Solar backup system vs generator

[GeorgeF]

I want your opinion about this conclusion of a "scientific research", if you can call it as such, performed by an university in south east Asia. This research is about backup system for grid connected private houses, 450VA up to 900VA only.

CONCLUSION:
"The most economical backup power supply system when viewed from routine costs is the PLTS system, followed by a rechargeable battery and generator set system. The most economical backup power supply system in terms of investment costs are generator sets, rechargeable batteries and solar power plants. For long-term use it is recommended to apply PLTS rechargeable battery and generator set"
* end conclusion *

Is this "scientific publication" a marketing promotion for solar home (backup)systems or really a constructive report??

[GeorgeF]

Plts = solar system


Pdf file research.

http://www.iaeme.com/MasterAdmin/UploadFolder/IJCIET_09_11_214/IJCIET_09_11_214.pdf

[J.P.M.]

Looking at the bibliography, I don't think it's a sales gimmick, but there's a lot of stuff such as this in any field that's little more than white collar welfare for folks hiding in academia.

Not everything that gets published is worthy of the effort.

Do a better literature search.

[Mike90250]

With either one, you have to both:
Size your Electrical Loads (starting and running)
Determine daily running time and battery drain/fuel consumption.

Then you start pricing out the gear.
Until you reach several weeks a year running on backup, the generator wins because of its much lower initial cost and installation,
Once you factor in several weeks or months of fuel, the expensive solar install cost begins to look better.

Don't forget to learn how to maintain, or the expense of maintenance for both systems. Batteries can be quickly ruined, they need care too, it's not buy once and then forget it.

[GeorgeF]

Looking at the bibliography, I don't think it's a sales gimmick, but there's a lot of stuff such as this in any field that's little more than white collar welfare for folks hiding in academia.

Not everything that gets published is worthy of the effort.

Do a better literature search.

Thanks for the above replies. I was just wondering how a "scientific research" can based its conclusion on just these 2 charts. First one only during sun-hours :/

No frequency nor duration analises on poweroutages and other factors, just one conclusion for all situations (areas).

Besides I think its more cost-effective, if you, for whatever reasons, want to have battery backup, to install just a AC-charger + inverter. No need for solar panels and CC.

Also, whatever battery backup system you choose you always need a genny. Huge battery backup for more than 8 hours poweroutage is I think way too expensive.

Do you agree?

[J.P.M.]

Thanks for the above replies. I was just wondering how a "scientific research" can based its conclusion on just these 2 charts. First one only during sun-hours :/

No frequency nor duration analises on poweroutages and other factors, just one conclusion for all situations (areas).

Besides I think its more cost-effective, if you, for whatever reasons, want to have battery backup, to install just a AC-charger + inverter. No need for solar panels and CC.

Also, whatever battery backup system you choose you always need a genny. Huge battery backup for more than 8 hours poweroutage is I think way too expensive.

Do you agree?

Since you're asking:

If you are critiquing the paper, and only FWIW, I mostly agree with your comments.

But, I'd back up and say I'd not use that paper to set any design criteria for serious system design.

It's background stuff that is of marginal value. Folks knowledgeable in the subject matter won't bother with it and neophytes will only get confused by it.

It looks, to me only, to be the academic equivalent of a B.S. session by one trick academics with more time on their hands than practical experience with what they're writing about and a need to publish something - anything - to keep their jobs. The solar resource assessment is, IMO only, pretty simplistic.

Beyond the academic publish or perish motive which is usually one big, if not the main driving force behind getting such stuff published, that paper probably best serves as not much more than more confirmation of a loose but common opinion by those who do know something about the subject that any off grid PV system will most likely need a backup.

At this time, it seems that for most applications and locations that backup task is best performed by a noisy, smelly, fossil fuel burning ICE powered generator. DUH !

If you want to learn about solar energy and it's applications, start with the basics as found in textbooks. If you do, you'll have a better chance of spotting stuff like this for what it is (or what it isn't).

[GeorgeF]

Just worrying, since im currently living in that country, if and when such a (un)"scientific journal" can be used for commercial purposes by dubious salesmen.

Appreciate you took the time to look at it and thanks again for your replies.

[GeorgeF]

...

At this time, it seems that for most applications and locations that backup task is best performed by a noisy, smelly, fossil fuel burning ICE powered generator. DUH !

If you want to learn about solar energy and it's applications, start with the basics as found in textbooks. If you do, you'll have a better chance of spotting stuff like this for what it is (or what it isn't).

It is really hard to explain to people that whatever SHS you use, you still need 24hours additional (standby)powersource. All that "green talk" , greener than the grass @ my garden ....yeah... free & green energy also with batteries. ..wonderful is it not?

[J.P.M.]

All that "green talk" , greener than the grass @ my garden ....yeah... free & green energy also with batteries. ..wonderful is it not?

Yea, its been giving me sticky knickers for years.

[solardreamer]

Thanks for the above replies. I was just wondering how a "scientific research" can based its conclusion on just these 2 charts. First one only during sun-hours :/

No frequency nor duration analises on poweroutages and other factors, just one conclusion for all situations (areas).

Besides I think its more cost-effective, if you, for whatever reasons, want to have battery backup, to install just a AC-charger + inverter. No need for solar panels and CC.

Also, whatever battery backup system you choose you always need a genny. Huge battery backup for more than 8 hours poweroutage is I think way too expensive.

Do you agree?

The study is clearly narrowly focused and it's plausible the conclusion could be valid within some limited conditions and assumptions but as you have pointed not necessarily realistic or practical. It's interesting the conclusion still recommends genset as first choice for short term backup power. I definitely get the impression that the authors are overselling solar for backup power.

[J.P.M.]

The study is clearly narrowly focused and it's plausible the conclusion could be valid within some limited conditions and assumptions but as you have pointed not necessarily realistic or practical. It's interesting the conclusion still recommends genset as first choice for short term backup power. I definitely get the impression that the authors are overselling solar for backup power.

The study is a paper, not a good place to start a design or get much practical information.

From what experienced off-gridders who are also solar knowledgeable say, do and report here and elsewhere, it looks to me like an ICE powered backup is a no brainer to the point that it's something better acquired before any attempt at meeting some/all of an electrical load using PV/batteries.

[Ampster]

.........
From what experienced off-gridders who are also solar knowledgeable say, do and report here and elsewhere, it looks to me like an ICE powered backup is a no brainer to the point that it's something better acquired before any attempt at meeting some/all of an electrical load using PV/batteries.

Yes, that is the state of things as they exist today in the offgrid market niche. On a global scale battery, systems have eclipsed Peaker plants economically. The recent past history of General Electric (2016-2018), who made a huge bet on thermal generation and lost 74% of its market value does suggest to me that we may be on the cusp of a market disruption driven by the economics of solar and Lithium batteries. I don't think those Indonesian professors have a clue to what the future holds. I place more emphasis on economic trends around the globe.

[SunEagle]

The problem I see is that unless people learn to "shed" their electric loads at night it would be easier to just power up another Peaker then to find more batteries to add to the grid.

Maybe batteries will win out if their price comes down but until then I place my bet on the Peakers for load support

[Ampster]

The problem I see is that unless people learn to "shed" their electric loads at night it would be easier to just power up another Peaker then to find more batteries to add to the grid.

Maybe batteries will win out if their price comes down but until then I place my bet on the Peakers for load support

I agree with you that in California the shift to TOU rates with peak pricing hours from 4 to 9 has not reduced consumption of power during those hours.

No doubt it is easier to fire up a peaker but the economics will drive whether they can run economically because that is a spot market for that type of generation. I have seen two examples that suggest that batteries have already won economic battles.
The Australian mega battery has reduced the price for frequency support in that market.
In California no new peakers have been built since 2009. In addition there was a push several years ago to add battery support to the grid in response to a shortage of natural gas. Further reductions in the price of grid support will accelerate those trends.

Speaking of bets, I posted the example of General Electric that made a big bet on thermal generation which did not pay off and they lost 70% of their market value. Contrast that with the growth in wind and solar during that time. These are only emerging trends and I have no way to predict how fast they will disrupt the traditional models of generation. I remember the Kodak, Nokia, Motorola, Handspring and other devices I had as that change was occurring.

Looking back in time as I type this on a Smartphone causes me to reflect on what a remarkable time we live in.

[GeorgeF]

The research of Panca Budi University is about backup solution for residential houses with a grid connection of 450 or 900 VA only.

I can not imagine that a solar system + batteries can be the first choice (solution) for backup power of such a residential house, especially, as the example of Mike above, if no frequency nor duration of poweroutages is mentioned in this scientific journal.

Suppose the grid is stable, what do you guys think of the most "cost-effective" solution for grid backup of houses with grid of 450-900VA only?


As an example, poweroutages in Europe: