Alex Carter's blog

 
The UK Government recently announced the reduction of the Feed In Tariff for installations between 4KW and 250KW  by 50%. A large cry went out from the industry, mainly the supply and installation companies saying that it was wrong and that they are doomed as a result. The reality is that this a fledgling industry that is a couple of years old and like all technologies the capital cost is falling so it is only reasonable that the return falls in line. 
Don't forget how this is funded, it is by all of us in our electricity bills, residential and commercial so it is not something for nothing, it is something paid by the many to the few.
A number of sources suggest that a £15,000 investment under the existing tariff before it is cut will enjoy a tax free income and after 15 years the installation will be paid for along with a profit of £3,500. Under the new feed in tariff and with the cost of installation falling this could still make sense but of course there will not be room for profiteering. Not a bad thing.
When talking about a commercial buildings then Photovoltaics make less sense. As a business it is unlikely that the FD will want to make an investment that takes 15 years to recover. With the commercial lighting load normally accounting for 50% of electricity used in an office then it makes far more sense to reduce the energy used rather than generate more to subsidise an inefficient building. By fitting good lighting controls that switch and dim it is relatively easy to obtain a payback far quicker than with Photovoltaics. It is not unusual to have a payback in less than three years
Using our simple but effective lighting controls the opportunity exists for any qualified electrician to help their clients reduce energy and in turn CO2 emissions. Another win/win scenario.
 
Reduce before Generating
 

I have had many conversations with people over the pros and cons of using DALI lighting controls. One of the things that became apparant is the lack of understanding what it is and how to use it. It seems that most people view it as the latest technology.The idea that every light or indeed ballast can be addressed and configured to do everything from automatic dimming and switching, testing the emergency lights automatically to reporting faults to a Building Management System. Sounds great, even 21st century stuff. Well, there are the pros but what about the cons.

Firstly lets address (no pun intended!) the initial commissioning. It is not practical to pre-commission a light so all commissioning is done after installation. A time consuming process whereby every light needs to be interogated and either re-addressed to something sensible and/or documented. Imagine an open plan office with maybe a few cellular offices. Is this level control really needed. The argument is very often 'if the office layout changes then the lighting control can be easily reprogrammed without disturbing the ceiling. Changes in offices involve building/removing/adding internal walls. Is the ceiling being entered really an issue?

Now consider the Ballast Life Expentancy.  Ballasts are electronic devices that have a finite life, This life is accelerated by heat so with the life will vary between light types and construction techniques but we all know failures occur and as time passes the failures become more frequent. Surely I hear you say, not a problem I will call a maintenance electrician and he will fix it. Wrong, he probably will change it and the light come on but be uncontrolled, it will need programming to work correctly and this will be expensive as a commisioning engineer will be needed.

My argument is Return on Investment (ROI), the original installation will cost more not less because of the cost of commissioning. The installing contractor costs will be higher. Will the building occupier understand what he has and benefit from the extra cost and complexity, probably not. Will the maintenance manager enjoy the repsonsiblity and ongoing costs, probably not.

DALI does not have to be this way, using a product like the DLC200 LightHarvester all the energy saving controls can be enjoyed from Presence/Absence Detection, Daylight Harvesting / Daylight Linking, Automatic Dimming, Two Staged Timeout, Scene Setting etc. The ballast is not programmed and the commissioning time is just about eliminated. The cost of maintenance becomes minimal and the Return on Investment greatly increased. The installation cost is reduced as is the cost of ownership.

What about the Emergency Light Test, two choices, use a keyswitch and and manually test or use DALI in conjunction with the DLC200 LightHarvester and have the best of both worlds.