ECN Forum Forums General Topics of the Trade General Discussion Area Solar Power: The Basics AND Business of it.

gfretwell,

outbackpower.com They have grid interactive inverters which are fed by 48V battery arrays, which then are charged of course by the PV system. Trace/Xantrex has just come out with some grid interactive ones as well now, but I'm kinda partial to Outback myself. Their reputation for their inverters producing VERY clean power especially for motors/refrigerators is well known when running off grid.

However I will say, when pricing these systems for a few customers, unless they REALLY want that instant UPS style transfer, its hard to beat a backup generator. Not many people want to deal with maintaining the batteries monthly, and replacing them years down the line. They like the idea of having a maintenance free PV system, especially since it is part of their house. And you are gonna have a hard time running your A/C off the inverters in a power outage. With a standby generator, at about a third the cost of a battery/grid interactive system, at least you will be able to run all your loads. And if you dedicate a 250gallon propane tank to it, you could go a pretty long time in a natural disaster.

I install solar in the South California, so if I can be of any help.

Greg:
FYI, both jobs are for a climate controlled warehouse operation, both bldgs are >75% refrigerated.

A "$300 electric bill might cover a few hours"

Thanks, That is good to know about the 48vDC system. It fits right in with my golf cart scenario. I am really only looking for enough battery backup to keep a fridge going and run my well pumps. Anything else is just bonus stuff.

If I can keep my pool blue the A/C is not really that big a deal. I am looking at a dedicated system that just runs the pool pump. Do you deal with them? It is a DC pump connected pretty much directly to a collector array.
Dollar for dollar that looks like the biggest money saver for me. Unfortunately Florida does not seem to think that is worth a rebate, in spite of the fact that about 20% of all residential electric usage here is the pool pump if you have a pool.

Most of my solar is northern and I am also partial to Outback. On paper they look great and I have yet to experience trouble with them.

To add though, the Outback can accept voltage input well above the nominal and seems to efficeintly down convert the voltage without much power loss. This is extremely helpful when dealing with voltage drop.

We go for a similar type system with water systems for Grundfos solar pumps which can accept up to 300 VDC and can run by 120 or 240 VAC from a generator.

I am beginning to sound like a salesman, but I have also worked with hybrid systems using both solar and generator with batteries. Atkinson Electronics offers generator start control modules for three wire start small generators. This works great for alot of our sites where there is no public utility.