Why not gridtie?

[GeorgeF]

I am rather impressed reading postings and replies of moderators and many members here.

A member bearing the ID Sunking once said: I am not "stupid" to live on batteries and PV. Even hybrid in a stabil grid area is not wise ive read here.

My question is: why not gridtie in an area with stable mains? Is gridtie a "win-win" in such areas?

[Ampster]

Gridtie is the most cost effective depending on the rate you pay for power and the Net Energy Metering policy of your power company.

[littleharbor]

Straight Grid Tie will pay for itself, some areas faster than others. Any Off Grid system will end up costing more than you will ever save by disconnecting from the grid due to the cost of and having to replace batteries. Hybrid systems are expensive and not likely to ever save you money.

[peakbagger]

IMO, The economics of grid tie are heavily impacted by the local utilities policies for grid tied systems. If the utility has net metering, a properly designed grid tie system on suitable site is win-win. Some local utilities have policies in place to discourage or prevent grid tie installations and grid tie would not be a great idea. In those situations hybrid systems sometimes swing the economics where grid tie may make sense by allowing load shifting so that the house never exports. That is very much a case by case call depending on the customers load profile.

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[J.P.M.]

At this time and for most residential applications and their common and usual load profiles, and except for some areas with less than acceptable power reliability, off grid with batteries is probably not cost effective.

For most applications that fit the adjectives "common" and "residential", if cost effectiveness is one goal of the exercise, those who think off grid with batteries is a cost effective way to meet a residential electrical demand are, for the most part, victims of their own ignorance. Stick around and you'll see a lot of that thinking here.

Hybrid systems which combine grid tie with some battery support may be cost effective in some applications at this time, but are probably not universally cost effective in all areas at this time. Such systems cost effectiveness may well improve in the future. If/When that time will happen is a matter of some debate/question, as are the means used to determine just what "cost effectivene" means.

At this time, a serious conservation ethic combined with a properly sized grid tie PV system is the most cost effective of the 3 options, but that is not to say PV is always a slam dunk. See the next paragraph.

Any attempt at cost effectiveness - that is, and somewhat simplistically described - as a way to meet an electrical load with the goal that "X" years in the future you'll have a reasonably high probability of being better off financially with the installed PV than if nothing had been done - is, at this time highly dependent on the net metering policies of a user's power provider, but if it is possible, the best (highest) probability of cost effectiveness is with a grid tie system.

And, another point with respect to net metering, many power companies ("POCOs") have, are in the process of, or probably will in the future, change, eliminate or otherwise modify the net metering tariffs that are in place at this time, making net metering less of a sweet deal than it once was.

Example: For the big CA POCO's, net metering changed about 2 years ago for new NEM customers. The bottom line to those changes made NEM approx. 20-25 % less cost effective for new users taking NEM service under the revised NEM rules than if the old NEM rules were still in effect. Other areas and other POCO's throughout the U.S. at least, are often doing similar. Folks considering PV might do well to keep an ear to the ground and an eye to the future with respect to NEM policies.

Welcome to the neighborhood.

[Mike90250]

Once you add expensive consumables (batteries) your average yearly cost goes up and the solar harvest sales, seldom has enough cash flow to pay for new batteries every 5 years,

[Ampster]

@GeorgeF,
Where are you located? That information makes it easier for people to relate and give real world examples that may be more relevant to your circumstances.

[QuantumSlice]

There are videos out there that describe areas with solar saturation during the day(duck curve). In that case your grid tie seems to be shut down or not allowed to connect. My area isn't there yet so I enjoy net metering albeit with a $32 monthly connection fee. $32 connection fee over 5 years? $1920. Can I do batteries for that? don't know. But wouldn't want to - seems like complexity and work for no reason right now.

[GeorgeF]

Ampster, I am living in South East Asia right now and some big cities already have netmetering.

[Ampster]

Ampster, I am living in South East Asia right now and some big cities already have netmetering.

Then the answer depends on the reliability of your power and whether you have any critical loads that cannot go without power for a period of time. How much does your power cost per kWhr?

[J.P.M.]

Ampster, I am living in South East Asia right now and some big cities already have netmetering.

Now that we know you're in SE Asia, that changes some things. Like grid reliability, system costs, equipment availability, permitting, and other stuff. Would have been nice to know your situation up front. My bad for assumptions.

Living in SE Asia right now ? Am I to infer that may be changing in some way that would change what you want to know ? Anything else you might want to share ?

[GeorgeF]

Just want to know if:
* there is no feed-in,
* no subsidised tariffs, no tax reduction, nada nada, and

* the surplus goes into the grid 1:65 , so total export immediately cut by 35%, and
* even if your daily consumption is less than your PV production you never get it back; the grid accumulate it as savings but they never pay you out in cash (transfer money)

if such a system can be profitable. All materials are avalaible and if imported (assuming) same prices as with yours

[foo1bar]

Just want to know if:
* there is no feed-in,
* no subsidised tariffs not tax reduction, nada nada, and

* the surplus goes into the grid 1:65 , so total export immediately cut by 35%, and
* even if your daily consumption is less than your PV production you never get it back; the grid accumulate it as savings but they never pay you out in cash (transfer money)

if such a system can be profitable. All materials are avalaible and if imported (assuming) same prices as with yours

Without knowing how much it costs to install the system, how much power it will produce, and how much it costs to use power from the POCO instead I don't think it's possible to know if a system will be "profitable". (I assume by "profitable" you actually mean that it willl cost you less over some period of time, like 10 years.)

If a system can be installed cheaply and produce quite a bit of power, and the POCO power is expensive, then it can make a lot of economic sense to install solar even without tax benefits and without net metering.

[NEOH]

Just want to know if:
* there is no feed-in,
* no subsidised tariffs not tax reduction, nada nada, and

* the surplus goes into the grid 1:65 , so total export immediately cut by 35%, and
* even if your daily consumption is less than your PV production you never get it back; the grid accumulate it as savings but they never pay you out in cash (transfer money)

if such a system can be profitable. All materials are available and if imported (assuming) same prices as with yours

OK, here are some rough "DIY" numbers ....

$7,500 = 5,000 watt PV kit containing 15 x 330w PV Panels + 5kW Inverter + Iron Ridge Roof Rack
$1,000 = Balance of System ?
==========
$8,500 Total

5,000 kWhr generated per year = 5kw system x 1,000 hours <<< average insolation
$750 per year savings = 5,000 kWhrs x $0.15 per kWhr <<< your cost of electricity here

11 YEARS to "break-even" = $8,500 cost / $750 savings

And 35% worse for all power that you "export" - ie don't self-consume during the day.
This assumes, no cost for any labor - you and your friends do the entire install.
Adjust the numbers above for your situation and then re-calculate.

My neighbors and I can can do this for significantly LESS than $8,500 and we get a 30% Tax Credit.

[GeorgeF]

Thanks Neoh for you calculation. Do I have to deduct that $0.15 value with 35% to 0.092.
5000 x 0.092 = 460, thus 8500 / 460 = 18.5 years if one theoretically export 100%

edited to answer foo1bar:
electricity here is cheaper than surrounding countries :/