ANSI SCTE 246 pdf free download
ANSI SCTE 246 pdf free download.Best Practices in Photovoltaic System Operations and Maintenance for Cable System Operator.
7. O&M and the Financing of PV Assets
An effective O&M program enhances the likelihood that a system will perform at or above its projected production rate and cost over time. Therefore, it reinforces confidence in the long-term performance and revenue capacity of an asset. Historically, O&M practices and approaches have not been standardized, and instead, they were implemented in various proprietary methods. This approach can increase the cost to projects and portfolios, as well as raise the perception of risk from investors. Specific recommendations from the PV O&M Working Group to reduce variations in O&M practices include:
• Define performance metrics uniformly. A system characterized by a guarantee to deliver I ,000 MWhlyear would be difficult to compare and bundle with another that has a guarantee to be operational 90% of the time. Investors need performance metrics and evaluation methods to be the same across a bundle of assets.
• Refer to specified standards. Practices and delivery of O&M services also differ, and investors need to know that an existing system has been maintained according to standard definitions and criteria.
• Make cost estimates uniform and predictable. Differences in types of systems and also geographic location and climate conditions can confound securitization. Investors want to know how much it will cost to perform required O&M and secure the performance of the investment. Cost estimates must he uniform and predictable so that they can he bundled, yet they should reflect the factors that cause O&M costs to vary from site to site.
Many investors are more interested in reducing risk than maximizing internal rate of return (IRR). Investors would prefer 5% IRR with 100% certainty over 10% IRR with 50% certainty, even though the two are of statistically equivalent value. Investors will make an investment decision based on mitigating performance risk with effective O&M, and then the financing rates are determined mainly through competition from other banks. Standardization of O&M Iractices will facilitate investor analyses of risk factors and can reduce due diligence time and costs. Risk reduced by effective O&M will enable banks to qualify more projects, and that will eventually increase competition and reduce borrowing costs.Although PV systems may have different origins, they can be pooled together in portfolios- -and thus, be financed more efficiently- -if they adhere to clear, industry-accepted business and technical guidelines regarding O&M. Industry groups important to this effort include the Institute for Building Technology and Safety (IBTS), the SunSpec Alliance, and the North American Board of Certified Energy Practitioners (NABCEP). National and international standards- developing organizations (SDOs) important to this effort include the American National Standards Institute (ANSI), the Institute of Electrical and Electronics Engineers (IEEE), the International Electrotechnical Commission (IEC), and ASTM International (formerly known as the American Society for Testing and Materials [ASTM]).
Two SDOs—the ASTM and the IEC—are coordinating directly with NREL and Sandia National
Laboratories to develop O&M standards, with drafts being made available to working group members.
These standards are primarily technical in nature and focus on life-cycle management. design for O&M
guidelines, and detailed maintenance processes and procedures.
Representatives from ASTM and IEC were involved in developing these best practices. This document is offered as what is referred to in the standards-making process as “research,” to be considered as the IEC and ASTM committees develop the language of the standards. The IECRE. which is the Renewable Energy IEC system for certification to standards, will receive this PV O&M Guide for consideration of recommendations. It will serve as input to PV industry certification and compliance approaches and practices.
8. Scope and Prerequisites for a Successful O&M Program
8.1. Scope of PV O&M Guide
This document is targeted at fleets of third-party-owned, grid-connected PV systems of the following size classes: residential rooftop (typically less than 10 kW): commercial and industrial rooftops and shade structures (10 kW to 1,000 kW); and ground-mounted systems (often greater than 1,000 kW).
Services covered in the guide include: asset management; monitoring: operations: preventive maintenance; corrective or condition-based maintenance (repair); and end of performance period (disposition).
The guide addresses dependencies due to system type such as: micro-, string-, or central inverter; ground versus roof mounted; attached versus ballasted mount; and tracking versus fixed mount. The guide also addresses dependencies based on site conditions including: sources of soiling; bird populations; snow:
pollen: and high temperatures.
The guide provides information on the delivery of O&M services including qualifications of service providers, contractual relations, and performance guarantees related to O&M.
8.2. Prerequisites for a Successful O&M Program
Borrowing from classroom grades, where “A” is best, it is possible to bring a PV system earning a grade up to a “C” or “B” with effective O&M. But it is not possible to earn an “A” unless O&M was a consideration in the design of a system. Also, O&M might not be able to save a failing system if the problems are intrinsic to the design or products used. O&M issues should be considered in design, engineering, and construction in order to:
• Select low- or no-maintenance alternatives when available
• Make use of network-connected inverters for remote testing, software configurations andJor updates, and remote resets
• Provide required access to and clearance around equipment for maintenance (EPRI 2010)
• Enable third-party inspection and commissioning of original EPC installations to spot operation problems before acceptance (EPRI 2010)
• Conform to the evaluation and quality-assurance protocol detailed in the SAPC PV System Installation Best Practices Guide (applicable to residential systems only)ANSI SCTE 246 pdf download.
