Comments on: They don’t have to win, they only have to confuse

By: Trevor29

Trevor29 — Tue, 29 Jul 2008 08:55:19 +0000

I have recently been impacted by the failure of a radio repeater powered by solar panels and a large back-up battery. After a week of dank weather, the battery voltage dropped too low for the repeater. This just proves that solar power cannot be relied on over periods of weeks.

Trevor.

By: Trevor29

Trevor29 — Tue, 08 Jul 2008 20:53:59 +0000

Cindy, PV solar cells don’t generate 12 hours a day even in summer. They need to face the sun and don’t generate when the sun is side on or even shining on the back of the panel. In winter, the sun is above the horison for only about 9 hours (Canterbury latitudes). Clouds block most of the light so the output falls to nearly zero with thick cloud.

The other problem with solar PV is the cost of the equipment to convert the DC output into something useful.

Trevor.

By: cindy

cindy — Tue, 08 Jul 2008 12:42:17 +0000

“the main limitation of solar power in New Zealand is that it is usually available when it is least required”.

hmmm…. so 12 hours every day wouldn’t cut it? … solar is PHOTOvoltaic ie needs LIGHT not necessarily SUN.

By: Kevyn

Kevyn — Tue, 08 Jul 2008 12:29:22 +0000

“The main limitation of solar power in New Zealand is that it is usually available when it is least required.”

We made that mistake with hydro. The damns fill up in spring and if it doesn’t rain in autumn by the time winter comes around there’s no safety margin left. It made sense at the time because every house had a fireplace (many with wetbacks) so why be extravagant with the size of your dams and lakes.

By: bjchip

bjchip — Tue, 08 Jul 2008 10:34:19 +0000

Trevor

Sorry I was being cute with my wording… “it is seasonal and not well regulated with respect to our needs” is intended to mean the same as “usually available when it is least required” … a little giddy after getting through one of the worst projects I’ve ever had to make work.

In the summer the AC load goes up and the wind goes down… leastways that;s what happens where I live. Solar has a place. It isn’t in first place here, but compared to the others it is dead simple and it IS cheap now that they’re printing the cells. Installed power is getting to be cheaper than coal fired electricity plants… provided you don’t try to store the energy.

My approach to planting a lawn and putting in a sidewalk is different from a lot of folks. First I plant the lawn. Then after people have worn holes in it, that’s where I put the sidewalk. Much the same approach applies here, because the need is to find all the things that work for us we try to do all and observe closely what works and when… a somewhat different form of market dynamic. More efficient in the end than anything I could plan or foresee.

respectfully
BJ

By: Trevor29

Trevor29 — Tue, 08 Jul 2008 08:32:19 +0000

The main limitation of solar power in New Zealand is that it is usually available when it is least required. We need a decent amount of wind, wave or tidal generation to provide enough winter power. When we have installed that, we won’t need significantly more power than that already generates in summer, so the extra output of solar power will be largely unnecessary. We could use it for generating hydrogen, etc but it just wouldn’t be economical to install.

Trevor.

By: bjchip

bjchip — Mon, 07 Jul 2008 22:46:10 +0000

If I were in Oz the solar plants would be somewhere above first place. Here I like the wind and wave power with the caveat that it does not matter WHAT you put in or near the ocean “rust never sleeps”. For that reason I prefer wind and geothermal here… but only for that, Maintenance of such a power system is going to be an ongoing affair.

But the power is there for the taking. We are in the “Roaring Forties” and the reason they are called that is for the roar of the wind in the rigging. Sailors respect these latitudes … with waves representing the collected power of the wind over the surface of thousands of nautical miles of ocean.

NZ gets more sunlight than you’d suspect I think, but because it is seasonal and not well regulated with respect to our needs, it is less popular as an option. It serves as a useful added source however, when the cells are cheap enough. When the wind is calm in the heat of the summer. The hydro lakes are our natural batteries. No sense draining them just to have AC.

Reminds me of a letter I meant to write to Kapi-Mana. They’re all in a tizzy about wind farms above Pauhatanui. We might have to SEE them.. Oh DEAR!

I’d be proud and pleased to have one in view. That’s a legacy to my kids that it makes some sense to leave to them. My kids know it too.

respectfully
BJ

By: Trevor29

Trevor29 — Mon, 07 Jul 2008 20:55:28 +0000

Let the Aussies get a solar PV cell factory going. New Zealand doesn’t really suit solar PV power generation. Our future lies with wind, geothermal and marine power sources. We have no less than three different marine power resources which individually can produce more electricity per year than our current consumption - wave, tidal flow and salinity gradient. All of them work during winter when our power consumption peaks. That is where we should be investing our research dollars.

Trevor.

By: Trevor29

Trevor29 — Sun, 06 Jul 2008 04:37:15 +0000

While finding ways of turning electricity into vehicle fuels such as Methane, Methanol or Ethanol would be useful in the long term, it is more urgent to stop wasting the Methane we do have by using it for electricity generation - or worse. We need to develop alternatives to gas-fired “peaking plants” to meet our peak electricity needs, such as vanadium redox flow batteries or pumped hydro storage. I believe geothermal also has a role to play in meeting our peak demands by firming up our hydro plant.

Trevor.

By: bjchip

bjchip — Sat, 05 Jul 2008 10:24:41 +0000

None of the “large scale” engineering projects is a tenth as challenging as getting people to accept the first project which “only” requires us to modify our behaviour, or the second which requires us to force ourselves to apply a cost to it The thing is that number three is something we ought to be doing because we’re running out of dead dinosaurs, never mind the environmental impact of burning them. Number four likewise. The economics are pretty compelling and only get more compelling as the years wear on.

Number 5 is a capability we had within our grasp. There was a a working prototype of an SSTO vehicle flying and landing out in the desert when some Lockheed executives white-anted the process and sold NASA some powerpoint slides and the reputation of the skunk-works and a performance guarantee… that happened to be a heap less than the profits they continued to take out of the DISPOSABLE launch systems market for the last 10 years. It isn’t actually as difficult to do as it is difficult to get started… and NASA has had a lot of difficulties placed in its path that have nothing to do with science and technology. Numbers 6 and 7 go together as my personal pet scheme to make the distribution of energy easier to manage. Distributing methane is actually easier than building power pylons undersea cables. Burning it in cars, also easier. The infrastructure needs only limited modifications to remain useful. It finesses the step from petrol to renewables… smooths the transition and has some potential to be an industry that NZ could claim for its own.

In any case, my point is that I know of NO way to influence humans to do the right thing at the right time or even much much too late… As a species and as nations we are pig-headed, stupid, arrogant and self-centered… except when we are much much worse than that. So the call is going out for the magicians to once more produce some sort of rabbit. Engineers and scientists are ridiculed and yet the only answers that have any hope of working are the technical ones.

Because people are people. They won’t be told what to do… and finding ways to persuade them to do what they ought is not something they teach in the Engineering and Physics classes. I don’t disdain to use the social sciences to the extent possible… but I am aware of their limitations in this application. Some answers play to our strengths as a species, others rely on us overcoming our weaknesses. I am happy to work on all of them… but only certain of being able to do the ones that DO NOT rely on the cooperation of my fellow humans.

respectfully
BJ