AMGEAWATTHOURSWORTH

Discussions about Renewable Energy, including photovoltaics, wind, and small scale hydro.
Creating power for your home, off grid.
Emphasis on nuts-n-bolts, hands-on projects.

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Sharkey
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AMGEAWATTHOURSWORTH

Post by Sharkey »

Say What?

Oh, sorry, caps lock, punctuation.

"A MegaWatt Hour's Worth"

Any Clearer now?

For the last four months or so, I've been closely watching the total accumulated production of power from my photovoltaic system, waiting until the system had produced 1,000 kiloWatt hours (kWh) in the space of a year's time. I was pretty sure that the system could do it, but there were some hurdles to leap.

When I first installed the system, I started with 9 panels or so, then added another 3, then 3 more, etc, so the production was ramping up during that time.

It took me a while to get all of the proper hardware installed so that the panels elevation (tilt) could be set to optimize the power collected during the late spring and summer months.

Then a friend who works for Outback came to visit and brought along a firmware update for my MX60 charge controller (actually, FlexMax 80 beta firmware!).

Some time around August, the utility company sent a crew to replace the old, mechanical disk-gears-and-pointers Watthour meter on my service entrance with a Centron Itron electronic Watthour meter. This meant that I cold no longer "spin the meter backwards" during the day, creating de facto net metering (also known as "Guerrilla Solar"). I could still pump AC power back into the utility grid, and the new meter could tell which direction the power was going, but it continued to count ever upwards, I was being charged for each and every kiloWatthour I was sending them.

It took me a week to build a solution, which was an electromechanical nightmare that can sense when power is going back to the utility, and strips it off the system, dumping it into the water heater. While this creation was being born, I basically shut down the system, or used it in "off-grid" mode. Production suffered until Frankenstein was ready to get up off the operating table.

The friend from Outback came to visit again, and brought the next version of firmware, resulting in even more production increases.

The upshot of all this is that as each of the dates of these events passed, I had an increasingly difficult time gaining ground on my goal. It was like being in a race where your opponent was given a head start, a handicap because they were slow, but during the race, they kept speeding up. Each improvement in the system's performance, or passage of the date of downtime meant that the other runner was going that much closer to the speed that I was running.

Anyhow, today, the total since Sept 12, 2007 was 1,003 kWh, or $58.87 worth of electricity at my utilities rate.

What are you laughing at? Hobbies are ~supposed~ to be a financial loser.

So what good is a million Watt hours?

It's enough to propel my electric car for 2,000 miles of pollution-free driving.

It would keep the reading lamp on my desk illuminated for ten years and four months, continuously.

It's about enough to run my refrigerator/freezer for two years of normal use.

It's about what an "average" home in the US uses in a month (not counting heating or air conditioning).

Total, in the past year, my utility has supplied me with 2,850 kWh ($167.30) of grid power. Compare that to my 1,003, and you see that I am producing about 26% of my own electrical consumption.

No, I'm not proud, I'd like to be able to cut utility loose and produce all my own power, but photovoltaic alone isn't going to do it. I do still heat some with electricity (mostly backup for when the fire dies down, but I do have guests occasionally who expect their living spaces to be heated). In the Winter the water is electrically heated for showers and laundry, and I do have some large machinery that isn't able to run on solar/batteries (2 Hp table saw, 6 Hp air compressor, arc welder, etc).

Once I get past the current financial bind that is keeping me from throwing money at frivolous hobbies, I really want to put in some hydro power. Even a small installation could serve to whack winter and night time utility loads down to nearly nothing. If I was able to run a big enough pipe up the hill, I could possibly kiss the utility goodbye for good, they's kiloWatt hours up in them thar hills!
AccordGuy
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Post by AccordGuy »

A milestone none the less...

My plug-in energy meter on my solar system records power-on hours and kWhs consumed and in about 2 weeks (since plugging it in) it has recorded 84 PO hrs and just over 4kWh. Although that's a lie as I drained the battery pack the other day to about 40% trying to use a 300W video projector and then it got cloudy for the next two days so I ended up topping up the battery bank from the utility to stop them getting damaged. I reckon I put 1.8kWh of utility into them that night so actually I've only made 2.2kWh of solar power.

Ironically, the next three days after I decided to charge the pack from the utility it was really sunny and I wasted the sun as the pack was full :roll:

I'll probably get another such energy meter and put that on the charger so that I can delta out any kWhs I put into the pack from the utility.

With the amount of rain we've been getting here lately I might be able to run a hydro unit just off the gutter on my roof :)
Sharkey
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Post by Sharkey »

Ironically, the next three days after I decided to charge the pack from the utility it was really sunny and I wasted the sun as the pack was full
That always seems to happen to me in the winter on the Housetruck system. Another reason to use NiCd batteries, I can let them sit around drained until the next sun events happen.
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Dennis The Bus Dweller
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Post by Dennis The Bus Dweller »

Hi Sharkey

When I started to put thought in to the PV system for the big bus I decided to do it as a grid-tie with a battery back that I would run off of and be able to plug in to my rented barn and feed the meter to keep the cost down. So, I decided on a Outback PS-1 set up with a GVFX3648 inverter and a MX-60 controller but, Outback doesn’t make the PS-1 any more so I started to buy my equipment one piece at a time. At this point I have GVFX3648 inverter and the MX-60. Do you think your Outback buddy would maybe put together a list of the remaining pieces of equipment that I will need to complete my system? I have both AC and DC disconnects as well. I decided that im not going to keep my “HUGEâ€
Peace along the way
Dennis the bus dweller N.Y.
Sharkey
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Post by Sharkey »

My friend at Outback is a software programmer, the one who wrote the code for the FlexMax 80. He's probably not the right person to approach with a question about hardware configurations.

I'd suggest you pose the question over at the Outback User Forum. You'd be more likely to encounter the proper staff person or get a recommendation from one of the other users who have knowledge of the PS-1 contents. They even have a forum category dedicated to PS Enclosures!
AccordGuy
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Post by AccordGuy »

[quote="Dennis The Bus dweller"]I decided that im not going to keep my “HUGEâ€
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