HEATING & HOT WATER
Making the vision a reality: a future for sustainable hot water
The government’s efforts to deliver climate action have been described as “worryingly slow,” its showcase green heat pump scheme “significantly off track” by the UK Climate Change Committee (CCC). Its latest conclusions are that the UK would struggle to reach its targets for cutting carbon emissions whilst losing its leadership position on climate issues. Greg Brushett, UK sales manager at Adveco explores what lies ahead
F
or those operating in the commercial and public sectors, the complexity of the challenge has been long apparent, as has been the government’s skewed focus on domestic carbon
reduction, despite the tremendous amount of existing commercial properties which contribute considerably to the UK’s total carbon emissions.
National Grid modelling incorporates heat pump installations as part of all future low- carbon scenarios, but within eight years its models also look to the introduction of hydrogen. Still to be formally decided upon by the government, all we can say for certain is that hydrogen may be part of the future, and most likely for commercial properties with large demands for heating and/or hot water. What we do know is electrification of heat is part of our future and it is available now. Whilst there are macro challenges for an all-electric network, from production and transmission of enough electricity to meet increasing demands, to speed and cost of delivering new grid connections, our concerns as an industry must focus on the buildings before us. As a hot water specialist, we recognise that low carbon heat sources need to do one thing – preheat the water, reducing energy consumption of the water heater to lower carbon emissions and manage costs. In recent years though it has become clear that carbon savings and cost savings for water heating are no longer aligned. As an example, if we take a building with an average occupancy rate of 23.5 with provision of basins, and shower/wet rooms, typically seen in student accommodations, care homes or boutique hotels, the yearly running costs resulting from a change from gas to direct electric would increase from £1,019 to £3,019 (based on electricity on average currently costing as much as 3.8 times that of gas). As a result, clients will push back when faced with increased running costs. Even with an ASHP operating at optimum efficiency (for 35% recorded reduction in energy) costs would still more than double to £2,862. Are modelled 70%+ reductions in carbon therefore enough of a reason to convince most organisations to actively invest in change? For some certainly, but many will struggle with this new reality. This means the deciding factor for investment in low-carbon systems needs to come from building regulations.
Although carbon intensity has been changing for years, Part L took five years to introduce new carbon figures in 2108, subsequently adopted by the Greater London Authority, and other larger UK cities. But delays have meant Volume 2 did not take effect until last year, and although
16 BUILDING SERVICES & ENVIRONMENTAL ENGINEER AUGUST 2023 Read the latest at:
www.bsee.co.uk
carbon intensity figures were revised, there still is no separate document for new build and refurbishment. There is, as a result, great hope for the next iteration of Part L, which currently is under consultation for publishing in 2025 and is expected to be active the following year. The Future Buildings Standard (FBS) sets out
proposals for providing a “pathway to highly efficient non-domestic buildings which are…fit for the future.”
What has become very clear from the consultation phase have been the concerns over reliance on the decarbonisation of the electricity grid, and as a result increased pressure on the grid. This could well mean that we see a softening of stance from the government toward hybrid systems that allow for a more holistic and necessary approach to sustainable water heating. With EU legislated EcoDesign also being updated (and the UK could again recognise its directives) new gas connections are unlikely to be approved for most building types, essentially making it impossible to use on a project from 2029. Under the new FSB regulations commercial properties with large domestic hot water (DHW) demands, and those buildings that cannot easily be supplied by electricity could remain exempt. This would come with the caveat that large amounts of renewables should also be installed. In terms of DHW, that could be simply achieved through the addition of solar thermal systems and/or heat pumps. Interestingly this approach neatly aligns with potential future hydrogen connections, bringing new build and large scale retrofit onto the same technology paths which could be decisive in helping reduce capital costs in the mid- to long-term. While some voice little belief in the likelihood of a hydrogen future, should the government opt to include it as part of a broader clean energy
mix hybrid systems will inherently be required. This also would help alleviate serious concerns that not enough connections would be available if entire building and transport system were to depend on electric-only power. We have alluded to the current higher operational costs of all-electric systems, but it would be a considerable surprise if, over the next five years, the government failed to address this. By matching the cost of electricity to that of gas, and levelling the field in terms of running costs, capital costs and emissions reductions become the decisive factors. The government remains convinced that as heat pumps become more mass market prices will, later this decade, markedly fall. But we would not advise holding off on sustainability projects on this basis. Despite the complexity of current commercial hot water systems, prices are unlikely to greatly shift downwards over time, plus there is the added incentive that investment today delivers an immediate impact on a building’s carbon emissions. To achieve Net Zero in buildings, we face a choice, electrify all equipment on the basis that the electricity grid will become zero carbon, or change natural gas to a carbon free gas such as hydrogen. While the final energy solution remains undecided, planning requirements are and will continue to force change in the near term. These regulations will not completely exclude gas, but they do advantage electric- based heating and hot water, such that many buildings are already built without gas supplies, even though this reduces options in the mid- to long-term. Whichever route chosen will require low carbon preheating and organisations need to understand this now if they are to successfully implement decarbonisation strategies. Simply relying on the grid becoming ‘green’ is not enough.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42
