Do we fully understand how to be sustainable, or what Net Zero really means to a business? If we look at the experts in the field they will talk about BREEAM as a tool for helping you achieve net zero for new construction, refurbishments & fit out, in use and communities.
Similarly we have NABERS which is another scheme focused on operational energy efficiency and comprises of a star rating system for how efficient your building performs.
Both schemes are great at benchmarking variables and saying whether an organisation is on a net zero trajectory and, it’s claimed, will provide confidence to the market that building owner/operators are aligned in the carbon reduction ambitions.
“We do not inherit the Earth from our Ancestors we borrow it from our Children”
— Native American Proverb
In addition, we have standards such as ISO 50001 (Energy Management) and ISO 14001 (Environmental Management Systems).
In each case the goal is the same: reduce your energy, minimise waste and maximise the life of the products. I fully support this approach; however, I would argue this is great on a major new build where you have a dedicated team of engineers working together to achieve targets defined by the client, building control, etc., and also where convergence of technology is possible.
When we consider refurbishment then our start point has changed as we have an occupied or partly occupied building with a fabric that might be dated or limited by its design.
Do these energy efficient standards adequately support refurbishment and do they penalise certain construction practices?
BREEAM does mention refurbishment and if you rip out and replace everything and start with a clean slate then, it’s not too dissimilar to new build.
If, however, we factor in circularity and look at how we can reuse rather than rip out and replace we have to perhaps have a slightly different metric to measure efficiency.
Upgrading to LEDs saves energy, and if these can be integrated into the existing luminaire housings then a significant impact can be made on waste and carbon.
Obviously, with all refurbishments — and especially the refit of LEDs to an existing luminaire — testing will have to be undertaken to prove the performance of the luminaire and the lighting scheme design reviewed to ensure compliance.
The same is true for the emergency lighting where a separate risk assessment must be undertaken to ensure you have sufficient emergency lighting and that it’s in good order and correctly placed.
Once we have upgraded the lighting then we need to review the controls, as any lighting scheme without controls is inefficient.
An old analogy I know, still it makes the point. You don’t drive your car at its maximum speed continuously or in a low gear at high revs as it’s inefficient, so you need to control the power and fuel consumption — and this is where controls make a huge difference.
Like your right foot easing off the gas or using the right gear, it’s about measuring variables and making an informed decision based on feedback.
I’ve tried to list a few of the factors below that I believe can and will make a difference if properly managed.
Initial lumens, maintenance factors
This is still somewhat of a black art and whether we like it or not we must build in maintenance factors for the ageing of the light source and perhaps more importantly the luminaire becoming dirty over time.
If we reduce the light output to reflect the initial lumens from a new light source and the maintenance factor, then we could be saving between 10% to 20% in energy.
Daylight
If you have glazing to the building, then balancing the artificial lighting with daylight can reduce your energy consumption dramatically, with systems being able to hold off lighting if there is sufficient daylight in the space.
Claims vary as to the amount of energy that can be saved and I have seen figures bandied about over the years from between 30% to 60%.
With smart daylight management we can manage daylight at different points in the space to ensure each row or group of lighting is in harmony with the daylight contribution.
Occupancy
This can be split into two methods of sensing: presence (is someone there) and absence (have they left).
Both systems work well, with a typical presence scheme turning the lighting on and off, with the absence scheme requiring human intervention with someone physically switching on the lighting.
If there is no-one in the space, then why light it?
These methods are well known and have been used for many years and are successful in saving energy. However the challenge is understanding: how much energy?
Over the years companies have employed several different approaches such as virtual metering where they know the base load and can then forecast energy saving based on the switching and dimming of the light source.
This whole process has been given a major facelift by the DALI Alliance with the ability to now obtain real-time data from drivers on their energy use, thereby achieving a level of accuracy that would be acceptable as an alternative to third party metering.
It’s also worth mentioning that as we have notional corridors in open plan spaces, with lighting controls we can create illuminated routes for anyone working late at night. These can be dimmed to maximise the energy saving until they need to be triggered.
The controls system
If we now look at how we manage the lighting, then we need to clearly understand what our strategic focus will be towards sustainability and what drives our journey to net zero.
All controls are generally good, so irrespective of the manufacturer or technology platform, if it switches and dims then you have the opportunity to save energy.
Will you save energy? Well that’s quite a different story as a poorly conceived and commissioned project adds no value and can in certain instances consume more energy over time.
A good example of this would be long switching periods for sensors where a shorter period would be acceptable.
Selecting the right controls solution is a process that can provide efficient management of your lighting, provide full diagnostics, and deliver a long service life.
The schemes we discussed at the start of this blog are aimed at measuring energy efficiency and the same is true of a well-designed lighting management system.
The right controls solution, I believe, should be based on a global standard such as IEC 62386 (DALI). Covering drivers, switch and sensor inputs as well as wireless controls, this standard is supported by the lighting industry and further supported by the DALI Alliance third party certification program.
The term interoperability is used in DALI, which in layman’s terms means you can mix and match components from multiple suppliers, so you are never restricted by any single manufacturer or supplier.
As hardware is interoperable, we can ask each device the same question and we get the same answer — so data is consistent.
Being an open standard also protects the supply chain for future upgrades or maintenance so a long service life is achieved.
Lighting control systems based on DALI-2 and the new DALI wireless standard/certification program DALI+ (soon to be released) will provide a framework where wired and wireless can work in a hybrid environment and where, like wired DALI, you will have future security for your wireless lighting.
In all cases, DALI data provides a consistent stream of information that can be presented to the user of the space so they can obtain data via a dashboard or power monitoring page to fully understand their usage and patterns of occupancy.
Intelligent sensors launched with DALI-2 are devices that can provide a level of granularity never before seen in lighting controls and as such we can create heat maps showing how buildings are being used and properly understand space utilisation.
As a commitment to sustainability, a modern smart lighting control system based on DALI-2 is a real breakthrough in data acquisition.
Combining a good control system with an efficient commissioning/service package allows the system to learn and adapt to usage and with cloud-based controls, changes can be swiftly and simply undertaken by a keystroke.
Long gone are the restrictions imposed on engineers having to visit site and the environmental impact as a consequence of such visits.
Integration
Combining building services and thereby reducing the duplication of hardware and services is a way of adding true value and ensuring the long-term efficiency of the whole building.
The silo approach to controls is out of date, with information now being shared over several platforms. By combining functionality you can have a lighting control device switching an HVAC controller and similarly the local room controller triggering the lighting.
The ability for lighting hardware to measure environmental data has provided a level of granularity never imagined. We can now control how a space is heated or cooled, the humidity, air pressure as well as CO2 and VOC levels.
A critical feature of modern sealed offices, air quality can be measured and data provided to the BMS on the status of the filters so service intervals can be optimised — lighting control protecting the users of the space whilst optimising efficiency.
Summary
As we try and work towards net zero, we must look at affordable and straightforward schemes that can be easily benchmarked and where Service Level Agreements (SLA) can be put in place that we can review and monitor along our sustainability journey.
Lighting controls are far smarter than you would imagine and with a clear strategy for sustainability — whether you’re building from scratch or refurbishing a building — it’s possible to minimise your environmental impact whilst at the same time reduce your overall operating costs.
Data is key and it’s critical you have a mechanism for sourcing data and a platform that’s open and interoperable.
Finally, the long-term goals for sustainability should be to extend the usable operating life through proper management with a resilient supply chain to support a long service life.
Standards are your friends and that’s why we base our controls solution on IEC 62386 and use the DALI certification scheme; hardware should be interoperable and never bespoke to any single supplier.
If you do want to use BREEAM or NABERS then I would encourage you to do so. However, if resources don’t permit that level of investment, then consider a smart lighting control platform such as zencontrol.
Much more than a lighting controls solution, we work to deliver a lifelong solution where the possibilities to upgrade are supported through open protocols and sophisticated software solutions either onsite or in the cloud.
Reviewing the data from a smart lighting controls solution provides an opportunity to continually update and adjust how a space is operated and, with wider integration to BMS, provide efficiency data to a wider audience to underwrite your commitment to net zero.
Author: Stewart Langdown FSLL (Fellow of the Society of Light & Lighting)