Keeping your house warm may not be a priority at the height of summer but achieving Scotland’s ambitious target of being net zero by 2045 requires all of us to act.
Domestic heating accounts for 13% of Scotland’s total greenhouse gas emissions, and 30% of Scotland’s total energy consumption. Reducing emissions requires not just a switch to green energy but also a decrease in demand. One way to achieve that is to ensure the heat produced by our existing domestic boilers does not escape our homes.
Heat retention
Traditionally built Scottish stone houses were unfortunately not designed with efficient heat retention in mind.
To make progress in this regard, a government must have benchmarks for their housing stock. Anyone who has bought or sold a property recently will be familiar with the UK-wide energy performance certificate (EPC) rating system. This ranks homes from band A to G (with G being the least efficient). The most recent statistics – published in 2019 – reveal that 55% of Scottish homes (approx 1.4 million) were at the lower end of the efficiency scale. Given the Scottish Government’s pathway to net zero assumes that all domestic dwellings will be rated at the higher end of this scale by 2033, this represents a major challenge over the next decade.
However, we do have some tools to help us, including the technology to build new houses and flats which achieve minimal heat loss. There are also several ‘DIY’ measures individuals can take for existing housing stock, such as stopping draughts, adding thermal linings to curtains, fitting secondary window glazing or putting insulation in lofts.
Going beyond those measures, however, requires expert advice, as incorrect fitting of cavity wall insulation for example could lead to costly problems such as condensation. For houses without wall cavities there are other options to retain heat in the home. Insulating can be expensive, particularly for older properties, but in Scotland the government has promoted its use via government grants.
There are two key challenges to the government’s progress towards net zero and as a result to people’s energy bills. The first is to stimulate homeowners to be proactive about checking their options and the support available. The second, and something where the government has made progress, is not relying on a ‘one size fits all’ solution. It must design flexible policy and funding for different buildings. With spiralling energy bills, it seems there is more incentive to tackle these challenges than ever.
Low carbon heating
Another strand to the government’s pathway to net zero is reducing the greenhouse gas emissions associated with heat production for our homes.
In 2019 only 11% of Scottish homes (approx. 27,8000) had a renewable or low emissions heating system, but the decision to change domestic heating sources is not solely in the hands of homeowners. In the same year, two million homes used gas as their primary heating source, and switching to electric heat pumps (an environmentally desirable heating source) would require the electricity grid to be upgraded to cope with the increased demand. Responsibility for changes to national infrastructure like this are a government’s responsibility, and will take time and investment.
It is possible to decrease our dependence on natural gas through partial replacement with biomethane or hydrogen (which can be sustainably sourced). The Scottish Government has set a target to replace 20% of natural gas by 2030. Total replacement of natural gas supply would require significant infrastructure change and has not yet been confirmed as the most cost-effective sustainable option. At a national level we see the same barriers as for heat retention targets; there is no ‘one-size fits all’ solution although change is inevitable.
The Scottish Government is currently revising its energy route map with publication of its new ‘Energy Strategy and Just Transition Plan’ expected later this year. It understands the needs to build agreement to move forward, and is seeking to engage “citizens, places, businesses and workers” on the priorities for change. The action required for those of us in Scotland is to participate in the consultations, even if you have more questions than views.
By feeding in questions, it helps the government understand people’s concerns and need for information. Given these issues are complex and possible success requires us all to act, it is essential we take the time to keep ourselves informed. On the plus side you will also have a greater understanding when next making decisions about replacing your boiler.
Professor Maggie Gill FRSE chaired an event by the Royal Society of Edinburgh called ‘Road to net zero – Heating our homes through local heat networks’ at Curious 2022. Find other events in the series here: https://www.rse-curious.com/
