Cut the carbon

Given the environmental and financial implications of high energy use, there’s no better time to take a fresh look at low carbon heating solutions, says Mike Hefford, Head of Renewable Technologies at Remeha Commercial.

At last it seems as though things are finally on the up as the UK inches its way out of recession and economic growth seems a possibility once more. It’s never easy running a profitable organisation, but it’s particularly challenging in today’s economic climate given the ever-rising fuel prices and increase in government-imposed environmental legislation and targets.

Taxing dilemma

Take the CRC Energy Efficiency Scheme, for example. This mandatory scheme is intended to improve energy efficiency and cut emissions in large public and private sector organisations, helping towards the government’s steep carbon reduction target of 80% by 2050 from its baseline 1990 levels. The CRC effectively taxes all organisations consuming over 6,000 MWh a year with half hourly metering for the carbon emissions that are attributable to energy consumption. However, as we enter Phase 2, the tariff, initially set at £12 per tonne of carbon emitted for Phase 1, has risen to £16.40 per tonne (albeit with a slightly discounted allowance for advanced purchases for 2014/15 consumption of £15.60) for Phase 2 participants for 2014/2015. And ironically, the predicted economic recovery may mean that organisations that escaped Phase I of the CRC will now qualify for the scheme due to growth in business or an expanded site. Equally, existing participants may see their financial responsibilities rise significantly due to greater energy use and the new higher tariff on carbon emissions.

The CRC is just one of many reasons why it is essential for us to continue to monitor carefully our energy use. Research undertaken by the Carbon Trust into large private and public organisations shows a 35% reduction in carbon emissions by 2020 from non-domestic buildings can be achieved using cost-effective measures, yielding a net benefit to the UK of at least 4bn. A recent paper produced by Deloitte also suggests the opportunity for reductions of energy consumption in the £647bn commercial property industry is substantial. Research suggests that investing in energy efficiency measures is the practical means of reducing energy consumption and carbon emissions.

Why waste?

Given the environmental and financial incentive to cut carbon, organisations should seek every possible opportunity to save energy. Heating and hot water production can account for as much as 60% of an organisation’s total energy use and around 40% of its carbon emissions, according to the Carbon Trust, so it is a good starting point for energy- and carbon-saving measures.

New build developments are designed to require less energy, with the low-carbon requirement often fulfilled by tried-and-tested renewable technologies such as biomass or heat pumps. But the real problem for organisations is our existing building stock. According to the Building Research Establishment, 60% of the buildings that will be standing in 2050 are already built. Here, a significant proportion of heating is provided by commercial boiler plant with the replacement of any inefficient boilers with a modern high-efficiency gas condensing boiler often topping of the list of carbon cutting measures.

LZCT Bolt-Ons

However, replacing the boilers can be seen as just the first piece of the energy- and carbon-saving puzzle. Depending on the nature of the building and the state of the coffers, including an allocation for complementary renewable LZC technologies in the budget for boiler plant renewal will help maximise the building’s saving potential and aid our progress towards achieving our carbon goals. Equally, in buildings where the heating is delivered by still serviceable gas condensing boilers, up to five years old for example, adding a renewable bolt-on is a further opportunity to lower your organisation’s carbon footprint without having to invest in a complete refurbishment of the heating system. It is an attractive ‘green’ solution to achieving greater carbon reductions and lower energy consumption at a lower capital cost.

Biomass

Which LZC technology to choose? Biomass is one of the most popular of all renewable technologies, offering high performance heating and excellent efficiencies of up to 96% with emission levels significantly below the new minimum levels of Building Regulations. The Carbon Trust suggests that lifetime CO2 emissions for woodchip biomass are in the range of 10-23 kg CO2/MWh compared with 263-302 kgCO2/MWh for natural gas. As technology advances, biomass boilers now offer greater ease of use and flexibility. A key factor for consideration is the space requirement: biomass systems are considerably larger than an equivalent fossil-fuel plant and require sufficient free space around the unit for maintenance and cleaning; they also require fuel storage either above or below ground, within an existing building or in an external container. Biomass is best suited to being operated fairly continuously (between around 26 per cent and 100 per cent of its full capacity), so perfect for buildings where the heating system is used for long periods during the year such as hospitals or hotels.

Heat pumps

Like biomass, heat pumps are a popular, reliable renewable technology that integrates well with condensing technology in a heating system. Gas absorption heat pumps use gas rather than electricity to fire the heat pump, making them a more cost-effective, environmentally-friendly option than other heat pumps as well as more familiar than some other renewable equipment and relatively straightforward to install. Gas absorption heat pumps like Remeha’s Fusion range can reliably achieve outstanding seasonal efficiencies of between 120 and 130% NCV with carbon reductions of up to 40% compared to traditional gas equipment.

Five steps to renewable success

Two important considerations before installing any renewable technology either as a bolt-on or in a newly-designed system are how it will work for a particular building and how it will operate with the other components in the heating system. The equipment needs to be accurately sized, the system well designed, the technologies properly installed and the appropriate controls added. An adequate budget should also be allocated for commissioning, the crucial last stage of the design concept. Failure to carry out any of these steps could result in unexpectedly high operating costs as the low-carbon technology could fail to perform as expected.

Finally, when integrating two technologies into the heating system, it often pays to use the same supplier whose knowledge and expertise of both components will support smarter system design, maximise efficiencies and reduce carbon emissions. And be sure to follow the five steps for success: if you want to cut carbon, then avoid cutting corners.

This article first appeared in Heating & Ventilating Review



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