Polaris solar PV net news: photovoltaic power station running roughly five different ways:
Optimum tilt angle fixed type (currently the most widely used);
-Inclined single-axis tracking;
Fixed and adjustable.
Different operating modes, the most fundamental difference lies in their power differences. Of course, the initial investment and maintenance costs will be different.
A different operating mode of generating capacity increase
In 2010, when I started looking at different operational modes, obtained from a stent manufacturers a number of measured data, complete the following figure.
From the diagram above, we can see that, compared with the optimum tilt angle stationary installations, horizontal single-axis tracking electricity generation increases 17%~30%, tilt 5 ° single axis tracking capacity enhances the 21%~35%, dual-axis tracking electricity generation increases 35%~43%. But under different latitudes, of various operation modes of output increase rate is obviously not the same. Generally, there are a few rules:
1) optimum tilt angle fixed type (hereinafter “way”)
At low latitudes, because the optimum tilt angle is small, so generating capacity increase was small (as in 8 °, almost unchanged); at higher latitudes, the optimum angle, power output increased significantly (such as 50 °, increased by approximately 25%).
2) single-axis tracking (hereinafter “mode II”)
Running this way, tracking the sun angle changes in one day, increased its generating capacity, at low latitudes is superior to high latitudes. Generally speaking, this operation mode is more suitable for the use in areas below 30 ° latitude, as opposed to “one”, 20%-30% generation can be improved. At high latitudes, of course, “one” can also increase close to 20%.
3) inclined-single-axis tracking (hereinafter “the way”)
Obviously, this operation mode is the combination of the “one” and “two” advantages. “One” is not suitable for low latitude regions, this mode of operation at low latitudes performed no better than “second” much better. Therefore, more suitable for high latitudes.
This way, arrayed on either side of the supporting structure (bracket, axis of rotation) force is certainly not the same. Due to the high latitudes of the optimum tilt angle is large, if the “optimum tilted angle of inclined shaft”, the unbalanced force will be large on both sides. Therefore, the project will generally use a smaller dip.
4) dual-axis tracking (hereinafter called “mode IV”)
Track one day, within a year of the attack angle of the Sun changes, improvement of the electricity in this way is clearly Supreme.
5) adjustable fixed (hereinafter “five”)
This operation mode is based on the sun angle changes within a year to adjust bracket angle, so as to achieve an output gain. More popular since last year, are highlighted below.
What about the different operational modes is how to increase the generating capacity of? Two diagrams do the actual data (Note: pictures from Wang Sicheng teachers ppt).
Monthly electricity generation, operation within one year difference
Can see from the chart, relative to horizontal radiation:
Fixed increases in spring, autumn and winter season, and summer generating capacity have been sacrificed;
Single-axis tracking and horizontal curve almost perfectly parallel;
Dual-axis tracking and single-axis tracking increased output in the spring, autumn and winter quarter.
Various operating modes each generation difference within a day (wuwei, the middle of May)
From the diagram above, we can see that:
Track (single shaft and double shaft) relative to the stationary, improves capacity sooner or later;
The data because it is spring, so electricity at noon, biaxial and stationary, is higher than that of the shaft.
Second, the application of different operation modes
No matter what, better track than the stationary power generation, so why is fixed is still everyone’s favorite running style?
First, the initial investment, covers, operation and maintenance cost
Both support investment and in the same capacity as the covers, or the operation and maintenance costs, and follows the following rules:
Dual-axis tracking > inclined single-axis tracking > flat single-axis tracking > fixed adjustable > optimum tilt angle fixed type
A 10MW project, for example, average 25 hours 1300h to consider investment increase of 0.1 Yuan/w, you may need to increase net earnings (annual income-generating capacity increased operation and maintenance costs) are getting about 100,000 yuan (0.95 Yuan per kWh of electricity prices, about improving 0.81% will get 100,000 yuan income).
For example, single-axis tracking investments increased approximately 1/w, future net annual income increase by 1 million flat and about 20%, about 2.4 million increase in income! Even after the operation and maintenance costs of hundreds of thousands of more than a year, is also cost-effective. Then why did you use?
Second, the failure rate and tracking accuracy
Tracking the high failure rate is a matter of General feedback. Existing solar power station in China, mainly in the Northwest, windy, particularly large damage to the track axis. Clapping once, let alone generating capacity increased, even basic electricity generation is no guarantee! I did not have specific figures, but know a few power plants, people think tracking type break easily.
In addition to failure rate, tracking accuracy up to ideal values, especially the dual-axis tracking. Therefore, the capacity increase will be less than initially expected.
Three, fixed and adjustable
“Fixed and adjustable” for singling out, simply because since last year, the fire in this way.
Qinghai somewhere below is for one year and 2 to 3 point angle of generating capacity.
Using three different angles, each month generating capacity
Different angle adjustment programmes, fitted values each month after electricity generation
Relative to the optimum tilt angle:
Ø three angles (regulation 3 times a year), can increase the capacity of 6.2%, before and after spacing should be increased, covers an area of increase;
Ø 15 ° and 36 ° (regulation 1 times per year), can increase the capacity of 2.9%, before and after spacing unchanged, covers an area of unchanged;
Ø 55 ° and 36 ° (regulation 1 times per year), can increase the capacity of 1.6%, before and after spacing to increase footprint increases.
Therefore, fixed the optimum tilt angle and a smaller angle is more appropriate.
Some time ago, Zhang made a technical exchange of Wuxi Yang-HO, drawing comparisons with the four fixed-adjustable bracket.
Based on the feedback of power plant operation and maintenance personnel: the tilt adjustment is a very hard thing, we are not willing to transfer, result in lower than expected. My personal feeling, Yang-Ho-Jack is a good solution to the problem (did not want to advertise it! ）。 Moreover, according to the construction site personnel of our company reflects, this way you can reduce construction installation difficulty.
Do not know how the accident rate for fixed-and adjustable.
Original title: various types of photovoltaic power plants and installation of support