Monday, April 13, 2015


Linear Fluorescents have largely been superseded by LED's,
but are still a good option in terms of efficiency. Ballast losses
are higher for older electromagnetic designs.
Factories are too diverse and complex for there to be meaningful benchmarks in terms of the contribution of lighting to overall energy consumption. In general however, except for very light industry (no pun intended), the proportion of a site's total energy that is employed for lighting tends to be small. Despite this fact, I always include lighting assessments when reviewing energy usage on any industrial site. My main reason for doing so is that this is often an area heavily laden with low hanging fruit from an energy efficiency perspective.
Often the basket of lighting opportunities identified has a payback of under 2 years, with many individual lighting solutions having an almost immediate payback. Of course one wants short paybacks for lighting projects, given that lighting retrofits will not have the lifespan of other larger investments. Savings with regards to lighting are about far more than lighting retrofits however, so be sure to include options such as work practice changes, maintenance and operational improvements when seeking to reduce lighting costs.
There is a huge amount of detail associated with the rigorous analysis of lighting opportunities, and I won't get into that here. What I want to highlight in this post is how simple it can be to identify and implement sustainable lighting savings. Firstly, the cost of lighting has to be appreciated along with the drivers of operating cost. The energy used for lighting is a function of input power to the lighting / luminaires and the operating hours involved. It is quite a simple exercise to carry out a lighting inventory which outlines, preferably on a "room-by-room" basis, the number of lights, their individual power consumption levels and their hours of operation. This can then be converted to an annual  energy value (in kWh), and then, depending on applicable tariffs, an annual energy cost can be calculated for each individual room. This is a simple enough exercise - don't forget to include ballast losses. It is also important to appreciate that lighting often contributes to maximum demand, and hence an apparent power value for individual lighting options must be determined. You might need to consider power factors should the site concerned not have a correction system in place, but to keep it simple, perhaps just take the power factor of individual fittings as unity and add the apparent power levels to assess the contribution to site demand. Ignoring demand can make a large difference to the estimated operating cost of lighting.
Once you have this inventory, you can set about identifying relevant solutions for each area. The plethora of modern lighting solutions can make this a minefield as you consider issues such as lumen output, lumen depreciation, lifespan, colour rendition, efficacy, lighting and installation costs, disposal considerations, human health impacts etc. The key point I want to convey with this post is that while the temptation often is to pursue the latest innovations in lighting technology, there are very simple ways that lighting costs can be reduced. Before embroiling yourself in cost benefit analyses for individual lighting technologies, take some time to apply some common sense to the matter of finding savings. Questions I often ask as I evaluate individual areas include:
  • Are there any obviously inefficient options in place e.g. mercury vapour lamps, T12 fluorescents with magnetic ballasts, incandescent lights etc? If so, what can they be replaced with? - there is no standard answer here, and it depends on the individual installation and characteristics of the room e.g. roof height, reflective surfaces etc.
  • Is there too much light available on working surfaces (as measured with a light meter) when the lights are on? This would be wasteful, and often savings are possible through a simple reduction in the number of luminaires. It is sometimes also possible to modify existing luminaires e.g. the control gear for mercury vapour lamps can be bypassed and the existing fittings can be used to house compact fluorescent lights. Be sure to adhere to regulatory lighting standards as a minimum.
  • Are daylight harvesting opportunities available? This may result in lights being switched off during the day, or to a reduction in the number of lights used during the day. Existing lighting may require supplementation with options such as transparent roof sheeting for example.
  • What are the switching arrangements? It is not uncommon to find a single switch for a large area, but with only part of the area used regularly. By applying a zoning strategy, lights can be switched on selectively, saving large amounts of energy. Switching options can also be used to provide flexibility in terms of the number of lights switched on e.g. all lights on dull days but only a few on typical sunny days.  
  • What are occupancy levels for individual areas? Motion sensors can be a useful solution when paired with the correct lighting types.
  • Are windows, roof sheeting and lamps themselves cleaned regularly? If not, can a simple cleaning regimen be easily implemented?
These simple solutions are every bit as important as the deployment of efficient lighting technologies, and most often cost very little to implement, if anything.
Copyright © 2015 Craig van Wyk, all rights reserved

Tuesday, September 16, 2014


Fuel switching can be a huge
cost-reduction opportunity
Fossil fuels are used extensively for activities such as steam generation and for process heating applications such as furnaces and curing ovens. There are a range of ways to make these operations more efficient and cheaper to operate, but often the fuel employed is not given much attention. This could however be one of the most impactful ways to reduce energy costs. So what is fuel switching, and how does one determine the nature and quantum of the cost reduction opportunities it presents?
Fuel switching is simply a change in the fuel used to one of a different type e.g. a switch from coal to wood pellets. It is sometimes done for operational reasons. Heavy fuel oil is an example of a fuel that if not properly stored and handled, can cause blockages and downtime, particularly in cold weather. Safety could be another factor, for example volatile fuels in a hot climate come with risks if not stored and handled properly (not to mention losses). Some fuels are not freely available, and hence reliability problems could prompt a switch. In the absence of these challenges, the biggest motivation for a fuel switch is however that of cost reduction, and this is what this post is about.
In determining whether a fuel switch is financially viable, the first thing to understand is what the cost of the fuel you currently use is relative to the cost of the fuel it could be substituted with. I refer here of course to the cost per unit of energy, not per unit of fuel. You also need to have a sense of the efficiency with which you would be able to use the new fuel relative to current efficiency levels. By noting the energy content per unit of fuel and then applying the efficiency with which the fuel will be used, you will be able to determine the cost of delivering energy to the process you are operating, whether this be steam generation or a heating application.  This immediately conveys the quantum of the potential savings on offer, and these savings then have to be contrasted with the potential additional costs that come with making the switch to determine the net financial benefit.
The method I use is to determine the stack losses for the two different fuels, since this is the biggest loss to consider. This is a function of flue gas temperature, flue gas oxygen and ambient temperature, and different fuels typically require different levels of excess air for effective combustion. I would typically use a common flue gas temperature for the two fuels (usually just the one currently achieved), fix the flue gas oxygen content at the minimum required for the fuel being assessed and then determine the boiler/furnace efficiency I could expect when making the switch. If the plant involved is equipped to deliver low flue gas temperatures (e.g. thorough the use of economisers or air pre-heaters) you could fix the flue gas temperature for the analysis at the acid dewpoint temperature for each fuel plus a small margin of safety. Of course if you are switching to a very clean fuel and this allows use of a condensing economiser, the whole equation changes, but let's leave that for another day. The efficiency determination allows me to calculate the fuel rate required (based on heating value per unit of fuel and the heat load of my process), and I can then make a comparison of expected fuel costs to current fuel costs. Where there is a large difference, I move onto the next phase of the investigation, which is a risk assessment.
There are several issues to consider when deciding to switch fuels, and it is important that a thorough risk assessment is done before making this change. Some questions you should ask before making any proposed fuel switch include:
  • Can you lawfully use the fuel? - local air quality regulations could preclude the use of certain fuels and before doing anything, check this first.
  • Can your boiler handle the new proposed fuel, or can it be modified to do so?
  • Can your fuel handling infrastructure support the new fuel, and if not, what modifications are required and at what cost?
  • Is the supply of fuel going to be reliable, and what price changes are expected going forward relative to the price changes expected for the fuel you currently use? (you may need a crystal ball for that one)
  • What are the emission impacts associated with the new fuel, not just in terms of GHG's but also particulate matter, sulphur, mercury and other pollutants?
  • What are the water pollution risks?
  • What are the safety risks associated with the new fuel? - here characteristics such as flash point are a consideration, among others
  • What impact, if any, will the fuel have on manning requirements and operating and maintenance costs?
Note that you could spend money on mitigating some of these challenges if the economics allow. There are examples I have seen where even a change in boiler was financially viable, so keep an open mind. Once all of these issues have been addressed and you are satisfied that none of them is a barrier to the switch, you are in a position to start planning for implementation, but the process is far from finished. Ideally you should observe the fuel in operation at another location (if you haven't already seen one) and engage directly with users of the fuel and suppliers of fuel and equipment to ensure that there are no unexpected surprises. If no plant modifications are needed for the switch, you should also use the fuel on a trial basis before committing to any long-term supply contracts. All of this due diligence can sound like hard work, but I can assure you that this could be one of the biggest cost reduction opportunities at your facility, and if you haven't looked into it, you should do so without delay.

Copyright © 2014, Craig van Wyk, all rights reserved

Tuesday, March 11, 2014


Every manufacturing site can be made more
sustainable, and this is NOT only about
Manufacturing sites are but one component of the value chain, in many cases not even the most important part from a sustainability perspective. Often, the suppliers of raw materials, packaging materials, logistical services, water and energy can have very significant life-cycle impacts. For manufacturing companies however, production sites represent the face of operations. Hence they are a natural place from which to start the sustainability journey.

An organisation’s sustainability strategy will include its entire value chain, and an examination of the life cycle impacts associated with individual products. Strategies at the factory level should of course be integrated with this broader organisational strategy, and hence factories should not develop strategies in isolation from the broader business within which they operate. Factory-level sustainability strategies do however require focus, and there are generic areas I tend to look at when I assess factories, in combination with industry-specific issues, which are typically very well known. Examples of industry-specific issues could be persistent organic pollutants arising from bleaching in the pulp and paper sector, hexavalent chromium pollution in the plating industry, food safety in the food processing industry or the water intensity of wet-cooled power generation processes. You will need to fully understand the issues relevant to your industry in addition to the generic sustainability matters I’ll discuss in this post in making your factory more sustainable.

What then does a sustainable factory look like, and what are the key focus areas that senior factory management should have in mind when embarking on a sustainability programme? My views on this issue are that one needs to take a simple, common-sense approach, identifying the broader issues and then taking action in each key area in an integrated way i.e. appreciating the interrelationships between individual aspects of sustainability. Of course, there is an awful lot of technical detail underneath the conceptual approach I’ll outline in this post, but there are many resources on the web and elsewhere that you can access to fill in the blanks. Simple and simplistic are two distinctly different things – incomplete analysis that does not take a systems view will yield incorrect conclusions that if acted upon will not lead to results, or worse, will lead to unintended consequences. However, when sustainability is made overly complicated the risk is that you will spend all of your time over-analysing and not implementing anything. So it’s important to strike a balance.

In line with keeping things simple, let’s step out of the detail for a moment and consider a broad view of the factory as a point of departure. The generic manufacturing site receives resources across its boundary, transforms these into products, and in the process also produces wastes. Sites interface with the environment, the local economy and local communities, but their influence can also extend to other countries, by virtue of aspects such as emissions to air and water and the geography of the markets for their products. At the factory level, sustainability strategy is not about saving the world. Rather, it is necessary to understand the basics of what sustainability means for a factory, and then to reduce that down to the key drivers of sustainable practice for your specific manufacturing site.

In my mind, the following issues represent the bare bones of the characteristics of a sustainable factory.

1.       The work environment would be safe to work in, not just in terms of the minimisation of safety incidents, but also in terms of long term occupational health. If this sounds like a basic issue to you, be warned that it is fraught with complexity. The safety issues are typically straightforward to identify and manage, and while I often see sites where glaringly obvious safety risks abound, it is the occupational health risks that worry me more. What I can tell you is that generally, even where detailed risk assessments have been undertaken, workers can still easily be exposed to hazardous substances. In most cases it is due to a lack of information on the dangers posed, but there really can be no excuse in this information age. It is necessary for you to research the hazards unique to your industry and to find out what the best practices are in terms of their mitigation. Just because something is not regulated in your country does not make it acceptable to ignore it. Not if you are serious about sustainability. It is useful to involve specialists, who can also assist you with measurements.


2.       The products produced should be safe to use and consume. At the site level this typically does not involve product design, though of course nothing prevents the site from giving feedback to the product development team. Manufacturing sites can render well-designed products unsafe to use or consume by virtue of deficient manufacturing processes. A simple example would be the contamination of a food product. The risks at every stage of the manufacturing process should be identified and mitigated, either through process redesign or the institution of robust control measures.


3.       Emissions to air should be understood and managed accordingly. Of course this includes GHG’s arising from local fossil fuel combustion and it is also a fairly simple matter to estimate the emissions associated with electrical energy use. However, other pollutants also require consideration, and are best assessed by investigating individual unit operations. A lot of attention is given to the GHG’s, particulates and sulphur compounds associated with coal combustion, for example, but what of the associated mercury pollution? A detailed emissions inventory is therefore essential. Air emissions are not necessarily a consequence of combustion. Dust, volatile organic compounds, fumes emitted from high-temperature manufacturing processes – all require assessment, and many are linked to occupational health as well as broader environmental issues.


4.       Water pollution risks should be understood and dealt with. Industrial sites can pollute both surface and groundwater resources, and can do so through a wide range of mechanisms. These problems are not necessarily localised, albeit that many arise from point sources. While the obvious control point would be to carefully monitor effluent discharges from the site, other pollution transport mechanisms could include:

·         Airborne pollution that is deposited in surface water bodies

·         Seepage of contaminants into groundwater

·         Site runoff, which can find its way into rivers or to municipal effluent treatment plants that are not designed to handle industrial pollutants


5.       Land pollution risks should be identified and managed. These are generally to do with spills, runoff and localised fumes that can result in deposition onto land. The nature of site surfaces plays an important role. Paving is attractive, but does not form an impermeable barrier between potential spills and the land underneath a site, as a simple example. Be wary of effluent streams that are discharged into un-lined dams or onto open fields.


6.       Resources should be used as efficiently as possible. The resources of interest on industrial sites are raw materials, energy and water, all of which have significant life-cycle impacts, and hence offer significant leverage for the reduction of an organisation’s footprint through actions taken at the site level. The cost reduction impacts associated with resource efficiency are generally high, providing good incentive to pursue this aspect of sustainability vigorously.


7.       Wastes should be recycled as much as possible. The first prize in terms of resource efficiency is to tackle problems at source, thereby limiting the amount of waste produced. While “zero waste” should be the intent of a sustainable manufacturing site, in most cases the production of some waste is unavoidable. Where possible, these wastes should be recycled. If waste can be employed in production processes, this is ideal, but where this can’t be done, supply chains should be set up to process the waste such that it becomes an input to downstream production processes, either for use elsewhere in the business or for sale on the open market. This is often a way to generate additional revenues, reduce the amount of waste diverted to landfills and create jobs. Where waste is recycled internally, take care that your ability to recycle does not divert your focus from the minimisation of this waste at source. Recycling is certainly not free.


8.       The local economy should be supported as far as possible, particularly where it makes sound financial sense to do so. This means providing locals with jobs and also procuring goods and services from local suppliers. This helps to ensure that the site is not an island of economic prosperity in an otherwise impoverished area, but also helps to build rapport with local communities, who are important stakeholders in the site’s sustainability initiatives. This can be particularly important for industrial sites in outlying areas, since a vibrant local economy attracts more residents, who may in turn contribute to economic and social upliftment. This may even support local demand for the organisation’s products.

9.       Social programmes should be in place to support local communities. While these could include charities, the idea is to make these programmes sustainable, and to structure them such that they help people to help themselves, while also contributing directly to the sustainability of the business. For example, a bursary programme could be instituted to assist students to finance their studies in skill areas critical to the site, thereby creating a pipeline of skills while also empowering local communities.


10.   Operational management systems should be well developed and continuous improvement should be part of the culture on the site. In general, good business practice contributes to sustainability. Maintaining productive assets effectively, managing operational risks, ensuring quality standards are met, developing a solid skills pipeline, instituting transparent management systems and all of the various aspects of operations management necessary for efficiency and effectiveness are integral to sustainable operations, not least because they help to ensure economic sustainability. The sustainable factory is hence not a goal requiring reinvention of every aspect of the enterprise. While operational excellence does not necessarily translate into sustainability, it certainly does support it. And hence, in organisations that are leading the way, the lines between operational excellence and sustainability are becoming increasingly blurred as sustainability is integrated into operations.

Is there really such a thing as a “sustainable factory”? To some this may sound like an oxymoron. Of course, this concept is something to aspire to rather than to treat as an end goal, since as I have mentioned many times in previous posts, sustainability is a journey rather than a destination. But as long as we humans are here on earth, the products we consume will continue to impact on the planet, and manufacturing can be considered to be a “hotspot” in this regard. Making factories more sustainable is an opportunity to be taken advantage of by forward-thinking organisations.