Small and medium business (SMB) owners have traditionally not been able to curtail, and sustain reduced energy usage on demand.
Note: This has not changed much in 4 years!
Let’s think about how SMBs in the 1,000 to 10,000 square foot range, run their businesses.
Typically these are retail, medical, light commercial, office, or light industrial spaces. Each tenant is most likely responsible for paying their electrical bill to the utility (separately metered). SMBs either run their operations extremely lean to reduce their overhead, or have a predetermined load requirement due to refrigeration, manufacturing, lighting, etc. These types of businesses operate their businesses on a regular schedule with little variation.
What choices do SMBs really have when the call to curtail energy usage occurs?
We know from participating in an ADR pilot by Lawrence Berkeley National Laboratory (
http://drrc.lbl.gov/publications/automated-demand-response-technology-demonstration-project-small-and-medium-commercial- ) that simply raising set points for air conditioning systems will only prove fruitful for short periods of time.
Pre-cooling is usually not an option because HVAC units typically run full out during these hot summer days already. The units are rarely oversized for this class of buildings.
Demand Response events typically occur in the summer time during the afternoon, when the weather is hottest.
So the call is made to reduce your energy usage, you reset your thermostat to allow your HVAC unit to shut down, or at least throttle back. Now as the interior of your building’s temperature begins to rise, approaching the new set point, what choices do you have? Shut the unit off and let the temperature continue to climb. How high will it go? How uncomfortable are you or our customers and/or staff willing to become?
In reality, the HVAC unit, probably your biggest energy hog, will only get you through the first 15-30 minutes of the event before it has to go back to work (events typically last 2 to 4 hours).
When your HVAC unit kicks back on to maintain the newer and higher set point it will soon be running full out again. It may cycle more often, but are we really achieving the savings the ADR event requires?
It is time to start looking for other loads to curtail. What do we have control over that can reduce our energy usage and sustain that reduction during the entire event?
Lighting is a good candidate, depending on the type of business. Retail or medical may require certain minimum light levels at all times (really these minimum levels should be what the lights are set to the majority of the time; if not there is already excess energy usage at the site).
Lighting can be dimmed if the appropriate controls are in place, or shut off in areas that are not critical. Ideally the light fixtures are “zoned” so that the customer has the ability to leave fixtures on where required.
What about plug loads? Could a refrigerator(s) in a break room be shut down for 2 hours? The employees would need to know that keeping the fridge door closed during the event would be in their best interest. Could employees go without printers, copiers, or fax machines for a few of hours? Perhaps shut them down, and only allow them to be used when absolutely necessary.
The story is becoming clear, the smaller the business the tougher it will be to make a significant contribution to reduce electrical demand.
To participate in even a trivial way SMBs will need a programmable thermostat capable of interpreting an ADR signal and reacting to that signal in an intelligent manner. As discussed above, this will only provide a minimal curtailment. Therefore, plug and lighting loads will also need to be capable of interpreting and reacting to ADR signals with predisposed routines.
Will the costs savings and incentives doled out by the utilities be enough to recover the costs of these smart devices? Will these new devices be easy to install and easy enough to maintain for the typical SMB owner? If the answer to these questions is no, ADR for SMBs will not be a reality.
Fortunately, with the advent of wirelessly connected programmable thermostats, plug loads, and lighting controllers things begin looking rosier. Throw in firmware for interpreting ADR signals and a straight forward way to program actionable events…even better. If kept simple and easy to use this could be a means for under served SMB owners to take charge of their energy usage year ‘round.
