OT: Honest Analysis of Solar Power

Ian Malcolm prodded the keyboard

I concur ! That would be my assesment too. The only people making money are the ones collecting government funds for pushing installations. Curious how they say 25 year life span without being prepared to say how efficient or productive the panels will be after

10 years never mind 25.

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Best Regards: 
                       Baron.

the TSMC panels are gauranteed >90% after 10 years, >80% after 25 years

-Lsse

Solar hot water is a good idea - photo-voltaic's not so good

[snip] [snip]

The insult was seen ONLY because you quoted it.

If everyone would simply killfile Slowman NO ONE would see his insults.

And Slowman would be left simply pissing into the wind... where out-of-touch Slowman belongs. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

Certainly, Arizona would be sensible place, especially, if the utility company electric price would vary by the hour, so that it would be highest on summer afternoons due to the need for using expensive peak power stations.

In a such environment, selecting the PV size based on your AC load would be sufficient. Just add an inverter and run the AC from solar cells, no need for grid connection or batteries.

One should look at the various national annual electric load curves.

At low latitudes, the peak load is in the summer due to air conditioning. At high latitudes, the peak consumption is in the winter due to electric heating and the need for artificial lights during the long nights.

At middle latitudes (e.g. Switzerland and Austria in Europe), the load curve does not change much during the year or there is a small peak in the spring and autumn.

Solar power makes sense in low and medium latitudes, in which the production and demand match quite well,

At high latitudes, in which the winter time maximum consumption can be nearly 3 times summer time minimum consumption, using PV solar power does not make much sense. There are a lot of sun light in the summer, but very little consumption, so many traditional power plants are down for the summer or at least all scheduled maintenance is done in the summer.

Solar power without subsidies do not make much sense in countries like Germany or the UK not to mention countries even more to the North.

If you go to the expense of installing any sort of solar power, the first thing to do is reduce unnecessary energy losses. And for PV, make as many loads non-electric as is practical. All-electric and solar makes no sense.

NT

Then I would *not* be storing power in the grid and, instead, consuming it directly (or storing it myself). AFAICT, the subsidies, here, don't apply to your private use of solar panels but, instead, connecting that to the grid so others ("society") benefit from your cogeneration capability.

As I said, the kicker is connecting to the grid negates the value of the subsidies (at least, here).

That's true of any "conservation" strategy -- why work to replace something if you don't truly *need* (to consume) that something (energy, water, etc.)?

Of course it does! Should we, instead, start burning coal to heat homes, cook our meals, light our rooms? Look at all the electricity that would do away with!!

The beauty of electricity as an energy "source" is that it is (relatively) easy to move it around, dynamically, as needed. Coal, gas, fossil fuels, etc. have mass. Much harder to move a given amount of "stored energy" in that form from point A to point B.

And, transport of those "energy sources" takes significant time. OTOH, if The Northeast has a sudden need for power, other portions of the country can supply it, *now* (a little from here, a little from there, etc.). Or, conversely, if they have a surplus of power generation capability, they can pass it along to others -- without having to store it in large piles (coal), tanks (gas), etc.

The problem is, our current energy usage is not a good instantaneous match for the power that we have available from (individual) solar arrays. So, storage (of some form) and augmentation become issues.

I have a small 24V battery pack in the garage that is part of a device I have. It sees very little use, normally. So, there is always the possibility that the battery will have "gone flat" between uses. OK, throw a float charger on it! Cost pennies to keep it "up".

Ah, but I can also use that battery to power the irrigation pump (rainwater harvesting) -- so I'm not "conserving water but burning electricity to do so". Replace float charger with tiny PV array built from discarded landscape lights (horribly inefficient but *free*... someone else's mistake!).

Now, knowing it doesn't cost me anything to keep that battery charged ALWAYS (even as I use it for irrigation), I can find OTHER uses that are similarly "free" (e.g., my recent UPS thread). I've *added* consumption to my normal load yet still not increased the cost of doing so.

Is that credit expressed in terms of power out == power back in? I.e., if I cogenerate X KWHr, I get X KWHr back, "for free"? Or, is it expressed as a dollar amount (cost of *electricity*) so I end up *paying* to get that X KWHr back (at a slightly reduced rate)? The latter is just plain silly. What incentive do I have to help the utility avoid building new power plants, CO emissions, etc. if I have to pay them (transmission costs) to do this? I should just store it (or use it) locally...

AZ has made some *colossal* blunders so it is par for the course. "Want to buy a (heavily subsidized) vehicle that runs on alternative fuel?"

Oooops!

Oh-oh. Nobody agrees with me. I must have done something wrong.

With the dropping cost of natural gas due to fracking, it's conceivable that natural gas might have a cost advantage over electric. 31% drop in wholesale prices in 4 years: should have produced at least a partial drop in consumer rates. Nope.

Yeah, but the producers claim that the difference is the cost of the infrastructure needed to deliver the power. Unlike other utilities, PG&E mixes the distribution charges and the consumption charges into one number, which is then graded into consumption tiers. Trying to extract the distribution costs from that mess is difficult. It would make more sense to charge separately for distribution and consumption, where the homeowners production could be balanced against consumption, but with the politicized PUC in power, that's unlikely to ever happen.

Example of PG&E net metering statement:

Well, that's for leased systems only: Since such leased systems were exempt from property taxes, this tax is just Arizona's way of adding it to the homeowners property tax bill.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

[snip]

There are some sucker-bait schemes where, for example, SRP has a program for you (SRP Community Solar) where you can actually pay more per kWh than time-of-use rates, just for that warm-and-cozy feeling that you're doing your community-minded thing and going solar. DUH!

Sucks in leftists, so I'm all for it >:-} ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

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exactly, then it has to stand on it's own with out incentives/subsidies

and it seem like if you get a system that isn't too big and you have a high base load, e.g. from an AC etc. so you can use all you make directly then the pay back isn't too bad

-Lasse

But people *don't* have *level* loads. So, you need to store it *somewhere* (or, you're buying capacity that you only need, occasionally). If everyone had flat loads, we could "solve" the problem with large generating stations instead of having to rely on gas/coal to bring more power online "quickly" (if everyone had a level load, there would be no "peak time"!)

My understanding of the subsidy rationale is not just to "move away from fossil fuels" but, also, to *distribute* the production of energy more uniformly. This reduces the need to build new power plants, more infrastructure to distribute that power (distributing *surplus* is easier than distributing *load*!), provide for more "reliability" in the network, etc.

I.e., issues that benefit "society" instead of "the individual" (hence the argument *for* the subsidy -- not just to throw money at developers).

Our load varies widely in EVERY given day. With an all electric kitchen and laundry, we can easily draw 10KW without blinking an eye! (oven, dryer, washer, ACbrrr) Yet, our "nominal" usage is far below that. It would only "make sense" to size a PV array to handle the "basic" load -- which can be almost *zero*. Things like the AC are *huge* loads but they aren't static.

A "smart" home would schedule power ("resource") consumption to try to level those loads -- but, there's only so much you can do. (should I *bake* just because we have surplus power that would otherwise be discarded?)

Speaking of which, another 5 dozens to get done, today. I'm starting to fall behind on my goal... (still have 35 pounds of flour)

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depends on the time frame, when you have enough users the load will even ou t in the short term

but during the day there will be periods where people use more power on ave rage

solar and wind can come and go really quickly, that is a nightmare for the power companies

it started as a simple question; if you could buy a device that makes 2kW f or 7 hours a day could it pay for it self in a reasonable time

-Lasse

Is the problem here that the grid represents 'socialised electricity' and is therefore bad?

Cheers

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Syd

No. The problem is you get a different tariff (i.e., pricing structure) when you do that. Local politics are... "weird" (to put it mildly).

If you can produce and consume the power IN PLAIN VIEW OF EVERYONE ELSE but *not* connect to the grid, then more power to you! But, once connected to the grid, you are taxed for the "convenience" of having the grid as a "backup". It is inevitable that as more folks move to solar, the utilities will argue that they should pay more for anything they take OFF the grid. I.e., as if that power was somehow *worth* more than the power being supplied to the non-solar neighbors (I guess they get *blue* electrons instead of *red* ones!)

It's an attempt to discourage the adoption of technologies that threaten existing business models. ("Change threatens existing power balances") So, until it makes sense to oversize your plant (and go "off grid"), you're at the mercy of whatever rationalization they (powers that be) want to impose.

"We need better identification to prevent voter fraud."

"OK, lets come up with a national ID card. And, hey, once we have that, we can require it of every government associated activity. E.g., require it to be presented to recevie any benefits/'entitlements'. Of course, that means every WELFARE RECIPIENT will be HIGHLY MOTIVATED to acquire one order to receive their benefits. And, as a pleasant consequence, that willmake it much EASIER for *them* to cast a non-fraudulent ballot! *AND* in the process, remove any impediments to *everyone* voting!"

"Er, um... No, we shouldn't tie the issues together..."

"Ah, I see. Yes, *really*, I do!"

[I am making no comment on any of these issues. Rather, illustrating the likely dialogues that such "issues" can lead to -- readily!]

Stated reasons are seldom the *actual* reasons for "rules".

[snip]

You forgot the green ones ;-)

I think the issue, seen from a power company point-of-view, is your system pumping power _onto_ the grid, which they (the power company) must manage... and "pay" you for.

I'm sure if you devised a solar system that used backup from the grid but _did_not_supply to the grid... some sort of swap-over relay, the power company could care less. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

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if normally you make most of you power yourself from solar the power compan y doesn't make any money from you for kWhs, but they still need to maintain a distribution system and generation capacity to supply you in case of a clo uded day, someone has to pay for that

-Lasse

That;s only if you *share* a PV array among several homes/consumers. If *I* am not home (consuming) and my PV isn't connected to the grid, then my power is "wasted".

Yes. So, you can't count on the *potential* (design specification) output of the array (unless you store it somewhere) but only the *actual* use AT THAT MOMENT. When the ACbrrr kicks on, the PV array won't meet my needs -- but, I'll be able to use every Watt that it produces! When it kicks off, the energy has no value (unless I arrange for my refrigerator to turn on at that time; or some other cyclic load)

[This is why energy management is so much easier (in terms of opportunity to save) in large installations -- businesses, etc.]

Exactly. So, you want individuals to assume that risk (or not?). Yet, not reward them for it?

Just like ToU metering: the individual alters their consumption habits (typically in a BIG way!) which benefits the utility (because load is now shifted off peak) -- yet, you're looking for a way (via tariff) to still get the same monies out of them? For *less* power consumption and more inconvenience?

Perhaps if there was a moratorium on building plants or burning fossil fuels, utilities might have a different outlook?

But it *doesn't*! Your initial investment goes down (though not proportionately -- there are some significant fixed costs to "get into the game" regardless of the size of your plant). But so does the amount that you recover from that investment. I.e., ROI is not significantly affected.

Here's Jeff's (up-thread) analysis LINEARLY SCALED to 2KW (assuming you can use all of it and that there are NO "fixed costs" that don't scale)

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