Key strategic decisions on the decarbonisation of heat in South Wales will likely need to be made in the next five years to enable critical infrastructure investment planning.
This is according to research by Western Power Distribution, Wales and West Utilities and Regen.
All three have collaborated to produce joint electricity and gas scenarios for a 2050 net zero in the region, looking specifically into heat, which they described as the “most significant variable in distribution net zero analysis”.
Three scenarios – High Electrification, Core Hydrogen and High Hydrogen – were modelled, alongside a hybrid heat sensitivity and an illustrative simulated day analysis for summer and winter in 2019 and scenario years 2035 and 2050.
In the High Electrification scenario heat is mainly produced through heat pumps, hydrogen is used for heat in urban areas only in Core Hydrogen and hydrogen is available to all existing gas customers in High Hydrogen.
The findings show that High Electrification and hybrid sensitivity result in the biggest declines in carbon emissions from heat in the short term, but Core and High Hydrogen assume a hydrogen switch over after 2035, meaning emissions decline from this point.
High Electrification also saw the lowest overall energy use, mainly due to the energy efficiency of heat pumps, which are assumed to have a seasonal performance factor of up to 300% by 2050, although higher energy efficiency in buildings would also contribute.
Across the three scenarios, the amount of renewables connected to the distribution network is largely the same, although large projects likely to be connected to the transmission network were not included in the modelling.
Distribution connected renewables were projected to provide between 50% and 60% of the annual electricity demand in South Wales by 2050, with distributed solar and wind capacity increasing by over 350% to 5.8GW.
Overall, it was concluded that decentralised energy supply of both gas and electricity is expected to meet an increasing proportion of annual demand.
Alongside this, it was predicted in all scenarios that battery storage capacity will significantly increase by 2050, reaching 599MW under the High Electrification scenario.
The summer and winter day analysis found that there is likely to be significant variance between electricity demand and decentralised electricity generation in both seasons, which the report said highlights the role of time of use tariffs, smart EV charging, more sophisticated heating control systems and Demand Side Response.
It also found, however, that a strong solar and moderate wind summer day can already potentially exceed underlying domestic and commercial electricity demand in South Wales, implying the region could be exporting c.1.2GWh of electricity generation across the day into the transmission system.
Commenting on the need for the modelling of the scenarios, which was funded through the Network Innovation Allowance, Poppy Maltby, senior manager at Regen, said the energy networks will be “fundamental” to supporting the net zero transition.
“This net zero scenario analysis helps them understand and plan for how this transformational change could impact their operations in the short, medium, and longer term.”