Can i power my immersion heater from my 4kw pv system?

screwdriver · Jan 1, 2012

Feasible, Yes, economical, probably not,

3 kw of solar thermal would cost you about £1500 plus the heat store and take up less roof space. 3 kw of PV would cost anywhere around £3k and take up 30 square metres of roof.
Using the existing grid tied systems to heat water makes financial sense because we don't get paid for exporting at the moment so why do it?

and · Jan 1, 2012

"A lot of DIY installers of such systems are running their 3Kw heater elements through a 110v site transformer. This is dropping the output to around 700w."

Stuart99 - please could you enlarge upon this a bit, as I'd like to know what that would envolve regarding the 110v transformer.

screwdriver · Jan 1, 2012

It basically means, take your immersion heater fit A 110V plug to the flex then plug that into a 110v site transformer ( which is well ventilated) which has been plugged into the supply somewhere. Dropping the input voltage to a heating element will drop the power , it does allow you to easily run the immersion at a rating which won't cause you to import on most decent sized systems.
hope that makes sense!

and · Jan 2, 2012

Thanks screwdriver for the above; I'm keen to set something up to run the immersion and as I have a spare 110v transformer, it could well be an idea for a cheaper option to the parsons switch.

thushar · Feb 2, 2012

One of the alternative solution could be to use a 1 kW immersion heater ( a rare item - but found on ebay - Business Building Kits items in Fair Trade Hub Shop store on eBay! ) . This is a neat and better solution than using a site transformer.