Chris King at eMeter sends me the following information as a follo-up to Vernon’s and my oped today:
Re your editorial, the equipment cost hierarchy you presented is debatable. Regarding load control, the expense is higher than implementing advanced metering, since the device cost is about the same (around $50), but installation is much more complex. A meter is a simple “unplug the old, plug in the new” (literally) installation, while a load control switch requires opening up the air conditioner control circuit to install the switch, a complex operation requiring a licensed electrician. Moreover, with metering you get what you pay for in demand response, while a major percentage (sometimes half or more) of customers on air conditioner load control deliver no load reduction (due to oversized A/C units, failed control switches, and tamper disabled control switches).
Regarding metering, advanced metering (time-based recording with communications) is actually cheaper than adding a second meter. The meter costs more ($50 vs. $25), but, again, the installation is vastly simpler. Installing a second meter requires installing a second circuit breaker box and rerouting of whatever circuit you are monitoring; this approach is cost prohibitive. Moreover, advanced metering provides significant utility operating savings – namely reduced meter reading costs and improved outage management via automatic detection and restoration verification – which further reduces the net cost. In fact, many utilities are implementing advanced metering for these operating cost savings alone (over 10 million units around the U.S.).
Thus, the lowest cost option is advanced metering, followed by air conditioner load control, followed by a load management system in a home
or business. These numbers are based on large-scale installations.