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Solar and wind are so different that comparing them doesn't really make any sense. Generally a combination is optimal. The news in this article though is that s

by gns24 10y ago

Solar and wind are so different that comparing them doesn't really make any sense. Generally a combination is optimal. The news in this article though is that solar prices have tumbled in the last few years - whereas wind prices have declined at a more expected rate. Comparing the photo-voltaic capacity installed in 2016 with wind capacity is a bit misleading, as wind typically has a much higher capacity factor than solar - so the 59GW of wind will almost certainly produce more electricity than the 70GW of solar.

philipkglass 10y ago
Utility scale solar projects, the majority of which in the US now use single axis tracking, attain significantly higher capacity factors than rooftop installations. There's still a wind advantage but I wouldn't say its CF is "much" higher. The EIA measured the capacity factors for US utility scale wind and PV respectively at 32.2% and 25.8% in 2015: https://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_6_07_b https://www.eia.gov/electricity/monthly/epm_table_grapher.cf... Wind still has a capacity factor advantage, but at 59 GW and 70 GW, multiplying by those above capacity factors, wind and large scale PV would be nearly matched for real output (18.998 real GW and 18.06 real GW respectively). Somewhere like Germany the real-output gap between wind and solar would be greater while in India I'd expect it to be lesser, due to relatively poor wind resources. (In fact single-axis PV might actually beat wind on capacity factor in India.)
- davedx 10y ago
  Keep in mind wind CF's are still increasing as the world moves more to offshore wind farms with taller turbine heights. See for example the new Burbo Bank extension off Liverpool. Dong Energy tweeted me this when asked about their Vestas CF's there: https://twitter.com/DONGEnergy/status/775692082497351680 https://twitter.com/DONGEnergy/status/775692082497351680 "In general it is fair to assume a capacity factor of app. 50% for new wind farms at good sites."
  - mikeyouse 10y ago
    One of my favorite charts: http://i.imgur.com/UUy8Xvz.png http://i.imgur.com/UUy8Xvz.png For the 4.5GW of wind installations that came online in 2014, the average capacity factor is above 40%. For 1/6 of the projects, they're above 45%. When we go to 140+ meter hub heights, NREL expects the best projects to have capacity factors of 60-65%: http://i.imgur.com/ebfPQYD.jpg http://i.imgur.com/ebfPQYD.jpg Nuclear obviously kills that with 92+% factors, but coal and natural gas plants are right there near 60%.. we're really on the precipice in the best possible way.
  - philipkglass 10y ago
    That's a good point too, and the happy surprise of recent low prices for new offshore wind projects indicates that wind will remain competitive in many scenarios.
imaginenore 10y ago
> 59GW of wind will almost certainly produce more electricity than the 70GW of solar. What do you mean? These are not some peak figures, they are expected energy production figures.
- pilom 10y ago
  Capacity factor means "take the amount of MWh actually produced by the plant, divide by the number of MWh that theoretically could be produced if it generated its maximum output 24/7/365." 70GW of solar refers to the maximum instantaneous production (note that it is measured in GW not GWh). So while in full sun, all of that solar is generating 70GW of power per unit time but at night, it generates 0W. Average that over a year and it generated about 28% of it's maximum power over time. Hydro plants have huge ranges of capacity factors depending on other restrictions on the dam like if it is used for flood mitigation, if it is operated as a peaker plant, and if it snowed a lot the past winter. Nuclear Plants generally have capacity factors in the 90% range to account for swapping out fuel periodically. Fossil fuel plants have capacity factors of >90% unless they are used as peaker plants.
- mikeyouse 10y ago
  pilom's answer was good, but a good metaphor is to compare light bulbs; Does a 100W light bulb use more energy than a 75W light bulb? It depends on how long each bulb is turned on. The same relationship exists between energy sources. Does 60GW of wind power create more energy than 70GW of solar power? It depends on how much the wind blows and how long the sun shines. If you divide the actual energy production by the ideal amount of energy production (aka if the wind blew steadily every minute of every day), that will give you your capacity factor.

by gns24 10y ago

philipkglass 10y ago

Utility scale solar projects, the majority of which in the US now use single axis tracking, attain significantly higher capacity factors than rooftop installations. There's still a wind advantage but I wouldn't say its CF is "much" higher. The EIA measured the capacity factors for US utility scale wind and PV respectively at 32.2% and 25.8% in 2015: https://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_6_07_b https://www.eia.gov/electricity/monthly/epm_table_grapher.cf... Wind still has a capacity factor advantage, but at 59 GW and 70 GW, multiplying by those above capacity factors, wind and large scale PV would be nearly matched for real output (18.998 real GW and 18.06 real GW respectively). Somewhere like Germany the real-output gap between wind and solar would be greater while in India I'd expect it to be lesser, due to relatively poor wind resources. (In fact single-axis PV might actually beat wind on capacity factor in India.)

davedx 10y ago
Keep in mind wind CF's are still increasing as the world moves more to offshore wind farms with taller turbine heights. See for example the new Burbo Bank extension off Liverpool. Dong Energy tweeted me this when asked about their Vestas CF's there: https://twitter.com/DONGEnergy/status/775692082497351680 https://twitter.com/DONGEnergy/status/775692082497351680 "In general it is fair to assume a capacity factor of app. 50% for new wind farms at good sites."
- mikeyouse 10y ago
  One of my favorite charts: http://i.imgur.com/UUy8Xvz.png http://i.imgur.com/UUy8Xvz.png For the 4.5GW of wind installations that came online in 2014, the average capacity factor is above 40%. For 1/6 of the projects, they're above 45%. When we go to 140+ meter hub heights, NREL expects the best projects to have capacity factors of 60-65%: http://i.imgur.com/ebfPQYD.jpg http://i.imgur.com/ebfPQYD.jpg Nuclear obviously kills that with 92+% factors, but coal and natural gas plants are right there near 60%.. we're really on the precipice in the best possible way.
- philipkglass 10y ago
  That's a good point too, and the happy surprise of recent low prices for new offshore wind projects indicates that wind will remain competitive in many scenarios.

imaginenore 10y ago

> 59GW of wind will almost certainly produce more electricity than the 70GW of solar. What do you mean? These are not some peak figures, they are expected energy production figures.

pilom 10y ago
Capacity factor means "take the amount of MWh actually produced by the plant, divide by the number of MWh that theoretically could be produced if it generated its maximum output 24/7/365." 70GW of solar refers to the maximum instantaneous production (note that it is measured in GW not GWh). So while in full sun, all of that solar is generating 70GW of power per unit time but at night, it generates 0W. Average that over a year and it generated about 28% of it's maximum power over time. Hydro plants have huge ranges of capacity factors depending on other restrictions on the dam like if it is used for flood mitigation, if it is operated as a peaker plant, and if it snowed a lot the past winter. Nuclear Plants generally have capacity factors in the 90% range to account for swapping out fuel periodically. Fossil fuel plants have capacity factors of >90% unless they are used as peaker plants.
mikeyouse 10y ago
pilom's answer was good, but a good metaphor is to compare light bulbs; Does a 100W light bulb use more energy than a 75W light bulb? It depends on how long each bulb is turned on. The same relationship exists between energy sources. Does 60GW of wind power create more energy than 70GW of solar power? It depends on how much the wind blows and how long the sun shines. If you divide the actual energy production by the ideal amount of energy production (aka if the wind blew steadily every minute of every day), that will give you your capacity factor.