Please reference the attached file for my comments regarding Case U

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1 -----Original Message----- From: Thomas Bowes Sent: Monday, November 03, :19 PM To: MPSCEDOCKETS Subject: RE: Case U Please reference the attached file for my comments regarding Case U Tom Bowes Warren, MI

2 Executive Secretary Michigan Public Service Commission P.O. Box Lansing, MI Re Case No. U To whom it may concern, I am writing to express my support for simplified and uniform provisions for the revised implementation of net metering per Part 5 of Public Act 295 of As a licensed electrician, educator in the field of electrical codes and installation, participant in the National Electrical Code making process, OSHA construction safety instructor, and advocate for the safe installation and use of renewable energy systems, I feel that there is much that can be done to simplify the metering and disconnecting portion of these installations while still maintaining sufficient levels of safety for utility workers and the public. Previous incarnations of net metering requirements by certain utilities in the state of Michigan have involved a number of obstacles for system installers which have resulted in unreasonable expenses and delays with no appreciable increase in the level of safety or convenience for any of the parties involved. They have in fact resulted in a set of circumstances under which both the system owner and the utility have borne additional costs in the process of review and installation. Under a revised set of net metering guidelines I would request that the MPSC adopt the following policies for systems of 20 kilowatts or less: 1) Net metering equipment, application, and approval requirements should be consistent for all utilities state-wide. 2) The number of meters required for a net metering installation should be reduced to only one bi-directional electromechanical or electronic meter. 3) No external alternating-current disconnect switch should be required for inverter output circuit of installations using UL 1741/IEEE approved grid tied inverters. 4) Utilities should not maintain a list of pre-approved inverters based on in-house (individual utility company) testing as the listing requirements for these inverters are sufficient to provide for public and utility personnel safety. 5) No additional insurance or indemnity requirements should be imposed upon the owner(s) of renewable energy systems which have been installed by a licensed electrical contractor(s) and inspected and approved by the local authority having jurisdiction. My rationale for these recommendations is as follows:

3 1) Consistent installation requirements tend to lead to higher levels of safety because the installing party learns through repeated experience the proper methodology for the installation. Having a hodgepodge of installation, application, and approval requirements throughout the state requires additional time and labor in the bidding and installation process and is unduly burdensome to contractors and renewable energy system owners. 2) The requirement for a generation meter is unnecessary and should be eliminated. Under true net metering plans in other parts of the United States the billing is handled adequately with only one bi-directional electromechanical meter. The net purchase of power from or delivery to the grid is recorded by the serving utility on a monthly basis with an annual settlement for any net purchase of energy from the utility, plus (in some cases) monthly access fees. This situation is somewhat complicated in Michigan given that some utilities have divested themselves of the traditional function of distribution, and the customer s bill therefore reflects both a generation and distribution fee. The bottom line is that under either method of billing the generation meter is not needed since bidirectional electronic meters can be installed which can record not only the amount of energy delivered by the utility, but also the amount delivered to the utility by the distributed generation source. The difference between these two values yields the net amount for credit or billing purposes. 3) The revised UL 1741 standard, which has now been harmonized with the provisions of the IEEE Anti-Islanding testing procedures ensures that inverters which are tested by a nationally recognized test laboratory to the requirements of the 1741 standard meet the highest levels of safety. This standard requires that the inverter shut down within two seconds if utility power is lost. The fact that these inverters incorporate algorithms to continually test their output against the standard of the utility power provided means that they provide an additional level of interactive safety assurance which is beyond that which is used in traditional protective relaying systems. These traditional relaying systems which are widely used by utilities for the interconnection of distributed generation sources are manufactured to follow the same IEEE guidelines as the inverters, but are typically not tested by an independent test laboratory to ensure their compliance with the IEEE standard. While it may be possible in the laboratory to create a set of conditions under which some of the early UL 1741 inverters remained energized upon loss of utility power, the realities of usage under field conditions and the redesign of the protective methods used within the inverters has resulted in a product which is virtually incapable of backfeeding into an inactive power grid. UL has unsuccessfully attempted to find a set of field conditions in which a listed inverter would create an islanding event. The realities of load fluctuation and the fact that the other loads on a connected line segment would have to precisely match the output of the inverter in both phase and magnitude yield the possibility of an islanding event with a listed inverter to be virtually nil.

4 Due to the five-minute timeout parameters built into the inverter, in which it must see a clean source of utility-grade power for at least five minutes prior to recoupling to the grid, it is unlikely that these inverters would ever create a safety hazard for line workers working on de-energized lines. These systems will not synchronize with portable generators such as might be inadvertently connected to the distribution grid during an outage. As the number of grid-tied photovoltaic systems has increased (exponentially) to approximately 30,000 across the United States we would expect to see an increase in reported unsafe events, power quality disturbances, and system failures caused by these products if there were any potential safety or design defects lurking in the milieu of the inverter/utility interaction. The lack of such reports is indicative of the high levels of safety and power production design built into these inverters. The National Renewable Energy Laboratory in a report entitled Utility- Interconnected Photovoltaic Systems: Evaluating the Rationale for the Utility- Accessible External Disconnect Switch, (Technical Report NREL/TP , January 2008, ( has made the following conclusions regarding external disconnect switches (EDS): Although utility arguments for requiring utility-accessible EDSs for grid-connected PV systems may have been justifiable 5 or 10 years ago, today the EDS issue is effectively addressed by UL and IEEE standards. Going forward, at least four factors are likely to convince additional utilities and PUCs that EDSs are redundant and unnecessary: Increasing utility experience with utility-interactive PV systems that demonstrates the effectiveness and safety of UL-listed inverters Re-evaluation of safety practices and rules in light of technological advances and regulatory changes A desire to reduce or eliminate the administrative burden and associated cost of requiring utility-accessible EDSs Growing pressure to remove barriers to entry to meet growing state-level targets for PV installations. Put simply, the utility-accessible EDS is increasingly viewed as redundant and unnecessary for residential and small-commercial PV systems with UL-listed inverters. Eight state PUCs (i.e., Arkansas, Delaware, Florida, Maryland, Nevada, New Jersey, New Hampshire, and Utah) have reached this conclusion and eliminated their EDS requirements for systems that meet criteria, and nine state PUCs have decided to leave the EDS decision up to individual utilities. In the states with utility choice, at least five utilities have eliminated the EDS requirement. These states and utilities accounted for more than 80% of total installed PV capacity in the United States in 2006.

5 I would therefore argue that the MPSC should adopt rules which DO NOT require the installation of external AC disconnects for listed utility interactive inverters on renewable energy systems. These disconnects are unnecessary and do not increase the level of safety for utility workers since they largely go unused in the event of a power outage and the inverters already provide for automatic disconnection. Such additional disconnects do however represent a significant installation cost to the system owner, especially in cases where the source of distributed generation within a building is located some distance away from the utility s point of service. The net result is that if the inverter is not located near the service, the external disconnect may require the inverter output circuit to be run all the way to the service entrance location and then back to the overcurrent protective device which feeds the inverter. This can be an expensive proposition with the cost potentially running into the range of thousands of dollars. 4) The self-testing of utility interactive inverters is redundant and should not be allowed as an evaluation method by individual utilities. Because of changes which continue to occur in inverter software and design it is unrealistic to expect that ratepayers should have to absorb the cost for re-evaluation of products which are already thoroughly researched and tested by independent test laboratories. The system of third-party testing of electrical products by nationally recognized test laboratories is long-established and is adequate for addressing product safety concerns. The practice of maintaining utility based lists of pre-approved products does not take into account the occasional software revisions which will occur within those products and is anti-competitive in that it gives certain manufacturers who have submitted their product to the utility for testing a competitive advantage over those who have not. Manufacturers should not have to deal with product approval on a utility-by-utility basis. 5) Additional insurance requirements for the owners of small distributed energy systems which interface with the grid through listed utility interactive inverters should not be imposed by the serving utility. These permanently installed systems, when properly installed and inspected, are several orders of magnitude more safe than their portable fossil fuel powered counterparts for which utilities have not required additional indemnification and over which they have virtually no control. Because listed interactive inverters are incorporated into a building as part of a permanent wiring system they are less subject to changes and errors in operation which could endanger line workers or the public. There are some safety concerns which although not under the general guidance of the MPSC rules should nonetheless be mentioned. Specifically there is an issue within the State of Michigan of unlicensed and untrained individuals who deem themselves as solar installers performing electrical work which requires both an electrical contractor s and electrical journeyman s or master electrician s license. It should be recognized by all parties involved that these installations by untrained, under-trained, and unlicensed entities do present a potential safety risk to the public and utility workers.

6 Fortunately, Michigan has a large base of qualified (and currently underemployed) electricians and electrical contractors who are fully capable of installing the electrical apparatus associated with distributed generation systems. These professionals, who have already proven themselves qualified by Michigan s rigorous electrical licensing procedures should be relied upon, along with the building inspection authorities and the utilities in the state to make sure that these systems are installed by qualified individuals to the prevailing standards of the electrical code and utility interconnection guidelines. By relying on three competent parties in the installation process; the contractor/electrician, the electrical inspector, and the utility, there should be no reason why these systems cannot be safely installed and operated. Respectfully Submitted, Thomas W. Bowes Michigan Licensed Electrical Journeyman # Warren, Michigan