Definition of Hydropower Plant Capacity 1

[SooryaShrestha]

which value will represent the Plant capacity of a Hydropower Plant:
a) Rated output capacity at rated power factor at rated frequency at rated voltage at rated temperature rise?
b) Maximum output capacity at any power factor at rated frequency at rated voltage at maximum temperature?
c) Maximum output capacity at any power factor at maximum possible frequency at maximum voltage at maximum temperature?
d) Maximum possible capacity? or any other capacity as defined by IEEE/ANSI or any standard?
This has lot of significance as royalties or levy for generation of power by private enterpreneurs, duties for import of plants depend upon Plant Capacity. Most of the time the plant capacity is taken as the nameplate rating, which can be different if the power factor is rated lower value.Any suggestion?

 

[jbartos]

Suggestion: One may start from References:
1. IEEE Std 100-2000 "The Authoritative Dictionary of IEEE Standards Terms," Seventh Edition, 2000
Where "Plant-Capacity Factor" is referred to "Plant Factor" that is defined as:
"The ratio of the average load on the plant for the period of time considered to the aggregate rating of all generating equipment installed in the plant."
2. Fink D. G., Beaty H. W., "Standard Handbook for Electrical Engineers," 14th Edition, McGraw-Hill, 2001, Paragraph 12.7.4 "Capacity Factor" on page 12-21
"Capacity Factor is the ratio of the total actual generation to the generation that would have been produced if the unit had operated continuously at maximum rating.
Annual capacity factor=(actual annual generation in MWh)/(Maximum rating in MW times 8760 h)"

 

[rhatcher]

For the purposes of assessing the monetary value of a power generation plant based on it's capacity, a common sense approach would be capacity based on "a) Rated output capacity at rated power factor at rated frequency at rated voltage at rated temperature rise". For example, of what importance (specifically what value) is the capacity at maximum frequency when the facility will never operate at other than rated (line) frequency. Same for maximum voltage. With respect to capacity at maximum temperature, the overload capability of the plant may be considered a factor in value if it actually represents a reserve capacity available for use when required, but it should not be the primary consideration as again the plant will not operate at this rating continuously. With respect to plants whose nameplate ratings are given at different power factors, it would be necessary to require that the manufacturer or operator of the plant provide alternate ratings based on a standard power factor as specified by you for the purpose of equalizing the ratings. Ratings at a 0.8PF seem pretty common, so you may adopt it as a standard and require those with other PF ratings to rerate their units at 0.8PF. As well, you could determine the rerated values yourself with the generator V curves.

Another consideration in power plant valuation was brought up by jbartos in terms of the "plant capacity factor". This relates to the question at hand because, in simple terms, will the value of the plant for your purposes be the amount of its' capacity that is actually used or the total rated capacity? The answer to that question is not obvious to me since it presumably would vary according to what type of agreement any capacity based charges (or payments) are assessed under.

Again, the above is a common sense approach to the question and is not based on expertise in the legal or financial aspects of royalties, levies, duties, or payments based on power generation or power generation capacity. Presumably any such arrangement or legal requirement would be acompanied with a lot of paperwork (and a lot of fine print) requiring the joint efforts of a lawyer, an accountant, and an engineer to fully understand.

 

[SooryaShrestha]

In the response of jbartos in the definition of capacity factor, it takes into account of the maximum rating, which as explained by rhatcher as I understood as the nameplate rating.
Let me further add a little more. The Electricity regulation of the country specifies the royalty charge based on the per kW generation capacity basis. The license issued by the Government also specifies generation capacity. But the IPPs bring bigger plant, which can use the secondary generation at the time of higher discharge in the river. This makes a problem determining the capacity of the plant as which rating is the plant capacity. I do not understand what it has to do with the capacity factor.

 

[jbartos]

Suggestions: References
1. IEEE Std 100-2000 "Dictionary"
2.

http://www.eia.doe.gov/cneaf/electricity/epav1/html/Glossary.htm

3. NEMA Std MG-1
Reference 1 defines "Capacity (nuclear power generating stations)" as
(2) The maximum output of a turbine generator unit.
(3) Measure of the ability to generate electric power, usually expressed in megawatts or kilowatts. Capacity can refer to the output of a single generator, a plant, an item of electrical equipment, an entire electric system, or a power pool.
Alternately, Reference 2 provides a different definition. Incidentally, the DOE site may have useful information pertaining to your activity.
When it comes to the original posting, one has some options in addition what is the industry standard (to look at the Plant Capacity stated in a)). However, the owner has some leeway in the generation of power, specifically, one may follow the generator capability curve that allows one to use the highest Watt power output that materializes at the power factor equal to one (some power factor compensation scheme may be needed for that). Usually, the rated temperature is kept since it is related to the generator cooling system and generator lifecycle. Therefore, it is not wise to increase temperature over the rated temperature limit/rise.
A good industry standard for generators is Reference 3.