diy solar

diy solar

New Irish member

BrianB

New Member
Joined
May 16, 2020
Messages
1
Hello all. I have a background as a telecoms tech in the offshore oil and gas industry and am familiar with batteries and setup through remote control helicopter and drone hobby. I want to fit a solar PV system in the house primarily with a view to heating water. The reason for PV as opposed to solar thermal is because it is an old house and physically fitting solar thermal is physically very difficult. My thoughts were to connect the solar array to a heating element in the existing hot water tank. If the sole purpose of the system is to heat water only while the sun is shining, I do not need a large bank of batteries to store energy. A hot water tank has 2 heating elements. My thoughts were to leave one heating element connected to the house mains supply, and the second (lower wattage) element connected to an automatic transfer switch which is fed from both the house mains electrical supply and from the solar inverter. In this way I should be able to heat water while the sun shines from the PV panels, and automatically switch to grid supply when the sun does not shine, trickling a few hundred watts into a well insulated tank over the course of the day slowly if the supply to the heating element was low wattage. I could fit a thermostat to the tank which if the water temperature came up fully from solar power alone, (unlikely in Irish conditions)..then power to be diverted to charging a battery or to a heat sink to drain off excess input from the system. I was thinking about about 1200W of PV panels, a minimal amount of battery storage in the system to reduce cost, and also because electrical storage it is not needed for this setup. Is it feasible? Alternatively could a DC heating element be fitted to the tank from the solar panels alone (48V), and then a thermostat switch this to a battery should water temperatures allow? Any thoughts or links to existing setups along this line appreciated. Brian
 
Welcome to the forum.

Have a look at this thread.
 
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