Guest essay by Philip Lloyd, Energy Institute, Cape Peninsula University of Technology
The annual Review has just been published. The data is readily downloaded as an Excel spreadsheet. A few minutes work soon gives an excellent idea of the trends in the world’s energy. The changes since 1965 in the consumption of the primary energy sources, in millions of tonnes of oil equivalent (Mtoe), are:
Global consumption continues to increase. A linear model suggest an annual growth of 176±7 Mtoe over the full period, although in this century it has been growing far faster, 265±18Mtoe annually. Much of this acceleration in growth has come from the use of coal, but that has slowed in recent years with the downturn in the Chinese economy.
Those who are concerned about our fossil fuel use will be gratified to know that we are getting a little less of our energy from fossils:
The Kyoto Protocol seemed to have the effect of increasing our fossil consumption. It took the economic catastrophe of 2008 to have any impact, and the relative consumption is now falling.
Some would point to the growth in renewable energy supplies, and indeed renewables are no longer completely insignificant. If we look at electrical generation rather than primary energy, then today nuclear yields about 2 500TWh annually, hydropower about 4 000TWh and renewables about 1500TWh:
Nuclear has started to grow slowly; hydropower is growing steadily at about 90TWh per annum; and renewable are growing exponentially – the past year added over 200TWh to renewable generation. This growth comes primarily from wind power:
although solar photovoltaics have started to grow rapidly.
The BP Review permits a review of the efficiency of wind and solar power, because it gives both the installed capacity and the energy generated. The global capacity factor for solar PV was below 10% but has risen to about 12% in recent years. The capacity factor for wind has been growing steadily and is now about 22%:
The annual BP Statistical Review is a rich resource indeed, and my mining has only just scratched the surface. For those having ambitions to control temperature rises by reducing fossil fuel consumption, it gives cold comfort – fossil fuel use is still growing at over 150Mtoe per annum and will make up more than 80% of global energy for quite a few years yet. “Decarbonisation” is the stuff of dreams.
The full report is available here: http://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html
“Efficiency of wind and solar power,” am I reading this stat correctly? Wind is about 22% and Solar is about 12.5%? Does that mean that it takes 4.5 1,000 km wind turbines to generate 1,000 kw and 8 1,000 kw Solar Panels to generate 1,000 kw? Is that a joke? Not only are these sources unreliable and intermittent, they are also inefficient?
So much rain on wind power’s capacity factor. The fact is that wind power has a decent annual average capacity factor compared to the other technologies. Wind is better than natural gas, and about the same as large hydroelectric. Here’s the data for the US in 2014, per the EIA. A graph is at the link below.
Natural Gas 29 percent
Wind 34 (note from above comment, range was 43 to 22 on a monthly basis)
Large Hydro 37
US Average 43.7
Coal 60
Nuclear 92
http://sowellslawblog.blogspot.com/2016/04/us-power-generation-capacity-factors.html
The reason (well one of the main reasons) why gas and big hydro have relatively low capacity factors is that they are so fast to bring on line and off line. Hydro especially, the wind-up time is measured in seconds. These are the cushions that allow large grids to deliver constant voltage as demand fluctuates.
And of course they are the cushions that allow renewables to form a part of a blended system. And that is why the cost of renewable power must include the cost of maintaining these backups ate idle. Which is a large part of their total operating costs, even when no fuel is consumed.
Roger Sowell June 12, 2016 at 7:01 am
Roger, you are comparing apples and oranges. Wind power has a low capacity factor because much of the time, there’s no wind.
Your comparison assumes that the same is true for the other energy sources, that e.g. natural gas has a low capacity factor because most of the time there’s no natural gas …
Sorry, amigo, but that’s apples and oranges
w.
Willis, with all due respect, let me share my thoughts on the grid, generation, and capacity factors. As you may (or may not) know, I write extensively on this at my blog, SLB.
First, every form of generation requires backup. This is because all forms of generation require mechanical servicing, or refueling, or have some other cause to be offline. The sudden shutdown of 2 nuclear reactors in 2012 in Southern California at the SONGS plant is a case in point. Many nuclear plants in the US experience unplanned shutdowns, with other assets on the grid expected to cover the sudden loss of 1000 MW or even more.
Second, not all forms of energy are available 24/7. The most attention is given these days to wind and solar, but large hydroelectric also is subject to availability of rain, or snowmelt. Hydroelectric has a low capacity factor at 37 percent (as above, for the US in 2014 per EIA), primarily because water in lakes has competing uses, but also due to a long drought in the western US. The main competing use is irrigation.
Natural gas plants have an even lower capacity factor than hydro and wind, but for a different reason. As one commenter above noted, (Smart Rock), the grid has large swings in demand on a daily basis. There are also seasonal variations in demand, such that the full complement of generation assets are only run on the few days of peak demand. During Spring and Autumn, many of the natural gas plants are usually loafing.
Coal and nuclear plants have high capacity factors in recent years because the grid operators called on those assets for power first, having lower cash costs to generate. That has changed in the past 5 to 10 years as natural gas prices have declined and wind capacity has increased. Nuclear is no longer the lowest-cost asset, as some of the US nuclear plants are shutting down due to inability to sell power profitably. Coal plants are also shutting down in the US but for a different reason: they cannot afford to install pollution controls now that their exemptions from regulations has ended.
It is also a fact that nuclear power plants only recently achieved high capacity factors. Prior to 1988, the US average capacity factor for nuclear plants was less than 60 percent (per Nuclear Energy Institute). Even after 1988, a full decade was required before the annual average capacity factor climbed from 60 to 90 percent for US nuclear reactors. One wonders where the outrage was prior to 1988 when nuclear plants could not deliver power at the 90 percent capacity.
Similarly, wind power capacity factors are increasing year over year due to taller towers, longer blades, and better blade designs. Older, less efficient and shorter wind turbines are being replaced with much better systems. There are also offshore installations in the works, with much better capacity factors compared to the onshore installations. As time passes, the capacity factors for wind power almost certainly will increase.
The economics for wind power just keep getting better and better.
Capacity factors have different real meanings for wind and solar. The grid has about a factor of 1.5 to 2 demand curve, more so in the summer than winter. There is more demand in daytime than at night. Here’s today’s California ISO plot: http://www.caiso.com/outlook/SystemStatus.html On most days, the wind production curve is opposite the demand curve trends, while the solar curve mostly tracks the demand.
Wind power fluctuates as the local wind speed changes, which is forecastable but still random. Solar power is generated during the daytime when demand is higher. Furthermore, in the summer, much of the load is for air conditioning, and if the day is cloudy, there is less demand when the solar farm produces less power.
Thanks, that is a helpful reminder. In addition, the market places a premium on daytime generation. Solar would be higher in the basic statistical measures had it not been pulled into less efficient and more costly rooftop policy turns. Solar costs continue to diverge between utility scale and rooftop, but still there is no meaningful recognition of this in policy land or the general public.
Distinguish between capacity factor and efficiency. The term Capacity Factor has no meaning with a gas-plant that turns on when wind stops or when clouds enter between the sun a solar collectors. The plant can obviously run 24/7 for months if needed, i.e. with CF close to 100 %, measured on several years basis. Efficiency is the criterion that applies here – the ratio of heat in and electricity out, the usual 33 %.
The CF is NOT a measure efficiency or power and has a vague meaning in literature. The number can be manipulated to serve a purpose. As to the efficiency of wind towers – not much has changed. The theoretical max efficiency (hard to measure that why the term it is not used in practice) is 59 % and the state of the art is as close to it as can be. The generators likewise; not much improvement there short of less viscosity oils, etc. Erecting bigger towers makes them generate more power but their efficiency is not much affected. Finding sites with steadier, high winds produces both higher CF and higher output, but not higher efficiency.
“Germany’s mad rush into renewable energies has led to huge spiralling electricity price increases and left power grid operators struggling to keep the wildly fluctuating system from crashing.
As the situation became increasingly precarious, the government was forced to admit that reforms were necessary to keep the situation from spiralling out of control, and thus recently agreed on a major reform of subsidies for renewable energies.
Experts say the new measure will result in a comprehensives scale-back in new renewable energy installations, thus putting the brakes on the green electricity scheme.”
http://notrickszone.com/#sthash.MJP4NKfe.dpbs
Germany’s grid is one of the world’s most reliable:
http://blogs.scientificamerican.com/plugged-in/data-show-that-germany-s-grid-is-one-of-the-world-s-most-reliable/
Even on days when most of its power is from renewables:
http://www.bloomberg.com/news/articles/2016-05-16/germany-just-got-almost-all-of-its-power-from-renewable-energy
current changes are to restrict growth which has meant targets would be reached years early (and thus budgets exceeded), plus limits are needed until the new north south grid connections come in (2021 & 2 in 2025).
Something does not add up here, much like the VW promises to regulators on the front end. Germany was first with huge solar subsidy and investment among all nations with much higher cost solar variants compared to recent cost experience. That included even higher than average solar with rooftop emphasis. It then cut back on all solar while forging ahead with wind power (aka VW) promises on costs and reliability). Now it is going back to modern solar with the exclusion of wind. The only way you can smooth over theses issues is with VW-style tactics. Also, the grid operators in Germany are not faring well financially. The main problem with renewable generation reporting is the lack of a full picture on cost to ratepayers in addition to headlines on the share of generation added, not just one of these or the other selectively!
I notice that you fail to tell the people that Germany uses it’s neighbors as grid backup.
The entire EU is one big grid. Any attempt to isolate Germany, or France, or Belgium, in order to talk about their grid alone, is just a fancy way of lying.
Mark, part of the model is that renewables are exported/imported across an European grid.
There is no national island of electricity in Europe any more. (Except Eire/NI)
“Much of this acceleration in growth has come from the use of coal, but that has slowed in recent years with the downturn in the Chinese economy.”
China GDP grew 6.9% in 2015. A slower growth is NOT a downturn. Economy growing at almost 7% needs more, not less, energy, The slowdown in the growth of use of coal should be explained by other reasons.
Griff June 13, 2016 at 4:55 am
Thanks, Griff. Yes, that is true, they are “designed to work” for twenty years … but it appears you are studiously ignoring how long they actually last in the field ….
Gosh, they’re wearing out twice as fast as claimed … who knew?
Well, actually, anyone paying attention knew …
w.
“Twice as fast” is on par with the past advocacy claims of the nuclear sector on costs and ratepayer liability. In such policy games, it’s critical to know who picks up the tab for the cost overruns. Everything else is marketing.
http://www.telegraph.co.uk/news/earth/energy/windpower/9770837/Wind-farm-turbines-wear-sooner-than-expected-says-study.html
“The report, published last week by the Renewable Energy Foundation (REF), a think tank that has campaigned against wind farms..”
And
“The report has been disputed by the wind farm industry. It points out that the consumer subsidy is paid only when turbines produce electricity, meaning there is a strong incentive for wind farms to be properly maintained to protect them from wear and tear.
Dr Gordon Edge, dthe irector of policy at RenewableUK, the body that represents Britain’s wind farm industry, said: “Wind farm developers only earn money for the clean electricity they actually generate, so it’s very much in their interests to make sure that their turbines are maintained… to an optimum level, which includes upgrading as the technology improves.
“Better turbines are being developed all the time, so it’s absurd to focus purely on the past as this report does, and pretend that that’s the way things are going to be in the future.” 2
If you look at the detail on what windfarms were surveyed, you’ll find a slightly different story to the headlines. and not quoting your source is misleading.
„(UK) Wind turbines are found to lose 1.6 ±0.2% of their output per year, with average load factors declining from 28.5% when new to 21% at age 19. This trend is consistent for different generations of turbine design and individual wind farms. This level of degradation reduces a wind farm’s output by 12% over a twenty year lifetime, increasing the levelised cost of electricity by 9%.“ http://tinyurl.com/wind-decline
Land-based wind mills in Germany and Switzerland used 17% of their capacity on average in recent years, less than promised. As subsidies go down in Germany, little new wind and solar capacity is built now; producers now have to bid for subsidies and the big wheels have to bid low to get into business. The government steps on the brake now as the costs are seemingly out of control. After 2030 no subsidies are planned; anyway, resistance to the nuisance of wind turbines would probably make them obsolete.
Anybody who believes what Griff writes here will be mugged by reality in Germany and Europe.
Electricity prices for the average household (3500 kwh/y) in Germany have increased 170% since 1998 and over 200% since 1980. 52% of the about 30 €uro-cent (= 27 ¢) are taxes and fees. 6.5 cent of the 30 goes to the wind and solar barons; the price for a kwh at the exchange is about 3 – 4 cents.
Electricity prices for the average household (3500 kwh/y) in Germany have increased 170% since 1998 and over 200% since 2000, of course.
feliksch
Germany will still install 2.8 GW of onshore wind and 600Mw of solar under the new rules – plus continue to build offshore wind.
It still intends to ditch nuclear in 2022 (is that a good idea, I wonder) and still intends to be on 45% of renewable electricity by 2030.
2.7 GW of lignite coal power are going on the reserve for closure by end 2019.
This is just regulation of the roll out and prudent control of subsidy, now they are only a couple of points off the 2020 target.
The energy programme in Germany remains wildly popular