Thermalux, residential hot water advancement via photovoltaics.

[bcroe]

I find Solar thermal drainback systems are very low maintenance If a stainless steel tank is used. The only Parts that could fail are the pump and the controller.
HW resistance elements are prone to failure as are the glass lined tanks that this company is using. Throw in some hard water and they may last 5-7 years. With 5 pv panels this system can't match the BTU output per day of a single 4 x 8 flat plate.
What about the inverter (Mppt) or micro inverters that they are using to power the resistance heaters? What will be the reliability of this control at the voltage and amperage required.
My Sunny Boy grid tie inverter is only guaranteed for 10 years and I think that is a long time for a high power control.
I've seen several new energy efficient heating manufacturers fail in the last few years that had a New Idea for an old problem. The problem was always the same, the equipement had too many parts and was too complicated.
Simpler is always better.

There isn't a one fits all solution to water heating. A thermal system would have had a
problem dealing with 3 months of 20 deg below zero a year ago. My solar stuff is 700'
from the house, out of site and where there aren't so many trees. A PV system powering
a heat pump has a COP multiplier of 2 or 3 to bring it closer to thermal performance. My
inverters have logged over 13,000 hours without issue, half of that at maximum power.
An MPPC from the panels to the water heater should be a lot simpler and more reliable.

However, we haven't found out yet, if the proposed system uses a heat pump, or an MPPC
to a resistor (no COP benefit), or just panels to a resistor (poor efficiency), or if there
even is any kind of control. Bruce Roe

[FishGun]

Can't seem to find the thermalux link.

Isn't this old news? Sunbandit has been around for a couple yrs I think? They prob have all the numbers crunched...

http://www.sunbandit.us/