Are buildings ready for renewable energy?
There is a huge amount of activity around renewables and a multitude of initiatives, but are buildings actually ready to maximise the benefits of renewable energy? Blane Judd considers the question.
Renewable heating and cooling technologies are a big business opportunity for the building engineering services sector. Installation is based on the tried-and-trusted thermodynamic principles of engineering that we use day-to-day, but there is also a huge amount of work for specialists to do in making sure buildings are ‘renewables ready’.
Overall, our use of energy is falling. According to the latest government figures, we used 7% less energy last year than in 2010. We consumed the equivalent of 203 Mt of oil to power our buildings, transport and industry. 10 years ago that figure was 240 Mt.
We are becoming more energy efficient, but not fast enough. The country still faces a looming energy gap, not helped by the recent news that German power giants RWE and E.ON have pulled out of projects to build two new nuclear power stations in Wales. The aftershocks from last year’s Japanese tsunami and subsequent nuclear meltdown are still being felt around the world. Germany led the way in mothballing its nuclear power capacity and we are now seeing the results of that policy further afield. Nuclear is not going to make up the difference when more of our old coal-fired power stations close down during this decade. So, what about renewables?
Currently renewables account for just 7% of our total electricity generation, but we are legally obliged to increase that to 30% by 2020 under EU rules. That target looks a very long way off, largely because we continue to focus on capacity rather than on reducing demand. We can narrow the gap by making sure buildings do not require so much power and by generating more of what we need at a local and individual building level.
To be truly sustainable, buildings need to be capable of adapting to a range of solutions so that the energy gap we ask renewables to plug continues to narrow. For example, there is growing enthusiasm for the wider deployment of voltage optimisation. This reduces the electricity supply from the standard 240 V to 220 V, which has a dramatic effect on demand and costs while also extending the life of appliances.
Optimisation units cost just a few hundred pounds and have been shown to cut energy costs by around 10%. The technology is used in the offices of the Department of Energy & Climate Change (DECC) and power regulator Ofgem, but receives nothing like the level of official promotional support enjoyed by renewables.
Our industry’s focus has to be on measures like this, to force down energy demand. Building engineering services contractors have the opportunity on a daily basis to advise clients on upgrading controls — perhaps looking to add weather optimisation to high-efficiency heating systems to further improve energy efficiency, for example. They also look at where energy-consuming plant has been oversized or wrongly commissioned — if commissioned at all.
|Meeting targets for the proportion of demand met by renewable energy will be made much easier by reducing demand rather than continuing to focus on capacity|
Heat pumps are another favoured technology, but their deployment has not been plain sailing. The 2010 Energy Savings Trust field trials exposed many problems with their operation, and none of those tested had a coefficient of performance (COP) higher than 2.5, which is well below the optimum. We know the technology itself is fine, but it is how it is deployed, commissioned and operated that counts. Ground-source systems are ideal with low-temperature heating systems, such as underfloor, and this combination works really well where it is properly applied — and that’s the key.
The Green Deal and the Renewable Heat Incentive (RHI) put this issue of performance fully in the spotlight. Our industry must be technically capable of keeping its promises. If systems do not perform as promised, the right level of payments to end users will not be forthcoming and these flagship Government policies will fail — not to mention the collapse of a fragile emerging market. By the same token, poorly performing buildings will not extract maximum benefit from any renewables added to them, with a consequent loss of consumer and client engagement.
There is also an emerging problem with heat meters. If they do not work properly or are wrongly calibrated, they will deliver erroneous data that could undermine the RHI payment system. The Building & Engineering Services Association (B&ES), formerly the HVCA, has been working with industry partners to develop guidance on this potential Achilles’ heel. The draft has now been put out for open industry consultation so that we can get something helpful out into the marketplace over the next few months.
The one thing all the technical solutions have in common is the need for robust commissioning and expert integration of technologies as part of an overall building energy saving strategy. Integration is the key to delivering the ongoing performance and energy savings so vital to our future economic prosperity. That is where building engineering services contractors come into their own.
We need a fully competent, multi-skilled workforce capable of understanding the wider issues around building performance, but also able to deliver at the equally important mechanical and electrical level. It is this mixture of detail, together with the ability to integrate systems, set in a wider whole-building performance context, that makes building engineering services so fascinating.
Blane Judd is chief executive of the Building & Engineering Services Association (B&ES), formerly the HVCA.