Quote:
Originally Posted by Xringer
It's not worth the investment to install a small grid-tie array.
If I did it, I would want the max kW my roof space could provide.
Years ago, I had three real nice Novan SDHW panels on my roof. The system worked great for a few years.
Then the leaks started. Followed closely by my wife wanting those 'things' off the roof. (Woburn water is hard on copper).
I'll never try another SDHW system. I doubt the city would even allow a DIY SDHW system, in these days of over-regulation.
I'm currently testing out the 800w array connected directly to the lower
heating element in my new GE water heater w/ A7 on top.
(No MPPT being used yet).
It seems like even the poor solar conditions we've had over the last 10 days
aren't stopping those 800w from doing some hot water heating.
I checked the log this morning, and the A7 has been using about 1 kWh per day, on average.
When the weather warms up and I'm in the shower all the time, that will change..
But, I'm collecting daily readings and making notes on solar conditions & HW use.
So it will be interesting to see how daily A7 power use impacted by the PV..
The load works well around noon time. If it's sunny, we get very good performance out of the array.
Sometimes in the 90% range.
My backyard panels are in a poor location.
However when the days get longer and, we see even better performance from the PV, I'll add MPPT to it.
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Don't be so hard on SDHW, you seem to have got a crappy system and the company seems to be gone anyway (which is a bit of a hint to its quality). It is not that hard to make a system that looks like skylights on the roof if that would appeal more to your wife and I am sure it could be done without hassle from either the city or the water supply.
One way or another you are using the grid as a battery whether officially or not, so it is grid tied