If the UK is to achieve its ambitious target to reduce its greenhouse gas emissions to net zero by 2050, we need to revolutionise the way we heat our buildings. While we await the publication of the government’s Heat and Buildings Decarbonisation Strategy, we take a look at the options.
Back in June 2019, the government signed into law the UK’s ground-breaking commitment to reduce its greenhouse gas emissions to net zero by 2050. This bold target will require the near complete decarbonisation of heat.
In tackling the challenge, the focus has centred primarily on the UK’s 28 million homes, 85% of which are connected to the gas grid. But a step change in how we heat non-domestic building stock will also be essential to achieve this goal.
So how do we envisage the future of commercial heating? Clearly a single ‘silver bullet’ approach to decarbonisation is impossible as older, less thermally efficient commercial properties will have very different requirements to well-insulated, well-designed new build stock.
Instead, we believe that applying a mix of different technologies, each appropriate for different applications, will offer a combined solution to the challenge ahead. These include electrification, heat networks and decarbonisation of the gas grid.
The government seems to agree. In his November 10-point plan for a green industrial revolution, the Prime Minister announced funding into a hydrogen infrastructure and support for heat pumps to support a multi-technology approach to net zero buildings for the next 30 years.
While we await definitive government guidance on the future energy mix, let’s consider how this blended approach could be applied to commercial heating in the immediate, medium and long term.
Electrification
In new and well-insulated commercial properties, the merits of applying electric technologies such as heat pumps are well established. We see Air Source Heat Pumps (ASHP) as the most popular and cost-effective choice of heat pump and will soon be offering them as part of our wide portfolio of commercial heating and hot water solutions.
Unfortunately, when it comes to our older buildings, the technically and economically viable solutions are constrained.
Retrofitting heat pumps onto older heating systems in poorly insulated commercial properties, for example, is not always straightforward.
One reason for this is that older systems tend to run on high flow and return temperatures (82ºC/71ºC) while heat pumps typically optimise their efficiency at low flow temperatures (around 30-55ºC). The existing system design will therefore need to be addressed if the required heat pump performance is to be achieved.
Additionally, only a small portion of ASHPs can efficiently generate temperatures high enough to store domestic hot water above legionella temperatures (60ºC or higher). Therefore, until heat pump technology evolves, a rethink of the hot water strategy in older buildings could well be necessary to accommodate.
Energy efficiency upgrades will also need to be carried out in thermally inefficient building stock to enable heat pumps to operate most effectively. A further consideration is the electricity supply into the building which will likely need to be increased. All of these factors will have considerable financial implications.
Hydrogen
So what are the alternatives for our existing buildings – around 80% of which will still be in use in 2050? One low disruption, medium to long term solution is to repurpose the gas grid to transport green gas.
As hydrogen is a gas, it can capitalise on existing infrastructure while transitioning us to a cleaner fuel source. We at Baxi Heating and BDR Thermea have been working closely with UK Government to trial hydrogen in a number of projects. 20% hydrogen blends are being demonstrated using current boilers at the HyDeploy project at Keele University. We are also demonstrating prototypes of 100% hydrogen boilers through the UK government Hy4Heat programme, with larger scale trial projects in development.
The government has committed £81m investment from 2021 to develop hydrogen generation capacity and to create the first hydrogen heated neighbourhood by 2023, the first village by 2025, then the first town by the end of the decade. So, it isn’t far-fetched to envisage businesses heating their buildings with low carbon hydrogen boilers long before 2050.
Evolving technologies
But where does that leave us in the short term? Heating is vital to keep our buildings functional, comfortable and safe. However, with many businesses financially impacted by the COVID crisis, building operators may struggle to balance environmental and economic concerns when the old boilers need replacing.
Realistically, many operators of commercial buildings will continue to depend on gas to heat their properties for the next decade. That being so, our focus must be to help them use this energy source as efficiently as possible.
Upgrading any dated or inefficient boilers to high efficiency condensing boilers is still one of the most cost-effective solutions available to reduce emissions associated with heat. At the same time, condensing boilers are a core component in hybrid heating systems and heat networks.
Recognising this, forward-thinking manufacturers are continuing to evolve condensing boiler design, optimising adaptability and performance to meet the demands of modern commercial heating solutions in new and old plant rooms alike.
Remeha’s next-generation Gas 320/620 Ace series, for example, has been designed to provide an adaptable project solution with a high temperature differential (∆T) of 10°C to 40°C and wide operating range of 20°C to 80°C/90°C.
As such, this range is the perfect heat source for heat interface units, low temperature heating and hybrid systems. But crucially it is equally well-suited to retrofit applications, while still paving the way for the addition of low carbon technology at a future date or when funds permit.
Preparing for net zero
The future of heat brings opportunities and challenges. At Baxi Heating, we are continuously evolving our products and expanding our portfolio to provide the complete low carbon solutions and immediate, achievable energy-saving opportunities required to propel the decarbonisation of heat. We look forward to supporting installers, contractors, designers and consultants with our specialist product knowledge and technical expertise, so that as an industry we can drive the UK’s move to net zero.