Saturday, May 28, 2016

Solar Power on Cloudy days?

Out of interest, today I continued to experiment with solar power. I have a 5W solar panel that produces up to about 24V. Although today was hot, I went inside the bus and put together a breadboard connected to my solar panel, two CPU fans and two large electrolytic capacitors.

As can be seen, there's plenty light but the fans aren't spinning. I don't know a lot about electronics but it seems that I need to be able to dump the power collected in the capacitors into the fans automatically. That setup works if something shades the panel for a few seconds in conditions of bright light.

In today's totally overcast, grey sky, nothing happened. The starting current for the fans was too big and the solar power too low to get them spinning. Interestingly, my smaller CPU fan needed more power to get it going. I did discover that by disconnecting the fan while the capacitor charged, when I reconnected the fan, the capacitor discharged into the fan, setting it going for a few seconds. What I need therefore is a way of doing that automatically. That will probably need a transistor or something.

In bright light, those fans shift a goodly quantity of air. In poor light they shift nothing because of the bottleneck in the system. What I need is some electronics guru to help me to get this working. Sadly the "gurus" I knew in the past were a rather immature bunch unwilling to share their knowledge. I'm rather suspicious of advice published online too which leaves me with somewhat of a problem to overcome. Perhaps I might find the answers in my electronics book if I can locate it.

As I worked in the bus, soldering contacts onto the fans, I used my plugin. That worked really well though it's not the first time I have used it.
Those with sharp eyes will notice that the ground underneath the bus now has grass on it. This is because I moved the bus for the first time in two months. Aside from my needing to move it because it was beginning to sink into the ground, I discovered a hornet nest underneath the front passenger side wheel arch. Hornets were ignoring me and buzzing past while they built their nest. A quick squirt of bug spray eliminated the hornets on the nest and moving the bus confused the others.
If you inspect my slightly fuzzy cellphone photo carefully, you can see the nest dead center. I'll jet wash the wheel arches in a few days as I want to paint them grey anyway.

As far as solar panels go, I'm not planning to buy any more of them. I have had a couple and they have been very disappointing in terms of power generated. I really don't feel that solar and wind power are anything more than a geek toy. It cracks me up to see the way that people have fallen for this "green" baloney.

  • First, solar panels contain cadmium, selenium and mercury- hardly environmentally friendly.
  • Second, solar panels only work well when it's sunny and there are no clouds.
  • Third when they're not angled precisely at the sun (which moves) they're not producing their rated output.
  • Fourth - the sun isn't available 24x7.
  • Fifth - as a kludge to cope with the fourth problem - extra solar panels are used in order to charge batteries. These batteries are typically lead-acid. Again - not very environmentally friendly.
  • Sixth there's the cost. To run just a microwave, 120v at 10A is needed. That's 1200W. 1200W of solar panels at $150 (current cost) for 100W would cost $1800 and would work only when full sun was shining. Double the panels for cloudy weather and double the cost. Add some batteries in while remembering that lead-acid batteries can't put out too much power in a short time. That means probably six batteries at about $100 each are needed. That's a total cost of $4200.
  • Seventh, solar panels get very hot and need ventilation behind the panels.
  • Eighth, the space taken up by one 100W panel is 4 feet by 2 feet. Now 12 of those would take up more than the entire surface area of the roof of my bus. Not very practical.
  • Ninth, the weight of 6 lead-acid batteries would be 360lbs. That's very heavy.

So, we're looking at 360lbs for just the batteries, huge heat generation on the roof plus the weight of the panels on the roof and the extra height they would add, not to mention potentially changing the stability of the bus and a total cost of $600 for batteries and $4200 for solar panels. I make no excuses for calling that a crock! For $200 I can get a generator powerful enough to run a microwave when needed. Typically such a generator will run for 4 hours on a gallon of fuel. Running the generator 24x7 at the current $2 per gallon, I could run the generator for over a year non stop for the price of the solar baloney.

As I said, most of Europe is dumping the solar and wind power nonsense. They let the greens have their way for 20 years and the greens totally failed to prove their case. When it was announced there was a real need for nuclear power, the greens just hung their heads, totally defeated by truth. Renewable energy is just a geek toy that's not at all green.

So, where now? If I can get my capacitor to dump it's load into the fans every time it's full then I should be ok. On a smaller scale, solar might work for ventilation. For cooking, it's total nonsense. As far as charging electronic devices, I'm not really sure solar is worthwhile either.

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