Lighting - questions you should ask

The ink is dry(ing) on Energy Savings Opportunity Scheme (ESOS) reports around the UK. Will they galvanise companies into creating achievable energy reduction plans as the government hopes? asks Richard Perry

25 February 2016 | By Richard Perry

What, if any, energy conservation measures (ECM) do you plan to implement?

If you haven't changed your lighting already, I bet it's in your top two.

Lighting can be a 'quick win', but many are fooled into thinking this makes it easy. LED lighting has more in common with a computer now - the inclusion of printed circuits brings increased capability, but also complexity. Lighting's pervasive nature, found at every point of human contact, makes it an ideal conduit for building monitoring and environment management as society embraces the Internet of Things (IoT).

To deliver an excellent lighting project with a good chance of living up to that quoted five-year warranty, certain common factors should always be addressed irrespective of whether you are using a supplier or going it alone.

1. What have we got?
A thorough site audit may sound easy, but it is cited by many large organisations as their biggest stumbling block.

You need to know precisely what lighting you have, the energy it consumes and whether/how it is controlled by sensors. Any mistakes here and your whole business case - and design - could collapse.

2. How do we use it?
Your peers have specific needs. Talk to them and watch how they behave. This is not only necessary to fine-tune your business case on legacy lighting power consumption, but also as to how new lighting can improve the work environment. Measurement and verification (M&V), be that formal or informal, helps you understand this and provides sponsor credibility. You probably don't need 24 months of energy data, just an excellent understanding of how lighting is used and a very good computer model.

3. How much will we save?
Critically a focus on energy/financial savings needs an excellent baseline, a precise knowledge of photometric performance and robust cost-versus-benefit modelling.

At Lumispec, we are often shown commercial proposals from companies where the projected benefits are overstated by 250 per cent or more, with hidden formulae in spreadsheets.
Remember, M&V modelling is all about a standardised approach such that, given the same data and a competent person, the results can be reproducible, measurable and auditable irrespective of toolset. A complex spaghetti of spreadsheet calculations may be worth checking.

4. What should we improve?
Savings are great, but don't lose sight of what a huge difference even a small capital investment can make to critical areas.

Reinvesting some of the savings can have dramatic benefit. Investing in colour tuneable and high CRI lighting in clothing store changing rooms has demonstrated a dramatic decrease in returns and therefore increase in profits for some stores, as well as productivity in offices using individually controlled task lighting.

5. Proper design
Good quality lighting design is hard - always obvious when bad, often taken for granted when good. Working with a reputable supplier or getting a lighting professional to review your design could be key.

Appropriate use of lighting controls, for instance, can often drive more savings than changing a metal halide lamp to an LED. Selecting the wrong one can be nightmare - phantom triggers of lights in an unoccupied meeting room mysteriously turning on can be because of that microwave sensor detecting the traffic through the wall in the neighbouring corridor!

For key areas get a detailed lux plot across area. Ensure that the specified lighting controls are fit for purpose.

Make sure that the lighting is appropriate, not just general space lighting, but task lighting where work is done, accent lighting for aesthetic. Small details can make an enormous difference.

6. Verify your savings
Measure and track your savings - it's imperative if you are on a shared rewards contract such as PFI or ESCO. Consider using energy use meters on key lighting circuits for a month before the project, so you can validate the business case, and for a period after to verify the projected savings. Consider a performance-related bonus clause for over-achieving project benefits, and a clawback for not.

7. Quality, not cost
Don't fall into the trap of "they look the same, so must be the same", they most likely aren't and that increased price, especially if validated with photometric data and proper certification is more for a reason. Looking at cost over the life of a project, initial purchase cost is between 15 per cent to 20 per cent of the total cost. A failure rate of 3 per cent a year could double this.
That extra initial cost may prolong your breakeven point by an extra three months, but it will be worth it!

8. Certification & warranty
Certification is a thorny issue, with that required CE certification difficult to validate. Bear in mind that UL and TUV-certified products, unlike CE, can be verified with the testing laboratory to provide extra confidence. Never lose sight that a warranty is only as good as the company that provides it is still in business. 

Richard Perry is a director at Lumispec