Re: Solar Panel Financing Trickery

Thanks. Every time the power goes out. I think about solar powering the well. I keep buckets of water in the shower to flush the toilet when there is a power outage. There is a storm big enough to create a risk of a power outage every other month. I lose power maybe 3 times a year and like every 3 years it last for days. The well pump is 240VAC 3amps but it only runs for maybe a minute a couple of times a day. So I would need a 1000W inverter, a battery that can supply a lot of current for a short duration and then be trickle charged most of the time. Sounds like a car battery to me, but maybe there are better batteries for the job. Sounds like a single panel would keep the battery charged between pump runs. But then I always think it is more expense and trouble than it is worth to avoid keeping buckets of water in the shower.

I've thought about that to, but it would have to be in the house to avoid freezing and there really isn't any room for it.

I have water in the well-head and in the water heater but I reserve that for drinking and keeping the pressure up in the system. I can refill buckets from the creek or the pond and in the summer I have a rain barrel and in the winter there is snow. I've only have had to use the creek and the rain barrel to refill the buckets. First thing I do when the power goes out is shut the valve on the toilet. I can flush that with non-potable water.

Yes, I do. Have 3.6kW of panels since 2003 - I was a very early adopter and did not do it for financial reasons but as a fun thing to do. In the early days it was very satisfying to watch the spinning disk meter run backwards on bright days. I reckon finances broke even about one-two years ago.

piglet

Forgive my ignorance, but what does that mean? Let's say you have 5 hours of sunshine, do you get 18kWh of energy? Does that mean the max voltage current is 3.6kW (36V, 100Amps)? And how big an area is that?

Thanks

In detail I have 20 panels each rated 180W output at standard solation. They are Sanyo hybrids each with approx 1.6m square area. Over the past

20+ years the price has fallen and output (i.e. efficiency) has increased. Hybrid here means mono-crystalline silicon cells with amorphous silicon cell layers.

Those 20 panels are wired as four strings of five in series. The open circuit voltage of one panel is 60-70V. Each pair of strings is paralleled and feeds one of two 1800W grid-tied inverters. The DC input voltage to the inverters is 300-350V

Yes, if there were 5 hours of "standard" sunshine then 18kWh energy would be generated.

piglet

It took almost none of my time, the crew did it in three days. I think now they are much quicker for similar sized installs.

It was a fun thing to do and I have no regrets!

piglet

... which is worth $3, or thereabouts. Looks like a lot of equipment for very little result.

Jeroen Belleman

18kWh 0.2$/kWh 365days/year 20years = $26,280

Based on below average solar insolation, cost of electricity and system life expectancy. Solar is the cheapest electricity you can buy in a lot of places. Why pay more?

Good point, the roof needs to be considered in your economic analysis, and unless you have a roof which can be expected to last more than 20 years - brand new fiberglass shingle, or metal, membrane, tile in good condition - then it will be most economical to replace the roof at the same time solar is installed. Unfortunately the low first cost fiberglass roofing is more popular than the durable low life cycle cost alternatives with a good chance of outliving a 30 year solar installation.

A common problem in the US, utilities which do not want competition are making the "contributions" which insure that legislation written by their lobbyists is enacted. In Florida a regulation requiring all solar systems meeting more than a small amount of customer demand be utility owned and operated - they rent your roof and give you a bit of a raw deal discount on electricity - was soundly defeated in a voter referendum despite heavy deceptive utility advertising, and then enacted by executive order by Ron DeSantis, recipient of big utility "contributions". Not much Solar in Florida. Texas by contrast has little regulation and loads of solar. Here in PA we have decent regulations but only moderate insolation, payback time is longer but still worthwhile for those with a good location.