Off grid system to run HVAC only, doable?

[inetdog]

Often a 3kW inverter will not be able to start even a 1500W motor.

[jflorey2]

I'm still not interested in a typical grid-tie but maybe a grid switch? Solar panels to a small battery to handle startup and then switch over to the grid when the sun goes down?

Sure; Outback has a mode that does just that (HBX.) You still have the same problem with battery costs though.

[DanKegel]

? The solar panels would generate and send all their power to the grid as normal; only if the grid was out would he throw the switch to run the A/C straight off the inverter's 'secure' output. Since that would almost never happen, I don't see how efficiency would be affected.

But it's moot anyway; from what I can tell, the secure output is not enough to run an A/C.

[ButchDeal]

He doesn't want to send to the grid when the grid is up. He wants to run off solarEdge when sun is up and never back feed. Secure power is a very bad fit for that

[DanKegel]

He now understands batteries kill the cost-effectiveness, and says the idea of not being grid-tied has lost its death-grip on him. So he might be willing to listen to sensible solutions.

But I don't think there are any grid-tie, batteryless inverters with enough oomph on an even-when-the-grid-is-down socket to run even a small minisplit A/C, are there?

[Mike90250]

The inexpensive way is to go pure Grid Tie and install a Transfer Switch for a generator, if the grid is down for very long, you start the generator and get minimal lights and cooling for 5 gallons a day. The battery bank to run an efficient air conditioner will cost way more than a transfer switch and generator.

[cebury]

As others have said via bits of truths above, the summary answer is you wont build a solarPV system to provide standalone power to run an AC based conventional A/C or heat pump. Even if you allocated US $100,000 to the initial installation of the project. Ongoing costs each few years, size/weight of bank, battery maintenance, disposal regulation, etc. This is stupendously foolish if you already have grid electric power at the location. The kind of thing might be done by billionaires who want to build an end-of-world fortified shelter.

[LucMan]

Here is another idea for you if you have natural gas available. Absorbtion a/c, not efficient (50%) and gas is not cheap anymore but if the power goes down in the summer you most likely will be the only one on your street to be drawing gas. Search for Robur Corp

[Sunking]

Here is another idea for you if you have natural gas available. Absorbtion a/c, not efficient (50%) and gas is not cheap anymore but if the power goes down in the summer you most likely will be the only one on your street to be drawing gas. Search for Robur Corp

NG is at historical low prices for the last 9 years and not expected to go up anything soon. That is why electric rates are plummeting.

[J.P.M.]

NG is at historical low prices for the last 9 years and not expected to go up anything soon. That is why electric rates are plummeting.

That may very well be and, FWIW, I agree with those points, but I also wonder if part of the reason the price of electricity seems to be dropping, at least in some markets, or at least maybe not increasing as fast in some (probably) undefinable way, particularly as the price of PV continues to drop into some type of (perceived ?) price competitiveness, has to do with competition from rooftop solar and the usual legislative mandates that, if you swallow the POCO line, make POCOs unwilling accomplices in screwing everyone, including themselves and anyone/everyone not well heeled enough to put PV on their property.

[azdave]

NG is at historical low prices for the last 9 years and not expected to go up anything soon. That is why electric rates are plummeting.

Plummet?

SRP was recently granted a rate increase in Arizona and APS is requesting an increase too as well with new demand penalties for all residential users. SRP got their foot in the door with demand fees with solar customers and I'm sure will soon go after all residential customers just like APS is trying. I guess it's costs more (in administration costs) to sell cheap electricity.

[SunEagle]

Plummet?

SRP was recently granted a rate increase in Arizona and APS is requesting an increase too as well with new demand penalties for all residential users. SRP got their foot in the door with demand fees with solar customers and I'm sure will soon go after all residential customers just like APS is trying. I guess it's costs more (in administration costs) to sell cheap electricity.

In some states where NG is now being used the fuel costs are much lower to generate so the cost of electricity has gone down.

Mine in Florida has dropped to what it was back in 2008 at around $0.09/kWh for the first 1000kWh where it had been about $0.11/kWh last year.

[Sunking]

AZ Dave you just live in a state with lousy energy policies. In TX electricity cost 12 cents in 2008. Today 7.6 cents. AZ and CA have to raise their rates to cover the cost of solar supplements. Or in other words a TAX on top of a TAX. You would e thrilled if you only paid 7.6 cents per Kwh. Look at this DATA table from DOE as you can plainly see for Residential Rates Prices in April 2016 are lower than April 2015. That trend has been going on since 2007 when we discovered we had a few hundred years more NG in the USA. More than we know what to do with. Energy prices in fact are going down and expected to continue going down.

[DanKegel]

Yes, fossil fuels are getting cheaper. Doesn't change the fact that continuing to use them will change the climate in a way that will be very expensive to adapt to.

[rubencito]

I live here in the sunny and hot carribean. Lots of our energy cost goes to cover our ac usage.
Me and a chinese friend are planning to build a thermal battery. We are awaiting the FCU (cold water Fan Coil Unit) to arive from china, where this kind of solar ac is being widely used. It uses a small FLA battery for 2kw during the night 8hrs usage, and during the day the solar energy from panels is being used to freeze water, or storage in thermal energy to be used at night to cool the room.
If more info is needed i can provide answer, we havent desided anything yet but, but i think it is posible and cost effective.

R. G. SPECHT
DUTCH CARRIBEAN.

[J.P.M.]

Yes, fossil fuels are getting cheaper. Doesn't change the fact that continuing to use them will change the climate in a way that will be very expensive to adapt to.

Good point. Since simply using less energy - not simply displacing energy use with a (perceived) environmentally more benign source - will probably have the greatest effect for the effort and money input on repairing or at least slowing the damage to the environment, such as it may be, it seems to me that if you are serious in what you write above, and not a hypocrite about it, you'd be putting your efforts into disseminating practical information about how to use less, information about conservation measures, and the economic and environmental advantages of such things rather than helping shysters and bloodsucker ne'er-do- wells separate the great unwashed masses from their often meager assets by spreading half truth junk that's usually misleading, misapplied or just plain B.S.

In any case since, by your own admission, you don't know much, you're in a shaky position to gauge the veracity of such stuff before you spread it around. Try learning something about the simpler and more cost effective ways to save energy (in usually the most cost effective ways BTW) and thus the planet. Spread that stuff around and do some real good rather than feeding your ego, helping con men, and sending people down blind alleys and into money pits by spewing half truth, innuendo and/or simply misapplied, inappropriate or useless information.

If you helped people to save money and improve their life at the same time with real information rather than the mostly useless junk you often link to, I and perhaps some others wouldn't be on your ass as much. Your actions remind me of those of a loose cannon. I believe a lot of your actions are inconsiderate, deceptive and harmful.

[DanKegel]

As usual, if you can point to an inaccurate statement I've made, and provide a reference showing more accurate information, I'll gladly acknowledge the mistake. But you'll have to be specific; your message just now doesn't actually identify any inaccurate statement.

I do advocate increasing energy efficiency, e.g. LEDs, hybrid cars, building insulation, and Energy Star-rated appliances, as long as it's cost-effective. ( Fun fact: the local dollar store has good high-r9, dimmable LED bulbs now, 3 for $5, thanks to PGE. )