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Reliability

Reliability is critical for electricity providers. As our economy becomes more dependent on complex computer technology, the standard for reliability has been raised to an unprecedented "six 9s:" reliable electricity must be available 99.9999% of the time. The power also must be of premium quality to supply highly sensitive equipment.

It may sound strange to describe renewable energy technologies as reliable. After all, they are intermittent resources — the wind does not always blow and the sun does not always shine. However, although the wind does not always blow, it is predictable and can be planned for quite reliably. When added to the electricity generation mix, renewable energy technologies can help energy suppliers stretch their other fuel supplies and mitigate the risk of blackouts during times of peak electricity demand.

Maximum sunshine coincides with peak electricity demand in commercial operations (somewhat less with residential demand). Solar electric cells (photovoltaics, or PV) installed on commercial roofs can supply quality power to sensitive electricity-using equipment during brownouts or blackouts, in addition to reducing the electricity system's need for peak power.

In some circumstances, renewable technologies can be more reliable than other forms of electricity service. For example, solar electricity systems may be used for disaster prevention, response, and recovery.

The most reliable kilowatt is the one that does not need to be generated, transmitted, distributed, or stored. In California, energy efficiency and energy-conserving behaviors enhanced system reliability during the 2001 energy crisis by reducing demand on the system. Moreover, this was a supremely cost-effective effort. The $1.3 billion that California taxpayers and ratepayers invested in energy efficiency and demand response programs in 2001 is favorable compared to the estimated $2 billion to $20 billion in potential losses from rolling blackouts that were avoided (in addition to the savings associated with avoided wholesale power purchases).