Heat Decarbonisation

THERE’S NO ONE-SIZEFITS-ALL SOLUTION TO DE-CARBONISING DOMESTIC HEATING

Daniel Burton, Wondrwall

De-carbonising heating is high on the agenda for many social landlords and housing developers. As well as playing a vital role in tackling climate change, increasing the energy-efficiency of housing is essential to reduce the ever-increasing fuel bills for residents. According to the Committee on

Climate Change’s 2019 report on UK housing, “the quality, design and use of homes across the UK must be improved now to address the challenges of climate change. Doing so will also improve health, wellbeing and comfort, including for vulnerable groups such as the elderly and those living with chronic illnesses.”

Government funding initiatives, such as the SHDF (Social Housing Decarbonisation Fund) and the Green Homes Grant tend to favour a ‘fabricfirst approach’. The established view is that the best way to decarbonise domestic heating is to invest heavily in insulation, and then install a low carbon heating system, such as an air-source heat pump. Whilst this approach can work in many situations, it will not always be the most costeffective way to achieve the end goal. In some cases, it is not even practical or possible to retrofit homes in this way. Housing developers and social housing landlords must therefore urgently consider alternative approaches.

A CHANGE OF MINDSET

For many years, gas has been the go-to solution for domestic heating and hot water. However, as part of its commitment to decarbonising energy, the UK government has declared that from 2025, no new homes should be connected to the gas grid. While some hold out hopes that clean hydrogen gas may be available by then, it is not currently an option. Housing developers must now look for the most efficient way to heat homes using electricity as a source of energy.

With gas being so much part of the current mindset, it’s hardly surprising that air source heat pumps – which rely

on a familiar set up of pipes, thermostats and radiators – are currently the most popular way to electrify domestic heating and hot water. But while air-source heat pumps do have a lot to recommend them, they are not necessarily the best option in every case. Heat pumps rely on a ‘low and slow’ approach – drawing heat from the environment to gently but steadily heat homes. This works well if homes are extremely well insulated and the outside temperatures are not too low. Otherwise, either the heat is lost too quickly, or the system needs to operate well outside its margins of efficiency.

Air-source heat pumps are particularly unsuitable for retrofitting properties, as upgrading insulation to sufficient levels pushes the overall costs up significantly. On top of the cost of extra insulation, air-source heat pumps are an expensive retrofit. The old central heating system needs to be completely replaced with an external compressor unit, a new central hot water immersion tank, heating water clusters and more. The radiators also need to be bigger to compensate for the lower running temperature. There are also some situations where fitting a heat pump externally is simply not viable – for example in high-rise buildings.

There is another option out there, however, that takes a radically different approach.

AN ENERGY SOLUTION FOR THE DIGITAL AGE

Manchester City Council recently explored a different approach to electrifying domestic heating in a newbuild development in West Gorton, Greater Manchester. The affordable houses were equipped with modern digital and renewable energy solutions that can deliver reductions to energy bills of up to 90% for tenants.

The mews-style three-bedroom homes, built in partnership with Manchester City Council, are fitted with solar PV and battery storage. But what makes them unique is the

intelligent solution that ties these elements together. The self-learning system, designed by Wondrwall, automatically adapts heating, lighting, security and energy consumption according to the behaviour of the occupants, environmental conditions and wholesale energy costs. A combination of electric underfloor heating and infrared panels can quickly provide warmth when needed, and the intelligent, partitioned, hot-water cylinder heats water only when needed. A system comprising solar panels, inverter and battery storage provides free electricity from the sun and enables the tenants to take advantage of hourly fluctuations in energy costs. For new and old properties, the cost of installing this ‘smart and agile’ solution compares favourably with wet heating systems, heat pumps and high levels of insulation.

A DAY IN THE LIFE OF AN INTELLIGENT HOME The key to the effectiveness of the system, is its ability to learn and adapt to the information in real time. The system will begin a typical day by checking the weather forecast shortly after midnight. Combining this information with what it knows about the behaviour of the occupants and the performance of the solar panels, it will predict how much electricity it needs to draw from the grid to meet the family’s needs for the day.

The system then analyses time-ofuse tariffs for the day and determines the most cost-effective time to charge the domestic batteries. If there is an unexpected energy requirement during the day, the system might respond by supplying energy from the battery and importing energy from the grid. Conversely, if there is a spike in energy from the PV solar panels, the system will export energy back to the grid. During the evening, when energy prices are at their peak the system powers the house entirely from energy stored in the battery. After midnight, the system processes the day’s data, adjusts its algorithm accordingly, and the cycle begins again.

A SMARTER APPROACH TO ALLOCATING RESOURCES

When faced with a big task and a limited budget, it makes sense to allocate resources where they will be most effective – even when that means questioning our assumptions. It’s clear from the West Gorton project that ‘fabric first’ is not the only way to decarbonise domestic heating. A smart and agile approach may be a better fit in many situations. Social housing landlords and housing developers should therefore evaluate projects on a case by case basis when choosing the right approach to decarbonise domestic heating, rather than putting their faith in a one-size-fitsall approach. https://wondrwall.co.uk/

DECARBONISING HEAT PRESENTS A HUGE CHALLENGE FOR THE UK

Large scale transformation in the way in which energy is generated, distributed, and consumed is paramount for the UK to hit its net zero commitment says Daniel Collins, Consultant, avieco.

Technology alone is not enough. If we are to decarbonise heat and convince 30 million homes to switch to low carbon heating, we require a combination of innovation, investment and incentives policies to expand on the current uptake and provide consumers with the confidence that new technologies can be as efficient, cost-effective and reliable as traditional heating systems.

While lockdown has brought about a significant drop in carbon emissions as well as a clearer London skyline, the economical and societal impacts of Covid-19 have served to amplify the urgent need to build resilience to climate change. We may not yet have been afforded an insight into the government’s proposed ‘green recovery’ to the pandemic, but the energy sector will unquestionably be at the epicentre of such plans.

The UK’s commitment to net zero carbon by 2050 requires a large-scale transformation in the way in which energy is generated, distributed, and consumed. The past decade has seen considerable advances in decarbonising the power sector. The closure of coalfired power stations and the increased proportion of renewable electricity in the grid (both large-scale schemes and

individual buildings and developments) have contributed to the plunge in electricity carbon intensity, which is predicted to be as low as 50g CO2e/ kWh by 2030 and must be less than 20g CO2e/kWh at net zero. However, heating remains the largest source of our greenhouse gas emissions in the UK, and progress towards its decarbonisation has flattered to deceive.

At 37%, heating accounts for the largest proportion of UK greenhouse gas emissions we must act now before the challenge magnifies even more.

“Heating is central to our lives. In our homes, we rely on it for comfort, cooking and washing. Businesses need heating and cooling for productive workplaces and heat is integral to many industrial processes. It is the biggest reason we consume energy in our society.” - Department for Business, Energy and Industrial Strategy

Fossil fuels deliver most of the heating in our buildings and industries; and natural gas remains the predominant heating source for most customers connected to the grid. At the current rate, it is estimated that it would take 1,500 years to decarbonise the heat sector. While the scale of the challenge may appear daunting, the time for action is now. The decarbonisation of heat is the greatest challenge the UK faces to become a net zero carbon economy.

WHAT MAKES DECARBONISING HEAT SO CHALLENGING?

Scale of the challenge - Around 85% of the 28 million UK households are connected to the gas grid. Only about 5% of homes currently have low carbon heating – mainly comprising electric heat pumps, wood burners and biomass boilers. We need to be converting 20,000 homes a week (1 million annually) by 2025 to hit our 2050 targets.

No silver bullet solution – As is so often the case, there is no ‘one size fits all’ approach to decarbonising heat. Moreover, estimates suggest that a top-down solution such as all-electric is projected to cost 2-3.5% more than a tailored approach looking at solutions at an individual building level.

Poor energy efficiency – The UK building stock is generally of poor thermal efficiency. Retrofitting low carbon heating poses a challenge as technologies operate most effectively in conjunction with energy efficiency upgrades. This has led to increased demands for new standards for zero carbon homes and commercial properties.

Current heat decarbonisation policies are not working – Policies like the renewable heat incentive (RHI) and the ECO scheme have failed to have the desired effect. Simply put, the high upfront cost of renewable heating systems reduces the viability for most households. Over nearly four years, only 60,000 renewable appliances were installed under the Domestic RHI, compared to 6.2m gas boilers. As a result, other policies are having to work harder to enable the government to meet its legal obligations.

Resistance to Change – Unlike the power sector, heat decarbonisation has a direct effect on consumers as it often involves upgrading technologies within the home. About 90% of UK homes still use gas boilers, many

of whom are opposed to removing a technology which has long been accepted as a comparatively efficient and convenient heating source.

HOW CAN WE MAKE ZERO CARBON BUILDINGS? • Heat pumps are the most efficient way of using electricity to heat your home. They offer a modern, low-carbon solution to provide space heating and domestic hot water. Heat pumps are particularly appropriate in countries which have both high heating requirements (in winter) and cooling requirements (in summer). Manufacturers offer either air-source and ground-source heat pumps, which sit outside a building and extract warmth from the air or ground to heat water for radiators. • District Heating involves a system of highly insulated pipes delivering heated water to radiators in numerous homes and buildings.

Heat is generated from a central boiler plant or other heat source, such as a biomass or gas-powered

‘combined heat and power plant’ or local waste heat from industry. • Other prospects to help achieve net zero in buildings include hydrogen boilers and Heat as a

Service, although these remain in the early stages of development.

But technology alone is not enough. If we are to convince 30 million homes to switch to low carbon heating, we require a combination of innovation, investment and incentives policies to expand on the current uptake and provide consumers with the confidence that new technologies can be as efficient, cost-effective and reliable as the traditional systems.

Government targets and increasing public awareness of the immediate action required to combat the effects of climate change have thrust heat decarbonisation to the forefront at a national and local level. With multiple stakeholders comes the urgent need for leadership and a clear path to net zero if we are to meet our targets for 2050 and beyond.

HOW CAN WE HELP?

Feasibility studies from Avieco, funded by the Rural Community Energy Fund (RCEF), will give you a compelling case for viable renewables projects to benefit your community – at no cost to you. We have worked with RCEF fund administrators across the country and know what makes a strong RCEF funding application. We have completed multiple RCEF feasibility studies, and many of those communities have gone on to complete a variety of renewables projects. Our recent success stories include supporting Swaffham Prior in implementing UK’s first “retrofit” heat network, identifying the best solution for onsite renewables for Cuxton Parish Council and many more. Our “Community-led heat projects” guide aims to support communities who want to explore the potential for local heat networks where they live. The guide originates from our experience in supporting communities in planning for and installing heat projects, and has been produced by Avieco and the Swaffham Prior community heat project board, funded by Cambridgeshire County Council, Cambridgeshire & Peterborough Combined Authority, and the Department for Business Energy and Industrial Strategy. As well as delivering RCEF-compliant feasibility studies, we work with companies on the journey to net zero, and how heat decarbonisation can play a central role in such plans. Head over to our case studies to know more about our work. www.avieco.com

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