Electrical Question -- Grid Tie Power Inverters for Home Use

sophiecentaur

Julie might be interested in the actual savings she can expect to make with her proposed system. They are marginal unless things are 'just right'. The only real clincher in any decision about PVs at the is the lunatic rates that the Government is prepared to give people who are lucky enough to qualify for Feed In Tariff. Meanwhile, all the rest of us are subsidising the government's cosmetic bit of green energy supply.
Doing it yourself is nothing like as attractive, financially - not to mention the safety aspect. Julie ought to shop around for an approved system and she wouldn't even need to do the work herself. The FIT rates are not as good as they were but still attractive, I believe.

Windadct

I think a lot of the people putting solar are not just paying to save - but get added values out of - environmental impact, being more independent - etc. I would also like to point out - that here in PA after Sandy and 2 other outages in the last 2 years- I would also include the "value" of having an on line standby generator. -- I would include batteries, they should last more then a "few" years if taken care of. With about 5KW-7 KW of solar - yes a decent amount, I would be able to selectively ( not all at once) run pretty much all of my appliances - except the AC - I do not Know if I could get it to start - although the Solar panels + batteries may have enough overload capacity to get it running.
Just adding a few panels to save a few $ - is actually the lowest "value" proposition.

jim hardy

For use in blackouts a gas generator is sure cheaper to own and operate. Better yet, a propane one, its carburetor won't gum up from old gas.
I had one big enough to run a tiny window airconditioner. After Hurricane George it let us sleep in comfort.

A friend installled a few KW solar system around 2000. His batteries lasted about five years and at ten he had to replace the panels. My opinion of them is they're just a fashion statement.

old jim

sophiecentaur

Not if your government is daft enough to subsidise you when you do FIT. But it must depend on where you live - both for the Sun consideration and the infrastructure situation.

Sylvia Else

As far as the environmental impact is concerned, the effect of solar panels is far from clear.

If one assumes a typical grid generating mix of coal or nuclear, combined cycle natural gas, single cycle natural gas, which covers the base load, medium load, and peak load, with each type being chosen based on the balance between capital costs (paid regardless of whether the plant is running) and fuel costs (paid only when the plant is running), then one has to look at the impact of including solar panels which displace the highest marginal cost plant that's running at the time. At times, that will be the combined cycle plant, thus reducing its return on investment.

Future investment decisions may then be to build single cycle plant instead of combined cycle plant. But single cycle plant is less fuel efficient, which is to say it produces more CO2 per unit of energy generated. Whether or not one personally believes that matters is beside the point - reducing CO2 is what people who install solar panels believe is their environmental contribution. Yet in the longer term, this may not actually be the outcome.

Sylvia.

Sylvia Else

I obviously cannot speak for your specific air conditioner, but they don't all require large starting currents. Indeed, when I did some specific tests on a Daikin model that I have, I found that its startup requirements were very benign. It is one of the "inverter" type, which I think are pretty much the norm now.

Sylia.

dlgoff

Personally, I'd rather have a small grid tied nuclear powered generator sitting in my backyard. And I'd buy a professional Automatic Transfer Switch.

the_emi_guy

http://www.nuscalepower.com/

dlgoff

Thanks guy.

wirenut

A few years back (6 or7) we had a major snowstorm in october (NE USA) and at the time almost all electricians were getting power restored to homes (some were out for 7+ days), and the utility company went down the street. If you had a portable generator or non registered permanent one they cut the power lines to the house @ the utility pole for the safety of all the linemen (local and out of state volunteers). A break before make approved transfer switch is required for all generator hook ups, whether automatic or manual. The NEC now has a section dealing with solar panel installations, and the AHJ and local power co. also have regs for the installation and tie in of on site power generation. Best to check with all of them to reduce hazard and liability.