Additional hydro generation could decrease generation levels of other technologies, based on the merit order. From 2019 onwards, the modelling suggests that generation from Combined Cycle Gas Turbines is displaced.
Greenhouse Gas Emissions
The introduction of additional hydro generation capacity could result in a reduction of Greenhouse Gas Emissions ( CO2) in Scotland through displacement of higher-emitting, fossil fuel generation. Table 2 outlines the potential CO2 impacts of each of the three scenarios outlined above.
Table 2: CO2 displacement
|Scenario||Additional Hydro Capacity ( MW)||CO2 Displaced (Annual, ktCO2)||CO2 Displaced (Annual, ktCO2)|
The central and high scenarios are expected to reduce CO2 emissions, contributing towards progress on Climate Change targets.
The introduction of additional hydro generation of the levels set out within the three scenarios covered is not expected to result in any changes to the cost of electricity within the energy system.