Page 37 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

28 Fundamentals of Ocean Renewable Energy

1000 W × 1h = 1 kWh (1.8)
of electricity.

Capacity Factor
Capacity factor is defined as the actual electricity production divided by the
maximum possible electricity output of a power plant, over a period of time.
In the example earlier, the microwave consumed a constant 1 kW of electricity
over 1 h. However, if we consider a renewable energy power plant, its power
output is unlikely to be constant—it will be intermittent. We will take the total
UK wind generation in 2016 as an example (Fig. 1.17A). As you can see, there
is a lot of variability in wind generation over a year, but the mean for 2016
(shown as a black dashed line) was 2.4 GW. Given the information that total
operational wind capacity at the end of 2016 was 14.5 GW, 14 this represents a
capacity factor of
Actual output 2.4
100 × = 100 × = 17% (1.9)
Potential output 14.5
By contrast, nuclear generation in the United Kingdom was less variable
(Fig. 1.17B), with a mean of 7.6 GW in 2016. With an installed nuclear capacity

FIG. 1.17 Time series of total UK (A) wind and (B) nuclear generation in 2016. Dashed lines are
the annual means for each power source. (Data from http://www.gridwatch.templar.co.uk/.)

14. See http://www.renewableuk.com/page/UKWEDhome.