Hawaii's solar power flare-up: Too much of a good thing?

[wy_white_wolf]

Time to pay attention to what's happening in Hawaii. How they handle this will be used as a guidline by PoCo when the rest of the country gets more renewables.

http://articles.latimes.com/2012/nov...solar-20121118

...As customers generate more than they need and feed the excess back into the grid for others to use, it makes managing the system much more complex. What happens when a cloud passes over and dozens of rooftop units suddenly grind to a halt? What's to be done on a sunny autumn day, when rooftop solar systems are producing way more power than the grid can use?

The problem is especially pronounced in Hawaii, where each island has its own isolated power grid and can't quickly compensate with power generated elsewhere. The result, if not carefully managed, can be computer-killing power surges (in cases of excess generation), flickering lights, isolated blackouts or worse...

[GregYohn]

Had a windup solar Free Play radio pop due to a power surge when I hooked it directly up to a 15 watt solar panel. The sun came out from behind the clouds too fast. I was a rookie so learned need a charge controller and battery even for that small solar panel.

Wondering if electric companies could pump water or release it during peak times to handle the power surges better.

[Jim-mi]

We have here in southwest Michigan a very large system that pumps water up hill, during the day time, into a big reservoir. At night the water turbines are fired up by that stored water. rushing back down hill to Lake Mich. . . . . . . .fine and dandy . . .

But the system response time is very slow...........No way in heck could it keep up to the "Edge cloud effect" *spikes* that you got on that radio.........

[CesumPec]

Originally Posted by Jim-mi

We have here in southwest Michigan a very large system that pumps water up hill, during the day time, into a big reservoir. At night the water turbines are fired up by that stored water. rushing back down hill to Lake Mich. . . . . . . .fine and dandy . . .

But the system response time is very slow...........No way in heck could it keep up to the "Edge cloud effect" *spikes* that you got on that radio.........

I love the idea of that sort of solar battery. How many gallons of uphill storage do you have?

[TNHermit]

This will be easy. The power company will figure it out and charge you when there is too much pumping power back into the system. NO way the consumer is going to win.

The water turbine sounds like a neat thing.

[Jim-mi]

The up hill storage is a measley ....27 Billion Gallon Reservoir...............

Capable of producing . . 1,872 Mega Watts . . . . . .

. . LOL . . . sorry I didn't mean that this "my own' system . . . . .

It is a large facility run by Consumers Energy.

I do not know how to post "links"

But you can see a very nice descriptive page at---- Ludington Pumped Storage { Consumers Energy.


I was back words . . they pump the water UP at night and use the turbines for peak day time demand.........

[TnAndy]

...As customers generate more than they need and feed the excess back into the grid for others to use, it makes managing the system much more complex. What happens when a cloud passes over and dozens of rooftop units suddenly grind to a halt?

I can see where that would be a problem, for sure. Balancing load with a sudden under supply, or a constantly varying up/down supply would be a nightmare on a small grid.

My 'guess' is the utility would have to set some fairly low allowance for the average solar input, then keep their generation amount up to the rest of the load, on average, and simply ignore the potential oversupply of power from solar in good times.



What's to be done on a sunny autumn day, when rooftop solar systems are producing way more power than the grid can use?

Ok, this one might be BS, I think. Solar doesn't produce more than the load. If there is no load, there is no flow.....just potential. Unlike wind generators, you don't use a "dump" load on solar.

[CesumPec]

Originally Posted by Jim-mi

I was back words . . they pump the water UP at night and use the turbines for peak day time demand.........

is that a nuke power system? Years ago there was talk of taking excess nighttime power in Virginia to pump water upstream into a mountain lake battery. AFAIK, it was never built but it seemed like a good idea since as i understand it, it is difficult to throttle down a nuke plant every night.

[hawaiisolar]

Originally Posted by wy_white_wolf

Time to pay attention to what's happening in Hawaii. How they handle this will be used as a guidline by PoCo when the rest of the country gets more renewables.

http://articles.latimes.com/2012/nov...solar-20121118

"What's happening in Hawaii..." is that rooftop solar PV installations have been doubling every year for the past five years. We haven't had a grid failure or power outage despite the exponential growth...not even a hint of one.

Funny quote in the same article. "As an engineer, you always want to look at the worst-case scenario. Well, they have it," project manager Elaine Sison-Lebrilla said."

She's with te Sacramento Municipal Utility District. That explains the problem. Utility executives look at renewable energy as "the worse case scenario."

Yes...you should watch what is ahppening in Hawaii...because we will show you that renewable energy can be integrated into the electrical grid without jeopardizing its stability.

[Azrael]

Yes, if the power executives can find a way to short circuit owner generated power they will. I know the Duke Energy CEO is on record as saying that they are all for alternative energy, as long as they are the ones owning & operating it. Duke also will not ever cut you a check back for excess generation, it will always be a credit to your bill, so at least in Indiana no point in generating more than 80-90% of your needs if grid tied.

I hope that what is happening in Hawaii will help drive innovation in the utility scale battery implementation, I think that riht now this is the sole factor propping up all the naysayers (especially the power companies) of course I am sure if someone overcomes the obstacle they won't install it because it will be 'too experimental' for actual grid use.

[ace admirer]

Originally Posted by CesumPec

is that a nuke power system? Years ago there was talk of taking excess nighttime power in Virginia to pump water upstream into a mountain lake battery. AFAIK, it was never built but it seemed like a good idea since as i understand it, it is difficult to throttle down a nuke plant every night.

philpot dam near danville va is a back pump dam, but its been there for decades

[AngieM2]

the last home I had when married had solar heat, and water and we put in a wind generator. For several months the excess electricity went back into the power grid, by running the house meter backwards.

That was until the power company discovered it happening - then they blocked it from running backwards.

It was very nice. This was about 1980.

[TnAndy]

Originally Posted by Azrael

Duke also will not ever cut you a check back for excess generation, it will always be a credit to your bill, so at least in Indiana no point in generating more than 80-90% of your needs if grid tied.

TVA will. I got a check for $329 last month for my 2012 excess, in addition to no power bill for 2012.

[Azrael]

Originally Posted by TnAndy

TVA will. I got a check for $329 last month for my 2012 excess, in addition to no power bill for 2012.

That's awesome!! I wish more munis/states would require that excess generation be paid back instead of credited.

[TnAndy]

Even better, they give you $1,000 when you connect, and pay 12 cents OVER retail for every hour of solar production ( separate meter ).