Generation Capacity
From the American Energy Society:“Capacity” – perhaps the most misused term in energy. On average, wind farms have a capacity factor of about 34%; meaning they work about a third of the time. Some of the best wind sites have factors above 60%. The capacity factor for solar photovoltaics is 10% in the UK, 19% in the US, and 24% in Chile’s Atacama desert (the highest rating for any solar in the world). By comparison, coal plants have a 40% capacity factor and nuclear about double that.
I would have put this differently.
“Capacity” and “capacity factor” mean two different things. Capacity, or nameplate capacity is the amount of the power coming from the device running at its maximum. Capacity factor is the percentage of that maximum capacity that is put out over a given period of time.
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To be precise, a capacity factor of about 34% doesn’t mean the device “works” about a third of the time; saying that ignores the fact that devices are often not either “working” or “not working.”
Craig,
Your description of “capacity factor” comparisons, is disingenuous.
The principle difference between the capacity of fossil fuel plants and renewable energy, is the availability of fuel.
Coal fired plants operate at a 96-98% “capacity facto” if sufficient consumer demand is required (up to 4% must be allowed for maintenance), since fuel can be continuously supplied. Lower capacity percentages are created by variances in power generation demand or government restrictions and policies. Except in extreme circumstances, the technology is not limited by supply factors.
In contrast, (with the exception of some ego-thermal) all renewable energy generation “capacity factor” face the problem of unpredictable, uncontrollable, variances created by using an unreliable intermittent source of raw material fuel supply.
For many years US power consumers were deceived and cheated by a subtle and cunning plan created by the Obama administration and US government to negatively distort the “capacity factor” of coal, and enhance the “capacity figure” of renewable, in particular Wind and Solar.
In a complicated series of incentives and regulations, power utilities were forced to only report the dumping of excess power from fossil fuel sources, while losses by renewables through a lack of consumer demand were concealed and hidden in the fossil fuel calculations.
Here you go again, blithely repeating the same old disinformation.
What? Maybe you should reread what I wrote. It’s about the definition of CF; I never mentioned anything about the relative CFs of coal and renewables.
Craig,
Maybe it wasn’t your intention, but the information, “Some of the best wind sites have factors above 60%,……(and)… By comparison, coal plants have a 40% capacity factor and nuclear about double that”, does exactly that by implication.
However, I’ll accept it’s just an unconscious Freudian slip in your narrative :).
Oh, now I get it. Yes, I don’t know where they got the 40% figure. But coal plants have a CF in the 50s, not the 90s. https://en.wikipedia.org/wiki/Capacity_factor
Craig,
The 40% figure is often quoted since coal power plants are often underutilized due to a wide range of demand factors. Many were built to service heavy industries that no longer exist or have moved elsewhere.
Most coal plants in the US provide baseload power when other sources fail. A great part of the US and European coal generation fleet is very old and still employs obsolete, inefficient technology.
It would be easy to blame government policies for this situation, and in part that’s true. However, the industry itself must also accept some of the blame as during the heyday, utilities were more interested in profit than investment in researching superior technology.
Unlike the rest of the fossil fuel industry, generating plants were divorced from the mining operations and the fractured industry didn’t invest in the big picture until very recently.
Issues such as public health, environment etc were largely ignored by an industry which had little opposition. In Europe and many countries outside the US, coal and power generation had been nationalized into government ownership for generations.As a result, very little investment was spent on R&D within the coal industry, especially in public health, environment, technology or even efficiency.
Quite deservedly, the coal industry acquired a bad image among environmentalists, not helped by troglodyte old fashioned coal barons like Robert Murray etc.
The position of some utilities in deserting coal fired plants made not only environmental, but good business sense. The enormous cost of refitting an aging coal fired plant, along with environmental considerations, lack of government support, cheaper and more versatile natural gas, renewable sources attracting government subsidies and incentives, better public image etc etc, often proved irresistible for utilities.
The decision to move away from coal made even more sense when the demand for power also changed from high use, heavy industry customers requiring scheduled demand to a widely distributed network of hundreds of thousands of small consumers.
During the 40 years the Coal industry remained moribund and complacent, other exciting new technologies arose to dethrone “King Coal”. Natural Gas, Wind Power, Solar, Nuclear, Geo-thermal etc, all were more attractive not only environmentally, but potentially economically more viable.
These new technologies arrived with an army of enthusiastic followers and advocates, a political popularity.
The argument to abandon coal altogether, started to make sense !
So why, (to the chagrin of many fervent anti-coal advocates) is coal making a comeback ?
IMHO, primarily for three reasons;
1) Intermittent renewables like Wind and Solar are unable to provide the sort of base load power required economically in industrial societies where “power on demand” is a priority requirement.
2) The price of Natural Gas is uncertain. As the demand for export of NG products such as LPG increases, so does the price and difficulty of supply.
3) Outside of the US and some European countries coal never went away ! In fast developing new industrial economies coal fired energy is the first choice. Heavy industry customers in China,India, Japan, South Korea, Taiwan, Thailand and many other industrializing nations see coal technology as the technology of preference.
In these nations, the environmental impact of coal technology is just beginning to become a matter of concern. These nations would rather solve the problem of emissions, rather than do without the befit of coal energy.
The election of a pro-coal administration in the US has brought about a huge renaissance in research and development of clean(er) coal technology.
Progress has been astonishing, although yet to attract the attention of environmentalists still stuck in anti-coal mindset.
With significant investment in new environmentally improved methods of exploiting the energy from coal to produce not only energy but valuable by products, the future of this old industry is starting to attract some of the best scientific and innovative minds to transform how we view coal as a resource.
Many of the by products of coal can be harnessed to not only reduce and eliminate the harmful effects of coal, but also make other industrial processes more environmentally friendly.
Clean(er)coal technology is making coal more economically competitive.
The “rehabilitation” of Coal technology will be a long journey, but the first steps are already showing great promise for future generations.