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The future of solar doesn't track the sun

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Re: The future of solar doesn't track the sun

#91

Post by barathr »

adamcharnock wrote: post #66

I just spent 6 years living off-grid, running 5kw of solar, and 14kWh of storage. I setup a fixed array that I welded together myself. I could certainly see that tracking wasn't worth it even then. However, in the off grid-setting I did discover some nuance. Sometimes you could really do with some power around sunset or sunrise. In the winter, being able to more reliably run my air-source heat pump at sun-up would ha…

Tom Murphy shows in his excellent book on energy that over-tilting your solar panels by 15 degrees is a good idea (Table 13.2):

https://escholarship.org/uc/item/9js5291m#section.13.4

Basically take your latitude and add 15 degrees and that'll get you good annual coverage.

Re: The future of solar doesn't track the sun

#93

Post by carpdiem »

I used to work on solar power plants and solar tracking technology back in the late 2000s. Even back then, I remember frequently discussing that "eventually panels will be cheap enough that we'll just wallpaper the world...". It's really nice to see that coming true.

Re: The future of solar doesn't track the sun

#94

Post by AngryData »

csr86 wrote: post #83

Nature has come up with moving limbs on animals, but none of the trees seem to be tracking the sun. Branches are in fixed positions.

Many trees don't but lots of smaller plants do tilt their leaves towards then sun and can be seen easily in a timelapse. And also like the other guy posted, sunflowers famously follow the sun.

Re: The future of solar doesn't track the sun

#95

Post by rsync »

lm28469 wrote: post #79
rsync wrote: post #63

Earlier quoted context omitted.

I read, and appreciated, your entire comment - thank you. You describe a simple and elegant solution to some portions of these problems and what you are doing with your hot water "battery" is smart. I am forced, however, to ask: Where do you live and how large is your family ? My suspicion is that you do not live in the United States and your family is relatively small ... ? Modern, "first world" ("global north" ?) 2…

Americans basically live like energy is unlimited, free and has no side effects, the rest of the world doesn't have that chance, last time I checked the average US household used anywhere between 3x and 4x more electricity than the average EU household They tend to prefer huge houses with relatively complex designs (less optimal in term of area/volume ratio) / poor insulation, they make up for it by relying on tech f…

"Americans basically live like energy is unlimited, free and has no side effects ..."

Agreed - and guilty as charged which is why we're switching entirely to solar.

(I will also note that my household "cheats" by living in California where we need relatively little heat and do not even own an air conditioner so our path is, perhaps, a bit easier)

My main point is that whether you're a frugal EU council house or a profligate Texas McMansion, we - all of us - will continue to invent new demands for energy and continue to trend towards more energy used per person per unit time.

Therefore, if you're looking ahead to deployment of solar resources you should be realistic about that trendline.

Re: The future of solar doesn't track the sun

#97

Post by didgetmaster »

weinzierl wrote: post #6

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the mover. If enough panels face the wrong direction for long enough it is worse than facing the sun in a good enough fixed position all the time. Our angle was to use a simple motor that runs with constant speed and use a special patented gear (called VIAX) to tu…

I always thought that someone would invent a cheap, simple, reliable, and passive tracking system. No need for sensors or intelligent electronics.

You have a simple motor that slowly tilts the array from facing East to facing West as power is being generated. The motor does not start until the panel is generating a certain amount of power. The motor runs at a fixed rate with a screw that takes about 7 hours to move the panel.

Once power stops (when the sun sets) weights on the opposite side slowly tilt the panel back to the starting position so it is ready for the next day.

Re: The future of solar doesn't track the sun

#98

Post by jules »

I don't understand how east-west arrays differ much from just a flat area. At the end of the day, don't they capture all sunlight in some large square? The east-west array only captures a bit differently around the outer edges. Can somebody explain? Is solar panel efficiency that dependent on incidence angle?

Re: The future of solar doesn't track the sun

#99

Post by londons_explore »

hx8 wrote: post #76
adamcharnock wrote: post #66

I just spent 6 years living off-grid, running 5kw of solar, and 14kWh of storage. I setup a fixed array that I welded together myself. I could certainly see that tracking wasn't worth it even then. However, in the off grid-setting I did discover some nuance. Sometimes you could really do with some power around sunset or sunrise. In the winter, being able to more reliably run my air-source heat pump at sun-up would ha…

I honestly don't think I would be comfortable off grid without 4x+ that size. Of course, environments vary so significantly that these numbers don't translate well when discussing them without geographic context. My primary concerns would be consecutive cloudy days, and winters with very short days. While my actual heating/cooling needs are more mild than global averages, I think the combination of short daylight hou…

I think it entirely depends if you want a 'just works' solution or you're willing to adjust your lifestyle day by day based on availability of sunlight.

Merely a 10 watt panel in the Netherlands has been fine whilst camping for weeks, but obviously I have to severely compromise on modern life - 10 watts powers a lamp for a few hours in the evening and a phone charge each day.

Re: The future of solar doesn't track the sun

#100

Post by b_emery »

didgetmaster wrote: post #97
weinzierl wrote: post #6

We researched this thoroughly in the early 2000s and came to pretty much the same conclusion even back then. For us the main problem was the reliability of the mover. If enough panels face the wrong direction for long enough it is worse than facing the sun in a good enough fixed position all the time. Our angle was to use a simple motor that runs with constant speed and use a special patented gear (called VIAX) to tu…

I always thought that someone would invent a cheap, simple, reliable, and passive tracking system. No need for sensors or intelligent electronics. You have a simple motor that slowly tilts the array from facing East to facing West as power is being generated. The motor does not start until the panel is generating a certain amount of power. The motor runs at a fixed rate with a screw that takes about 7 hours to move t…

Like a big, very simple clock basically.
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