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Author Topic: Questions about Solar Power  (Read 35054 times)

Noam

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Re: Questions about Solar Power
« Reply #15 on: March 25, 2014, 10:08:46 AM »

Sorry it's taken me so long to reply, but here's an update:
The initial system design came back 25% smaller because the salesman over-estimated the size of the roof (he guess the wrong roof angle, and we can blame the rest on trigonometry).  Simply put - the roof is smaller than he originally thought - so they can't fit as many panels on it.

However - the engineer came back with another option: Even though the front of my house faces almost directly north, the low slope of the roof means that panels installed on the front of the house would get enough sun to meet SolarCity's minimum efficiency threshold.

So the new plan is to put a total of 61 panels on the front and the back of the house (36 back, 25 front), and they expect to generate an average of 18,500 kWh per year.
I approved the design, they submitted the permit application to the county, and now I am back to waiting.

If anyone has any information on issues with the SolarEdge SE6000A-US inverter (or similar models) and X10 communication, I'd appreciate it.
I might end up buying an XTBM (*finally* - I've been "thinking about it" for almost 4 years!), since I still want to replace more bulbs with LEDs. The incandescents use much more power, and the CFLs take too long to warm up to full brightness.

Hopefully we can catch a break with this weather (Snow in DC on March 25th for the *second* year in a row is not funny), so my roofing contractor can finish the three jobs he has lined up ahead of mine.
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HA Dave

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Re: Questions about Solar Power
« Reply #16 on: March 25, 2014, 10:51:14 AM »

Please keep us up on this project. I am following with great interest.
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Tuicemen

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Re: Questions about Solar Power
« Reply #17 on: March 25, 2014, 12:41:18 PM »

The initial system design came back 25% smaller because the salesman over-estimated the size of the roof (he guess the wrong roof angle, and we can blame the rest on trigonometry).  Simply put - the roof is smaller than he originally thought - so they can't fit as many panels on it.
My wife looked into a similar setup here for our city place.
Here they do all the calculating via satellite, sadly it to has to small of a roof area to qualify. :( :(

 
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Noam

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Re: Questions about Solar Power
« Reply #18 on: March 26, 2014, 10:43:56 AM »

Please keep us up on this project. I am following with great interest.

I'll do my best to keep everyone updated.
In the interest of full disclosure, I do get a referral credit if I refer new customers. With that in mind, I still want to try to keep the discussion focused mainly on the specific interaction between the SolarCity equipment and my X10 equipment.
I'm happy to talk more offline if anyone is interested in finding out more about SolarCity, and how their pricing model works - just send me a private message.

My wife looked into a similar setup here for our city place.
Here they do all the calculating via satellite, sadly it to has to small of a roof area to qualify. :( :(
I think that's how most of the companies do their initial calculations. It is pretty easy to do, and is accurate enough to let them know if it is worth pursuing. It takes time and money to send out a person to climb on the roof and take precise measurements. Looking at my neighborhood in Google Earth, I never realized how many trees there are (and I grew up in this neighborhood, too!). Yes, the trees have grown over the past 30+ years, but the are was all woods before the development was built in the 1950's-60's, so most of the big trees were already here.
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dhouston

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Re: Questions about Solar Power
« Reply #19 on: April 21, 2014, 10:07:57 AM »

Oklahoma has passed a law that will require those with solar or wind installations that feed excess power to the grid to pay a monthly fee which, ostensibly, will compensate the utility for grid upkeep.
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dave w

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Re: Questions about Solar Power
« Reply #20 on: April 21, 2014, 08:37:27 PM »

Oklahoma has passed a law that will require those with solar or wind installations that feed excess power to the grid to pay a monthly fee which, ostensibly, will compensate the utility for grid upkeep.
<grin> They (the utility) would have to maintain the grid anyway. Sounds like more of a win for the power company than the customer. I wonder if the utility buys back power at the same rate per kWh as they sell it?
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HA Dave

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Re: Questions about Solar Power
« Reply #21 on: April 21, 2014, 09:29:03 PM »

....<grin> They (the utility) would have to maintain the grid anyway.

So.... since you'll be driving near me and my work place everyday anyway.... why not just chafer me around everyday (for free) since you'll be spending money for the car and fuel anyway?!? <grin>

I think people who have their life's savings invested in the local utility company... desire a little return on there investment.

There are some darn great uses for all sorts of energy... alternate and otherwise. But most of the ideas.... of trying to force solar and wind into tired 100 year old paradigms into modern times doesn't make good sense. Currently there are BILLIONS of American tax dollars being thrown around in solar and wind power schemes... none of which seem to be able to stay out of bankruptcy court. 
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beelocks

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Re: Questions about Solar Power
« Reply #22 on: April 22, 2014, 07:43:09 AM »

<grin> They (the utility) would have to maintain the grid anyway. Sounds like more of a win for the power company than the customer. I wonder if the utility buys back power at the same rate per kWh as they sell it?

Business Rule #1
Always sell at a profit unless absolutely necessary to make a loss in order to shift product before it's out of date - it's likely that the utility will buy at somewhere around half the sell rate.

Charging a fee to pump power INTO the grid makes perfect sense. Imagine the scenario where everyone has solar/wind pumping into the grid and does not pay a fee. The grid is no longer profitable as it cannot sell the required amount of electricity to maintain the grid. No money to maintain the grid means the grid will cease to exist. The failure of the grid means nowhere to pump your solar/wind excess. Nowhere to pump your excess solar/wind energy means you would be self-sufficient for power with no source of backup unless you buy an alternative power source.
In effect tying your own energy into the grid and paying a fee is like insurance - maybe you'll never need to use it, but you'll be happy if you do need it.

It's like the plan that appears occasionally to put a road maintenance tax on fossil fuel for your car - the theory goes that those who use the roads the most will pay more for the maintenance, but those who go to church once a month pay very little for road upkeep. What happens if this comes to pass and everyone buys an electric vehicle instead (tied into their own wind/solar)? No road maintenance fees because no tax is collected - roads break down over time due to lack of maintenance - Granny cannot get to church because her electric vehicle cannot handle the ruts and dirt tracks that are left by the lack of paving - Granny has an expensive battery operated lawn ornament.

Nothing is free - especially not lunch with a grid tied power backup system  :)
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dhouston

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Re: Questions about Solar Power
« Reply #23 on: April 24, 2014, 12:11:03 PM »

Every year there seems to be some advancement in solar panel production.
Outputs increase which could be the reason for the smaller design. ;)
From numerous articles in Forbes, Fortune and other business related publications (do a search on solar death spiral), it seems there are two things happening. The efficiency of solar cells is improving significantly while increased production is driving down manufacturing costs (i.e. economies of scale). So, solar panels are getting cheaper to manufacture while also getting more efficient. I've seen projected rates of 10 cents per kWh in the near future.

A very recent development is a solar panel that can store excess power to release later as heat which is then used directly or to generate more power.

For the utility companies, I think it makes more financial sense to get into the residential solar panel business (as suggested by former Energy Secretary Chu - see link in message #14) than to charge residential solar panel users for grid maintenance.

And, solar is not necessarily limited to the sunny southwest. See the final paragraph at...
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HA Dave

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Re: Questions about Solar Power
« Reply #24 on: April 25, 2014, 10:29:17 AM »

...... For the utility companies, I think it makes more financial sense to get into the residential solar panel business (as suggested by former Energy Secretary Chu - see link in message #14) than to charge residential solar panel users for grid maintenance.

What makes sense.... for individuals, for home owners, for utility company's, or for fixed income (retirement) investors... all seems to differ. And is always based on the best-guesses of future events.

One fact that can not be denied... (even using current best guesses of solar and wind production). If we covered every farm and ranch in the USA with solar panels and windmills.... Americans would starve to death.. in the dark.

Alternate energy forms have their uses. But they can not fulfill the needs and desires of a modern society. If we are going to continue to progress as a species we must also progress scientifically. Vast amounts of energy is encapsulated inside of every atom in the universe. Only expanding our knowledge of manipulating atoms will solve mankind's need for energy.

Todays.... "energy dark age"... is an embarrassment at best. Wasting food producing farm areas to power flashlight-like lighting sources would only seem silly if it wasn't that billions of Earths humans go hungry. The people who live on this planet need clean water, food, and energy to distribute and preserve the food. Solar will not... cannot accomplish that.  We need to exploit the energy of the universe to fulfil mankind's destiny. 
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dhouston

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Re: Questions about Solar Power
« Reply #25 on: April 25, 2014, 05:09:40 PM »

I don't recall that anyone here has argued that solar will replace all other sources. Noam, in his first post, specified that he isn't even expecting to totally replace his supply from his utility.

But, the falling costs and increased efficiency are certainly making it a viable alternative for anyone wanting to reduce their total costs and, as Noam's case shows, with little or no initial investment by the homeowner. And, it's also apparent that it's approaching the point where those wanting to go off-grid may be able to do so, especially if they combine solar with passivhaus construction. And, as Professor Cole has demonstrated, this may even be economically viable in the frozen north.

However, to HA Dave's point, there is a timely article in today's Forbes discussing both costs/efficiencies and what percent of power generation comes from the various sources.
If the utilities continue to increase the price of the electricity they supply, more and more homeowners are likely to follow Noam.

Finally, to address Noam's question about how this will affect his X10 gear, the fact that they will feed excess power to the grid means they must maintain both the frequency and sinusoidal wave form so his X10 system should be happy as long as his neighbor stays away from those CFLs he received in the mail.  ;)
 
« Last Edit: April 26, 2014, 08:05:32 AM by dhouston »
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dhouston

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Re: Questions about Solar Power
« Reply #26 on: April 25, 2014, 07:32:52 PM »

... I wonder if the utility buys back power at the same rate per kWh as they sell it?
In most, if not all, cases they are required to pay the same amount as they charge for an equivalent amount of power.
« Last Edit: April 25, 2014, 07:55:22 PM by dhouston »
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Noam

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Re: Questions about Solar Power
« Reply #27 on: April 29, 2014, 01:27:47 PM »

Okay, I've got some more updates (I'll put them in a separate post), but I'll comment on some of the more recent posts first:
Oklahoma has passed a law that will require those with solar or wind installations that feed excess power to the grid to pay a monthly fee which, ostensibly, will compensate the utility for grid upkeep.
Good thing I don't live in Oklahoma, I guess.;-)

I wonder if the utility buys back power at the same rate per kWh as they sell it?
In my case, I guess the answer is "yes and no." My system is set up such that the panels connect to my house BEHIND (on the customer side of) the electric meter. The utility has no way of knowing how much the panels are producing. If I'm producing more than I'm using during the day, then the excess goes backward through the meter, running the meter backward, and I earn a credit for that power (in kWh). My expectation is that I'll use those credits pretty quickly (likely that night). In that scenario, the utility is being used as if it were a giant battery (even though it isn't), storing my excess power until I need it later. If I over-produce more than I can use in a month (as is quite possible in the spring and fall), then those credits show up on my electric bill, and are carried over to the next month. The way I understand it, I have a year to use those credits (presumably I would use the ones earned in the spring during the summer, and the ones earned in the fall during the winter), or the utility will pay them out - at a rate lower than what I paid SolarCity for that energy.
That's the kicker - I *don't* want to get to a point where my total annual consumption is less than the annual production of my system, or I end up selling the extra power back at a loss.

I have seen other setups in other parts of the country (some with SolarCity, some not) where the inverters are connected *only* to the grid (via a second electric meter), and the customer buys ALL of their power from the utility at one (possibly variable) rate, while selling the utility ALL the power their panels produced at a second (possibly variable) rate. But mine isn't set up that way.

A third setup would be to attach a set of storage batteries on the house side of the meter, to store any over-production. If it doesn't go backward through the meter, the utility can't bill for it.

... Noam, in his first post, specified that he isn't even expecting to totally replace his supply from his utility.
Correct - Their estimate was about 77% (based on our usage over the past 12 months). As we reduce our energy usage, though (like by replacing the 1979 refrigerator in our basement with a new one), that percentage should increase (as the total decreases).

Quote
If the utilities continue to increase the price of the electricity they supply, more and more homeowners are likely to follow Noam.
Hopefully, those homeowners will contact me first, so I can earn a referral credit. ;-)

Quote
Finally, to address Noam's question about how this will affect his X10 gear, the fact that they will feed excess power to the grid means they must maintain both the frequency and sinusoidal wave form so his X10 system should be happy
As I'll detail in my next post, my initial test results were excellent.

Quote
...as long as his neighbor stays away from those CFLs he received in the mail.  ;)
I don't think he got them in the mail (but it *is* possible).
« Last Edit: April 29, 2014, 02:14:50 PM by Noam »
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Noam

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Re: Questions about Solar Power
« Reply #28 on: April 29, 2014, 01:39:14 PM »

Alright, time for another update:

I'm happy (thrilled/ecstatic/overjoyed/etc) to report that SolarCity installed my system yesterday.
It was one very long day (close to 9 hours - and they didn't even take a break for lunch), but they got everything done, and they were a really great crew.
I have 61 panels on my roof (25 on the front, 36 on the back), split across into two inverters. They added two big service disconnects (one outside next to the meter, the other inside next to the breaker box), and a load center next to the inverters (one double-pole breaker for each inverter, and a third for the SolarGuard monitoring device).

They turned the system on for a few minutes, to check everything out, and make sure all of the components registered properly. Once they had, I took a few minutes to test my X10 stuff (all the lights, etc) before they had to shut the system down again.
Now I have to wait for the county to do their inspection (hopefully at the end of this week), and then for the utility to come out and change the meter to one configured for net-metering), and then I should get approval to turn it on "for real."
I'll post more updates as I go through those next steps.
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dhouston

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Re: Questions about Solar Power
« Reply #29 on: May 03, 2014, 07:18:37 AM »

Oklahoma has passed a law that will require those with solar or wind installations that feed excess power to the grid to pay a monthly fee which, ostensibly, will compensate the utility for grid upkeep.
While the law was passed and, apparently, signed by the governor, it was immediately gutted by an executive order from the same governor.
Quote
The order directs the state energy commission to impose solar fees only as a last resort and to continue making expansion of solar power a priority.
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